| Rodents abundance evaluation: |
high
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Breeding conditions:
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Arctic Foxes were common in the area. Reproduction was observed in more places then ever before. The original litter size was probably high, but the number of cubs seen at dens was relatively low and some cubs and adults were found dead later in the season. This high mortality might be explained by the severe competition for food between the different predators.
Least Weasel was seen frequently on the rocky outcrops in the tundra, among driftwood along the coast, and in the camp itself. This species has not been observed in the area in earlier years. Some Least Weasels were trapped and this revealed that both males and females were present, and that females were reproducing. Fresh tracks of Wolves were found, but animals were not seen. One Muskox was observed near the field camp, which is the first record in this area. A specialist, judging the animal from photographs, estimated its age at 10-11 years. Reindeers were seen later in the season in small numbers.
Pomarine Skuas were extremely abundant with 6.2 nests/km2. This is more than in 1994, also a lemming peak year, when an abundance of 3.4 nests/km2 was recorded. Nearly all nests contained two eggs and they all hatched successfully (except one). Some predation on chicks was observed (by unknown predators, presumably Snowy Owl and Rough-legged Buzzard) but most of the young birds fledged successfully. Skuas were extremely aggressive to other predators (like Snowy Owls, Rough legged Buzzard, White-tailed Eagle, Arctic Fox, Long-tailed Skuas and other Pomarine Skuas).
Long-tailed Skuas bred in very low numbers. Only one nest was found outside the standard 5 km2 monitoring plot. In 2004 two nest were found inside the 5 km2 plot. One nest of Rough-legged Buzzard was found, containing 5 eggs. Just before hatching the nest was deserted and the eggs did not hatch.
Inside a 13.5 km2 monitoring plot, 5 nests of Snowy Owls where found. All nests contained 7 or 8 eggs and they all hatched successfully. Some fledged young birds were found dead. This seems to be a result of a shortage of food.
Brent Geese were breeding in the direct vicinity of these owls. 14 nests were found in three different colonies.
White-fronted Goose and Steller's Eider bred in higher numbers than recorded in previous years.
Brent Geese and Herring Gull (or Taimyr Gull) nests were counted on offshore islands. Except for one larger island, no foxes were present on these islands. Every island was visited at least once, except for one island that was studied in more detail. We recorded fewer nest of Brent Geese than in 2004. Herring Gulls were breeding in slightly higher numbers than in 2004. There was not much predation on Brent Goose and other gull nests.
We monitored the abundance of breeding waders in a plot of 5 km2. Because of their extremely high abundance, Little Stints were surveyed in a subset of the plot of about 1km2. Little Stints seemed to be more abundant than in other years with an average density of 50 nests/km2 (in comparison 39 nest nests/km2 in 2004). However this might also be caused by a more intensive nest search in 2005. Curlew Sandpipers were more abundant than in other years with an average density of 3,2 nests/km2 (1 nests/km2 in 2004). Pacific Golden Plover and Grey Plover bred in the same numbers as in other years. Pectoral Sandpiper and Grey Phalarope seemed to be slightly more abundant. For detailed breeding information see part two of this form.
Mayfield daily nest survival rate over the whole period was 0.988 for Little Stints and Curlew Sandpipers. This equals an estimated nest success of about 78% for an incubation period of 21 days. This is higher than in 2004, a year with very low lemming numbers, but not as high as in other years with high lemming densities (1991 and 1994). This might be a result of the wide variety and high numbers of predators present (Pomarine Skua, Least Weasel, Snowy Owl and Arctic Fox).
We ringed 555 waders, both chicks and adults. Adults where caught on their nests with "luchocks" and during autumn migration using a large clapnet. Chicks where caught in the nests or on tundra. Juveniles were caught during autumn migration using a large clapnet. Most of the ringed waders were Little Stints (442 birds). 368 geese were caught and ringed, both adults and goslings. Incubating birds were caught on nests and moulting birds were caught in groups. In addition, we ringed 4 Steller's Eiders (all adults), 36 Pomarine Skuas (2 adults), 126 Herring Gulls (2 adults), 43 Snowy Owls (all chicks) and 23 passerines. Biometric data were collected for all birds.
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