Investigating Whimbrel use of a critical nocturnal roost

Using GPS transmitters to better understand foraging and roosting habitat selection during migratory stopover

A Whimbrel arriving to roost for the night

Whimbrel (Numenius phaeopus) are experiencing dramatic declines, in part due to the degradation and loss of migratory stopover sites.1 The Georgia-South Carolina coast is one of these critical stopover regions, and in fact may be one of only two staging areas used by nearly all Atlantic flyway Whimbrel during northward migration.2 For shorebirds like Whimbrel that rely on intertidal habitats, a critical component of high-quality stopover habitat is the availability of safe roost sites that provide a place to rest when feeding areas are inundated by high tide and offer safety from predators and disturbance at night. These nocturnal roost sites may be especially rare,3 requiring birds to make long flights to and from their foraging areas each day. For this project, we are tracking the daily movements of Whimbrel that roost on the South Carolina island Deveaux Bank, the largest known nocturnal roost for the species.

Whimbrel arriving to the nocturnal roost at dusk.
Whimbrel arriving to the nocturnal roost at dusk.

Together with collaborators Felicia Sanders, Adam Smith, and my advisor Dr. Nathan Senner, I am seeking to better understand how Whimbrel select roosting and foraging habitat during migratory stopover, and investigate what role nocturnal roost sites play in Whimbrel stopover ecology and migratory performance.

Tagging Whimbrel with PinPoint GPS transmitters.
Tagging Whimbrel with PinPoint GPS transmitters.

As of Spring 2021, we have deployed Lotek solar-powered PinPoint GPS transmitters on 12 individuals. These transmitters record over 100 GPS-quality positions per day and allow data download via antenna base stations that we install seasonally at the nocturnal roost site on Deveaux Bank.

Temporary antenna base station and example of high-resolution movement data downloaded from Whimbrel tagged with GPS transmitters.
Temporary antenna base station and example of high-resolution movement data downloaded from Whimbrel tagged with GPS transmitters.

Partners

From navigating choppy waters at night to tirelessly troubleshooting trapping methods, this work would not be possible without the patience and persistence of many partners. Your insights and guidance have strengthened this project beyond measure. For the time and energy you have poured into fieldwork to make this project possible, thank you to:

Funding

This research is supported by:


  1. Watts et al. 2019 ↩︎

  2. Johnson et al. 2016 ↩︎

  3. Watts et al. 2021 ↩︎

Maina Handmaker
Maina Handmaker
PhD Student

I am a graduate student in the Senner Lab at the University of South Carolina. My current research is focused on the stopover ecology of long-distance migratory shorebirds.