BIRDS OF PREY PELLET ANALYSIS: MORPHOMETRY AND CONSUMPTION INTERVAL OF CAPTIVEACCIPITRIDAE SPECIES
Keywords:
Birds of prey, retention time, egestion, healthAbstract
Pellet production is a typical characteristic of the digestive physiology of birds of prey. Alimentary pellets consist of non-digested parts of prey, such as fur, feathers, bones, and parts of insects, that are regurgitated. Obtained dietary samples, such as regurgitated pellets, can noninvasively contribute to the knowledge of the anatomical alimentary channel and the digestive efficiency of birds of prey. The aim of this study was to evaluate the pellet morphometry and meal-to-pellet interval (MPI) of the Accipitridae family subjected to two experimental diets. Heterospizias meridionalis, Rupornis magnirostris,and Geranoaetus albicaudatus were subjected to (1) mice and (2) quail pre-treating diets. Both diets were individually weighed and provided by removing excess feathers, skin, and some viscera. After consumption, the MPI was noted and, immediately after collection, the pellets were carefully weighed on a precision balance and morphometric measurements were taken using a caliper. Pellet weight, length, width, height, and volume were higher when raptors consumed mice. Differences in morphometric characteristics were found between species. Heterospizias meridionalis presented the highest values for the morphometric parameters evaluated. Consumption of mice increased the frequency of regurgitation and the number and weight of pellets egested, indicating that by providing this type of food, we can underestimate the consumption by birds if we do not consider nutritional losses by the pellets when calculating diets. Pellet assessment and MPI are important tools for monitoring the health and nutritional aspects of birds of prey.
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