31 March 2014

Rare Gull Occurrences Continue at Carter Lake

Sightings of gulls rare to Carter Lake continue to occur. Suitable habitat conditions have been attracting hundreds of gulls. Low water levels have not only provided beach area useful as day roosts ... especially the southern shoreline of the Iowa West Ranch, the slice of Levi Carter Park on the west side of the east arm of the lake, and the former beach area at the northwest portion of the lake. Fewer birds are seen floating on the lake waters, or coursing in flight above the lake.

More significant — and as never known to have occurred in recent years — has been the "gull flats" north of Bird Isle in the southeast portion of the lake. Use of the shallow-water flats was first noted on March 20th, and has continued to be a significant roost area during each subsequent visit by various area birders. It is in this area where the three types of rare gulls have been observed and where a huge number of Ring-billed Gulls occurred. The number of gulls present at the flats has declined as the water level has continually increased due to the pumping of Missouri River water into the lake by the Omaha Public Works Department.

Availability of a forage resource has also made a difference.

Rare Sightings

Two species observed have not been previously seen at this locality, resulting in an overall increase in the variety of species present through the end of March, 2014. These are notes on occurrence of the different gulls:

» Iceland Gull: the first-ever observation at the lake was on March 24th, with a second sighting on March 27th. The two observations are also significant in a regional sense, as the nearest other locale of occurrence has been at Branched Oak Lake.
» Lesser Black-backed Gull: first ever observation during the late afternoon to evening period on March 29th.
» California Gull: the four sightings during March 2014, are the first since this species was last noted in November, 1993. A surprising 7-8 of these birds were noted on March 29th, which is a peak count for eastern Nebraska.

California Gulls. Photographs courtesy of Justin Rink

» Thayer's Gull: from 1 to six have been noted on the four days of occurrence during the later part of March. The only previous record of observation was in November 1993. The six seen on March 25th is a peak count for eastern Nebraska.

Thayer's Gulls.

» Ring-billed Gull: an amazing flock of 2,000 noted on March 27th by Justin Rink. Other significant counts of 255 (March 20th) and 210 (March 29th) are among the top five counts ever noted at the lake.
» Herring Gull: lesser numbers have been noted during March in comparison to counts made in the 1920-30s.
» Franklin's Gull: have yet to occur, but can be expected any day. Larger larger numbers have typically been noted mostly in mid-April; up to 1700 have been observed on one occasion.

This is a summary of the gull species recorded at Carter Lake during the past two decades, based upon records for the Carter Lake environs, with records starting in the 1890s, as compiled into a database. There are more than 185 gull records, the first from 1926 when the Omaha Nature Study Club were doing regular waterbird censuses at the lake.

Common Name 1993 2000 2002 2003 2004 2005 2006 2007 2009 2010 2011 2012 2013 2014
Franklin's Gull - - - - 2 1 - - - - - - - - - - - - 5 3 12 - -
Bonaparte's Gull - - - - - - 1 - - - - - - 1 - - - - - - - - 6 - -
Ring-billed Gull 1 1 3 10 1 1 1 1 3 2 9 16 35 10
California Gull 1 - - - - - - - - - - - - - - - - - - - - - - - - 4
Herring Gull 3 - - - - 1 - - - - 1 - - 1 - - - - 2 - - 8
Thayer's Gull 1 - - - - - - - - - - - - - - - - - - - - - - - - 5
Iceland Gull - - - - - - - - - - - - - - - - - - - - - - - - - - 2
Lesser Black-backed Gull - - - - - - - - - - - - - - - - - - - - - - - - - - 1
Glaucous Gull - - - - - - 2 - - - - - - - - - - - - - - - - - - - -
The value given is a count of the number of reports. These records are comparable, especially for 2012-2014, since numerous and regular surveys of waterbirds have been done at the lake and vicinity. The numbers of birds present has not been recorded for every report.

Justin Rink deserves special thanks for his ongoing interest in observing and reporting many of the unusual gull species in 2014.

In addition to gulls, the "gull flats" have also attracted use by dabbling ducks, and as a roosting place for Canada Goose, for example.

Video of the gathered gulls, including Ring-billed and Thayer's gulls. Taken March 25, 2014 through a spotting scope.