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SITE NAME
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Zackenberg, Greenland, Denmark
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| Contact
details (phone/fax//e-mail//address): |
| +45 46301939(dir.)/+45 46301200(switchb.)/+45 46301914(fax) // mel@dmu.dk // National Environmental Research Institute Department of Arctic Environment Frederiksborgvej 399 Postbox 358 DK-4000 Roskilde DENMARK |
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PROJECT DETAILS
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Start of survey:
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End
of survey:
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Team
size:
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31.05 |
31.08 |
3 |
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WEATHER CONDITIONS
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| Season
phenology: |
average |
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Weather conditions: |
The breeding season for waders at Zackenberg Research Station in Northeast Greenland started with close to average conditions, i.e. moderate snow cover and sunny 24-hour days. So, the birds prepared for egg laying in mid-June with the first Sanderling clutch initiated on 10 June as the very earliest found. But from 13 to 21 June poor weather prevailed culminating with a genuine snowstorm on 16 June. The ground was covered with about 10 cm of new snow that took 1-2 days to melt in the lowland, but about a week on the higher slopes, where the cover may have been considerable thicker.
The result was devastating for the waders. Many birds gathered in flocks on the few snow free feeding sites, and a few eggs were found scattered on the ground - many more may have been found by the foxes and skuas. A single Dunlin was found dead, but again the skuas may have "cleared the ground" before we had a chance to find anything. Out of a total of 43 clutches and broods found during the season - the lowest number since the very first year - only one Common Ringed Plover, three Sanderling, one Dunlin and one Ruddy Turnstone clutch had been initiated before or during the snowstorm, and some of these held incomplete clutches of down to one and two eggs. The others were either initiated shortly after the storm or - most - were replacement clutches initiated 6-12 days after the loss of the original clutch. The Ruddy Turnstone clutch initiated around the storm was incubated for about 32 days and held no embryos.
Apparently, most Sanderlings and Dunlins produced replacement clutches, while only about one third of the Ruddy Turnstones apparently did so. To what extent the Red Knots relaid is unknown, but this was the species with most birds seen in flocks during the inclement weather period - i.e. up to 33 in one group. |
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| Date of 50%
snow-cover: |
26.06 |
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| Date of ice-break
on rivers: |
8.06 |
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| Date of final loss
of snow: |
late June |
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BIOTIC CONDITIONS
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| Rodents abundance evaluation: |
average |
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Breeding conditions:
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At least 19 pairs of Long-tailed Skuas and two pairs of Snowy Owls produced eggs, and three fox dens held pups inside the valley. Predation on wader nests found was at least 30%, which is in the upper end of the range found so far. On top of this comes nests predated before found. So, our data do not support the "alternative prey theory", i.e. that waders and other tundra nesting birds escape nest and young depredation in lemming rich years. Foxes seem to search for and eat whatever they find edible, and predation on bird nests is more likely to be primarily a function of "fox effort" per area square, and hence, the variation in nest and young depredation a result of fluctuating fox numbers and reproduction.
In spite of all this, the numbers of juvenile waders recorded during counts in the deltas at the coast every third day during August pointed to a good breeding season in central high Arctic Greenland. Even Ruddy Turnstones appeared in good numbers, so the snowstorm may not have had the same effect in other parts of the region. |
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Rodent dynamics:
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| As expected, numbers of lemmings were building up this year. 10 individuals were seen in by one observer.
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Rodent species recorded:
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| Latin | Abundance |
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| Dicrostonyx groenlandicus | common |
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Summary
of fauna studies: |
| http://biobasis.dmu.dk |
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