06 June 2007

Dry Conditions for Spring Shorebird Migration in Crescent Lake Sandhills

By James Ed. Ducey.

Continuing dry conditions meant lesser shorebird numbers during spring migration in the western sandhills.

“This year, dry conditions precluded above average rainfall after the majority of the migration had past,” said Neil J. Powers, manager of Crescent Lake NWR.

Shorebird and migratory waterfowl numbers were so far down this year in this part of Nebraska because it was so dry, so long, Powers explained during a visit May 24th by an ornithology class from the Cedar Point Biological Station, operated by the University of Nebraska-Lincoln along the Platte River in Keith county. Then the rains came too late to attract and keep the birds.

The instructor, John Faaborg of University of Missouri, Columbia, expressed disappointment and apologized for an absence of typical birds according to a student’s post on NEBirds.

The shorebird migration was lighter than normal, said Marlin French, wildlife biologist at the refuge of lakes and prairie in central Garden county. “Most notably we did not have the large groups of phalaropes. Breeding bird numbers are the same to slightly up.”

Several thousand Wilson's Phalarope have been regularly noted during May bird counts, and is the most numerous migratory shorebird at refuge habitats, such as Gimlet Lake, Border Lake, Crane Lake and Roundup Lake.

There were about 14,000 counted on May 1, 1978 at Goose Lake, according to refuge records, this being the largest count of this species for the sand hills region. Another large count was 12,500 noted during a birders survey on May 6, 2006 at nearby Alkali Lake, on the Eldred Ranch.

Large numbers of the Red-necked Phalarope are occasionally noted in the Crescent Lake region. Long-billed Dowitchers, Baird's Sandpiper and Least Sandpiper can also be especially numerous during refuge surveys.

Rainfall on April 24-25, nor the heavy rains of ca. 2.5” on May 29-30, did improve water conditions for the onset of the typical breeding season for shore- and water-birds.

“Water levels are still low but slightly better than the past few years,” French said.

“In any given year, our annual evaporation is almost triple that of our annual precipitation,” Powers said. “With below average snowfall and a relatively dry early spring (March and early April) leads to conditions which unfortunately drive wetland associated migratory birds to areas with better habitat conditions.”

“This situation could be completely reversed next spring and is one of nature’s dynamics which keeps wetlands productive,” Powers added.

Homepage of Crescent Lake NWR

No comments:

Post a Comment