Written by Olivia Hinds, USGS Biologist
Photo (above) American avocet, a common shorebird throughout the Great Basin terminal lakes Photo by Garth Herring, USGS.
The United States Geological Survey (USGS) partnered with the Malheur National Wildlife Refuge to investigate the importance of the preserve as a breeding ground for native birds. In doing so, the refuge has joined a larger USGS project known as the Saline Lake Ecosystems Integrated Water Availability Assessment. This project’s goal is to better understand the importance of the Saline Lake ecosystem to migratory waterbirds and to determine how water management decisions impact them. Over 600 species of birds have been identified in the Great Basin, and with the loss of terminal lake wetlands and habitats, we need to know more than ever the factors impacting the birds’ success.
One of the main pillars of this project is understanding waterbird prey availability (primarily for shorebirds), resources, and habitat suitability. Prey availability influences many aspects of the waterbirds’ annual cycle, including movements and habitat selection, reproduction, physiology, and survival. Critical bottlenecks in the birds’ life where prey can become a limiting factor include migration and reproduction, due to increased energetic demands. Because these shorebirds depend on these terminal lakes for migratory fueling and breeding, a decline in prey quantity, or energetic value could have important ramifications.
Malheur is a terminal lake in the Great Basin that serves as a pivotal freshwater habitat where waterbirds frequently nest, rest, and refuel during migration. It is one of nine lakes determined by the USGS to be of high importance in these long-distance journeys. In 2024 across these nine lakes, USGS collected over 2,200 individual aquatic invertebrate samples at over 390 sites. At Malheur Lake, 29 samples were collected, including a mix of benthic and water-column invertebrate samples, along with paired water chemistry samples. Additional USGS research at Malheur Lake is focused on water quantity and quality, water inundation extent via remote sensing, as well as waterbird movements. This includes an instrument in Malheur that captures data every 30-minutes on water-quality parameters such as temperature, dissolved oxygen, pH, specific conductance and turbidity throughout all seasons.
By examining aquatic prey, habitat availability, and shorebird energetic needs, we can model the carrying capacity of lakes like Malheur to know how many birds it can support and for how long. Malheur Lake is an integral place for many migrating shorebirds’, and it can help resource managers better understand and identify the factors most critical to protecting their populations.
We want to send Malheur Wildlife Refuge a huge thank you from everyone at USGS for helping us to do this important work!
Resource: Prey Availability | U.S. Geological Survey
