Counts of Alaska Steller Sea Lion Adult and Juvenile (Non-Pup) on Rookeries and Haulouts in Alaska From 1904–2015
This dataset contains counts of adult and juvenile (non-pup) Steller sea lions on rookeries and haulouts in Alaska Aleutian Islands, Bering Sea, and other areas made between that beginning of 1904 and June 18, 2015.
Non-pup counts were conducted throughout the year. Breeding season (June to mid-July) non-pup counts are used for population trend analysis, while counts at other times are used for analyses of distribution and for other purposes. Non-pups are counted from the ground (by walking along the rookery), from cliff-side overlooks, and from aerial imagery (oblique and vertical orientation). Non-pup counts represent only a fraction of the total number of animals that may use a site. Sea lions haulout less frequently in winter than in summer; thus, winter counts represent a smaller fraction of the total population than summer counts.
Data may be searched and downloaded using online services provided by NCEI using the online resource URLs in this record. Contact NCEI Information Services for custom orders. When requesting data from NCEI, the desired data set may be referred to by the unique package identification number listed in this metadata record.