SALT LAKE CITY, Utah (ABC4 News) – 5 million Eared Grebes call the Great Salt Lake home for several months a year. Believe it or not, the weather and the water are the foundation for that accommodation.
Many Utahns admit they’ve never actually visited the Great Salt Lake to take in its breathtaking views and diverse wildlife. But one man and nature photographer, Keith Vaught, has been visiting the lake for the last 14 years.
“It’s how much you can see. You can see miles and miles from here and on the macro level there is so much to see down in the ground,” says Vaught, “…I think the landscape grows on you, the more time is spent out here, you see the change in the seasons and bird migration”
Eared Grebes are one species of bird that keeps coming back to the Great Salt Lake on its annual migration, and there are millions of them. They are night-fliers, whose survival depends on the lake’s unique ecosystem. Because they fly under the mask of the night, they can only be spotted on weather radar as they head south for the winter.
Right now, however, you can spy them feasting on a buffet of brine shrimp near the south arm of the lake.
Kyle Stone, a wildlife biologist for the Division of Wildlife Resources, says, “Great Salt Lake is such an important resource for them because just the uniqueness of the Great Salt Lake and productivity of the brine shrimp as a species…During the time that they are here, from August to December, the Eared Grebes go through a feather molt and lose all their flight feathers. During this time, their flight muscles also atrophy and they actually lose body mass, and weight and muscle mass, but they increase their stomach organs to where they can actually pull out more nutritional value in brine shrimp.”
Stone says the grebes population has exploded in the last decade, from 1 million to 5 million,
and the reason is microscopic. Brine shrimp, otherwise known as sea monkeys, are tiny crustaceans that contribute to the lake’s ecosystem in an enormous way.
A single Grebe eats about 30,000 brine shrimp a day. When you consider the number of Eared Grebes snacking–it calculates out to a whopping 165 billion shrimp a day. Fortunately for the migrating birds, there are roughly 14 trillion sea monkeys swimming in the lake’s salty waters.
“They can occur in freshwater, but they are so delicious they get eaten by shrimp, birds, insects and at low salinities you don’t find brine shrimp because they get eaten before they can reproduce,” explains Stone.
The southern part of the Great Salt Lake has roughly four times more salt than ocean water. The high salinity level of the lake not only protects the brine shrimp, but their food source as well: a nearly invisible algae called Phytoplankton.
“The salinity changes with the water levels as the water level fluctuates. more water, the same salt, remove water increase the salinity, and that will change the phytoplankton,” says Stone.
With a slow start to winter, and Utah’s recent drought history, a couple more dry years could mean less lake, more salt, and fewer brine shrimp. This could lead to a decline in aquatic visitors like the stealthy and nocturnal Eared Grebes.
Adult Brine Shrimp will die off when the water temperature reaches 4 degrees Celsius, and that is about when Eared Grebes will wrap up their migration.