<?xml version="1.0" encoding="UTF-8"?>
<item xmlns="http://omeka.org/schemas/omeka-xml/v5" itemId="91" public="1" featured="0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://omeka.org/schemas/omeka-xml/v5 http://omeka.org/schemas/omeka-xml/v5/omeka-xml-5-0.xsd" uri="https://cpw.cvlcollections.org/items/show/91?output=omeka-xml" accessDate="2026-04-09T20:21:25+00:00">
  <fileContainer>
    <file fileId="142">
      <src>https://cpw.cvlcollections.org/files/original/c3c0df3402f00380cdc329d044123b05.pdf</src>
      <authentication>2cff231a95518befb022e55daaf094e6</authentication>
      <elementSetContainer>
        <elementSet elementSetId="4">
          <name>PDF Text</name>
          <description/>
          <elementContainer>
            <element elementId="92">
              <name>Text</name>
              <description/>
              <elementTextContainer>
                <elementText elementTextId="1503">
                  <text>The research in this publication was partially or fully funded by Colorado Parks and Wildlife.

Dan Prenzlow, Director, Colorado Parks and Wildlife • Parks and Wildlife Commission: Marvin McDaniel, Chair • Carrie Besnette Hauser, Vice-Chair
Marie Haskett, Secretary • Taishya Adams • Betsy Blecha • Charles Garcia • Dallas May • Duke Phillips, IV • Luke B. Schafer • James Jay Tutchton • Eden Vardy

�RESEARCH ARTICLE

The effects of demographic, social, and
environmental characteristics on pathogen
prevalence in wild felids across a gradient of
urbanization
Jesse S. Lewis1¤*, Kenneth A. Logan2, Mat W. Alldredge3, Scott Carver4, Sarah N. Bevins5,
Michael Lappin6, Sue VandeWoude7, Kevin R. Crooks1

a1111111111
a1111111111
a1111111111
a1111111111
a1111111111

1 Department of Fish, Wildlife, and Conservation Biology, Graduate Degree Program in Ecology, Colorado
State University, Fort Collins, CO, United States of America, 2 Mammals Research, Colorado Parks and
Wildlife, Montrose, CO, United States of America, 3 Mammals Research, Colorado Parks and Wildlife, Fort
Collins, CO, United States of America, 4 School of Biological Sciences, University of Tasmania, Hobart,
Tasmania, Australia, 5 USDA-APHIS-Wildlife Services’ National Wildlife Research Center, Fort Collins, CO,
United States of America, 6 Department of Clinical Sciences, Colorado State University, Fort Collins, CO,
United States of America, 7 Department of Microbiology, Immunology, and Pathology, Colorado State
University, Fort Collins, CO, United States of America
¤ Current address: Arizona State University, College of Integrative Sciences and Arts, Mesa, AZ, United
States of America
* jslewis.research@gmail.com

OPEN ACCESS
Citation: Lewis JS, Logan KA, Alldredge MW,
Carver S, Bevins SN, Lappin M, et al. (2017) The
effects of demographic, social, and environmental
characteristics on pathogen prevalence in wild
felids across a gradient of urbanization. PLoS ONE
12(11): e0187035. https://doi.org/10.1371/journal.
pone.0187035
Editor: Emmanuel Serrano Ferron, Universidade de
Aveiro, PORTUGAL
Received: June 7, 2017
Accepted: October 12, 2017
Published: November 9, 2017
Copyright: © 2017 Lewis et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: Data are available as
Supporting Tables S17–S31 associated with this
paper.
Funding: Funding and support were provided by
Colorado State University, Colorado Parks and
Wildlife (CPW), Boulder County Parks and Open
Space, Boulder City Open Space and Mountain
Parks, the Bureau of Land Management, US Forest
Service, and a grant from the National Science

Abstract
Transmission of pathogens among animals is influenced by demographic, social, and environmental factors. Anthropogenic alteration of landscapes can impact patterns of disease
dynamics in wildlife populations, increasing the potential for spillover and spread of emerging infectious diseases in wildlife, human, and domestic animal populations. We evaluated
the effects of multiple ecological mechanisms on patterns of pathogen exposure in animal
populations. Specifically, we evaluated how ecological factors affected the prevalence of
Toxoplasma gondii (Toxoplasma), Bartonella spp. (Bartonella), feline immunodeficiency
virus (FIV), and feline calicivirus (FCV) in bobcat and puma populations across wildlandurban interface (WUI), low-density exurban development, and wildland habitat on the Western Slope (WS) and Front Range (FR) of Colorado during 2009–2011. Samples were collected from 37 bobcats and 29 pumas on the WS and FR. As predicted, age appeared to be
positively related to the exposure to pathogens that are both environmentally transmitted
(Toxoplasma) and directly transmitted between animals (FIV). In addition, WS bobcats
appeared more likely to be exposed to Toxoplasma with increasing intraspecific space-use
overlap. However, counter to our predictions, exposure to directly-transmitted pathogens
(FCV and FIV) was more likely with decreasing space-use overlap (FCV: WS bobcats) and
potential intraspecific contacts (FIV: FR pumas). Environmental factors, including urbanization and landscape covariates, were generally unsupported in our models. This study is an
approximation of how pathogens can be evaluated in relation to demographic, social, and
environmental factors to understand pathogen exposure in wild animal populations.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

1 / 22

�Demographic, social, and environmental pathogen factors

Foundation-Ecology of Infectious Diseases
Program (NSF EF-0723676; EF-1413925).
Competing interests: The authors have declared
that no competing interests exist.

Introduction
Infectious diseases play important roles in wildlife conservation and can threaten species and
populations across local to global scales [1–6]. By modifying landscapes and altering wildlife
communities, humans can influence patterns of disease dynamics in wildlife populations [1,
7–9], increasing the potential for spillover and spread of emerging infectious diseases in wildlife, human, and domestic animal populations [1, 10–12]. A primary driver of landscape alteration is urbanization. The conversion of natural areas to human development, including
residences, buildings, and roads, is one of the most extensive anthropogenic disturbances
affecting wildlife populations globally [13, 14] and urbanization is projected to increase by millions of hectares over the next few decades [15–17]. To conserve animal populations and
reduce the risk of infectious and zoonotic pathogen spread in wildlife and humans, it is critical
to understand the mechanisms that affect patterns of disease in wildlife populations across different forms of urbanization, particularly as it relates to modes of pathogen transmission [18–
21].
Transmission of pathogens among animals is influenced by demographic, social, and environmental factors [7, 22, 23]. With regard to demography, males and older individuals often
exhibit a greater prevalence of parasites and disease [24–28]. In many mammals, males tend to
have larger extents of space use [29] and greater potential for contacts among animals [30]. In
addition, because larger extents of space use allow animals a greater opportunity to interact
with the landscape, animals can potentially experience increased exposure to pathogens in the
environment. Increases in population density can result in both higher contact rates [31] and
greater prevalence and diversity of pathogens among individuals [22]. In contrast, transmission of parasites within populations also can decrease with increasing host density, associated
with less mixing among individuals within a population and more localized disease transmission [32].
Social organization plays an important role in disease transmission through intra- and
interspecific interactions and contact patterns [22, 33]. For many solitary species (such as
many carnivores), intraspecific social interactions primarily occur during the mating season or
when defending and maintaining territorial boundaries [34]. In addition, space-use overlap of
animals can lead to kleptoparasitism (where one animal steals the food of another) [35, 36],
aggressive encounters, and intraguild predation [37, 38], which are behaviors that can increase
the opportunity for pathogen transmission through direct and indirect interactions [4, 39].
Interspecific interactions can be important determinants of pathogen spillover from a reservoir species to another species and in some cases this has led to population decline and extirpation [4, 40, 41]. Although social organization is often associated with direct contacts between
animals, it can also impact indirect contacts. Overlap in space use and maintaining territorial
boundaries through marking behavior can influence indirect disease transmission pathways
for animals using shared areas through environmental contamination [42].
Lastly, the environment plays a critical role in disease transmission. Landscape characteristics, including habitat features, geographic barriers, and anthropogenic factors, can influence
the spread and occurrence of pathogens [43–48], and land-use change can have important
implications for the distribution and abundance of pathogens [49]. Urbanization can alter
the environmental conditions that influence the transmission and prevalence of pathogens
through modifying landscape patterns [18, 48, 50–53] and disease spillover [54]. Pathogens
originating from anthropogenic sources can increase in prevalence in animal populations associated with urbanized environments [55]. Although population densities for some species can
be substantially higher in urban environments compared to rural areas, the number of infected

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

2 / 22

�Demographic, social, and environmental pathogen factors

individuals and burden of disease vectors can be substantially greater in rural populations as a
result of the population ecology of intermediate hosts [56–59]. For example, agricultural areas
can experience high prevalence of Toxoplasma due to abundant small mammals acting as
intermediate hosts [60].
Carnivores harbor a suite of pathogens, which can impact predator populations, ecological
communities, and human health [2]. In addition, pathogen exposure can vary by anthropogenic factors, such as in bobcats (Lynx rufus) and pumas (Puma concolor) [47, 48, 61], which
share a broad geographic distribution in western North America. Cross-species transmission
of species-specific pathogens has been reported between bobcats and pumas in highly urbanized landscapes, potentially as a result of increased contacts and aggressive encounters resulting from elevated space-use overlap within habitat fragments [62]. In addition, domestic cats
(both pet and feral populations) associated with human residences harbor a suite of pathogens
that can be transmitted to and from wild felids in rural and urbanized environments [54, 61,
63, 64]. Previous research evaluating pathogens in wild and domestic felids across California,
Florida, and Colorado found that several demographic, social, and environmental factors were
important determinants of exposure to multiple pathogens at broad scales [48, 61]. However,
analyses across finer scales are necessary to understand the effects of these three factors at the
individual level, particularly related to space use and social interactions within and between
species.
Our goal was to investigate how multiple mechanisms influence seroprevalence of pathogens in medium and large-sized carnivores persisting across a gradient of urbanization. We
evaluated bobcat and puma populations across wildland-urban interface (WUI), low-density
exurban development, and wildland habitat in relation to four common pathogens in felids:
Toxoplasma gondii (Toxoplasma), Bartonella spp.(Bartonella), feline immunodeficiency virus
(FIV), and feline calicivirus (FCV). We predicted that (1) pathogens acquired primarily
through prey and the environment (i.e., Toxoplasma) would be associated with suitable habitat
for the pathogen and greater amounts of space use sharing among felids; (2) pathogens transmitted by flea vectors (i.e., Bartonella) would be associated with habitat that harbored fleas and
increased social interactions (i.e., space-use overlap and number of potential contacts); and (3)
pathogens that are directly transmitted between individuals (i.e., FIV and FCV) would be positively related to social interactions (Table 1). In addition, owing to potential associations with
domestic cats, we expected that animals associated with habitat modified by urbanization
(exurban and wildland-urban interface) would exhibit greater prevalence of pathogens shared
between domestic and wild felids, compared to wild felids within wildland areas (Table 1).
Consistent with previous research, we also expected that older individuals and males would be
more likely to be exposed to pathogens [48, 61].

Materials and methods
Study area
We conducted our research across two study areas in Colorado, USA that exhibited varying
degrees of urbanization and human influence. In 2009–2010, we worked on the Western Slope
(WS) of Colorado on the Uncompahgre Plateau near the towns of Montrose and Ridgway,
which sampled areas of exurban development and wildland habitat (Fig 1). In 2010–2012, we
worked on the more urbanized Front Range (FR) of Colorado, which sampled wildland-urban
interface (WUI) habitat associated with the city of Boulder (population = 97,385, US Census
Bureau 2010) and wildland habitat (Fig 1). Although uncommon, a small number of free-ranging domestic cats also occurred on our sampling grids on the WS and FR. See [65] for an
expanded description of the study area.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

3 / 22

�Demographic, social, and environmental pathogen factors

Table 1. Predictions of how demographic, social, and environmental characteristics will influence exposure of pathogens in bobcat and puma
populations. For each pathogen, the transmission model is included in parentheses. For each factor (demographic, social, and environment), the expected
relative effect strength of each prediction is included in parentheses.
Pathogen

Demographic

Social

Environment

Toxoplasma gondii
(Consuming infected
intermediate host or acquiring
oocysts from environment)

1. Higher prevalence in males and
older animals (strong).
2. Higher prevalence as space-use
extent increases due to interacting
with more of the landscape
(moderate).

1. Increased space-use overlap (both intraand interspecific) increases oocyst presence
in environment leading to greater prevalence
in prey and increasing opportunity to be
infected through environmental
contamination (moderate).

1. Animals with more NDVI in
their extent of space use will be
more likely to be infected
(moderate).
2. Greater prevalence in areas of
low-density residential
development (strong).

Bartonella spp.
(Vector-borne)

1. Higher prevalence in older
animals (strong).
2. Higher prevalence as space-use
extent increases due to interacting
with more of the landscape
(moderate).

1. Increased opportunities for intraspecific
interactions leads to greater opportunity to
transmit fleas (moderate).

1. Animals with more NDVI in
their extent of space use will be
more likely to be infected
(moderate).
2. Greater prevalence in areas of
low-density residential and WUI
development (strong).

Feline
Immunodeficiency
Virus (FIV)
(Direct contact)

1. Higher prevalence in males and
older animals (strong).
2. Higher prevalence as space-use
extent increases due to interacting
with more individuals (moderate).

1. Increased opportunities for intraspecific
interactions in both felids (strong) and
interspecific interactions for pumas (weak)
increases prevalence.

1. Greater exposure is expected
in urbanized areas due to
increased interactions (strong).

Feline Calicivirus
(FCV)
(Direct contact)

1. Higher prevalence in males and
older animals (strong).
2. Higher prevalence as space-use
extent increases due to interacting
with more individuals (moderate).

1. Increased opportunities for intra- and
interspecific interactions increases
prevalence (strong).

1. Greater exposure is expected
in urbanized areas due to
increased interactions (strong).

https://doi.org/10.1371/journal.pone.0187035.t001

Animal capture and telemetry data
Bobcats were captured in black metal-wire cage traps during March 2009–2011 and immobilized through hand-injection of a combination of Ketamine (10.0 mg/kg) and Xylazine (1.0
mg/km), and Yohimbine (0.125 mg/km) was used to reverse Xylazine [66]. Adult-sized bobcats were fit with GPS collars (210–280 g, Telemetry Solutions, Concord, CA, USA). Pumas
were captured from 2005–2011 with the use of hounds and baited cage traps, immobilized
with Telazol (5.0–9.0 mg/kg), and fit with GPS collars (Lotek, Newmarket, Ontario, Canada;
Northstar, King George, VA, USA; Vectronics, Berlin, Germany). See [65] for further details
on animal capture methods and GPS telemetry. Methods for animal capture were approved by
the Colorado State University Animal Care and Use Committee (11-2453A).

Screening of pathogens in felids
We sampled 37 bobcats and 29 pumas on the WS and FR, although sample sizes varied across
pathogens for groups of felids depending upon sample availability and quality (Fig 2; S1
Table). For each captured bobcat and puma, we collected blood (~10 mL) and saliva samples
from immobilized animals for pathogen analysis. In the field, blood and serum samples were
stored in ethylenedriaminetetraacetic acid (EDTA) and serum-sampling tubes that were
immediately refrigerated. Samples were then transported within 24 hours to the CSU retrovirus research laboratory, where they were processed as previously reported [48, 61, 67]. To evaluate seroprevalence of pathogens (the detection of antibodies reacting against pathogen
antigens used as a proxy for exposure to that pathogen), serum samples were analyzed for antibodies of Toxoplasma (enzyme-linked immunosorbent assay; ELISA), Bartonella (ELISA),
FIV (Western Blot analysis), and FCV (ELISA) [48, 61]. Based on serum sample evaluations,
individuals were classified as testing positive (i.e., antibodies against the pathogen detected = 1)

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

4 / 22

�Demographic, social, and environmental pathogen factors

Fig 1. Locations of two study areas in Colorado, USA, which exhibited varying levels of urbanization, where bobcats and pumas were fit with
telemetry collars. The more rural Western Slope (WS) was characterized by an exurban development south grid and a wildland north grid during 2009–2010.
The more urbanized Front Range (FR) study area was characterized by a wildland-urban interface (WUI) south grid and wildland north grid during 2010–
2012.
https://doi.org/10.1371/journal.pone.0187035.g001

or negative (i.e., antibodies against the pathogen not detected = 0). For further information
about the accuracy of serological analyses for the four pathogens evaluated in our study, please
see [48, 61, 67] and references therein.

Pathogen characteristics and predictions
We hypothesized that multiple ecological factors would affect pathogen exposure in felid populations and focused our predictions on the expected relative strength that each mechanism
would contribute to exposure of pathogens in felid populations.
Toxoplasma gondii (Toxoplasma) is a common pathogen in felids, with seroprevalence
ranging from approximately 20–90% [61, 68–70]. Felids (domestic and wild cats) are the
definitive host of Toxoplasma, in that infected animals excrete millions of oocysts into the

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

5 / 22

�Demographic, social, and environmental pathogen factors

Fig 2. Prevalence of pathogens (estimates of seroprevalence and 1 standard error) for bobcats (a) and pumas (b) in exurban and wildland habitat on the
Western Slope (WS) and for bobcats (c) and pumas (d) in wildland-urban interface (WUI) and wildland habitat on the Front Range (FR), Colorado. Sample
sizes for the total number of animals screened for antibodies of each pathogen occur on the right side of each figure panel for the urbanized grid, wildland grid,
and when both grids are combined.
https://doi.org/10.1371/journal.pone.0187035.g002

environment over the course of approximately one week [71]. Felids can become infected by
consuming infected prey, or less commonly, through direct environmental contamination by
ingesting oocysts [54]. Once the infection is cleared, felids are assumed to be immune to reinfection and cease shedding oocysts into the environment, which can survive between several
months and up to one year [60, 71]. Although Toxoplasma generally does not cause fitness
effects in felids or humans, there are known behavioral impacts, and individuals that have a
weakened immune system can experience complications [71, 72]. Environment and prey characteristics dictate patterns of Toxoplasma across the landscape (Table 1). Toxoplasma is associated with domestic cats, and thus can be more prevalent near areas of human residences,
although the prevalence of Toxoplasma is predicted to vary across different forms of urbanization [60]. Low density urbanization, such as agricultural areas, can experience especially high
prevalence of Toxoplasma due to an abundance of small mammals acting as intermediate
hosts and sufficient predation of infected prey by domestic and wild felids. Some urban areas
are predicted to exhibit lower prevalence of Toxoplasma due to fewer intermediate hosts and
reduced numbers of predation events [54, 60, 73, 74]. Toxoplasma is reported to be more prevalent, and oocysts survival might be extended, in cool and wet years across regional to local

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

6 / 22

�Demographic, social, and environmental pathogen factors

Table 2. Definitions of variables used in models evaluating pathogens in bobcats and pumas across a gradient of urbanization on the Western
Slope (WS) and Front Range (FR) of Colorado. For further explanations of covariates see Methods.
Covariate

Category

Definition

Sex

Demographic

Male or female. For modeling, males = 0 and females = 1.

Age

Demographic

Continuous measure of age in years for adult-sized animals estimated based on dental
characteristics and body size.

Space-use extent

Demographic

Spatial extent (km2) that an animal used based on space-use estimation of utilization distribution
using the Brownian bridge movement model or kernel density methods. Because space-use
extent is related to sex and age it was grouped with these variables.

Space-use overlap

Social (Intra- and
Interspecific)

Overlap in space use between animals using the utilization distribution overlap index (UDOI)
statistic [76].

Degree

Social (Intra- and
Interspecific)

The number of neighbors an individual potentially interacted with based on overlap in space-use
extents [77, 78].

In-strength

Social (Intra- and
Interspecific)

The sum of space-use overlap values across all neighbors associated with an individual [79].

Equivalent social connectivity

Social (Intra- and
Interspecific)

Equivalent social connectivity (ESC) among animals incorporates space-use overlap and extent
[30]. This metric was based on equivalent connectivity [80], which was simplified to evaluate for
an individual animal as follows:
qffiP
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
n
�
ESCi =
j¼1 ai aj pij
where ai is the space-use extent for the focal animal i, aj are the spatial extents of space use for
animals j, and p�ij is the Bhattacharyya’s affinity (BA) statistic [76] used to define space-use
overlap between animals i and j [30].

Amount of urbanization in
space-use extent

Environment (Urban)

Human occurrence points (HOP; residences and structures) were digitized in ArcMap 10 and a
kernel of 1000 m was fit over each HOP and kernels were summed to calculate human influence
on the landscape [81]. An animal’s space-use extent was intersected with this layer and the
amount of human influence was summed for each individual.

Grid

Environment (Urban)

Whether an animal was associated with exurban development or wildland grid on the WS or
wildland-urban interface or wildland grid on the FR. For modeling, in each study area, urbanized
grid = 0 and wildland grid = 1.

Amount of NDVI in space-use
extent

Environment
(Landscape)

The sum of the amount of Normalized difference vegetation index (NDVI; Pettorelli et al. 2005),
which measures plant productivity and moisture across the landscape, within an animal’s extent
of space use. NDVI was evaluated using eMODIS images (USGS August 2009 data on WS and
August 2010 data on the FR).

NDVI per area of space-use
extent

Environment
(Landscape)

The amount of NDVI within an animal’s space-use extent divided by the area of space use for an
individual.

https://doi.org/10.1371/journal.pone.0187035.t002

areas [54, 73, 75]. Based on these relationships, we expect that animals inhabiting landscapes
with greater plant productivity and moisture (i.e., as measured by Normalized difference vegetation index; NDVI; Table 2) would have a greater opportunity to be exposed to Toxoplasma
(Table 1).
Bartonella spp. (Bartonella) are a bacteria transmitted through flea, tick, and other arthropod vectors and can possibly lead to persistent or recurrent infection [64]. The bacteria are not
generally deleterious to felid health, but can cause “cat scratch disease” in humans. There is a
broad range in prevalence of Bartonella among bobcat populations (approximately 15–75%)
and lower range for puma (approximately 10–40%) populations [61, 70, 82], where prevalence
likely reflects each species’ exposure to arthropod vectors [61, 64]. Similar to Toxoplasma, Bartonella is associated with domestic cats (Table 1), which can potentially transmit the pathogen
to wild felids primarily through flea vectors [64]. Bartonella is more prevalent in warm and
humid climates where flea survival is increased [83, 84] and ticks can be associated with more
moist environments [85–87]. Therefore, we might also expect that on finer spatial scales, animals with greater amounts of the landscape characterized by mesic environments (e.g., as measured by NDVI) within their extents of space use would have a greater likelihood of being
exposed to vectors that harbor Bartonella (Table 1).

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

7 / 22

�Demographic, social, and environmental pathogen factors

Feline immunodeficiency virus (FIV) is the felid equivalent of human immunodeficiency
virus (HIV) and its prevalence varies widely across distinct bobcat and puma populations
(approximately 20–60% prevalence) [28, 61, 62, 88]; however, it reportedly is not detected
(prevalence of 0% for bobcats) in some populations [70, 89]. Each felid species is typically
infected with a unique strain of FIV [90, 91], although cross-species transmission uncommonly occurs [62, 89, 90, 92]. FIV transmission events primarily occur through direct interactions (e.g., mating or aggressive encounters). Felids are infected with FIV throughout their
lifetime; although most felids do not demonstrate clinical signs of infection, some individuals
can potentially exhibit sublethal complications after many years of infection [91, 93]. Because
FIV is transmitted through direct contacts, we expected greater prevalence in populations that
exhibit more opportunity for interactions (Table 1). For example, populations that occur at
higher densities would be expected to result in greater FIV prevalence [91]. Landscape pattern
that is altered through urbanization can potentially influence population density and animal
movement patterns, which could increase intra- and interspecific interactions [94] and thus
the opportunity for FIV transmission [62, 95].
Feline calicivirus (FCV) is a widespread pathogen in felids, occurring at moderate levels in
bobcat (prevalence ranging from 17–67%) [70] and puma (prevalence ranging from 17–56%)
populations [88, 96, 97]. Although highly infectious and easily transmitted through direct contacts between animals, it typically only causes minor to moderate oral, ocular, and upper respiratory disease; however, more virulent outbreaks have occurred in domestic cats resulting in
high mortality [98]. It is believed that felids can shed the virus for up to several months (and
uncommonly throughout their lifetime) and although cats are believed to clear the virus, they
can be reinfected with a related or novel viral variant of FCV [98]. The virus can be transmitted
from adult females to their young, as well as among older animals. The prevalence of FCV
increases with cat density [98], thus more contacts among animals increase the likelihood of
being infected (Table 1). Although FCV can exhibit similar prevalence in male and female
felids [99], we predicted that male bobcats and pumas might exhibit greater prevalence, compared to females, due to their larger home ranges and potential for increased contacts with
other animals. Further, although FCV is probably most commonly transmitted via direct contacts between animals, the virus can persist in the environment (at least in clinical settings) for
up to several weeks and thus potentially be transmitted indirectly (e.g., through urine and
feces) [98], although it is unknown if this occurs in the natural environment. Because FCV is
associated with domestic cats, we expect FCV prevalence to increase with the proximity to
human residences where owned and feral cats reside and interactions with wild felids are most
likely to occur [70] (Table 1). Lastly, within wild felid populations, the prevalence of FCV
would be expected to follow similar predictions as presented for FIV above (Table 1).

Modeling approach
Pathogen prevalence for felids across forms of urbanization. For each grid and study
area, we evaluated bobcat and puma exposure to pathogens. We estimated the seroprevalence
of each pathogen within felid populations across exurban development and wildland habitat
on the WS and WUI and wildland habitat on the FR. Pathogen analysis was sometimes
restricted by limited handling time of captured animals and sample quality that was occasionally inadequate for robust diagnostic testing. Therefore, the number of samples and animals
evaluated was sometimes lower than the total number of animals captured in the field.
Evaluation of demographic, social, and environmental factors. Based on our predictions of pathogen prevalence in bobcat and puma (Table 1), we compared a suite of models
[100, 101] evaluating demographic, social, and environmental characteristics for each

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

8 / 22

�Demographic, social, and environmental pathogen factors

Table 3. Variable importance values (VIV) for demographic, social (intraspecific and interspecific), and environmental (urban and landscape) categories for bobcats and pumas on the Western Slope (WS) and Front Range (FR) of Colorado, USA. VIV were used to assess the relative importance of
groups of covariates in models evaluating pathogens in felid populations. A dash (i.e., -) indicates that models with this covariate could not be evaluated (see
Methods).
Demographic

Social Intraspecific

Social Interspecific

Sex Age Space-Use
Extent

Space-Use Degree
Overlap

Space-Use Degree
Overlap

Study
Area

Species Pathogen

WS

Bobcat

Toxoplasma 0.08 0.09

0.09

0.41

0.08

0.09

WS

Bobcat

Bartonella

0.10 0.13

0.14

0.15

0.13

0.33

WS

Bobcat

FIV

0.15 0.44

0.14

0.13

0.13

WS

Bobcat

FCV

0.04 0.05

0.42

0.55

WS

Puma

Toxoplasma

- 0.21

-

WS

Puma

Bartonella

-

-

WS

Puma

FIV

0.10 0.08

WS

Puma

FCV

0.10

FR

Bobcat

FR

Bobcat

Bartonella

FR

Bobcat

FR

Environmental Urban

Environmental
Landscape

Human Grid
Development

NDVI

0.18

0.20 0.08

0.16

0.11

0.20 0.16

0.11

0.14

0.21

0.12

-

0.13

0.05

0.16

0.17

0.06 0.08

0.04

0.20

-

-

-

-

0.13

-

0.12

-

0.18

-

0.39

-

-

0.26

-

Toxoplasma 0.13 0.34

0.12

0.14

0.13

- 0.09

0.03

0.19

FIV

- 0.06

0.55

Bobcat

FCV

-

-

FR

Puma

FR
FR
FR

-

-

-

0.15

0.12 0.12

0.18

-

0.18 0.08

0.05

0.13

-

0.19 0.07

0.11

0.16

0.14

0.13 0.15

0.16

0.05

0.70

0.04

0.08

-

0.13

0.09

0.21

0.14

0.25

0.13 0.14

0.18

-

-

-

-

-

Toxoplasma 0.15 0.51

-

0.15

0.10

0.13

Puma

Bartonella

- 0.15

-

0.30

0.18

Puma

FIV

0.13 0.09

-

0.07

0.84

Puma

FCV

0.25 0.19

-

0.11

0.13

-

-

-

-

0.12 0.22

0.18

0.23

-

0.15

-

0.15

0.10

-

0.13 0.06

0.10

0.18

-

0.10 0.15

0.37

https://doi.org/10.1371/journal.pone.0187035.t003

pathogen in each felid population, which included 15 model sets (Tables 3 and 4). Sample size
restricted the number of models that we could evaluate in some instances. Covariates were
grouped into one of five categories: demographic, social intraspecific, social interspecific, environment urban, or environment landscape (Table 2). The demographic category included not
only sex and age, but also space-use extent because this characteristic is related to both sex and
age. Telemetry data were used to estimate space use of individuals by calculating the utilization
distribution (UD) for felids that occurred on our sampling grids from June 2009 to June 2010
on the WS and September 2010 to September 2011 on the FR [30]. For animals fit with GPS
collars (bobcats n = 37; pumas n = 25), UDs were estimated with the Brownian bridge movement model (BBMM) with the mkde package [102] in program R [103]. For pumas on the WS
fit with VHF collars (n = 4), UDs were estimated with the kernel home range estimator using
likelihood cross validation [104] in the Animal Space Use package [105]. We used the 99%
cumulative probability of space use for all analyses.
For social interactions, to evaluate the opportunity for direct and indirect contacts between
individuals, we estimated space-use overlap among animals [79, 106, 107]; this information was
used to estimate degree, in-strength, and equivalent social connectivity for intra- and interspecific social interactions (Table 2) [30]. We defined social interactions as potential direct or
indirect contacts occurring between animals, including both intra- and interspecific interactions. Although social behavior is most commonly associated with intraspecific interactions
(e.g., [108, 109]), social interactions can also occur between species, for example in the context
of interspecific dominance relationships [110, 111].
We also evaluated several environmental covariates, including the amount of urbanization
in space-use extent, grid, and NDVI (Table 1). Each continuous covariate was standardized
by subtracting the sample mean from the input variable values and dividing by the standard
deviation [112]. Covariates were evaluated for collinearity using Pearson’s correlation and

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

9 / 22

�Demographic, social, and environmental pathogen factors

Table 4. Model-averaged parameter estimates with associated standard errors for demographic, social (intraspecific and interspecific), and environmental (urban and landscape) categories for bobcats and pumas on the Western Slope (WS) and Front Range (FR) of Colorado, USA. A dash
(i.e., -) indicates that models with this covariate could not be evaluated (see Methods).
Demographic
Study
Area

Species Pathogen

WS

Bobcat

WS

Social Intraspecific Social Interspecific

Environmental Urban

Environmental
Landscape

Sex

Age

SpaceUse
Extent

SpaceUse
Overlap

Degree

SpaceUse
Overlap

Degree

Human
Development

Grid

NDVI

Toxoplasma

-0.21
(1.02)

-0.11
(0.27)

-0.10
(0.57)

1.06
(0.63)

0.00
(0.52)

0.00
(0.54)

-0.68
(0.68)

0.80 (0.77)

0.46
(1.21)

-0.50 (0.56)

Bobcat

Bartonella

-0.31
(1.07)

0.16
(0.25)

0.42
(0.63)

-0.45
(0.62)

0.57
(0.65)

1.08
(0.77)

-0.31
(0.59)

0.74 (0.57)

-1.10
(1.28)

-0.33 (0.64)

WS

Bobcat

FIV

-1.34
(2.53)

0.71
(0.47)

-0.53
(1.37)

-0.26
(1.15)

-0.31
(0.81)

-0.75
(1.38)

1.50
(1.52)

-0.36 (1.13)

-

0.56 (0.88)

WS

Bobcat

FCV

-0.13
(1.04)

0.08
(0.25)

-1.72
(1.24)

-1.72
(1.26)

0.26
(0.63)

-1.03
(0.95)

-1.53
(1.53)

-0.52 (0.73)

-1.22
(1.35)

0.10 (0.54)

WS

Puma

Toxoplasma

-

1.23
(2.08)

-

1.57
(2.32)

-

-

-

-

-

-

WS

Puma

Bartonella

-

-

-

-0.71
(1.06)

-

0.44
(0.91)

-1.02
(1.59)

-0.43 (1.07)

-0.87
(1.83)

-1.78 (1.96)

WS

Puma

FIV

-0.90
(1.87)

0.19
(0.73)

-

1.50
(1.70)

-

-2.81
(2.42)

-

1.41 (1.11)

0.16
(2.01)

-0.32 (1.21)

WS

Puma

FCV

0.08
(1.66)

-

-

1.52
(1.64)

-

0.27
(0.82)

-

1.14 (1.28)

-1.70
(3.71)

0.03 (1.22)

FR

Bobcat

Toxoplasma

0.55
(1.33)

0.57
(0.44)

-0.03
(0.65)

0.73
(0.88)

-0.22
(0.67)

0.57
(0.75)

-0.49
(0.67)

0.27 (0.68)

1.10
(1.23)

-0.53 (0.74)

FR

Bobcat

Bartonella

-

-1.18
(1.24)

0.76
(1.08)

1.71
(2.61)

1.22
(1.73)

5.46
(4.81)

0.98
(1.11)

-5.02 (4.48)

-

-0.51 (2.29)

FR

Bobcat

FIV

-

-0.05
(0.47)

2.53
(2.34)

0.15
(1.02)

-1.58
(1.55)

-0.83
(0.86)

-3.02
(3.33)

-1.03 (1.97)

-3.52
(4.72)

-2.53 (3.40)

FR

Bobcat

FCV

FR

Puma

Toxoplasma

-

-

-

-

-

-

-

-

-

-

1.08
(1.26)

1.08
(0.69)

-

0.65
(0.76)

-0.14
(0.60)

0.47
(0.63)

-

-0.43 (0.82)

1.65
(1.24)

0.87 (1.02)

FR

Puma

Bartonella

-

0.34
(1.32)

-

2.24
(3.03)

1.30
(2.80)

-2.06
(2.42)

-

-0.39 (1.78)

-

0.66 (1.96)

FR

Puma

FIV

1.44
(1.36)

-0.30
(0.44)

-

0.25
(0.74)

-4.05
(2.79)

0.52
(0.77)

-

0.93 (1.28)

-0.33
(1.28)

0.65 (1.08)

FR

Puma

FCV

1.73
(1.31)

0.47
(0.44)

-

0.23
(0.64)

0.49
(0.76)

0.67
(0.61)

-

0.22 (0.91)

-0.84
(1.17)

3.57 (3.61)

https://doi.org/10.1371/journal.pone.0187035.t004

considered correlated if r &gt; 0.7; amount of NDVI in space-use extent and intra- and interspecific in-strength and effective social connectivity were highly correlated with multiple covariates
and were subsequently excluded from analyses. In addition, space-use extent for WS and FR
pumas and interspecific-degree for FR pumas were highly correlated with multiple covariates
and were excluded from analyses. For further explanations about how social interaction and
urban covariates were calculated see Table 2 and [30].
Using logistic regression in R (i.e., glm with binomial logit link [103]), we evaluated model
sets that were comprised of all possible combinations of univariate covariates and pairwise
comparisons (56 total models) for each species in each study area and ranked models using
Akaike’s Information Criteria corrected for small sample size (AICc) [101]. We evaluated all
possible combinations of covariates in models [113] with up to 2 covariates based on sample
size recommendations of evaluating 1 covariate per 5–10 observations [114]. Larger sample
sizes would allow the evaluation of all variable combinations. To evaluate the relative importance of variables in models, we calculated variable importance values (VIV) and model-

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

10 / 22

�Demographic, social, and environmental pathogen factors

averaged parameter estimates across models in which they occurred [101, 115]. Likely due to
either relatively low or high prevalence of the pathogen in logistic regression models, coupled
with relatively low sample sizes, models sometimes failed to converge; these models generally
had little support in our data sets (i.e., AIC weight � 0.01) and were removed to calculate VIV
and model-averaged parameter estimates. To evaluate which covariates were supported in our
model sets, we first identified covariates based on whether they occurred in models that performed better than the intercept-only model. We then evaluated their VIV in model sets and
the direction of their model-averaged parameter estimates.

Results
Both felids used areas in close proximity to human residences in exurban development and
along the wildland-urban interface. Seroprevalence for pathogens was evaluated for 71%–
100% of sampled individuals within populations (Fig 2), with the proportion of the sampled
population screened based on sample quantity and quality. Although seroprevalence for some
pathogens varied between grids (Fig 2), we did not find support for a statistical difference in
seroprevalance between urbanized and wildland grids based on the covariate Grid not occurring in top models (S2–S16 Tables) and when evaluating VIVs (�0.22; Table 3) and modelaveraged parameter estimates (95% confidence intervals overlapped 0; Table 4).

Effects of demographic, social, and environmental factors
Demographic factors. As predicted for some pathogens, individuals were more likely to
be exposed with increasing age; this covariate occurred in the top-ranked models for FIV in
WS bobcats (S3 Table) and Toxoplasma in FR bobcats (S10 Table) and FR pumas (S13 Table).
VIV in these instances ranged from 0.34 to 0.51 (Table 3), and the model-averaged parameter
estimates indicated a positive trend, although 95% confidence intervals overlapped 0, between
exposure and age (WS bobcats FIV: β = 0.71, se = 0.47; FR bobcats Toxoplasma: β = 0.57, se =
0.44; FR pumas Toxoplasma: β = 1.08, se = 0.69; Table 4). In support of our predictions, spaceuse extent for FIV in FR bobcats occurred in the three top-ranked models (S12 Table) with a
VIV = 0.55 (Table 3) and a positive trend with exposure (β = 2.54, se = 2.34; Table 4). However,
counter to predictions, space use extent was negatively related to FCV for WS bobcats (β =
-1.72, se = 1.24; Table 4); this covariate occurred in top-ranked models (S5 Table) and had a
VIV = 0.42 (Table 3).
Social factors. As predicted, WS bobcats appeared more likely to be exposed to Toxoplasma with increasing intraspecific space-use overlap (β = 1.06, se = 0.63; Table 4); this covariate occurred in the top-ranked model (S2 Table) with a VIV = 0.41 (Table 3). However,
counter to predictions for directly transmitted pathogens, exposure to FCV for WS bobcats
and FIV for FR pumas appeared negatively related to intraspecific space-use overlap (β = -1.72,
se = 1.26) and intraspecific degree (β = -4.05, se = 2.79), respectively (Table 4); these covariates
occurred in the suite of top-ranked models (S4 and S14 Tables, respectively) with VIVs of 0.55
and 0.84, respectively (Table 3). Exposure to Bartonella appeared to be positively related to
interspecific space-over overlap for WS (β = 1.08, se = 0.77) and FR (β = 5.46, se = 4.81) bobcats
(Table 4); this covariate occurred in the top-ranked models for each model set (S3 and S11
Tables, respectively) with VIVs of 0.33 and 0.70, respectively (Table 3).
Environmental factors. In contrast to predictions, the environmental covariates evaluating urban and landscape features were not well supported in our models (Tables 3 and 4; S2–
S16 Tables). In general, environmental covariates did not occur in top-ranked models, with
the exception of NDVI for FCV in FR pumas (S16 Table), which exhibited a VIV of 0.37
(Table 3) and was positively related to FCV exposure (β = 3.57 and se = 3.61; Table 4).

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

11 / 22

�Demographic, social, and environmental pathogen factors

Discussion
Demographic, social, and environmental factors varied in their association with pathogen
exposure in bobcat and puma populations. As expected, demographic factors helped explain
exposure to some pathogens in our study. Specifically, age appeared to be positively related to
exposure to pathogens that are both environmentally transmitted (Toxoplasma) and directly
transmitted between animals (FIV), consistent with our predictions and other studies of felid
populations [28, 48, 61]. We predicted that animals with greater extents of space use would be
more likely to interact with other individuals and greater extents of the landscape, leading to a
greater probability of pathogen transmission [30]. However, we found weak and equivocal
support for the effects of space-use extent on pathogen exposure. Although these results were
counter to our predictions, other factors related to space use might be important considerations for explaining pathogen characteristics, including social interactions and status, as
explained below.
Social interactions appeared to influence exposure to some pathogens via indirect and
direct means of transmission. As predicted, as intraspecific space-use overlap increased within
bobcat populations, animals were more likely to be exposed to Toxoplasma. Felids may
increase marking behavior along territorial boundaries and in areas of sympatry [34]. Because
felids are the definitive host of Toxoplasma and excrete oocysts into the environment via scats
[54, 60, 71], areas of shared space use would likely exhibit increased concentrations of Toxoplasma and elevated levels of Toxoplasma in prey. In addition, Toxoplasma likely is present at
high concentrations at felid marking locations where animals repeatedly scat and urinate [54];
because animals revisit these sites and investigate the markings of other animals (both within
and between species), animals could experience a relatively high chance of being exposed to
Toxoplasma through environmental contamination.
Both space-use overlap and degree are positively correlated with space-use extent, which itself
is related to gender and the behavior of resident or transient animals [30]. In wild felids,
females and residents generally express smaller extents of space-use than males and transients,
which are associated with increased movement extents with less pronounced site fidelity [34].
Transients, which often are younger animals without a defined home range, could potentially
exhibit two different patterns of behavior that would influence pathogen characteristics. They
might either (1) exhibit reduced interactions due to fewer opportunities to mate and defend a
territory [34], which could explain the negative correlation between FCV exposure and space
use extent in WS bobcats, or (2) exhibit increased interactions when attempting to establish a
home range. Because these patterns have not been well evaluated in wild felid populations, the
effect of social status and behavior on contact and disease transmission is in need of further
study.
Counter to studies in other systems (e.g., [40, 62]), our data did not indicate that the interspecific factors that we evaluated strongly influenced cross-species transmission of our four
target pathogens between bobcats and pumas. However, interspecific space-use overlap did
appear to increase exposure to Bartonella in bobcats. This is possibly related to both bobcats
and pumas using similar habitat with elevated levels of Bartonella, such as areas associated
with domestic cats or other sources (e.g., vectors such as fleas or ticks) of the pathogen [64]. It
is also possible that bobcats acquired vectors that transmitted this pathogen from pumas.
Environmental variables in our models appeared to have the least support in explaining
exposure of the four pathogens we evaluated in felid populations. Neither the amount nor the
type of urbanization with which animals were associated predicted exposure to pathogens. Different forms of urbanization (i.e., exurban vs urban) can alter prey and domestic cat populations, both of which could be important factors for transmitting pathogens to wild felids [54,

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

12 / 22

�Demographic, social, and environmental pathogen factors

60]. Additional research, however, is necessary to quantify how these factors varied across the
landscape in our study system, especially in relation to feral cat populations and seroprevalence
of Toxoplasma in small mammal populations. Further, although directly-transmitted pathogens might be more likely to be transmitted in urbanized landscapes due to increased interactions of felids [62], other research in our study areas reported similar amounts of interspecific
space-use overlap and potential contact rates in felids across broad scales between urbanized
and wildland habitat [30]. Importantly, increased interaction opportunities at fine temporal
scales can occur in urbanized landscapes [116], which is predicted to increase cross-species
pathogen transmission in urban areas. For pathogens that are associated with specific vectors
(e.g., ectoparasites) or intermediate hosts (e.g., small mammals), it could be useful to create
predictive maps of habitat association for these organisms [117–124] and use this information
as covariates in models. Additionally, other environmental factors, such as soil characteristics,
can be associated with the risk of disease [125].
The relatively small number of individuals screened for pathogen exposure reduced our
power to detect differences in this parameter in relation to covariates [126]. Although we used
GPS telemetry to track a comparatively large proportion of the population of bobcats and
pumas occurring concurrently within our study areas, studies with greater sample sizes are
needed to further understand the effects of demographic, social, and environmental factors on
pathogen characteristics in wildlife populations. In addition, variation in diagnostic assay sensitivity and specificity can result in false negative or false positive assignments, further increasing uncertainty [127, 128]. In our study, although we detected low seroprevalence of FIV in
bobcats [61], FIV PCR analyses for the same individuals failed to detect the presence of FIV
[89], indicating uncertainty that FIV infection occurred in this cohort. Further, the spatial
scale of analysis can strongly influence inference [129]. Although our study did not find strong
results at relatively fine spatial scales, broad-scale analyses of pathogens might better explain
patterns [48, 126]. At fine scales, patterns of pathogen exposure might appear homogenous,
but at broader spatial scales patterns may become more heterogeneous. For example, some
vectors, such as ticks, demonstrate a gradient of population densities across their geographic
range, where they are most abundant at the interior of their range and decrease in density by
1–2 orders of magnitude at the edge of their range [130]; such patterns could affect the opportunity for animals to be exposed to pathogens.
Although many studies focus on single pathogen characteristics within a single species,
pathogen spillover between species is increasingly recognized as important to understanding
disease epidemics in wildlife populations [1, 126, 131]. Spillover events may be occasional, followed by self-sustaining transmission within the new host species. For example, although each
felid species typically harbors a unique strain of FIV [90], transmission of species specific
strains of FIV has occurred between pumas and bobcats [62, 132]. In other cases, spillover may
not occur between species due to the specificity between the pathogen and host. Due to the
lack of genotypic information to assess pathogen spillover in a multihost, multipathogen system additional investigation are warranted to further investigate this important topic in relation to anthropogenic landscape change.
In addition to providing insight on pathogen exposure in wild felids, our study provides an
approach for evaluating how demographic, social, and environmental factors influence disease
dynamics in animal populations, which allows for the comparison and evaluation of the relative strength among multiple mechanisms and hypotheses. Future work applying this strategy
will be necessary to gain a better understanding about how ecological mechanisms influence
pathogen exposure and transmission, with important implications for the conservation of animal populations.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

13 / 22

�Demographic, social, and environmental pathogen factors

Supporting information
S1 Table. Sample sizes for pathogen samples of bobcats and pumas for exurban and wildland habitat on the Western Slope (WS) in 2009 and wildland-urban interface (WUI) and
wildland habitat on the Front Range (FR) in 2010–2011, Colorado, USA.
(DOC)
S2 Table. Model results for Toxoplasma in bobcats on the Western Slope of Colorado,
USA.
(DOC)
S3 Table. Model results for Bartonella in bobcats on the Western Slope of Colorado, USA.
(DOC)
S4 Table. Model results for FIV in bobcats on the Western Slope of Colorado, USA.
(DOC)
S5 Table. Model results for Calicivirus in bobcats on the Western Slope of Colorado, USA.
(DOC)
S6 Table. Model results for Toxoplasma in pumas on the Western Slope of Colorado, USA.
(DOC)
S7 Table. Model results for Bartonella in pumas on the Western Slope of Colorado, USA.
(DOC)
S8 Table. Model results for FIV in pumas on the Western Slope of Colorado, USA.
(DOC)
S9 Table. Model results for Calicivirus in pumas on the Western Slope of Colorado, USA.
(DOC)
S10 Table. Model results for Toxoplasma in bobcats on the Front Range of Colorado, USA.
(DOC)
S11 Table. Model results for Bartonella in bobcats on the Front Range of Colorado, USA.
(DOC)
S12 Table. Model results for FIV in bobcats on the Front Range of Colorado, USA.
(DOC)
S13 Table. Model results for Toxoplasma in pumas on the Front Range of Colorado, USA.
(DOC)
S14 Table. Model results for Bartonella in pumas on the Front Range of Colorado, USA.
(DOC)
S15 Table. Model results for FIV in pumas on the Front Range of Colorado, USA.
(DOC)
S16 Table. Model results for Calicivirus in pumas on the Front Range of Colorado, USA.
(DOC)
S17 Table. Data used to evaluate Toxoplasma seroprevalence in bobcats on the Western
Slope of Colorado, USA.
(TXT)

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

14 / 22

�Demographic, social, and environmental pathogen factors

S18 Table. Data used to evaluate Bartonella seroprevalence in bobcats on the Western
Slope of Colorado, USA.
(TXT)
S19 Table. Data used to evaluate FIV seroprevalence in bobcats on the Western Slope of
Colorado, USA.
(TXT)
S20 Table. Data used to evaluate Calicivirus seroprevalence in bobcats on the Western
Slope of Colorado, USA.
(TXT)
S21 Table. Data used to evaluate Toxoplasma seroprevalence in pumas on the Western
Slope of Colorado, USA.
(TXT)
S22 Table. Data used to evaluate Bartonella seroprevalence in pumas on the Western Slope
of Colorado, USA.
(TXT)
S23 Table. Data used to evaluate FIV seroprevalence in pumas on the Western Slope of
Colorado, USA.
(TXT)
S24 Table. Data used to evaluate Calicivirus seroprevalence in pumas on the Western
Slope of Colorado, USA.
(TXT)
S25 Table. Data used to evaluate Toxoplasma seroprevalence in bobcats on the Front
Range of Colorado, USA.
(TXT)
S26 Table. Data used to evaluate Bartonella seroprevalence in bobcats on the Front Range
of Colorado, USA.
(TXT)
S27 Table. Data used to evaluate FIV seroprevalence in bobcats on the Front Range of Colorado, USA.
(TXT)
S28 Table. Data used to evaluate Toxoplasma seroprevalence in pumas on the Front Range
of Colorado, USA.
(TXT)
S29 Table. Data used to evaluate Bartonella seroprevalence in pumas on the Front Range
of Colorado, USA.
(TXT)
S30 Table. Data used to evaluate FIV seroprevalence in pumas on the Front Range of Colorado, USA.
(TXT)
S31 Table. Data used to evaluate Calicivirus seroprevalence in pumas on the Front Range
of Colorado, USA.
(TXT)

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

15 / 22

�Demographic, social, and environmental pathogen factors

Acknowledgments
Funding and support were provided by Colorado State University, Colorado Parks and Wildlife (CPW), Boulder County Parks and Open Space, Boulder City Open Space and Mountain
Parks, the Bureau of Land Management, US Forest Service, Arizona State University, and a
grant from the National Science Foundation-Ecology of Infectious Diseases Program (NSF
EF-0723676; EF-1413925). We greatly thank R. Alonso, B. Dunne, M. Durant, D. Morin, and
L. Sweanor for their invaluable assistance in the field. In addition, we thank the numerous
landowners who allowed us access to their properties for our research. We greatly appreciate
the discussions and commentary about our project and manuscript provided by D. Theobald,
as well as insight from anonymous reviewers that improved the paper.

Author Contributions
Conceptualization: Jesse S. Lewis, Sue VandeWoude, Kevin R. Crooks.
Data curation: Jesse S. Lewis, Kenneth A. Logan, Mat W. Alldredge, Scott Carver, Michael
Lappin.
Formal analysis: Jesse S. Lewis, Scott Carver, Sarah N. Bevins.
Funding acquisition: Kenneth A. Logan, Mat W. Alldredge, Sue VandeWoude, Kevin R.
Crooks.
Investigation: Kenneth A. Logan.
Methodology: Jesse S. Lewis.
Resources: Mat W. Alldredge, Scott Carver, Sarah N. Bevins, Michael Lappin.
Supervision: Kevin R. Crooks.
Writing – original draft: Jesse S. Lewis.
Writing – review &amp; editing: Jesse S. Lewis, Kenneth A. Logan, Mat W. Alldredge, Scott
Carver, Sarah N. Bevins, Michael Lappin, Sue VandeWoude, Kevin R. Crooks.

References
1.

Daszak P, Cunningham AA, Hyatt AD. Emerging infectious diseases of wildlife—threats to biodiversity
and human health. Science. 2000; 287(5452):443–9. PMID: 10642539

2.

Murray DL, Kapke CA, Evermann JF, Fuller TK. Infectious disease and the conservation of free-ranging large carnivores. Animal Conservation. 1999; 2(4):241–54.

3.

Czech B, Krausman PR, Devers PK. Economic associations among causes of species endangerment
in the United States. BioScience. 2000; 50(7):593–601.

4.

Dybas CL. Infectious diseases subdue Serengeti lions. BioScience. 2009; 59(1):8–13.

5.

Seimon T, Miquelle D, Chang T, Newton A, Korotkova I, Ivanchuk G, et al. Canine distemper virus: an
emerging disease in wild endangered Amur tigers. mBio. 2013: https://doi.org/10.1128/mBio.0041013 PMID: 23943758

6.

Pedersen AB, Jones KE, Nunn CL, Altizer S. Infectious diseases and extinction risk in wild mammals.
Conservation Biology. 2007; 21(5):1269–79. https://doi.org/10.1111/j.1523-1739.2007.00776.x PMID:
17883492

7.

Morse SS. Factors in the emergence of infectious diseases. Emerging Infectious Diseases. 1995; 1
(1):7–15. https://doi.org/10.3201/eid0101.950102 PMID: 8903148

8.

Levi T, Kilpatrick AM, Mangel M, Wilmers CC. Deer, predators, and the emergence of Lyme disease.
Proceedings of the National Academy of Sciences. 2012; 109(27):10942–7.

9.

Young HS, Dirzo R, Helgen KM, McCauley DJ, Billeter SA, Kosoy MY, et al. Declines in large wildlife
increase landscape-level prevalence of rodent-borne disease in Africa. Proceedings of the National
Academy of Sciences. 2014; 111(19):7036–41.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

16 / 22

�Demographic, social, and environmental pathogen factors

10.

McMichael AJ. Environmental and social influences on emerging infectious diseases: past, present
and future. Philosophical Transactions of the Royal Society of London Series B: Biological Sciences.
2004; 359(1447):1049–58. https://doi.org/10.1098/rstb.2004.1480 PMID: 15306389

11.

Woolhouse ME, Haydon DT, Antia R. Emerging pathogens: the epidemiology and evolution of species
jumps. Trends in Ecology &amp; Evolution. 2005; 20(5):238–44.

12.

Keesing F, Belden LK, Daszak P, Dobson A, Harvell CD, Holt RD, et al. Impacts of biodiversity on the
emergence and transmission of infectious diseases. Nature. 2010; 468(7324):647–52. https://doi.org/
10.1038/nature09575 PMID: 21124449

13.

Sala OE, Chapin FS, Armesto JJ, Berlow E, Bloomfield J, Dirzo R, et al. Global biodiversity scenarios
for the year 2100. Science. 2000; 287(5459):1770–4. PMID: 10710299

14.

McDonald RI, Kareiva P, Forman RT. The implications of current and future urbanization for global
protected areas and biodiversity conservation. Biological Conservation. 2008; 141(6):1695–703.

15.

Cohen JE. Human population: the next half century. Science. 2003; 302(5648):1172–5. https://doi.
org/10.1126/science.1088665 PMID: 14615528

16.

Theobald DM. Landscape Patterns of Exurban Growth in the USA from 1980 to 2020. Ecology and
Society. 2005; 10(1):1–34.

17.

Seto KC, Fragkias M, Güneralp B, Reilly MK. A meta-analysis of global urban land expansion. PLoS
One. 2011; 6(8):1–9.

18.

Bradley CA, Altizer S. Urbanization and the ecology of wildlife diseases. Trends in Ecology &amp; Evolution. 2007; 22(2):95–102.

19.

Shochat E, Warren PS, Faeth SH, McIntyre NE, Hope D. From patterns to emerging processes in
mechanistic urban ecology. Trends in Ecology &amp; Evolution. 2006; 21(4):186–91.

20.

Daszak P, Cunningham AA, Hyatt AD. Anthropogenic environmental change and the emergence of
infectious diseases in wildlife. Acta Tropica. 2001; 78(2):103–16. PMID: 11230820

21.

Bradley CA, Gibbs SE, Altizer S. Urban land use predicts West Nile virus exposure in songbirds. Ecological Applications. 2008; 18(5):1083–92. PMID: 18686573

22.

Altizer S, Nunn CL, Thrall PH, Gittleman JL, Antonovics J, Cunningham AA, et al. Social organization
and parasite risk in mammals: integrating theory and empirical studies. Annual Review of Ecology,
Evolution, and Systematics. 2003; 34:517–47.

23.

Wilcox BA, Gubler DJ. Disease ecology and the global emergence of zoonotic pathogens. Environmental Health and Preventive Medicine. 2005; 10(5):263–72. https://doi.org/10.1007/BF02897701
PMID: 21432130

24.

Zuk M, McKean KA. Sex differences in parasite infections: patterns and processes. International Journal for Parasitology. 1996; 26(10):1009–24. PMID: 8982783

25.

Hudson P, Dobson A. Macroparasites: observed patterns in naturally fluctuating animal populations.
In: Grenfell BT, Dobson AP, editors. Ecology of infectious diseases in natural populations. Cambridge,
UK: Cambridge University Press; 1995. p. 144–76.

26.

Wilson K, Bjørnstad O, Dobson A, Merler S, Poglayen G, Randolph S, et al. Heterogeneities in macroparasite infections: patterns and processes. In: Hudson PJ, Rizzoli A, Grenfell BT, Heesterbeek H,
Dobson AP, editors. The Ecology of Wildlife Diseases. Oxford: Oxford University Press; 2002. p. 6–
44.

27.

Monello RJ, Gompper ME. Relative importance of demographics, locale, and seasonality underlying
louse and flea parasitism of raccoons (Procyon lotor). Journal of Parasitology. 2009; 95(1):56–62.
https://doi.org/10.1645/GE-1643.1 PMID: 18578574

28.

Biek R, Ruth TK, Murphy KM, Anderson CR Jr, Johnson M, DeSimone R, et al. Factors associated
with pathogen seroprevalence and infection in Rocky Mountain cougars. Journal of Wildlife Diseases.
2006; 42(3):606–15. https://doi.org/10.7589/0090-3558-42.3.606 PMID: 17092891

29.

Lindstedt SL, Miller BJ, Buskirk SW. Home range, time, and body size in mammals. Ecology. 1986;
67:413–8.

30.

Lewis JS, Logan KA, Alldredge M, Theobald DM, VandeWoude S, Crooks KR. Contact networks
reveal interspecific interactions of sympatric wild felids driven by space use along an urban gradient In
Review.

31.

Ramsey D, Spencer N, Caley P, Efford M, Hansen K, Lam M, et al. The effects of reducing population
density on contact rates between brushtail possums: implications for transmission of bovine tuberculosis. Journal of Applied Ecology. 2002; 39(5):806–18.

32.

Fenton A, Fairbairn JP, Norman R, Hudson PJ. Parasite transmission: reconciling theory and reality.
Journal of Animal Ecology. 2002; 71(5):893–905.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

17 / 22

�Demographic, social, and environmental pathogen factors

33.

Tompkins DM, Dunn AM, Smith MJ, Telfer S. Wildlife diseases: from individuals to ecosystems. Journal of Animal Ecology. 2011; 80(1):19–38. https://doi.org/10.1111/j.1365-2656.2010.01742.x PMID:
20735792

34.

Sunquist M, Sunquist F. Wild cats of the world. Chicago, IL, USA: University of Chicago Press; 2002.

35.

Gorman ML, Mills MG, Raath JP, Speakman JR. High hunting costs make African wild dogs vulnerable to kleptoparasitism by hyaenas. Nature. 1998; 391(6666):479–81.

36.

Merkle J, Stahler D, Smith D. Interference competition between gray wolves and coyotes in Yellowstone National Park. Canadian Journal of Zoology. 2009; 87(1):56–63.

37.

Polis GA, Myers CA, Holt RD. The ecology and evolution of intraguild predation: potential competitors
that eat each other. Annual Review of Ecology and Systematics. 1989; 20:297–330.

38.

Palomares F, Caro TM. Interspecific killing among mammalian carnivores. The American Naturalist.
1999; 153(5):492–508.

39.

Totton SC, Tinline RR, Rosatte RC, Bigler LL. Contact rates of raccoons (Procyon lotor) at a communal feeding site in rural eastern Ontario. Journal of Wildlife Diseases. 2002; 38(2):313–9. https://doi.
org/10.7589/0090-3558-38.2.313 PMID: 12038131

40.

Rushton S, Lurz P, Gurnell J, Fuller R. Modelling the spatial dynamics of parapoxvirus disease in red
and grey squirrels: a possible cause of the decline in the red squirrel in the UK? Journal of Applied
Ecology. 2000; 37(6):997–1012.

41.

Gurnell J, Rushton S, Lurz P, Sainsbury A, Nettleton P, Shirley M, et al. Squirrel poxvirus: landscape
scale strategies for managing disease threat. Biological Conservation. 2006; 131(2):287–95.

42.

Afonso E, Lemoine M, Poulle M-L, Ravat M-C, Romand S, Thulliez P, et al. Spatial distribution of soil
contamination by Toxoplasma gondii in relation to cat defecation behaviour in an urban area. International Journal for Parasitology. 2008; 38(8):1017–23.

43.

Smith DL, Lucey B, Waller LA, Childs JE, Real LA. Predicting the spatial dynamics of rabies epidemics
on heterogeneous landscapes. Proceedings of the National Academy of Sciences. 2002; 99(6):3668–
72.

44.

Russell CA, Smith DL, Waller LA, Childs JE, Real LA. A priori prediction of disease invasion dynamics
in a novel environment. Proceedings of the Royal Society of London Series B: Biological Sciences.
2004; 271(1534):21–5. https://doi.org/10.1098/rspb.2003.2559 PMID: 15002767

45.

McCallum H. Landscape structure, disturbance, and disease dynamics. In: Ostfeld RS, Keesing F,
Eviner VT, editors. Infectious disease ecology: effects of ecosystems on disease and of disease on
ecosystems. Princeton, NJ: Princeton University Press; 2008. p. 100–22.

46.

Biek R, Drummond AJ, Poss M. A virus reveals population structure and recent demographic history
of its carnivore host. Science. 2006; 311(5760):538–41. https://doi.org/10.1126/science.1121360
PMID: 16439664

47.

Wheeler DC, Waller LA, Biek R. Spatial analysis of feline immunodeficiency virus infection in cougars.
Spatial and Spatio-temporal Epidemiology. 2010; 1(2):151–61.

48.

Carver S, Bevins SN, Lappin MR, Boydston EE, Lyren LM, Alldredge MW, et al. Pathogen exposure
varies widely among sympatric populations of wild and domestic felids across the United States. Ecological Applications. 2016; 26(2):367–81. PMID: 27209780

49.

Vanwambeke SO, Lambin EF, Eichhorn MP, Flasse SP, Harbach RE, Oskam L, et al. Impact of landuse change on dengue and malaria in northern Thailand. EcoHealth. 2007; 4(1):37–51.

50.

Langlois JP, Fahrig L, Merriam G, Artsob H. Landscape structure influences continental distribution of
hantavirus in deer mice. Landscape Ecology. 2001; 16(3):255–66.

51.

Farnsworth ML, Wolfe LL, Hobbs NT, Burnham KP, Williams ES, Theobald DM, et al. Human land use
influences chronic wasting disease prevalence in mule deer. Ecological Applications. 2005; 15(1):119–26.

52.

Skelly DK, Bolden SR, Holland MP, Freidenburg L, Freidenfelds N, Malcolm TR, et al. Urbanization
and disease in amphibians. Disease ecology: community structure and pathogen dynamics2006.
p. 153–67.

53.

Brearley G, Rhodes J, Bradley A, Baxter G, Seabrook L, Lunney D, et al. Wildlife disease prevalence
in human-modified landscapes. Biological Reviews. 2013; 88(2):427–42. https://doi.org/10.1111/brv.
12009 PMID: 23279314

54.

Gilot-Fromont E, Lélu M, Dardé M-L, Richomme C, Aubert D, Afonso E, et al. The life cycle of Toxoplasma gondii in the natural environment. In: Djakovic OD, editor. Toxoplasmosis-Recent Advances
10: InTech. 10.5772/2845; 2012. p. 2845.

55.

Carver S, Scorza AV, Bevins SN, Riley SP, Crooks KR, VandeWoude S, et al. Zoonotic parasites of
bobcats around human landscapes. Journal of Clinical Microbiology. 2012; 50(9):3080–3. https://doi.
org/10.1128/JCM.01558-12 PMID: 22718941

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

18 / 22

�Demographic, social, and environmental pathogen factors

56.

Page LK, Gehrt SD, Robinson NP. Land-use effects on prevalence of raccoon roundworm (Baylisascaris procyonis). Journal of Wildlife Diseases. 2008; 44(3):594–9. https://doi.org/10.7589/0090-355844.3.594 PMID: 18689644

57.

Hegglin D, Bontadina F, Contesse P, Gloor S, Deplazes P. Plasticity of predation behaviour as a putative driving force for parasite life-cycle dynamics: the case of urban foxes and Echinococcus multilocularis tapeworm. Functional Ecology. 2007; 21(3):552–60.

58.

Reperant LA, Hegglin D, Fischer C, Kohler L, Weber J- M, Deplazes P. Influence of urbanization on
the epidemiology of intestinal helminths of the red fox (Vulpes vulpes) in Geneva, Switzerland. Parasitology Research. 2007; 101(3):605–11. https://doi.org/10.1007/s00436-007-0520-0 PMID: 17393184

59.

Reperant L, Hegglin D, Tanner I, Fischer C, Deplazes P. Rodents as shared indicators for zoonotic
parasites of carnivores in urban environments. Parasitology. 2009; 136(03):329–37.

60.

Lélu M, Langlais M, Poulle M-L, Gilot-Fromont E. Transmission dynamics of Toxoplasma gondii along
an urban–rural gradient. Theoretical Population Biology. 2010; 78(2):139–47. https://doi.org/10.1016/
j.tpb.2010.05.005 PMID: 20685358

61.

Bevins SN, Carver S, Boydston EE, Lyren LM, Alldredge M, Logan KA, et al. Three pathogens in sympatric populations of pumas, bobcats, and domestic cats: implications for infectious disease transmission. PLoS One. 2012; 7(2):e31403 1–10.

62.

Franklin S, Troyer J, Terwee J, Lyren L, Boyce W, Riley S, et al. Frequent transmission of immunodeficiency viruses among bobcats and pumas. Journal of Virology. 2007; 81(20):10961–9. https://doi.org/
10.1128/JVI.00997-07 PMID: 17670835

63.

Deplazes P, van Knapen F, Schweiger A, Overgaauw PA. Role of pet dogs and cats in the transmission of helminthic zoonoses in Europe, with a focus on echinococcosis and toxocarosis. Veterinary
Parasitology. 2011; 182(1):41–53. https://doi.org/10.1016/j.vetpar.2011.07.014 PMID: 21813243

64.

Breitschwerdt EB, Kordick DL. Bartonella infection in animals: carriership, reservoir potential, pathogenicity, and zoonotic potential for human infection. Clinical Microbiology Reviews. 2000; 13(3):428–38.
PMID: 10885985

65.

Lewis JS, Logan KA, Alldredge MW, Bailey LL, VandeWoude S, Crooks KR. The effects of urbanization on population density, occupancy, and detection probability of wild felids. Ecological Applications.
2015; 25:1880–95. PMID: 26591454

66.

Kreeger TJ, Arnemo JM, Raath JP. Handbook of wildlife chemical immobilization. Fort Collins, Colorado: Wildlife Pharmaceuticals Inc.; 2002.

67.

Franklin SP, Troyer JL, TerWee JA, Lyren LM, Kays RW, Riley SP, et al. Variability in assays used for
detection of lentiviral infection in bobcats (Lynx rufus), pumas (Puma concolor), and ocelots (Leopardus pardalis). Journal of Wildlife Diseases. 2007; 43(4):700–10. https://doi.org/10.7589/0090-355843.4.700 PMID: 17984266

68.

Kikuchi Y, Chomel BB, Kasten RW, Martenson JS, Swift PK, O’Brien SJ. Seroprevalence of Toxoplasma gondii in American free-ranging or captive pumas (Felis concolor) and bobcats (Lynx rufus).
Veterinary Parasitology. 2004; 120(1):1–9.

69.

Franti C, Riemann H, Behymer D, Suther D, Howarth J, Ruppanner R. Prevalence of Toxoplasma gondii antibodies in wild and domestic animals in northern California. Journal of the American Veterinary
Medical Association. 1976; 169(9):901–6. PMID: 977457

70.

Riley SP, Foley J, Chomel B. Exposure to feline and canine pathogens in bobcats and gray foxes in
urban and rural zones of a national park in California. Journal of Wildlife Diseases. 2004; 40(1):11–22.
https://doi.org/10.7589/0090-3558-40.1.11 PMID: 15137484

71.

Dubey JP. Toxoplasmosis of animals and humans. Boca Raton, FL: CRC Press; 2010.

72.

Flegr J. How and why Toxoplasma makes us crazy. Trends in Parasitology. 2013; 29(4):156–63.
https://doi.org/10.1016/j.pt.2013.01.007 PMID: 23433494

73.

Afonso E, Germain E, Poulle M- L, Ruette S, Devillard S, Say L, et al. Environmental determinants of
spatial and temporal variations in the transmission of Toxoplasma gondii in its definitive hosts. International Journal for Parasitology: Parasites and Wildlife. 2013; 2:278–85. https://doi.org/10.1016/j.
ijppaw.2013.09.006 PMID: 24533347

74.

Gotteland C, Chaval Y, Villena I, Galan M, Geers R, Aubert D, et al. Species or local environment,
what determines the infection of rodents by Toxoplasma gondii? Parasitology. 2014; 141(02):259–68.

75.

Afonso E, Thulliez P, Gilot-Fromont E. Local meteorological conditions, dynamics of seroconversion
to Toxoplasma gondii in cats (Felis catus) and oocyst burden in a rural environment. Epidemiology and
Infection. 2010; 138(08):1105–13.

76.

Fieberg J, Kochanny CO. Quantifying home-range overlap: the importance of the utilization distribution. Journal of Wildlife Management. 2005; 69(4):1346–59.

77.

Newman ME. The structure and function of complex networks. SIAM review. 2003; 45(2):167–256.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

19 / 22

�Demographic, social, and environmental pathogen factors

78.

Wey T, Blumstein DT, Shen W, Jordán F. Social network analysis of animal behaviour: a promising
tool for the study of sociality. Animal Behaviour. 2008; 75(2):333–44.

79.

Godfrey SS, Moore JA, Nelson NJ, Bull CM. Social network structure and parasite infection patterns in
a territorial reptile, the tuatara (Sphenodon punctatus). International Journal for Parasitology. 2010; 40
(13):1575–85. https://doi.org/10.1016/j.ijpara.2010.06.002 PMID: 20637210

80.

Saura S, Estreguil C, Mouton C, Rodrı́guez-Freire M. Network analysis to assess landscape connectivity trends: application to European forests (1990–2000). Ecological Indicators. 2011; 11(2):407–16.

81.

Lewis JS, Rachlow JL, Horne JS, Garton EO, Wakkinen WL, Hayden J, et al. Identifying habitat characteristics to predict highway crossing areas for black bears within a human-modified landscape.
Landscape and Urban Planning. 2011; 101(2):99–107. https://doi.org/10.1016/j.landurbplan.2011.01.
008

82.

Chomel BB, Kikuchi Y, Martenson JS, Roelke-Parker ME, Chang C- C, Kasten RW, et al. Seroprevalence of Bartonella infection in American free-ranging and captive pumas (Felis concolor) and bobcats
(Lynx rufus). Veterinary Research. 2004; 35(2):233–41. https://doi.org/10.1051/vetres:2004001
PMID: 15099499

83.

Chomel BB, Kasten RW, Henn JB, Molia S. Bartonella infection in domestic cats and wild felids.
Annals of the New York Academy of Sciences. 2006; 1078(1):410–5.

84.

Yamamoto K, Chomel BB, Lowenstine LJ, Kikuchi Y, Phillips LG, Barr BC, et al. Bartonella henselae
antibody prevalence in free-ranging and captive wild felids from California. Journal of Wildlife Diseases. 1998; 34(1):56–63. https://doi.org/10.7589/0090-3558-34.1.56 PMID: 9476226

85.

Hugh-Jones M, Barre N, Nelson G, Wehnes K, Warner J, Garvin J, et al. Landsat-TM identification of
Amblyomma variegatum (Acari: Ixodidae) habitats in Guadeloupe. Remote Sensing of Environment.
1992; 40(1):43–55.

86.

An Estrada-Peña. Forecasting habitat suitability for ticks and prevention of tick-borne diseases. Veterinary Parasitology. 2001; 98(1):111–32.

87.

Estrada-Peña A. Increasing habitat suitability in the United States for the tick that transmits Lyme disease: a remote sensing approach. Environmental Health Perspectives. 2002; 110(7):635–40. PMID:
12117639

88.

Roelke ME, Forrester DJ, Jacobson ER, Kollias GV, Scott FW, Barr MC, et al. Seroprevalence of
infectious disease agents in free-ranging Florida panthers (Felis concolor coryi). Journal of Wildlife
Diseases. 1993; 29(1):36–49. https://doi.org/10.7589/0090-3558-29.1.36 PMID: 8445789

89.

Lagana DM, Lee JS, Lewis JS, Bevins SN, Carver S, Sweanor LL, et al. Characterization of regionally
associated Feline Immunodeficiency Virus (FIV) in bobcats (Lynx rufus). Journal of Wildlife Diseases.
2013; 49(3):718–22. https://doi.org/10.7589/2012-10-243 PMID: 23778629

90.

VandeWoude S, Apetrei C. Going wild: lessons from naturally occurring T-lymphotropic lentiviruses.
Clinical Microbiology Reviews. 2006; 19(4):728–62. https://doi.org/10.1128/CMR.00009-06 PMID:
17041142

91.

Troyer JL, Pecon-Slattery J, Roelke ME, Johnson W, VandeWoude S, Vazquez-Salat N, et al. Seroprevalence and genomic divergence of circulating strains of feline immunodeficiency virus among Felidae and Hyaenidae species. Journal of Virology. 2005; 79(13):8282–94. https://doi.org/10.1128/JVI.
79.13.8282-8294.2005 PMID: 15956574

92.

Troyer JL, VandeWoude S, Pecon-Slattery J, McIntosh C, Franklin S, Antunes A, et al. FIV cross-species transmission: an evolutionary prospective. Veterinary Immunology and Immunopathology. 2008;
123(1):159–66.

93.

Pecon-Slattery J, Troyer JL, Johnson WE, O’Brien SJ. Evolution of feline immunodeficiency virus in
Felidae: implications for human health and wildlife ecology. Veterinary Immunology and Immunopathology. 2008; 123(1):32–44.

94.

Crooks K, Riley S, Gehrt S, Gosselink T, Van Deelen T. Community ecology of urban carnivores. In:
Gehrt S, Riley S, Cypher B, editors. Urban carnivores: ecology, conflict, and conservation. Baltimore,
MD, USA: The John Hopkins University Press; 2010. p. 185–96.

95.

Tracey JA, Bevins SN, VandeWoude S, Crooks KR. An agent-based movement model to assess the
impact of landscape fragmentation on disease transmission. Ecosphere. 2014; 5(9):1–24.

96.

Paul-Murphy J, Work T, Hunter D, McFie E, Fjelline D. Serologic survey and serum biochemical reference ranges of the free-ranging mountain lion (Felis concolor) in California. Journal of Wildlife Diseases. 1994; 30(2):205–15. https://doi.org/10.7589/0090-3558-30.2.205 PMID: 8028105

97.

Foley JE, Swift P, Fleer KA, Torres S, Girard YA, Johnson CK. Risk factors for exposure to felid pathogens in California mountain lions (Puma concolor). Journal of Wildlife Diseases. 2013; 49(2):279–93.
https://doi.org/10.7589/2012-08-206 PMID: 23568903

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

20 / 22

�Demographic, social, and environmental pathogen factors

98.

Radford AD, Coyne KP, Dawson S, Porter CJ, Gaskell RM. Feline calicivirus. Veterinary Research.
2007; 38(2):319–35. https://doi.org/10.1051/vetres:2006056 PMID: 17296159

99.

Berger A, Willi B, Meli ML, Boretti FS, Hartnack S, Dreyfus A, et al. Feline calicivirus and other respiratory pathogens in cats with Feline calicivirus-related symptoms and in clinically healthy cats in Switzerland. BMC veterinary research. 2015; 11(1):282.

100.

Plowright RK, Sokolow SH, Gorman ME, Daszak P, Foley JE. Causal inference in disease ecology:
investigating ecological drivers of disease emergence. Frontiers in Ecology and the Environment.
2008; 6(8):420–9.

101.

Burnham KP, Anderson DR. Model selection and multimodel inference: a practical information-theoretic approach. Second Edition ed. New York, NY, USA: Springer Verlag; 2002.

102.

Tracey JA. mkde. R Core Development Team. 2014.

103.

R. R: a language and environment for statistical computing, Version 3.0.2. R Foundation for Statistical
Computing. Vienna, Austria. Development Core Team 2014.

104.

Horne JS, Garton EO. Likelihood cross-validation versus least squares cross-validation for choosing
the smoothing parameter in kernel home-range analysis. Journal of Wildlife Management. 2006; 70
(3):641–8.

105.

Horne JS, Garton EO. Animal Space Use 1.3 &lt;http://www.cnr.uidaho.edu/population_ecology/
animal_space_use&gt;. 2009.

106.

Robert K, Garant D, Pelletier F. Keep in touch: does spatial overlap correlate with contact rate frequency? The Journal of Wildlife Management. 2012; 76(8):1670–5.

107.

Vander Wal E, Laforge MP, McLoughlin PD. Density dependence in social behaviour: home range
overlap and density interacts to affect conspecific encounter rates in a gregarious ungulate. Behavioral
Ecology and Sociobiology. 2014; 68:383–90.

108.

Seidensticker JC, Hornocker MG, Wiles WV, Messick JP. Mountain lion social organization in the
Idaho Primitive Area. Wildlife Monographs. 1973; 35:1–60.

109.

VanderWaal KL, Wang H, McCowan B, Fushing H, Isbell LA. Multilevel social organization and space
use in reticulated giraffe (Giraffa camelopardalis). Behavioral Ecology. 2014; 25(1):17–26.

110.

Morse DH. Niche breadth as a function of social dominance. American Naturalist. 1974; 108
(964):818–30.

111.

Farine DR, Garroway CJ, Sheldon BC. Social network analysis of mixed-species flocks: exploring the
structure and evolution of interspecific social behaviour. Animal Behaviour. 2012; 84(5):1271–7.

112.

Schielzeth H. Simple means to improve the interpretability of regression coefficients. Methods in Ecology and Evolution. 2010; 1(2):103–13.

113.

Doherty PF, White GC, Burnham KP. Comparison of model building and selection strategies. Journal
of Ornithology. 2012; 152(2):317–23.

114.

Hosmer DW, Lemeshow S, Sturdivant RX. Applied logistic regression. Hoboken, New Jersey: John
Wiley &amp; Sons; 2013.

115.

Anderson DR. Model based inference in the life sciences: a primer on evidence. New York, NY:
Springer; 2008.

116.

Lewis JS, Bailey LL, Vandewoude S, Crooks KR. Interspecific interactions between wild felids vary
across scales and levels of urbanization. Ecology and Evolution. 2015; 5(24):5946–61. https://doi.org/
10.1002/ece3.1812 PMID: 26811767

117.

Eisen L, Eisen R, Lane R. Geographical distribution patterns and habitat suitability models for presence of host-seeking ixodid ticks in dense woodlands of Mendocino County, California. Journal of
Medical Entomology. 2006; 43(2):415–27. PMID: 16619628

118.

Eisen RJ, Lane RS, Fritz CL, Eisen L. Spatial patterns of Lyme disease risk in California based on disease incidence data and modeling of vector-tick exposure. The American Journal of Tropical Medicine
and Hygiene. 2006; 75(4):669–76. PMID: 17038692

119.

Eisen RJ, Eisen L. Spatial modeling of human risk of exposure to vector-borne pathogens based on
epidemiological versus arthropod vector data. Journal of Medical Entomology. 2008; 45(2):181–92.
PMID: 18402133

120.

Mize EL, Tsao JI, Maurer BA. Habitat correlates with the spatial distribution of ectoparasites on Peromyscus leucopus in southern Michigan. Journal of Vector Ecology. 2011; 36(2):308–20. https://doi.
org/10.1111/j.1948-7134.2011.00171.x PMID: 22129402

121.

Krasnov B, Korallo-Vinarskaya N, Vinarski M, Shenbrot G, Mouillot D, Poulin R. Searching for general
patterns in parasite ecology: host identity versus environmental influence on gamasid mite assemblages in small mammals. Parasitology. 2008; 135(02):229–42.

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

21 / 22

�Demographic, social, and environmental pathogen factors

122.

Vanwambeke SO, Somboon P, Harbach RE, Isenstadt M, Lambin EF, Walton C, et al. Landscape and
land cover factors influence the presence of Aedes and Anopheles larvae. Journal of Medical Entomology. 2007; 44(1):133–44. PMID: 17294931

123.

Guerra M, Walker E, Jones C, Paskewitz S, Cortinas MR, Stancil A, et al. Predicting the risk of Lyme
disease: habitat suitability for Ixodes scapularis in the north central United States. Emerging Infectious
Diseases. 2002; 8(3):289–97. https://doi.org/10.3201/eid0803.010166 PMID: 11927027

124.

Eisen RJ, Eisen L, Castro MB, Lane RS. Environmentally related variability in risk of exposure to Lyme
disease spirochetes in northern California: effect of climatic conditions and habitat type. Environmental
Entomology. 2003; 32(5):1010–8.

125.

Walter WD, Walsh DP, Farnsworth ML, Winkelman DL, Miller MW. Soil clay content underlies prion
infection odds. Nature Communications. 2011; 2:200. https://doi.org/10.1038/ncomms1203 PMID:
21326232

126.

Craft ME, Volz E, Packer C, Meyers LA. Distinguishing epidemic waves from disease spillover in a
wildlife population. Proceedings of the Royal Society B: Biological Sciences. 2009; https://doi.org/10.
1098/rspb. 2008.1636:1–9

127.

McClintock BT, Nichols JD, Bailey LL, MacKenzie DI, Kendall W, Franklin AB. Seeking a second opinion: uncertainty in disease ecology. Ecology Letters. 2010; 13(6):659–74. https://doi.org/10.1111/j.
1461-0248.2010.01472.x PMID: 20426794

128.

Walker BL, Naugle DE, Doherty KE, Cornish TE. West Nile virus and greater sage-grouse: estimating
infection rate in a wild bird population. Avian Diseases. 2007; 51(3):691–6. https://doi.org/10.1637/
0005-2086(2007)51[691:WNVAGS]2.0.CO;2 PMID: 17992928

129.

Forman RT. Land mosaics: the ecology of landscapes and regions. Cambridge, UK: Cambridge University Press; 1995.

130.

French JB. Ixodes scapularis (Acari: Ixodidae) at the edge of its range in southern Wisconsin. Journal
of Medical Entomology. 1995; 32(6):876–81. PMID: 8551513

131.

Power AG, Mitchell CE. Pathogen spillover in disease epidemics. The American Naturalist. 2004; 164
(S5):S79–S89.

132.

Lee J, Malmberg JL, Wood BA, Hladky S, Troyer R, Roelke M, et al. Feline immunodeficiency virus
cross-species transmission: implications for emergence of new lentiviral infections. Journal of Virology. 2017; 91(5):e02134–16. https://doi.org/10.1128/JVI.02134-16 PMID: 28003486

PLOS ONE | https://doi.org/10.1371/journal.pone.0187035 November 9, 2017

22 / 22

�</text>
                </elementText>
              </elementTextContainer>
            </element>
          </elementContainer>
        </elementSet>
      </elementSetContainer>
    </file>
    <file fileId="143">
      <src>https://cpw.cvlcollections.org/files/original/a19c8d585aa69ad48fb6d0f9c4659b87.zip</src>
      <authentication>9bcd5e16e3a07a4393e555da2e5ddf07</authentication>
    </file>
  </fileContainer>
  <collection collectionId="2">
    <elementSetContainer>
      <elementSet elementSetId="1">
        <name>Dublin Core</name>
        <description>The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.</description>
        <elementContainer>
          <element elementId="50">
            <name>Title</name>
            <description>A name given to the resource</description>
            <elementTextContainer>
              <elementText elementTextId="479">
                <text>Journal Articles</text>
              </elementText>
            </elementTextContainer>
          </element>
          <element elementId="41">
            <name>Description</name>
            <description>An account of the resource</description>
            <elementTextContainer>
              <elementText elementTextId="7018">
                <text>CPW peer-reviewed journal publications</text>
              </elementText>
            </elementTextContainer>
          </element>
        </elementContainer>
      </elementSet>
    </elementSetContainer>
  </collection>
  <itemType itemTypeId="1">
    <name>Text</name>
    <description>A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text.</description>
  </itemType>
  <elementSetContainer>
    <elementSet elementSetId="1">
      <name>Dublin Core</name>
      <description>The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/.</description>
      <elementContainer>
        <element elementId="50">
          <name>Title</name>
          <description>A name given to the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1475">
              <text>The effects of demographic, social, and environmental characteristics on pathogen prevalence in wild felids across a gradient of urbanization</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="39">
          <name>Creator</name>
          <description>An entity primarily responsible for making the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1476">
              <text>Lewis, Jesse S.&#13;
</text>
            </elementText>
            <elementText elementTextId="1477">
              <text>Logan, Kenneth A.</text>
            </elementText>
            <elementText elementTextId="1478">
              <text>Alldredge, Mathew W.</text>
            </elementText>
            <elementText elementTextId="1479">
              <text>Carver, Scott</text>
            </elementText>
            <elementText elementTextId="1480">
              <text>Bevins, Sarah N.</text>
            </elementText>
            <elementText elementTextId="1481">
              <text>Lappin, Michael</text>
            </elementText>
            <elementText elementTextId="1482">
              <text>VandeWoude, Sue</text>
            </elementText>
            <elementText elementTextId="1483">
              <text>Crooks, Kevin R.</text>
            </elementText>
            <elementText elementTextId="1484">
              <text>Serrano Ferron, Emmanuel</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="41">
          <name>Description</name>
          <description>An account of the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1485">
              <text>&lt;span&gt;Transmission of pathogens among animals is influenced by demographic, social, and environmental factors. Anthropogenic alteration of landscapes can impact patterns of disease dynamics in wildlife populations, increasing the potential for spillover and spread of emerging infectious diseases in wildlife, human, and domestic animal populations. We evaluated the effects of multiple ecological mechanisms on patterns of pathogen exposure in animal populations. Specifically, we evaluated how ecological factors affected the prevalence of &lt;/span&gt;&lt;em&gt;Toxoplasma gondii&lt;/em&gt;&lt;span&gt; (Toxoplasma), &lt;/span&gt;&lt;em&gt;Bartonella spp&lt;/em&gt;&lt;span&gt;. (Bartonella), feline immunodeficiency virus (FIV), and feline calicivirus (FCV) in bobcat and puma populations across wildland-urban interface (WUI), low-density exurban development, and wildland habitat on the Western Slope (WS) and Front Range (FR) of Colorado during 2009–2011. Samples were collected from 37 bobcats and 29 pumas on the WS and FR. As predicted, age appeared to be positively related to the exposure to pathogens that are both environmentally transmitted (Toxoplasma) and directly transmitted between animals (FIV). In addition, WS bobcats appeared more likely to be exposed to Toxoplasma with increasing intraspecific space-use overlap. However, counter to our predictions, exposure to directly-transmitted pathogens (FCV and FIV) was more likely with decreasing space-use overlap (FCV: WS bobcats) and potential intraspecific contacts (FIV: FR pumas). Environmental factors, including urbanization and landscape covariates, were generally unsupported in our models. This study is an approximation of how pathogens can be evaluated in relation to demographic, social, and environmental factors to understand pathogen exposure in wild animal populations.&lt;/span&gt;</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="49">
          <name>Subject</name>
          <description>The topic of the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1486">
              <text>Felidae</text>
            </elementText>
            <elementText elementTextId="1487">
              <text>Virology</text>
            </elementText>
            <elementText elementTextId="1488">
              <text>Theoretical models</text>
            </elementText>
            <elementText elementTextId="1489">
              <text>Microbiology</text>
            </elementText>
            <elementText elementTextId="1490">
              <text>Lynx</text>
            </elementText>
            <elementText elementTextId="1491">
              <text>Puma</text>
            </elementText>
            <elementText elementTextId="1492">
              <text>Parasitology </text>
            </elementText>
            <elementText elementTextId="1493">
              <text>Animal behavior</text>
            </elementText>
            <elementText elementTextId="1494">
              <text>Colorado</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="80">
          <name>Bibliographic Citation</name>
          <description>A bibliographic reference for the resource. Recommended practice is to include sufficient bibliographic detail to identify the resource as unambiguously as possible.</description>
          <elementTextContainer>
            <elementText elementTextId="1495">
              <text>Lewis, J. S., K. A. Logan, M. W. Alldredge, S. Carver, S. N. Bevins, M. Lappin, S. VandeWoude, and K. R. Crooks. 2017. The effects of demographic, social, and environmental characteristics on pathogen prevalence in wild felids across a gradient of urbanization. PLoS One 12(11):e0187035. &lt;a href="https://doi.org/10.1371/journal.pone.0187035" target="_blank" title="https://doi.org/10.1371/journal. pone.0187035" rel="noreferrer noopener"&gt;https://doi.org/10.1371/journal.pone.0187035&lt;/a&gt;</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="78">
          <name>Extent</name>
          <description>The size or duration of the resource.</description>
          <elementTextContainer>
            <elementText elementTextId="1496">
              <text>22 pages</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="56">
          <name>Date Created</name>
          <description>Date of creation of the resource.</description>
          <elementTextContainer>
            <elementText elementTextId="1497">
              <text>2017-11-09</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="47">
          <name>Rights</name>
          <description>Information about rights held in and over the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1498">
              <text>&lt;a href="http://rightsstatements.org/vocab/InC-NC/1.0/" target="_blank" rel="noreferrer noopener"&gt;In Copyright - Non-Commercial Use Permitted&lt;/a&gt;</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="44">
          <name>Language</name>
          <description>A language of the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1500">
              <text>English</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="70">
          <name>Is Part Of</name>
          <description>A related resource in which the described resource is physically or logically included.</description>
          <elementTextContainer>
            <elementText elementTextId="1501">
              <text>PLoS One</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="42">
          <name>Format</name>
          <description>The file format, physical medium, or dimensions of the resource</description>
          <elementTextContainer>
            <elementText elementTextId="1502">
              <text>application/pdf</text>
            </elementText>
          </elementTextContainer>
        </element>
        <element elementId="51">
          <name>Type</name>
          <description>The nature or genre of the resource</description>
          <elementTextContainer>
            <elementText elementTextId="7136">
              <text>Article</text>
            </elementText>
          </elementTextContainer>
        </element>
      </elementContainer>
    </elementSet>
  </elementSetContainer>
</item>
