Does human disturbance affect physiological traits of Two-banded Plovers nesting on an urban beach?

HEVIA GD; BERTELLOTTI M; GIBSON D; D'AMICO VL

Avian Conservation and Ecology

Avian Conservation and Ecology

Año: 2023 vol. 18

1712-6568

Abstract - Shorebird populations inhabiting coastal areas are highly susceptible to human disturbance and recreational activities, including dog-walking and driving motorized vehicles, which typically increase during spring and summer, overlapping with shorebird breeding seasons. In northern Chubut, Patagonia Argentina, we captured 50 adults of Two-banded Plover (Charadrius falklandicus), 31 and 19 in one urban and one rural beach-nesting area, representing a disturbed and undisturbed site, respectively. We assessed physiological traits related to body condition (size-corrected body mass to corresponding wing-chord lengths), nutritional status (haematocrit, glucose, triglycerides, cholesterol, total proteins), cellular immunity (total leukocyte counts, heterophils, lymphocytes, eosinophils, monocytes), and stress responses (heterophil/lymphocyte ratio, plasma corticosterone). We evaluated univariate associations between each of these physiological parameters and six predictor variables: treatment (disturbed/control), year (2016/2017), sex, handling time, day of year (DOY), and an interaction between DOY and treatment (DOY × treatment). A significant DOY × treatment effect was observed in reduced body condition and triglycerides, and monocytes increased, across the breeding season at the control site. Sex differences were only found for body condition, with females exhibiting higher body condition than males. Cholesterol, triglycerides, and total leukocyte counts were significantly greater in 2017, suggesting annual variation in food availability, local weather conditions, and/or abundance of predators