In the field, bird researchers regularly encounter raptor pellets, which are regurgitated clumps of indigestible animal material such as fur, feather, and bones. However, where multiple species of similar-sized raptors occur, it can be hard to tell which species produced a pellet based on the pellet’s appearance alone. After field seasons spent on two Nova Scotian islands collecting raptor pellets as part of a study on predation on seabirds, one sample of pellets raised our eyebrows. The pellets we collected from an island known to host Great Horned Owls were small, about half the size of a computer mouse; those we collected from another island were huge — easily four times the size. We speculated about what could have disgorged such a monstrosity. Could it have been a Snowy Owl? Probably not, given the similar size of the two owls. An eagle? Seemed more likely, but how could we know for sure? Thus, we became interested in developing a way to identify bird species producing pellets based on residual environmental DNA (eDNA). We suspected DNA in pellets could come from a bird’s digestive tract cells, leaving behind a genetic signature in the field telling us “Who puked?”
Over the course of many field seasons at a colony of several thousand Glaucous-winged Gulls at Protection Island National Wildlife Refuge, Washington, I noticed large accumulations of broken eggshell littering a few of the nesting territories. I watched the owners of these territories invade the territories of fellow residents, grab an egg, fly the egg back to their own territories, and eat the contents. Eggshell fragments from the stolen eggs accumulated on the territories of these egg cannibals.
Bird banders take standard measurements on all birds they process as they build their datasets, some of which require banders to use their breath to blow gently to part a bird’s feathers. One of the most universal of these measurements is an inspection of the fat layer visible under the skin, which gives information about things like migratory readiness and refueling performance. Depending on the season, banders may also need to part feathers to check for breeding condition (whether the bird has a brood patch or cloacal protuberance), the level of skull development (which aids in ageing), and any sign of molt activity.
As a member of the Honors Program at Eastern Kentucky University, I was expected to write an undergraduate thesis. Since my major was wildlife management and I had just completed an incredible internship with the National Audubon Society, I knew I wanted to study birds. With the help of Dr. David Brown, I began to research a quirky shrubland bird known as the Eastern Towhee. We are only beginning to understand the non-breeding season ecology of shrubland bird species. The amount and quality of food that an individual bird is able to find in the non-breeding season seems to have lasting effects through other seasons of the year, potentially affecting its arrival time on its breeding grounds, health, survival, and breeding success. Therefore, winter habitat quality may have population-level impacts. We hope that learning more about the winter behavior of these birds will give us a greater understanding of what factors have led to population changes, especially since towhees and other shrubland bird species are in decline.
European Starlings are an invasive species in North America. They’re known to harass native woodpeckers and take over active woodpecker nests for their own use. So imagine my surprise when I happened to find a Hairy Woodpecker nest with three young in spring of 2020 being fed by a mother woodpecker and a starling! For the mother woodpecker, this was as if a known intruder entered her home, helped feed her family and clean her house until her kids were grown, then disappeared. This bizarre behavioral narrative is not complete without the events that led me to discover it, so I’ll begin there.