Bergmann’s and Allen’s rule suggest that for the same species individuals found further north, tend to have larger body sizes and smaller appendages compared to individuals further south, respectively, due to constraints for thermal regulation. This has shown especially true for birds and mammals. In this paper, I test to see if global warming has led to a change in morphology for birds, i.e. body weight and wing size. We use year as a proxy for temperature as global warming has on average lead to an increase in the earth’s surface temperature over the last century with most of the change occurring since the 1980’s. To test the hypothesis, I gathered data of male, young of the year birds during autumn migration for a select number of species with different wintering strategies, i.e. resident to long-distance migration. This data came from two Swedish bird observatories where standardized wing and weight measurements have been collected since 1986, coincident with the observed climate warming. The results of this study show that during this period, changes in body mass and wing length did not support the hypothesis that global warming has had a broad impact on the morphology of birds. Given that these results contradict that of other studies, analysis from species across a much wider latitudinal breadth of Europe, including, additional species and different age and sex classes should be investigated.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:umu-174122 |
| Date | January 2020 |
| Creators | Al-Hayali, Abdullah |
| Publisher | Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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