What Kind of Fish to Pelicans Eat?
A researcher releases a Strawberry Lake pelican after a belly-articles evaluation. Utah.gov
It is an age-outdated struggle: pelican vs . trout angler. All those gangly thieves are scooping up all the fish, appropriate? Not so quickly, claims a workforce at Utah Condition University’s Quinney Higher education of Pure Resources studying predator-prey associations concerning pelicans and cutthroat trout. Turns out the winged pescatarians may be helping us capture more fish.
Strawberry Reservoir, a 27-square mile male-produced lake southeast of Salt Lake Town, is Utah’s most popular fishery. As section of the state’s Blue Ribbon Fisheries plan, it logs 1.5 million hrs of fishing a year, supplying anglers enough prospect to capture prize cutthroat and rainbow trout and kokanee salmon. Its lore goes back again to a capture in 1930, when, according to the Utah Division of Wildlife Means, Mrs. E. Smith caught the state record non-native cutthroat there weighing in at 26 lbs . 12 ounces.
But migrating American white pelicans, which breed in Canada and the northwestern U.S. and wintertime in California, Mexico, and the Gulf Coast, also end there to fish. And given that cutthroat populations have fluctuated drastically in the reservoir in current a long time, guide writer Phaedra Budy and her workforce made the decision to investigate whether the pelicans were being to blame.
While cutthroats are nicely founded in the reservoir and its system of feeder streams, the inhabitants of grownup fish has ranged broadly more than the earlier two many years, from 220,000 to 464,000. So, Budy’s workforce captured pelicans in excess of a two-yr time period and studied the contents of their stomachs. They discovered the birds’ eating plans consisted of 85 p.c Utah sucker, 6 percent Utah chub, and 3 per cent cutthroat trout. During spawning operates, when squadrons of pelicans form feeding “fences” that blockade the mouths of tributaries, the share of cutthroats consumed by the pelicans rose to 10 per cent. But on combination, approximately 1 per cent of the reservoir’s adult cutthroats were being taken by the birds, the research identified.
“Because pelicans are very visible and congregate in huge quantities at Strawberry Reservoir, anglers suppose that they are ingesting tons of trout,” mentioned Frank Howe, a member of Budy’s workforce. “But the examine shows that pelicans are not intrigued in the identical fish species that are prized by human anglers.” Alternatively, pelicans mostly consume the native suckers and chubs, species whose populations have been on the rise and a worry for wildlife administrators. So, Budy and her review conclude, the pelicans are probable undertaking anglers a favor by taking away competing indigenous fish.