Pelicans at Strawberry Reservoir: what do they eat?
Quinney College of Natural Resources explains study results.
Shauna Leavitt is a guest contributor to the DWR blog. She writes for the Quinney College of Natural Resources at Utah State University and has written for many regional and national wildlife magazines including, The Mule Deer Foundation, The Wildlife Professional and People, Land & Water.
Anglers spend 1.5 million hours a year on Strawberry Reservoir, one of Utah’s most popular fishing spots. Anglers are not the only ones attracted by the fish; the reservoir has become a favorite fishing spot for American white pelicans. In the spring, flocks of up to 500 birds can be seen gathering at the reservoir’s tributaries.
The growing number of pelicans caught the attention of managers and anglers. “They’re eating all the trout,” was the concern. In response, we teamed up with and Utah State University and began tracking the eating habits of the birds. On July 6, the near-final results of the multi-year project were presented by USU graduate student Kevin Chapman.
The results show pelicans eat mostly non-game fish. Their diets consisted of 85 percent Utah sucker, 6 percent Utah chub and 3 percent cutthroat trout. The 3 percent equals about 2,000 trout per year.
Initially, this amount hardly seemed significant since there are an estimated >250,000 trout in the reservoir. But, a female cutthroat trout in Strawberry Reservoir may produce 2,000 eggs per year, representing a significant loss to natural reproduction.
Fortunately, the study also showed that there may be just a short time window when pelican numbers are over a certain threshold, in which managers may need to intervene.