Leukocyte profile and body condition of the house finch (Haemorhous mexicanus) in two sites with different levels of urbanization in central Mexico

Abstract

Urban birds are exposed to many potentially detrimental factors including human disturbance, noise, changes in predator communities, exposure to toxins, etc., which May influence their health and reproductive success. Some physiological indices provide immediate measures to evaluate the effects of human-induced disturbances on birds and May offer information on the ability of populations to adapt to these disturbances. In this study we compared leukocyte profile (cellular immunity) and the H/L ratio (heterophils/lymphocytes) in House Finches (Haemorhous mexicanus) captured at two sites with different levels of urbanization in central Mexico. A total of 73 individuals were captured, 41 at the highly urbanized site and 32 at the site with lower urbanization. In general, we did not find differences in the H/L ratios, although some leukocyte parameters differed between sites. Birds captured at the site with higher urbanization had higher percentages of lymphocytes and eosinophils, which May be a response to parasitic illness. The proportions of basophiles were higher in individuals captured at the site with lower urbanization, which suggests physiological stress and disease. Even though only two sites were compared in this study, our results suggest an effect of the level of urbanization, and more studies are required that include various sites and that represent different urbanization conditions.