Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals
Intraspecific variation in resource use by individuals of different age, sex or size may reflect differing energetic requirements and physiological constraints. Males and females often show differences in diet owing to sexual size dimorphism, different life histories and/or habitat use. Here, we inv...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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The Royal Society
2021-02-01
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| Series: | Royal Society Open Science |
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| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.202226 |
| _version_ | 1818617103364653056 |
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| author | Marie Louis Mikkel Skovrind Eva Garde Mads Peter Heide-Jørgensen Paul Szpak Eline D. Lorenzen |
| author_facet | Marie Louis Mikkel Skovrind Eva Garde Mads Peter Heide-Jørgensen Paul Szpak Eline D. Lorenzen |
| author_sort | Marie Louis |
| collection | DOAJ |
| description | Intraspecific variation in resource use by individuals of different age, sex or size may reflect differing energetic requirements and physiological constraints. Males and females often show differences in diet owing to sexual size dimorphism, different life histories and/or habitat use. Here, we investigate how sex and size influence the long-term foraging ecology of belugas and narwhals in Greenland, using stable isotopes of carbon and nitrogen from bone collagen. We show that males have a higher trophic level and a larger ecological niche than females in West Greenland belugas and in East Greenland narwhals. In addition, for these two populations, we find that δ15N increases with size, particularly in males. We hypothesize that sexual size dimorphism together with strong maternal investment drive these differences. By contrast, we find no differences in foraging ecology between sexes in West Greenland narwhals and observe no influence of size on trophic level. This may reflect the influence of interspecific competition in West Greenland, where the distributions of belugas and narwhals overlap, and/or geographical resource partitioning among different summer aggregations of narwhals. Our results suggest that sex and size variations in diet are population dependent, and probably the result of varying ecological interactions. |
| first_indexed | 2024-12-16T17:00:22Z |
| format | Article |
| id | doaj.art-7e301de3316246cd990265cee8b0d795 |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-16T17:00:22Z |
| publishDate | 2021-02-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-7e301de3316246cd990265cee8b0d7952022-12-21T22:23:45ZengThe Royal SocietyRoyal Society Open Science2054-57032021-02-018210.1098/rsos.202226202226Population-specific sex and size variation in long-term foraging ecology of belugas and narwhalsMarie LouisMikkel SkovrindEva GardeMads Peter Heide-JørgensenPaul SzpakEline D. LorenzenIntraspecific variation in resource use by individuals of different age, sex or size may reflect differing energetic requirements and physiological constraints. Males and females often show differences in diet owing to sexual size dimorphism, different life histories and/or habitat use. Here, we investigate how sex and size influence the long-term foraging ecology of belugas and narwhals in Greenland, using stable isotopes of carbon and nitrogen from bone collagen. We show that males have a higher trophic level and a larger ecological niche than females in West Greenland belugas and in East Greenland narwhals. In addition, for these two populations, we find that δ15N increases with size, particularly in males. We hypothesize that sexual size dimorphism together with strong maternal investment drive these differences. By contrast, we find no differences in foraging ecology between sexes in West Greenland narwhals and observe no influence of size on trophic level. This may reflect the influence of interspecific competition in West Greenland, where the distributions of belugas and narwhals overlap, and/or geographical resource partitioning among different summer aggregations of narwhals. Our results suggest that sex and size variations in diet are population dependent, and probably the result of varying ecological interactions.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.202226stable isotopesarctic cetaceanscarbonnitrogen |
| spellingShingle | Marie Louis Mikkel Skovrind Eva Garde Mads Peter Heide-Jørgensen Paul Szpak Eline D. Lorenzen Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals Royal Society Open Science stable isotopes arctic cetaceans carbon nitrogen |
| title | Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals |
| title_full | Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals |
| title_fullStr | Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals |
| title_full_unstemmed | Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals |
| title_short | Population-specific sex and size variation in long-term foraging ecology of belugas and narwhals |
| title_sort | population specific sex and size variation in long term foraging ecology of belugas and narwhals |
| topic | stable isotopes arctic cetaceans carbon nitrogen |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.202226 |
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