Migratory birds may cut short Utah visits due to drought

Jun 21 2013 - 6:18am


 A pair of Canadian geese fly over the waters of Farmington Bay. This summer's drought could shorten the time migratory game birds visit Wasatch Front-area wetlands

(Standard-Examiner file photo)
 A pair of Canadian geese fly over the waters of Farmington Bay. This summer's drought could shorten the time migratory game birds visit Wasatch Front-area wetlands

(Standard-Examiner file photo)

FARMINGTON -- With little freshwater runoff and a forecast of a "typical" dry Utah summer, the migratory game birds visiting Wasatch Front-area wetlands -- mainly the marshes of Great Salt Lake -- may not stay as long.

Because of a lack of mountain runoff this summer, less plant vegetation will be available for the birds to eat, particularly waterfowl belonging to the swan species, said Blair Stringham, migratory game bird coordinator for the Division of Wildlife Resources.

The state will begin to transition into its typical summer pattern next week, which means, on average, about an inch of precipitation per summer month, say National Weather Service officials.

"A lot of wetlands along the Great Salt Lake don't have the freshwater," Stringham said. 

As a result, he said, fewer stands of alkali bulrush and pickleweed plant are available -- plants that game birds typically feed on.

Freshwater helps produce much of the vegetation the birds eat, while other areas surrounding the lake have soil with high concentrations of salt, making it difficult for vegetation to grow, he said.

Great Salt Lake marshlands are primarily a large staging area for migratory waterfowl flying both north and south, much like a rest stop along a freeway, and when vegetation there is in short supply, Stringham said, those waterfowl are less likely to stay long.

One particular species of bird that may be affected more than others this summer will be the swans, which feed off of the sago pondweed, a freshwater plant, Stringham said.

"What they will do is pass through," Stringham said of the swans, "but they won't stay as long."

The birds that nest along the lakeshore are also dependent on freshwater runoff, which is in short supply this year, said John Cavitt, Weber State University zoology professor.

Because of the lack of runoff, areas where shoreline birds can nest have been reduced, Cavitt said, forcing them to congregate in smaller and smaller areas. As an indirect result, predators are able to find the birds' nests more easily, he said.

Cavitt said he has kept data on shoreline birds for the past 12 years and has noticed, unfortunately, that a reduced supply of freshwater runoff seems to be occurring frequently from year to year.

"We just have to be very careful about our water use and realize that it affects more than just us," Cavitt said.

The particular shoreline birds he specializes in studying, such as the American avocet and black-necked stilts, are species that are long-lived, so one year of reduced freshwater supply shouldn't affect their population sizes, he said.

But, Cavitt said, "it is a concern of mine over the long term that we continue to see these problems."

As the human population along the Wasatch Front continues to grow, Cavitt said, there will be less water available downstream.

And waterfowl are drawn to a freshwater habitat, small ponds of freshwater, such as is held at the various management areas along the shoreline of Great Salt Lake.

Waterfowl management areas prevent freshwater feeds from dumping directly into the lake, which has a high level of salinity.

But, Stringham said, outside those lakeshore waterfowl management areas -- such as the one at Farmington Bay -- when there isn't enough freshwater runoff, other areas surrounding the lake can dry out, resulting in a receding lake level.

When the lake level recedes, he said, it can reach a point where the surrounding area has such a high salt content in the soil, vegetation is not able to grow. In turn, when the lake level is too high, it can cover some of the freshwater areas that are generally available to waterfowl.

"So, there is a happy medium between having a higher and a lower lake level," Stringham said. "It is just kind of a natural cycle of the lake going up and the lake going down."

But despite the shortage of freshwater reaching the lakeshore, Davis County officials reported having a very successful birdwatching festival in May.

"We saw record numbers on our marathon birding trip," said Neka Roundy, coordinator of the Great Salt Lake Bird Festival.

Roundy said the birders who participated in the festival's field trip activities did not indicate to county staff that the Great Salt Lake shoreland bird population was amiss.

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