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SITE NAME
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Canning River Delta, Arctic National Wildlife Refuge, Alaska, USA
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| Contact details
(phone/fax//e-mail//address): |
| (907) 456-0303/(907) 456-0428(fax) // Steve_Kendall@fws.gov // U. S. Fish and Wildlife Service, Arctic National Wildlife Refuge, 101 12th Ave., Room 236, Fairbanks, AK 99708, USA
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PROJECT DETAILS |
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Project name:
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Nest Survival of Tundra Nesting Birds and Abundance of Nest Predators Relative to Human Development on Alaska's Arctic Costal Plain
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Start of survey:
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End
of survey: |
Team
size: |
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31.05
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18.07
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6
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WEATHER
CONDITIONS
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Weather conditions: |
| There was more snow cover present when we arrived at the study site this year and it persisted later into the season, compared to the previous 3 years at the study site. Near-shore sea ice persisted into mid July, compared to mid to late June in other years. Daily average air temperature during nest initiation and incubation were similar to previous years.
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| Date of 50%
snow-cover: |
6.06
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| Date of ice-break on
rivers: |
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| Date of final loss of
snow: |
15.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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| In 2005, we located and monitored 160 of nests of 14 species. The most abundant nesting species were: pectoral sandpiper (24.0 nests/km2), Lapland Longspur (21.5 nests/km2) and semipalmated sandpiper (12.0 nests/km2). Pectoral sandpiper's nest densities were the highest observed thus far at this study site. Red Phalaropes continued to nest in low densities (5.5 nests/km2) compared to 2002 (21.1 nests/km2), when they were the most abundant nesting shorebird. Low densities of phalaropes are expected in years of late snow melt, such as 2005. Their nesting habitat is typically found in low area which are the last areas to become available. We observed one spectacled eider nesting at the study site, a first for this species. Mayfield estimates of nest success rates have shown much variability among years and for most species in 2005 the success rates were within the range of variability previously observed. Among species with samples of 10 or more nests success was 0.428 in Pectoral Sandpiper, 0.785 in Semipalmated Sandpiper, 0.621 in Stilt Sandpiper, 0.714 in Red-necked Phalarope, and was 0.465 (including incubation and nestling stages) in Lapland Bunting. Based on anecdotal observations at the study site, small mammal populations appeared to be slightly higher in 2005 than in previous years. As a result numbers of some predator species, jaegers, gulls and snowy owls were higher compared to other years.
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Rodent dynamics:
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| Capture data are available.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus trimucronatus | rare |
| Dicrostonyx groenlandicus | rare |
| Microtus oeconomus | rare |
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Summary
of fauna studies: |
Since 2002, several partners have been investigating the survival and fate of shorebird nests in relation to human infrastructure on the Arctic Coastal Plain of Alaska. This region is an important breeding area for several bird species, some of which have experienced recent population declines. Anthropogenic factors on the breeding grounds may have contributed to these declines, particularly through enhancement of predator populations. Availability of human food sources and man-made structures for use as nest, den, or surveillance sites may influence predator populations. Increased numbers of predators may have deleterious consequences for productivity of breeding birds via increased predation on eggs and young. The dynamics of this predator-prey system are poorly understood, however. The Arctic National Wildlife Refuge joined several partners in 2002 in a multi-year, multi-site study of nest survival and predation of tundra-nesting birds on the Arctic Coastal Plain in an effort to determine anthropogenic influences on this relationship.
In 2005 at the Canning River Delta we conducted our fourth season of field data collection. We have data from >2,100 nests from all sites and years combined, including >1,300 shorebird nests. These data have been pooled and are now being analysed by an independent statistician, using a spatially adjusted proportional hazards survival model with covariates for distance to and density of infrastructure, predator abundance, nest site habitat, and climate conditions to compare nest survival relative to human developed areas. The analysis will be complete in January 2006 and the results will be written up within the following months.
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