Article
Eared grebe diet on Great Salt Lake, Utah, and competition with the commercial harvest of brine shrimp cysts
The Journal of Wildlife Management
(2013)
Abstract
Interactions between wildlife and commercial harvest industries need to be understood to manage resources for all users. About 1.5 million eared grebes (Podiceps nigricollis), half the North American population, stage on Utah's Great Salt Lake (GSL) each fall. A $56 million commercial harvest industry also operates during fall when the harvest of brine shrimp (Artemia franciscana) cysts occurs. Eared grebes and commercial harvest both utilize brine shrimp cysts creating a potentially adverse relationship. We assessed the diet of eared grebes to determine the extent to which they are dependent on brine shrimp and their cysts. We collected individual birds to measure diets and examine changes in body condition of staging eared grebes. Cysts were consumed by 40% of collected eared grebes and made up >75% of aggregate biomass of stomach samples. Despite the high occurrence of cysts in stomach samples, cysts were not the primary food item of eared grebes. Cysts were held in the stomach for longer periods by feather mass, so esophagus samples were a better indicator of diet.
Disciplines
Publication Date
2013
DOI
DOI: 10.1002/jwmg.580
Citation Information
Michael Conover. "Eared grebe diet on Great Salt Lake, Utah, and competition with the commercial harvest of brine shrimp cysts" The Journal of Wildlife Management Vol. 77 Iss. 7 (2013) p. 1380 - 1385 Available at: http://works.bepress.com/michael-conover/83/