Managing water for birds— A tool for the Malheur National Wildlife Refuge

The “Water for Birds Tool” is an Excel-based model designed for resource managers to assess the spatial extent and types of bird habitats in the Malheur National Wildlife Refuge. The model quantifies the area of open water, partial water, and water depths on a monthly timescale during the irrigation season (April–July) from 2021–2024. This model combines previously published datasets and incorporates new measurements collected by partners. Results show that the relation between the amount of bird habitat and the extent (partial and open water) of Malheur Lake varies by bird guild. The Donner und Blitzen River supplied nearly all the surface water inflow to Malheur Lake during the analysis years, emphasizing the importance of informed management of the river. Additional gaging of inflows and diversions, and better estimates of recharge and irrigated areas, will refine estimates of water use on the refuge.