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

The “Water for Birds Tool” is a spreadsheet-based tool (using Microsoft Excel) designed to help resource managers assess the spatial extent and types of bird habitats in the Malheur National Wildlife Refuge, southeastern Oregon. The tool quantifies the areas of open water, partial water, and water depths on a monthly timescale during the irrigation season (April–July) from 2021 to 2024. This tool combines previously published datasets and models but also 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 all or most of 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 can help refine estimates of water use on the refuge.