Visual health assessment of North Atlantic right whales (Eubalaena glacialis) using photographs. Canadian Journal of Zoology 82:8–19
Abstract: Although trends in reproduction, mortality, and entanglement events have been analyzed for the endangered North Atlantic right whale (Eubalaena glacialis) population, no method has been available to assess individual right whale health. Here, we describe a technique for assessing health ba...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2004
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.532.1842 http://www.nmfs.noaa.gov/pr/interactions/injury/pdfs/day1_945_cole_pettis.pdf |
| Summary: | Abstract: Although trends in reproduction, mortality, and entanglement events have been analyzed for the endangered North Atlantic right whale (Eubalaena glacialis) population, no method has been available to assess individual right whale health. Here, we describe a technique for assessing health based on evaluation of selected physical parameters from archived photographs of right whales. A scoring system was developed to assess body and skin condition, blow-hole cyamids, and rake marks in over 200 000 photographs. Comparison of body condition scores of females during calving and noncalving years found that females were significantly thinner in calving years and in the year after calv-ing compared with the year before calving, showing that changes in body condition known to occur during the repro-ductive cycle can be successfully evaluated from photographs. Comparison of scores for all parameters between living whales and whales with more than a 5-year gap in sighting history (“presumed dead”) found that presumed dead whales received health assessment scores indicating compromised health with body condition emerging as a key visual indicator. This health assessment method provides a new tool to monitor health trends in right whales at individual and population levels and may provide a model for assessments of other well-photographed cetaceans. Résumé: Alors qu’il a été possible d’analyser les tendances de la reproduction, de la mortalité et des incidents d’enchevêtrement chez la population menacée de la baleine franche de l’Atlantique Nord (Eubalaena glacialis), il n’y a pas de méthode disponible pour évaluer la santé des baleines individuelles. On trouvera ici une technique pour juger de |
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