Science Questions

The two objectives of the Great Chicken Coop Stakeout are:

1. Survey the carnivores of urban and rural areas.
2. Determine which predators are attracted to back yard chicken coops.

Carnivores along a rural-urban gradient

Carnivores have historically been strongly persecuted by humans and thus avoided all human settlements.  The legacy of this persecution is that the largest predators, cougars and wolves, remain absent from most of the Eastern United States.   Fortunately, trapping and hunting of predators is now regulated to avoid over-hunting, and most carnivore populations have recovered across much of North America.

Today, populations of carnivores are thought to be affected by two main factors: harvest (i.e. hunting and trapping) and habitat fragmentation.  However, different carnivore species respond differently to fragmentation and hunting pressure.  For example, Collins and Kays found that larger species were at more risk to hunting by humans, but that this hunting pressure decreased in more developed habitats (i.e. more hunting pressure in rural than in urban areas).  In California, Kevin Crooks found that larger predators, with larger home-ranges, were absent from smaller fragments of natural habitat while smaller predators could survive even in smaller fragments.   However, animal species continue to evolve in their behavior and habitat preferences, adapting to survive even in highly developed  areas.  For example, Chicago hosts a robust coyote population, and fishers are returning to suburban areas of the Northeast.

Based on this background we will test the following alternative hypotheses:

Hypothesis 1A. If hunting is the primary determinant of carnivore populations we expect larger predators (e.g. bear, coyotes, bobcats) to be more common in urban areas, where hunting is less common than in rural areas.

Hypothesis 1B. If fragmentation is the primary determinant of carnivore populations we expect larger predators (e.g. bear, coyotes, bobcats) to be more common in rural areas, where fragmentation is less sever than urban areas.

Do Chicken Coops Attract Predators?  If so, which ones?

Most back yard chicken coops occasionally loose chickens to predators.  Presumably this is related to a high level of activity of predators around chicken coops.  However, this has never been tested.  By comparing the activity of different predators near back yard chicken coops, with their activity in nearby back yards without chicken coops, as well as the natural woods nearby, we can test this hypothesis.

Hypothesis 2. Chicken coops attract all predators, resulting in a high level of predator activity and diversity in yards with chicken coops.

We will tabulate data from this project and present results during the NRC Grand Opening.

Camera trap pictures from Smithsonian Wild