Willamette Falls Pinniped Monitoring Project, 2014

California sea lions (Zalophus californianus) are seasonal migrants in the Pacific Northwest, generally arriving around August and departing by the following June. With few exceptions, the majority of California sea lions in the Pacific Northwest are juvenile and adult males, whereas females and young generally stay in the breeding range in California and Mexico (Odell 1981). California sea lions typically occur at upriver sites such as Bonneville Dam and Willamette Falls only in the spring, peaking around late April and early May (Wright et al. 2010, Stansell et al. 2013). 2014 NMFS (National Marine Fisheries Service) Submitted Public Domain 1861