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RESPONDENT
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Joseph Liebezeit
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SITE NAME
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Prudhoe Bay Oilfield, USA
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| Contact details
(phone/fax//e-mail//address): |
| 503-241-7231/503-241-7925(fax) // jliebezeit@wcs.org // Wildlife Conservation Society, North America Program - Pacific West office, 718 SW Alder Street, Suite 210, Portland, OR 97205, USA
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PROJECT DETAILS |
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Project name:
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Nest survival of tundra-nesting birds and human development on the North Slope of Alaska
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Start of survey:
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End
of survey: |
Team
size: |
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01.06
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25.07
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2
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WEATHER
CONDITIONS
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Weather conditions: |
| Snow cover should have reduced to 50% by approximately 3 June (assuming that snow melt occurred consistently across time), as our snow cover surveys indicate that snow cover in the flat areas was about 42% on 5 June. Snow melted completely on flat areas by approximately 14 June. It appeared that the study plots closest to the Beaufort Sea had the deepest snow and highest snow cover. At this site, our study plots range 2-13 km inland from the coastline. The Kuparuk River ice break-up occurred approximately on 24 May (J. Harth, personal comm.). Days were consistently colder than in 2004 for much of the season (especially June). There was more rainfall in 2005 compared to 2004 although it was not excessively rainy (3 days of pouring rain) and there were no snow storms during our time in the field although flurries did occur on 3 days.
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| Date of 50%
snow-cover: |
3.06
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| Date of ice-break on
rivers: |
24.05
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| Date of final loss of
snow: |
14.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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We reduced our effort at this site in 2004 by only sampling 12 of 24 established 10-ha plots. Nest densities were noticeably higher this season (75.8 nests/km2) compared to the two previous years (68.3 nests/km2 in 2003, 58.3 nests/km2 in 2004). The proportion of successful nests was comparable to 2004 (75.8 % in 2005 vs. 73% in 2004) and noticeably higher than in 2003 (55%).
We discovered and monitored all nests on (or near) 12 10-hectare study plots every 3-6 days until nesting fate was determined. We discovered 129 nests of 13 species from 10 June to 25 July. Of the 129 nests, 36 were discovered off-plot. Eighty-two nests successfully hatched/fledged and 29 failed. We were unable to reliably assess the fate of 13 nests. Nest predation was the most important cause of nest failure (25 of 29 nest failures, 86%). Other sources of nest failure were abandonment (n = 3) and predation due to observers (n = 1). Mayfield estimates of nesting success for the three most common species were: Semipalmated Sandpiper (n=33): 0.906, Lapland Longspur (n=19): 0.291, and Pectoral Sandpiper (n=17): 0.422.
We conducted three10-minute point count surveys for potential nest predators on each plot at three different times (three replicates) during the course of the season. A total of seven potential predators were detected (n= # of detections): Glaucous Gull (n = 43), Parasitic Jaeger (n = 23), Common Raven (n = 5), Long-tailed Jaeger (n = 5), arctic fox (n = 3), Sabine's gull (n = 1). The most common potential predators were Glaucous Gull and Parasitic Jaegers.
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Rodent dynamics:
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| Lemming numbers were low based on our field observations though we did no trapping. We only observed 3 lemmings during the season. No observations were made during timed surveys. No trend in lemming abundance was apparent during the course of the season.
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Rodent species recorded:
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Summary
of fauna studies: |
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