2024 Oregon and Washington double-crested cormorant (Nannopterum auritum) colony surveys – aerial photos and count data

Aerial surveys were undertaken to monitor selected double-crested
cormorant (DCCO; Nannopterum auritum) colonies in Oregon to fulfill
monitoring requirements associated with the United States Fish and
Wildlife Service (USFWS) final environmental impact statement: Management
of Conflicts Associated with Double-crested Cormorants (USFWS 2020).
Survey methods follow guidelines established by the Pacific Flyway Council
monitoring strategy: A Monitoring Strategy for the Western
Population of Double-crested Cormorants within the Pacific Flyway (PFC
2013). This dataset presents high resolution aerial imagery and
corresponding nest counts from areial surveys of double-crested cormorant
(DCCO; Nannopterum auritum) colonies in Oregon and Washington. Survey
results are intended for use by USFWS and Pacific Flyway Council members,
including ODFW and other state and federal agencies, to determine
population size and evaluate long-term trends in abundance of DCCO within
the Pacific Flyway. Additionally, colonies in coastal Washington were
surveyed opportunistically and aerial photos were shared with WDFW.
Monitoring DCCO numbers is essential for evaluating effects on population
size of permitted management actions currently underway across the western
United States.