Counting cranes

• Lesser Sandhill Cranes Observations in the Homer Area, Summer 2012
By Kachemak Crane Watch

Photo provided - Sandhill cranes enjoy a peaceful moment around Kachemak Bay. Populations are currently estimated to run around 200 in the Homer/Anchor Point area.

Photo provided - Sandhill cranes enjoy a peaceful moment around Kachemak Bay. Populations are currently estimated to run around 200 in the Homer/Anchor Point area.

Despite the late spring and near-record snowfall, Homer’s Sandhill Cranes arrived on schedule with the first report received by Kachemak Crane Watch on April 11. By April 18, a flock of 100 plus was reported in the Beluga Slough area.
Activity for the summer was similar to previous years, with flocks seen along Morning Star Road (2.3 miles out East End Road), about 14 miles out East End Road, on Diamond Ridge and West Hill roads, and in the North Fork area.
Once again, observers reported that the flocks of non-breeders virtually disappeared from their traditional sites in June and July.
It is still a mystery where the majority of these non-breeders, or failed breeders, go during this period. By mid-August, the non-breeding flocks started filtering back to the regular reporting sites around town.
This year, Kachemak Crane Watch gathered data for the second year of its three-year Sandhill Crane Nesting Ecology Study. Biologist Michelle Michaud contacted landowners about nesting cranes to determine location, numbers of colts and nesting habitat.
This year, nesting crane pairs laid their eggs between May 5 and May 27.
Of the 35 known nesting pairs in the Homer/Anchor Point area, only 28 crane pairs are known to have nested in 2012. Of these 28 pairs, only 19 had successful nests, producing 33 colts.
Of the 33 colts hatched in 2012, only 23 fledged. Reproductive success in 2011 was lower than in 2012. Factors affecting nest success include potential predation from mainly eagles, coyotes and dogs. One mated crane was killed by an arrow, but troopers have not learned who killed it.
Weather could also be a factor in reproductive success, as the Homer area experienced heavy snowfall in winter 2011/2012, and the summer was cool. Kachemak Crane Watch posted a slide video last year about the Nesting Ecology Project, with photos of the nests and habitat at www.cranewatch.org under the “videos” tab.
The public also participated in this year’s population count via a citizen science project. Participants reported crane sightings on Aug. 23, 29, and Sept. 4. From this information, an observational estimate of the crane population for the Homer area was 178.
This estimate is based on the highest number of cranes observed at one location at a given time, plus the number of crane pairs and colts not included in that number.
Kachemak Crane Watch estimates the total crane population in the Homer/Anchor Point area at 200 (pers. comm. Edgar Bailey).
Once again, migration occurred on several different dates. On Sept. 6 and 13, two different migrating flocks left Homer after staging at Inspiration Ridge Preserve. A small flock of about 15 cranes, including three colts, was still being reported as of Sept. 16. Several other families of three have been seen in town, as well with the last report received on Sept. 17.
With the late spring, some colts appeared not ready to leave with the main migration. The parents will hold back until the colts develop enough strength for the rigors of a 2,400-mile migration to central California.
Based on Kachemak Crane Watch data since 1999, the average departure date of most local cranes is on or about Sept. 10, depending on weather conditions.
Sandhill Cranes normally migrate during daylight, with clearing skies and favorable tailwinds. They usually begin migration mid-day, after foraging.
A map of the cranes’ migration route is available on the Kachemak Crane Watch website. Also, a brochure published by Kachemak Crane Watch and the International Crane Foundation entitled, “Annual Travels of Sandhill Cranes from Homer, Alaska,” is available at Islands and Ocean Visitor Center. A copy can also be downloaded at www.cranewatch.org.
New this year is a brochure entitled, “Human Induced Threats to Sandhill Cranes in Homer.” The brochure includes information about how to be a responsible pet owner, threats created by feeding bald eagles, Sandhill Crane viewing etiquette, and what to do if dogs are harassing cranes. It is also available on the website.

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Posted by on Sep 26th, 2012 and filed under Sports. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.

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