A Four‐Week Urban Diet Impairs Vasodilation but Not Nutritional Physiology in Wild‐caught Mourning Doves (Zenaida macroura)

Abstract

Birds living in urban areas routinely consume anthropogenic foods, but the physiological consequences of this consumption are poorly understood. To address this question, we investigated the effects of an urban diet (UD) in wild, urban-caught mourning doves in a controlled environment. Since anthropogenic foods often contain a high proportion of refined carbohydrate and fat, we predicted that UD consumption alters body mass as well as plasma and tissue metabolites and impairs vasodilation. To test this prediction, we compared the nutritional physiology and peripheral vasodilation of doves fed an UD (1:1 ratio of bird seeds and French fries; n=7) with those of doves receiving a control diet (CON: bird seed diet; n=6) for four weeks. At the end of the dietary manipulation period, birds were euthanized and we dissected cranial tibial arteries to measure ex vivovasodilation in response to acetylcholine treatment after phenylephrine-induced vasoconstriction. We also collected cardiac blood as well as liver, pectoralis and gastrocnemius muscle samples to measure nutritional metabolite concentrations. The vasodilation of tibial arteries was impaired in UD compared to CON-fed birds (p=0.004), suggesting the potential for UD consumption to cause cardiovascular pathologies. Neither body mass, plasma osmolality, glucose, sodium, insulin, triglyceride, uric acid, liver glycogen and triglycerides, nor muscle glycogen differed between groups. The results suggest that short term consumption of a diet comprised of 50% anthropogenic foods is not associated with major metabolic perturbations in urban mourning doves.