The Wildlife Center’s Research on Free-roaming Cat Interactions with Wildlife

The 11-year study conducted by former veterinary director Dr. Dave McRuer vividly illustrates how much of an impact outdoor cats have on wildlife. The study examined nearly 21,000 patient records, including 11,144 small mammals and 9,777 small birds, admitted between 2000 and 2010. Of this total, 2,970 patients were confirmed cat-attack victims. 

Many cat owners believe that their cat “just” catches rodents, but this study shows a different situation. For the study period, 83 different species of birds and mammals were admitted due to cat interactions. 


Cat attacks were the second highest cause of admission for mammals during the 11-year study period. Despite treatment, which begins immediately after admission, the mortality rate for cat-attacked mammals was 70.8 percent.  

Those mammal species admitted with the highest percentage of cat interactions were Eastern Chipmunks, Eastern Cottontails, and Southern Flying Squirrels. 


The overall songbird mortality rate for cat attack victims was 80.8 % (despite treatment). 

Of the 98 songbird species admitted during the study period, 62 species were affected – 2/3 of all songbird species admitted. Those birds admitted with the highest percentage of cat interactions were Northern Cardinals, Mourning Doves, American Robins, and Blue Jays. 

All Species

When combined, the patients in the 11-year study that were most commonly harmed by free-roaming cats are (in order): Eastern Cottontails, Gray Squirrels, American Robins, Mourning Doves, and Blue Jays. 

Larger birds and reptiles were not included for this particular study, but the Center has documented cases of raptors that have been attacked by cats (including Eastern Screech-owls and American Kestrels) as well as snakes, toads, and skinks. 


Most patients admitted after interaction with a cat came in between April and September, with the majority of patients admitted in May and June. 

In the News

•    Cats versus wildlife: study finds a negative impact, The News Virginian 
•    JWM study: Domestic cat attacks cause variety of wildlife deaths, The Wildlife Society 

Questions or comments about the research? Please email