Habitat selection, elevational shift, and population trend in the Norwegian population of the Eurasian Dotterel (Charadrius morinellus)
Master thesis
Permanent lenke
https://hdl.handle.net/11250/3079946Utgivelsesdato
2023Metadata
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- Master’s theses (MINA) [668]
Sammendrag
Climate change occurs at a faster rate in alpine areas and in northern latitudes compared toother regions. However, we have too little knowledge of the consequences of such changeswithin alpine areas. Studies regarding this subject have to our knowledge been geographicallyrestricted, mainly to central Europe and the western hemisphere. We conducted a study inNorway during the breeding season regarding the Eurasian Dotterel (Charadrius morinellus).We counted territories, registered site variables, and used historical data to address thepopulation trend and to uncover a potential shift in elevation. We found a significant, negativerelationship between the number of territories and the density of sheep. Additionally, differentlevels of bedrock nutrition influenced the number of territories, where areas with intermediatebedrock richness contained the most territories. The mean elevation of a territory was 1429 ma.s.l. (range: 1221-1656 m a.s.l.) We also found that the dotterel had experienced anelevational shift in Norway from 1970 to 2022, equalling an upward shift of 17.4 m a.s.l. foreach decade. If this trend continues, the loss of breeding habitat in our study sites may amountto ca 20% during the next 50 years. However, we found no significant shift in elevation for theperiod 2008-2022 in the same region. The population trend within our study sites was alsostable from 2008 to 2022. Even though we found a stable population trend, a continued shift inthe elevation will likely lead to future population declines. A potential management tool thatwe present here, is to limit the density of grazing sheep in alpine breeding areas. It might alsobe crucial for management to gather more data regarding population trends in alpine birds andthe potential drivers for elevational shifts. Such data could then be used to create mitigatingefforts to reduce the effects of these drivers.