Maina Handmaker

PhD Candidate

Department of Environmental Conservation

University of Massachusetts Amherst

Tracking Whimbrel movements with GPS transmitters

Attaching a solar-powered GPS transmitter to a Whimbrel on the Deveaux Bank nocturnal roost. Photo: Andy Johnson/Cornell Lab of Ornithology
When our team discovered that Deveaux Bank, a small island off the coast of South Carolina, was hosting nearly 20,000 Whimbrel each night during peak spring migration (that's half the entire Atlantic flyway population!), the question quickly became: where are all these Whimbrel going during the day?

Between 2020 and 2023, we deployed 30 solar-powered Lotek pinpoint GPS transmitters on Whimbrel that use the Deveaux Bank nocturnal roost to answer this question. These tags collect precise GPS fixes every 10 minutes while birds are in South Carolina, and every 15 minutes at all other times of year. 
Measuring a Whimbrel before fitting it with a GPS transmitter on Deveaux Bank. Photo: Richard Joyce
The only catch? In order to download the data off the tags, the birds need to come within range of two temporary VHF radio towers we build on the nocturnal roost each season. Anytime one of our tagged birds is roosting near one of these towers, any new data stored on the tag is automatically downloaded and waiting for us when we come out to the island during the day -- allowing us to reduce disturbance to the roosting birds at night.

The GPS data we download from these transmitters are the foundation of all our ongoing research questions about Whimbrel movement ecology, habitat selection, site fidelity, and migratory behavior.
Downloading data from our VHF receiver station
Assembling VHF radio towers on Deveaux Bank. Photos: Kaitlyn Hackathorn/SCDNR
Me about to release the final bird tagged for my PhD fieldwork -- it only took three years to catch all 30!