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SITE NAME
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Churchill, Manitoba, Canada
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| Contact details
(phone/fax//e-mail//address): |
| + 585 256 0842/+ 585 256 0842(fax) // jokli@FRONTIERNET.NET // 410 Linden St, Rochester, NY 14620-2442, USA
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PROJECT DETAILS |
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Project name:
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American Golden-Plover (Pluvialis dominica) Demography and Behaviour
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Start of survey:
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End
of survey: |
Team
size: |
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6.06
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15.07
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1
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WEATHER
CONDITIONS
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Weather conditions: |
In wet places snow cover reduced to 50% probably 10 days or more before 6 June, on which date it almost completely disappeared. On moss-heath tundra 50% level was reached on 1-6 June. In narrow areas between ponds and in places shadowed by trees some snow was still present on 1 July. Ice broke about 10 June on Churchill River.
The years of 1998 and 1999 were both very early and warm, with the mean monthly anomalies of May and June of +4 to +6øC, when compared to the respective mean values of the base period of 1961-2000, using the data from the Global Historical Climatology Network from the National Climatic Data Center. In 2000, the mean temperature anomalies of May were +1øC, and of June -1øC, respectively, which indicates this year was close to the average. For comparison, in the year of 1992, remembered as an exceptionally cold and late, average anomalies of May were -0.5øC, and of June -3øC. Despite average temperatures, commence of shorebird (but not geese) nesting in 2000 appeared to be very late. Most probably it have been delayed not only by low temperatures, but rather by long-lasting snow cover and high water level early in the season, caused by heavy precipitation in February and May (anomalies of +50% and +60%, respectively).
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| Date of 50%
snow-cover: |
1-6 June
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| Date of ice-break on
rivers: |
10 June
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| Date of final loss of
snow: |
1 July
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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 2000 markedly fewer Killdeer (Charadrius vociferus) nested in the Churchill area, and markedly fewer Semipalmated Plovers (Ch. semipalmatus) nested on the dry tundra near the coast than in two earlier years. Several known to me territories of American Golden-Plovers (Pluvialis dominica) and Whimbrel (Numenius phaeopus) stayed unoccupied and nonbreeding Whimbrels were numerous throughout the whole season. This was also the first year when no nest of the Stilt Sandpiper (Calidris himantopus) was found, the species common in some areas in 1960's and steadily declining in the recent decade. Although no formal surveys were made, the numbers of the Lesser Yellowlegs (Tringa flavipes) seemed to be lower, and the numbers of the Common Snipe (Capella gallinago) higher than in 1998 and 1999.
Canada Geese (Branta canadensis) nested throughout the area in similar numbers as previously, and size of the clutches was relatively large, as most of the accidentally found nests contained 4 or 5 eggs. Hatching started only few days later than in earlier years. This might be probably explained by the spells of warm weather early in the season. Gosling mortality was markedly higher than in previous years, and broods with large chicks were much less common.
In the American Golden-Plover, clutch size was very large (3.95, n=21); predation rate was higher (min. 52.3%), but not significantly so, than in previous years (min. 40% in 1999). Hatching was much more synchronised than in previous years, and occurred at exactly same dates as the second wave of hatching in warmer years. There were also some behavioural differences: some pairs were seldom present on their future territories prior to incubation, and no nests from the previous years were re-used.
There was high predation rate on the Yellow Warbler (Dendroica petechia) nests early in the season, (Morgan Wilson, pers. comm) possibly due to lack of concealment (leaves) at that time.
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Rodent dynamics:
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| Small mammal population was very low, both in the vicinity of Churchill (Peter Scott, Churchill Northern Studies Centre), and at Owl and Broad rivers, ab. 50 km away (Jack DuBois, Manitoba Museum of Man and Nature, Winnipeg, Manitoba, pers. comm.). One lemming seen for the period of works.
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Rodent species recorded:
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| Latin | Abundance |
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| Dicrostonyx groenlandicus | rare |
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Summary
of fauna studies: |
| This was the first year of population study on American Golden-Plovers (Pluvialis dominica). Max nesting densities were 4 pairs/sq.km.
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