Predation

It is generally agreed among deer managers and researchers that coyote and bobcat predation on deer does not significantly affect deer populations.

Coyotes

Coyotes are opportunistic feeders and eat a variety of foods including small mammals (mice, voles, shrews and rabbits), plants, insects, fruits, carrion, garbage and pet foods. They also will take deer.

In the Chicago metropolitan area, researchers examined the feeding habits of urban coyotes by examining 1,429 scats and found that the most common food items were small rodents (42%), fruit (23%), deer (22%), rabbits (18%) and birds (13%).

In a recent study in southern Illinois, predation accounted for almost two-thirds of all fawn deaths, with coyotes being the dominant predator. In an earlier study, mortality rates for fawns in a southern Illinois study averaged 30 percent. The primary cause of death was coyote predation (69%), followed by disease (12.5%), starvation (6.5%) and unknown causes (12.5%). Almost three-fourths of the canid-killed fawns (11 of 16) were 4 to 9 weeks old.

Bobcats

An examination of stomach contents from 100 bobcats collected in southern Iowa between 2002 and 2006 found deer had been consumed by less than 10% of the juvenile females and by no juvenile males. Nearly 30% of adult males and about 5% of adult females had consumed deer.

In “The Bobcat in Illinois”, researchers reported that the diets of bobcats in southern Illinois were similar to those reported in other Midwestern populations. Of the food items identified in 85 stomachs of southern Illinois bobcats, small rodents were the favorite prey item, appearing in 32.8% of the stomachs, followed by cottontail rabbits (22.7%), and squirrels (19.3%). Deer were present in just three (2.5%) of the stomachs.