Larger body size leads to greater female beluga whale ovarian reproductive activity at the southern periphery of their range
Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic i...
| Main Authors: | , , , , , |
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| Format: | Dataset |
| Language: | unknown |
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2022
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| Subjects: | |
| Online Access: | https://zenodo.org/record/7315901 https://doi.org/10.5061/dryad.hmgqnk9j3 |
| Summary: | Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species' geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to ovarian reproductive activity (ORA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Our study aim was to assess the relative influence of age and body size of female beluga whale on ovarian reproductive activity in the two populations. Female beluga whale ORA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whales accounted for considerably more of the total variation (12 vs 1%) in ORA compared to BB whales. We speculate that female HB beluga whale ORA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how ORA varies across a species' range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet. Excel file: Whale ID, Group (northern or southern), Population (High Arctic, Cumberland Sound, Hudson Bay), Year, Age, Body length, Total corpora Funding provided by: Fisheries and Oceans CanadaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000041Award Number: The dataset included 172 female reproductive tracts with at least one corpus: 41 from BB and 131 from HB. To create a complete dataset required for robust statistical testing (Moritz & Bartz-Beielstein 2017), missing length and age ... |
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