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Q&A with Anthony J. Basile: Please do not feed the birds? – Effects of an urban diet on mourning doves

Anthony J. Basile, MS, NDTR, Evolutionary Biology PhD Candidate, School of Life Sciences, Arizona State University

We are delighted to share this interview with Evolutionary Biology PhD Candidate, Anthony Basile, MS, NDTR, who is working with Dr. Karen Sweazea at Arizona State University. We asked Anthony about his research that he presented at the 2021 Experimental Biology conference.

What made you interested in studying the effects of urbanization on doves?

I’m sure everyone reading this has seen a bird walking around with bread or French fries in their beak. Have you ever wondered what that human food is doing to them? To determine the effects of urbanization, most studies simply look for differences in urban and rural birds, which fails to account for all the other variables within an urban environment. Since we know that anthropogenic foods often contain a high proportion of refined carbohydrate and fat, which can be problematic for mammals, we decided to test the effects of an urban diet on avian physiology.

Mourning dove, Zenaida macroura; open source image

How did you test the effect of an urban diet on doves?

We caught adult male and female birds from an urban setting using a walk-in style trap. We created an “urban diet” which was comprised of half French fries and half bird seed and fed it mourning doves (image at right) for four weeks and compared the results to a control group which was fed just bird seed. We then examined body mass, various nutrition physiology markers, and vasodilation between diet groups.

What have you learned about the way they handle urban diets?

Overall, body mass and other nutritional physiology markers (plasma osmolality, glucose, sodium, insulin, triglyceride, uric acid, liver glycogen and triglycerides, and muscle glycogen) did not differ between diet groups. However, we did show that vasodilation was impaired in the urban diet group compared to the control group but was not impaired compared to freshly captured urban mourning doves. These results suggest that urban, wild-caught mourning doves can largely maintain homeostasis, except for vasodilation, in response to consumption of a diet comprised of 50% anthropogenic foods. This also suggests that urban birds may be adapted or well acclimated to consuming an urban diet comprised of anthropogenic foods.

Photo credit: Anthony J. Basile

The results from this study were just accepted for publication in Physiological, Biochemical, Zoology.

Should we think twice about throwing French fries out to birds?

Our study has several limitations which doesn’t suggest that it is 100% safe to feed birds French fries. Specifically, since the results suggest that removing anthropogenic foods (i.e., French fries) improves vasodilation, removal of anthropogenic foods from the avian community may improve the cardiovascular health of birds. In addition, future studies are needed to test this in other species and to determine if anthropogenic foods negatively affects younger doves who are still developing.

So, in the meantime, please keep your French fries to yourself!

What are you studying right now?

Due to the Covid-19 pandemic, all research in our lab switched to remote, online research. To better understand the effects of urbanization on birds, we are currently conducting a systematic review of literature to determine the effects of urbanization on avian plasma metabolites. 

As we celebrate Memorial Day today, perhaps we should think twice before feeding the birds that stop by our barbecues and picnics.

Categories: Environment, Stress, Urbanization

Tags: , , , , , , ,

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