Abundance is commonly sought after as a state variable for the study of populations. However, density (number of animals per unit area) can be a more meaningful metric because it casts the state of a population into a common currency. For example, using closed capture models from Chapter 14, we estimate 500 animals at site A and 200 animals at site B. Thus one conclusion we may reach is that habitat management at site A has positively impacted the population there compared to site B. However, if we know site A is 250 hectares and B is 100 hectares, then we realize that each has 2.0 animals/hectare. That is, on a relative scale, the different management scheme at A had no effect compared to site B. Conversely, we may estimate abundance at 2 sites to be similar and conclude management actions, or habitat types, or harvest regulations, etc. are having a similar impact, but if the sites are different sizes, then the impacts are actually quite different on a relative scale and our conclusion is erroneous. Thus, while abundance can be a useful metric, estimating density can be helpful as well.
Ivan, J. S. 2019. Density estimation. Pages 20.1–20.19 in E. G. Cooch and G. C. White, editors. Program MARK - 'a gentle introduction'.
Ivan, Jacob S.
Ivan, Jacob S. , “Density estimation...,” CPW Digital Collections, accessed February 27, 2024, https://cpw.cvlcollections.org/items/show/282.