Eastern Towhee Project
While Eastern Towhees are still common and widespread, their population trends in the Northeast, where they are listed as a Species of Greatest Conservation Need, are alarming. There are many theories about why bird populations are declining including habitat loss, light pollution, and the presence of free-ranging cats. All of these factors merge together to create inhospitable landscapes for birds. During the first year of a bird’s life, they are especially susceptible to these dangers. Mortality for juvenile birds making their first migration is much greater than for adults. Even in adults, the migration phase is often where mortality is greatest and may drive population declines. However, much of what we know about juvenile migration patterns comes from larger bird species and not songbirds.
Statement from project leader, Shelly Eshleman:
“GMI has been actively involved in tracking small species through the Motus Wildlife
Tracking System, a network of automated radio-telemetry stations, since a Motus
station was installed there in 2017. These stations listen for signals emitted from small
radio tags that can be placed on birds, insects, and bats, allowing researchers to follow
these individuals and their movement patterns. GMI’s Motus station has contributed to
studies of Wood Thrush, Rusty Blackbird, and Purple Martin, just to name a few
species. In 2022, GMI partnered with the Willistown Conservation Trust (WCT) and the University of Delaware, with funding
from the Pennsylvania Game Commission, to study a declining songbird of the eastern
forest: the Eastern Towhee (Pipilo erythrophthalmus). This work, led by Shelly
Eshleman, the Motus Avian Research Coordinator at WCT and a PhD candidate in Dr.
Jeffrey Buler’s Lab at the University of Delaware, focuses on learning more about the
migratory timing and pathways of Eastern Towhees. We chose to study this species
because they have a range-wide annual population decline rate of 1.4 %. These
declines are linked to a loss of the early successional habitat that Eastern Towhees and
many other songbird species need to survive. This shrubby habitat is a rich source of
wildlife forage including insects, fruits, seeds, berries, and nuts. This helps support the
energy requirements of breeding and migrating birds. While considered a partial and
short-distance migrant, no published migration pathways or distances of individual birds
exist for this species. Without clear information on migration pathways, it is difficult to
know the hazards or environments that Eastern Towhees encounter on migration, a time
when mortality is generally greatest for songbirds. We tagged birds in Pennsylvania,
New York, Virginia, and Maryland among eight sites. The results will be published soon, but you can see MOTUS records from the tracked birds here.”
About Shelly
Shelly is a staff member at the Willistown Conservation Trust and a Ph.D. student in Dr. Jeff Buler’s Aeroecology lab at the University of Delaware. Her dissertation research will focus on the conservation of Pennsylvania’s avian species and will utilize the Motus tracking system, a network of automated radio telemetry receivers. Her previous research used data logging tags to track the migratory movements of Red-winged Blackbirds (Agelaius phoeniceus) and correlated reproductive hormones with spring migration distance in a collaborative project with the USDA.