As we have become increasingly aware of the rapidity of climate change in high elevation and high latitude environments, conservation concern has grown for arctic-alpine species. This thesis capitalises on the rare availability of detailed data from intensive site monitoring and Scotland-wide surveys conducted over five decades and supplements this with new data to investigate the potential factors driving declines of Dotterel (Charadrius morinellus), an enigmatic arctic-alpine specialist bird species in decline. In accordance with expectations of predictions of climate warming, Dotterel shifted uphill in their distribution and contracted their breeding range within Scotland to their historic core. Dotterel were less likely to be retained at survey sites at low elevations, with a narrow elevational range, where nitrogen deposition was high, where vegetation was tall and dominated by graminoids, and where Ravens were present. Data also suggested that snow lie patterns affected Dotterel distribution between sites, with abundance being substantially greater at generally snow rich sites when these were relatively snow-free (possibly due to the physical restrictions to breeding that snow lie imposes). Despite an increased presence of Ravens in the alpine zone, dramatic declines in the abundance of Tipula montana (a previously important prey resource) at many lower elevation sites and shifts to breeding earlier, we detected little substantial change in breeding success between 1987 and 2011. Despite identifying numerous mechanisms through which environmental change may have acted on Dotterel we found little quantitative evidence for climatic changes to have driven Dotterel abundance declines, suggesting factors elsewhere in the species distribution are worthy of investigation as driving changes within Scotland. This thesis contributes valuable knowledge that can be used to help increase the resilience of arctic-alpine species to environmental change and highlights the pressing need for an integrated, international approach to monitoring and research to contextualise regional changes in abundance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:707500 |
| Date | January 2016 |
| Creators | Baxter, Alistair |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231634 |
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