Barnacle geese Branta leucopsis on Nordenskioldkysten, western Spitsbergen:In thirty years from colonisation to saturation
Goose surveys on Nordenskioldkysten, a 40-km stretch centred at 78 degrees N on the western shoreline of Spitsbergen, were undertaken during 13 seasons in the period 1975-97. The surveys show that peak numbers of adults and goslings during the moult period July-August have flattened out since 1986....
| Main Authors: | , , , |
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| Other Authors: | , |
| Format: | Other Non-Article Part of Journal/Newspaper |
| Language: | English |
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Norsk Polarinstitutt
1998
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| Online Access: | http://hdl.handle.net/11370/715dd124-f7d1-4065-b7b1-c79fc502b393 https://research.rug.nl/en/publications/barnacle-geese-branta-leucopsis-on-nordenskioldkysten-western-spitsbergen(715dd124-f7d1-4065-b7b1-c79fc502b393).html |
| Summary: | Goose surveys on Nordenskioldkysten, a 40-km stretch centred at 78 degrees N on the western shoreline of Spitsbergen, were undertaken during 13 seasons in the period 1975-97. The surveys show that peak numbers of adults and goslings during the moult period July-August have flattened out since 1986. In agreement with predictions on grazing capacity of shoreline vegetation, the density of geese in the various lake systems has now converged to the same value throughout. This suggests that the lakeside tundra limits capacity during the flightless period when the geese are vulnerable to fox predation. The area was colonised for nesting in 1963, but despite the current stability in summer numbers, the nest counts on the three major breeding islets continue to rise. Gosling production from the study area has dropped in absolute terms since at least 1980, and this decline is viewed as evidence for density-dependence on the breeding grounds. Losses on the breeding islands and among very young goslings have risen dramatically and a plea is made for further research to identify the causal mechanisms behind these changes. |
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