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RESPONDENT
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Joseph Liebezeit
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SITE NAME
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Teshekpuk Lake - Olak, Alaska, 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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Breeding bird diversity, density, nesting success and nest predators in the Olak region of the Teshekpuk Lake Special Area
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Start of survey:
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End
of survey: |
Team
size: |
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3.06
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16.07
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4
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WEATHER
CONDITIONS
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Weather conditions: |
| There was less than 50% snow cover on our arrival on 3 June. There was approximately 30% snow cover on 6 June and it completely melted on 14 June. The stream next to our camp broke up on approximately 5 June. With respect to 2005, snow melt occurred earlier in 2006. On 6 June, snow cover was nearly twice as much (~55%) in 2005 compared to 2006. Likewise, snow melt was complete approximately two days later in 2005 (16 June) compared to 2006. June was warmer than in 2005 (with mean daily temperatures >+5øC), but early July was cooler. There were no major snow storms during the field season. We did have more rainfall this season particularly in July. The first mosquitoes emerged on 20 June, about 10 days earlier than in 2005.
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| Date of ice-break on
rivers: |
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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: |
high
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Breeding conditions:
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| Nesting success was very high at this site with most species having Mayfield nesting success estimates greater than 50%. Pomarine Jaeger abundances were also much higher than in 2005 and at least 5 active Pomarine Jaeger nests were seen on or near study plots this year.
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Rodent dynamics:
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| 2006 was a year of high lemming abundance. We detected lemmings 159 times during incidental predator counts on our study plots (only 7 detections last year). We did not capture lemmings. We believe we saw both Brown and Collared lemmings although we did not try to identify them to species.
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Rodent species recorded:
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Summary
of fauna studies: |
We discovered and monitored all nests on (or near) 16 10-ha study plots every 2-6 days until nest fate was determined. We discovered 246 nests of twenty species from 7 June to 15 July. Of the 246 nests, 33 were discovered off plot. One-hundred sixty-two nests successfully hatched/fledged and 70 failed. We were unable to reliably assess the fate of 14 nests. Nest predation was the most common cause of nest failure (63 of 70 nest failures; 90%). Other sources of nest failure were abandonment (n = 3), predation due to observers (n = 2), and trampling (n = 2). Trampling was most likely due to caribou. Mayfield estimates of nesting success for the 4 most common species were: Lapland Longspur (n=64): 0.756, Pectoral Sandpiper (n=32): 0.797, Red Phalarope (n=24): 0.941, and Semipalmated Sandpiper (n=15): 0.722.
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 eleven species of potential nest predators were detected (n= # of detections): Pomarine Jaeger (n = 66), Parasitic Jaeger (n = 47), Sabine's gull (n = 32), Long-tailed Jaeger (n = 30), Glaucous Gull (n = 25), lemming sp. (n = 5), Arctic Tern (n = 4), Short-eared Owl (n = 3), Jaeger sp. (n = 2 ), Snowy Owl (n = 1), Golden Eagle (n = 1), Arctic Fox (n = 1).
We also conducted incidental surveys for lemmings (i.e. tallied lemmings the entire time we were on our study plots on predator count days). We detected 159 lemmings (brown and collared) this year compared to 7 seen in 2005.
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