By Kachemak Crane Watch
Homerʼs spring 2013 was very late, following periods of freezing and thawing, and some late snow which kept the high country locked up almost into June. Homerʼs Sandhill Cranes arrived a bit later this year with the first report received by Kachemak Crane Watch on April 19. By April 22, a flock of 200 plus cranes was reported by Lani Raymond and Otto Kilcher flying toward town.
Sandhill Crane activity mirrored previous years with the usual flocks seen along Morning Star Road, also about 14 miles out East End Road, on Diamond Ridge and West Hill roads, and in the North Fork area. Early-to mid-June, the non-breeders left the Homer loafing areas for other unknown places. Fewer non-breeding cranes were observed this year in and around town. In mid-June we only got a high count of about 15, compared to counts of 50-60 in the previous two years out around MP 14 East End Road. Mid-August, the non-breeding flocks returned to the Homer area.
This year Kachemak Crane Watch gathered data for the third year of its three-year Sandhill Crane Nesting Ecology Study. Biologist Michelle Michaud worked with private landowners who have cranes nesting near their homes to determine nest location, nesting habitat, numbers of eggs hatched, and colt survivorship. Due to the late spring, eggs were laid several days to several weeks later than in previous years. The nesting crane pairs laid their eggs between approximately May 3 and June 2, 2013. Of the 37 known nesting pairs, we only know of 27 who actually nested this year (See Table 2 below), including one pair whose nest failed when the male crane (C046) was allegedly killed by a Bald Eagle.Of the 27 nesting pairs, only 21 pairs had one or more eggs for a total of 31 eggs – apparent nest success of 67.74 percent. Of these 31 colts produced, only 21 survived to fledge (fly) – a reproductive success rate of 67.74 percent.
Even with completion of the 3-year Nesting Ecology Study, Kachemak Crane Watch plans to continue collecting information about known nesting pairs to keep track of annual recruitment to the local crane population. You can help by sending information about new or known nesting pairs next summer to firstname.lastname@example.org or calling 235-6262.
Factors affecting nest and fledgling success include potential predation, primarily from eagles, coyotes, and dogs. Weather may also be a factor in nesting and reproductive success, as the Homer area experienced a later and colder than normal spring, which in turn may have affected food availability for both cranes and their predators. This year Kachemak Crane received an eyewitness report of an adult crane taken on the wing by a Bald Eagle. The observer watched the crane and eagle tumble to the ground and went to the site where he saw the eagle eating the crane. In the second report, a banded crane, C046, was most likely killed by the neighboring eagle that had been stalking the craneʼs nest. The transmitters were recovered on the other side of East End Road. The female abandoned the nest.
This yearʼs citizen science Crane Population Count occurred on Aug. 29, Sept. 4, and Sept. 9. Crane count reports provide data to allow Kachemak Crane Watch to estimate the total crane population in the Homer area south of Anchor Point. This yearʼs estimate is 112, considerably lower than last yearʼs total of 178. This number could be low because some cranes migrated on Sept. 9. However, this count did not distinguish between adults and colts, therefore the number is most likely higher as not all of the nesting pairs and their colts would congregate with this large group. Kachemak Crane Watch has estimated the total crane population in the Homer/Anchor Point area at 200 (pers. comm. Edgar Bailey), but it is difficult to know with certainty whether the local population is increasing or decreasing. Also this number could be influenced by cranes who breed on the Alaska Peninsula and stopover on their way to California.
Once again, fall migration in 2013 occurred on several different dates. On Sept. 9 and 14, two different migrating flocks left Homer after staging at Inspiration Ridge Preserve. A pair with one colt departed on Sept. 16, the last cranes to leave Inspiration Ridge Preserve this year. If colts hatch late, families will stay up to several weeks after the main migration to allow colts time to 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, usually departing about mid-day after foraging.
With ever changing land uses in areas important to Sandhill Cranes for nesting, foraging, and overwintering, assuring the continued protection of critical areas, particularly in the heavily populated Sacramento Valley is very important. Kachemak Crane Watch looks forward to working with private landowners in future years to help preserve crane habitat and increase nesting and survivorship. Education is the key.
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