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RESPONDENT
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Gilles Gauthier
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SITE NAME
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Bylot Island, Nunavut, Canada
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| Contact details
(phone/fax//e-mail//address): |
| // Gilles.Gauthier@bio.ulaval.ca // Departement de biologie & Centre d'etudes nordiques, Universite de Laval, St. Foy, Quebec City, Quebec, G1K 7P4 Canada
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PROJECT DETAILS |
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Start of survey:
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End
of survey: |
Team
size: |
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29.05
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WEATHER
CONDITIONS
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Weather conditions: |
| The spring of 2000 was characterized by a thick snow-pack: snow depth on 1 June was 45 cm compared to a long-term average of 34 cm. Temperature in spring was cold with an average air temperature of -3.0 øC between 20 May-20 June compared to a long-term average of -0.3 øC. This resulted in a delayed snowmelt even though conditions were exceptionally sunny and dry in June (0 mm of precipitation). In contrast, temperature in late June and July were much warmer than normal and precipitation near average (55 mm in July and 9 mm up to 21 August). These conditions, combined with a good spring run-off, resulted in an excellent growing environment for plants this year.
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| Date of ice-break on
rivers: |
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| Date of final loss of
snow: |
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
average
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Breeding conditions:
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We found signs of fox activity (digging or fresh prey remains) at 18 of 39 known denning sites (46%), compared to 38% in 1999 and 56% in 1998. We confirmed the presence of pups at 7 dens, compared to 3 in 1999 and 9 in 1998. Five dens were occupied by Arctic foxes and two by Red foxes (Vulpes vulpes). Litter size was a minimum of 1 to 5 pups. This suggests that fox breeding activity was high, presumably a consequence of the high lemming abundance. After 3 years of nesting absence, we found 1 Snowy Owl nest in the Camp-2 area and 12 in the Base-camp Valley, a high value. In previous lemming peaks, 7 owl nests were found in the Base-camp Valley.
Greater Snow Goose breeding phenology:
Even though departure of geese from spring staging areas in Quebec occurred at the usual dates, arrival of geese on Bylot Island was delayed for a second year in a row. Virtually no geese were present upon our arrival on 29 May and daily counts of geese on the hills surrounding the Base-camp Valley were low until 10 June (<200 pairs). There was then a large influx of birds with a peak count of 400 pairs on 19 June, which was about 10 days later than usual.
Median egg laying date was 16 June, which is relatively late. For the second consecutive year, reproductive effort of geese was low at the main breeding colony, but relatively good at the Base-camp Valley thanks to the presence of several Snowy Owls around which many geese established their nest. Nest density was nonetheless low as most nests were widely dispersed in the hills rather than in the lowlands in the Base-camp Valley. Clutch size was 3.65, which is near the long-term average. Nesting success was excellent this year with 83% of the nests hatching at least one egg, the second highest value recorded. Activity of predators at goose nests was much reduced due to the abundance of alternative preys (high lemming density) and the abundance of snowy owls with which many geese nested in association. During nesting and brood-rearing, 267 neck-collared birds were sighted, a relatively low number.
Peak hatch was on 13 July, the second latest on record. The gosling:adult ratio among geese captured at banding (1.08:1) was close to the long-term average, and mean brood size (2.78 young, SD = 1.10, n = 180; counts conducted between 2-6 August) was slightly higher. By combining information on brood size and young:adult ratio at banding, we estimate that 78% of the adults captured were accompanied by young. This suggests that brood survival was good in 2000 and that predation rate was relatively low.
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Rodent dynamics:
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| For our small-mammal survey, we captured 39 brown lemming (Lemmus sibiricus) and 5 collared lemmings (Dicrostonyx groenlandicus), for an index of abundance of 4.39 lemmings/100 total trap nights, the highest value recorded since the beginning of the small mammal monitoring in 1994. Five collared lemmings were captured at the Camp-2 site, which yielded a moderate index of abundance (1.03 lemmings/100total trap nights). This suggests that overall lemming abundance in 2000 was very high and that populations were at the peak of their cycle.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus sibiricus | abundant |
| Dicrostonyx groenlandicus | common |
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Summary
of fauna studies: |
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