Productivity of marbled murrelets in California from observations of young at sea
Ralph CJ and Long LL. 1995. Productivity of marbled murrelets in California from observations of young at sea. Pages 371-377. In Ralph CJ, Hunt GL, Raphael MG, Piatt JF. Ecology and conservation of the marbled murrelet. Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. Albany, CA
Excerpts: "We designed and tested an intensive survey method in 1993 to identify juvenile Marbled Murrelets at sea. From this, we used the percent of juveniles seen in the sample as an index of productivity of murrelets along the California coast. We conducted productivity surveys in various areas of California during 1993, near Crescent City [near Redwood National and State Parks], Trinidad, Eureka, and Santa Cruz, both at sea and from shore. Surveys began 21 June and continued until 1 October. We found 2.2 percent of the population sampled were juveniles, similar to our estimates in 1989-1992 of 3 percent from less stringent survey methods in this area. Percent of juveniles in the 1993 sample ranged from almost 6 percent in late June to none in mid-August and September. Juveniles were as often alone as in a group with 1 or 2 adults, and showed similar distribution in distance from shore as adults."
- Type
- Book Chapter
- Authors
- Ralph, C; Long, Linda
- Units
- REDW
- Keywords
- Animal Studies, Brachyramphus marmoratus, Marbled Murrelet, Marine Birds, Productivity, Seabirds, Survey Methods, Threatened Species, Wildlife