Nest box colony field observations and avian egg tissue laboratory analyses from Lake Koocanusa and the Kootenai River Basin, Montana, 2022-2023

This data release includes nest box field observations (N = 98 nest boxes) and avian egg tissue laboratory analyses (N = 60 eggs) collected from Lake Koocanusa (also known as Koocanusa Reservoir) and the Kootenai River Basin, Montana, 2022-2023. Nest box field observation data (occupancy rate, clutch size, and hatching success) and avian eggs were collected by the U.S. Fish and Wildlife Service (USFWS) Montana Ecological Services Field Office (Helena, Montana), in cooperation with the University of Montana Bird Ecology Lab (Missoula, Montana), U.S. Army Corps of Engineers-Seattle District, Libby Dam-Kootenai River, (Libby, Montana), and U.S. Geological Survey (USGS) Wyoming-Montana Water Science Center (Helena, Montana). Preparation of egg tissue samples for metal(loid) analyses were conducted by the USFWS Montana Ecological Services Field Office and USFWS Mountain-Prairie Region (Lakewood, Colorado). Laboratory analyses [metal(loid)s] were conducted by the U.S. Environmental Protection Agency (USEPA), Region 10 Laboratory (Port Orchard, Washington). Specific metal(loid)s analyzed in avian egg tissue were arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), selenium (Se), and zinc (Zn). This data release also compiles laboratory quality-assurance (QA) and quality-control (QC) data associated with the avian egg samples.