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RESPONDENT
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Joseph Liebezeit
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SITE NAME
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Kuparuk 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:
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Team
size:
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8.06 |
25.07 |
4 |
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WEATHER CONDITIONS
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Weather conditions: |
Upon arrival on 2.06, snow cover in the flat areas was roughly 25-35% (noticeably more than 2002). The second week of June was particularly cold (near or just below 0øC). July was warmer than June with only one major rainstorm on 3 July.
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| Date of 50%
snow-cover: |
20-30.05 |
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| Date of ice-break
on rivers: |
2.06 |
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| Date of final loss
of snow: |
16.06 |
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BIOTIC CONDITIONS
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| Rodents abundance evaluation: |
low |
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Breeding conditions:
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Mean nest initiation dates were later in 2003 than in 2002. For two species, Lapland Bunting and Greater White-fronted Goose, this trend was significant - possibly the result of the later snowmelt during the 2003 season.
We discovered and monitored all nests on 24 10-hectare study plots every 3-6 days until nesting fate was determined. We discovered 223 nests of 17 species from 8 June to 25 July. Nests of Lapland Bunting, Pectoral Sandpiper, Semipalmated Sandpiper, and Greater White-fronted Goose accounted for the majority (75%) of those found. Of the 223 nests, 65 were discovered off-plot. One hundred thirty-one nests successfully hatched, 74 failed, and we were unable to reliably assess the fate of 18 nests. Most nests failed due to predation (67 of 74 nests, 91%). Other causes of nest failure included: human-induced (n=5) and infertile eggs (n=3). Mayfield estimates of nesting success for the three most common species were: Lapland Bunting (n=58): 0.466, Pectoral Sandpiper (n=28): 0.379, and Semipalmated Sandpiper (n=19): 1.0.
We conducted three 10-minute point count surveys for potential nest predators on all plots. We conducted a total of 3 replicates of this survey on all plots during the course of the season. A total of 7 potential predators were detected (number of detections in brackets): Peregrine Falcon (n=1), Common Raven (n=4), Arctic Fox (n=5), Pomarine Skua (n=2), Arctic Skua (n=70), and Long-tailed Skua (n=42), Glaucous Gull (n>100). The most common potential predators were Glaucous Gull, Arctic and Long-tailed Skuas, while Arctic Foxes and Ravens were much less abundant.
Overall nest densities were similar at this site between years (64.6 nests/km2 in 2003, 60.4 nests/ km2 in 2002). However, there were considerable fluctuations in nest density among some of the species between years. A slightly higher percentage of nests were successful in 2003 versus 2002, but these differences (per species) were rarely significantly different in terms of daily survival rate. Predation was the most important cause of nest failure in both years. The same potential nest predators in relatively the same proportions were recorded in both years. |
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Rodent dynamics:
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| All 4 observers over 2 months in the field only observed lemmings a few times. No trend in lemming abundance was apparent during the course of the season. We did not capture lemmings.
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Rodent species recorded:
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Summary
of fauna studies: |
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