Willamette Falls Pinniped Monitoring Project, 2016

California sea lions (Zalophus californianus) are seasonal migrants to the Pacific Northwest, generally arriving around August and departing by the following June. The majority of California sea lions in the Pacific Northwest are juvenile and adult males, while females and young generally stay in the breeding range in California and Mexico (Odell 1981). A small fraction of the population congregates at upriver sites such as Bonneville Dam and Willamette Falls each spring, typically peaking in late April and early May (Wright et al. 2010, Wright et al. 2014, Stansell et al. 2013, van der Leeuw 2015). 2016 NMFS (National Marine Fisheries Service) Submitted Public Domain 1861