Carnivore community response to anthropogenic landscape change: species-specificity foils generalizations
Human exploitation of landscapes result in widespread species range loss and spatial community redistribution. Reduced species occupancy for large ranging terrestrial carnivore communities in disturbed or fragmented landscapes is a common outcome but the underlying mechanisms are ambiguous and the complexity of interacting mechanisms often under-appreciated.
To examine for similarity in spatial responses of carnivores to human-mediated landscape disturbance, we hypothesize common mechanism(s) to manifest at the community-level. To then incorporate a competitive surface, we evaluate the relative role interspecific interactions may play, where some species are benefited by altered habitat conditions.
We deployed camera-trap arrays across a systematic grid-based study design to quantify carnivore occurrence. We tested hypotheses to understand spatial patterns of carnivore occurrence, in relation to biophysical and anthropogenic landscape factors, using multivariate analysis and species distribution models under an information-theoretic approach.
Differential response was found within the carnivore community, with some species occurring more frequently in disturbed landscapes while others displayed landscape scale avoidance of more highly disturbed areas. Interspecific interactions played an additive role to human-mediated response by some carnivores—suggesting generalist, human-adapted species, exaggerate interference interactions for other more sensitive species.
Generalizable patterns are highly sought as clues to consistent mechanisms effecting changes to spatial distributions, but evidence weighs heavily in favour of species-specificity in responses implicating mechanisms that likewise vary for each species. Our findings underscore the value of a trait-based and community-level approach to understanding and managing the effects of anthropogenic land-use change on vertebrate biodiversity.
KeywordsAnthropogenic disturbance Carnivore Community composition Occupancy Spatial distribution Generalist Conservation
Thanks to Kent Richardson (AITF) and Scott Jevons (Alberta Parks) for GIS expertise and support. This project was achieved through many contributions by those behind the scenes and on the ground, including: Melanie Percy, Jon Jorgenson, Sandra Code, Jay Honeyman, Tom Partello, Alex MacIvor, Stephen Holly, Anne Hubbs, Carrie Nugent, Joyce Gould, Matthew Wheatley, Michelle Hiltz, Brenda Dziwenka, Susan Allen, Luke Nolan, Daivuan Pan, and Connie Jackson.
- Alberta Biodiversity Monitoring Institute (ABMI) (2010) Alberta human footprint maps. http://www.abmi.ca/abmi/rawdata/rawdataselection.jsp. Accessed Jan 2013
- Crawley MJ (2007) The R book chichester. Wiley, UKGoogle Scholar
- Estes JA, Terborgh J, Brashares JS, Power ME, Berger J, Bond WJ, Carpenter SR, Essington TE, Holt RD, Jackson JBC, Marquis RJ, Oksanen L, Oksanen T, Paine RT, Pikitch EK, Ripple WJ, Sandin SA, Scheffer M, Schoener TW, Shurin JB, Sinclair ARE, Soulé ME, Virtanen R, Wardle DA (2011) Trophic downgrading of planet earth. Science 333:301–306CrossRefGoogle Scholar
- Gehrt SD, Clark WR (2003) Raccoons, coyotes, and reflections on the mesopredator release hypothesis. Wildl Soc Bull 31:836–842Google Scholar
- Gittleman JL (2001) Carnivore conservation. Cambridge University Press, IrvintonGoogle Scholar
- Global Forest Watch Canada (2014) State of Alberta’s forests with a focus on the Eastern slopes. Presentation and maps. http://www.globalforestwatch.ca/node/205. Accessed Jan 2013
- Koen EL (2008) Surveying and monitoring wolverines in Ontario and other lowland, boreal forest habitats: recommendations and protocols. Northwest Science and Information Section, Ministry of Natural Resources, PeterboroughGoogle Scholar
- Lotka AJ (1925) Elements of physical biology. Williams and Wilkins, BaltimoreGoogle Scholar
- Long RA, MacKay P, Ray J, Zielinski W (2008) Noninvasive survey methods for carnivores. Island PressGoogle Scholar
- MacKenzie DI (2006) Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. Academic Press, New YorkGoogle Scholar
- McCune B, Grace JB, Urban DL (2002) Analysis of ecological communities. MjM Software Design, Gleneden BeachGoogle Scholar
- Mittlebach Gary G (2012) Community ecology. Sinauer Associates, Inc., SunderlandGoogle Scholar
- Putman R (1994) Community ecology. Springer, New YorkGoogle Scholar
- R Core Team (2014) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. URL: http://www.Rproject.org. Accessed 2012–2015.
- Riley SJ, DeGloria SD, Elliot R (1999) A terrain ruggedness index that quantifies topographic heterogeneity. Int J Sci 5:23–27Google Scholar
- Rota CT, Fletcher RJ Jr, Dorazio RM, Betts MG (2009) Occupancy estimation and the closure assumption. J Appl Ecol 46:1173–1181Google Scholar
- Šálek M, Drahníková L, Tkadlec E (2014) Changes in home range sizes and population densities of carnivore species along the natural to urban habitat gradient. Mammal Rev 45:1–14Google Scholar
- Smith RL, Smith TM (2001) Ecology and field biology: hands-on field package. Benjamin-Cummings Publishing Company, San FranciscoGoogle Scholar
- Thompson W (2004) Sampling rare or elusive species: concepts, designs, and techniques for estimating population parameters. Island Press, Washington, DCGoogle Scholar
- Zuur AF, Hilbe J, Ieno EN (2013) A beginner’s guide to GLM and GLMM with R: a frequentist and Bayesian perspective for ecologists. Highland Statistics, NewburghGoogle Scholar