2025/12/15 by Lillian C. Fooks, Eric B. Liebgold · 1 voice
Environmental Science · Immunology and Microbiology · Agricultural and Biological Sciences · #Avian ecology and behavior #Bird parasitology and diseases #Livestock and Poultry Management
paper · doi:10.1080/15594491.2025.2591505
In many color polymorphic species, the niche divergence hypothesis predicts that color affects survival of each color morph differently in different habitats. Camouflage and/or differences in behavioral preferences for habitat can affect survival; however, whether diet differs between color morphs in color polymorphic species is typically unknown. The Eastern Screech-Owl (Megascops asio) is a small species of owl found in eastern North America that is color polymorphic, with red and gray screech-owls present in the same populations. To understand the potential effects of color polymorphism on diet, we checked artificial bird boxes suitable for screech-owl winter roosting from 2020 to 2023, taking note of the color of screech-owls found as well as any prey remains left in the box. We found that 90% of red screech-owls’ diet consisted of bird prey, while gray screech-owls had significantly less avian prey (62%) and more amphibian prey (31%) in their diet. While the color morphs varied in higher order taxa prey, there was no significant difference in the proportions of bird species in their diets. The differences in diet between the color morphs is potentially due to colors’ differential camouflage when hunting in different habitats or light regimes or behavioral preferences for those habitats. Camouflage during hunting may, therefore, be an underlying evolutionary factor affecting the persistence of color polymorphism, not only in this species, but in other color polymorphic predators.