Female reproductive success and calf survival in a North Sea coastal bottlenose dolphin (Tursiops truncatus) population
Robinson, Kevin P., Sim, Texa M.C., Culloch, Ross M., Bean, Thomas S., Aguilar, Isabel Cordoba, Eisfeld, Sonja M., Filan, Miranda, Haskins, Gary N., Williams, Genevieve, and Pierce, Graham J. (2017) Female reproductive success and calf survival in a North Sea coastal bottlenose dolphin (Tursiops truncatus) population. PLoS One, 12 (9).
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Abstract
Between-female variation in reproductive output provides a strong measure of individual fitness and a quantifiable measure of the health of a population which may be highly informative to management. In the present study, we examined reproductive traits in female bottlenose dolphins from the east coast of Scotland using longitudinal sightings data collected over twenty years. From a total of 102 females identified between 1997 and 2016, 74 mothers produced a collective total of 193 calves. Females gave birth from 6 to 13 years of age with a mean age of 8. Calves were produced during all study months, May to October inclusive, but showed a seasonal birth pulse corresponding to the regional peak in summer water temperatures. Approximately 83% (n = 116) of the calves of established fate were successfully raised to year 2-3. Of the known mortalities, similar to 45% were first-born calves. Calf survival rates were also lower in multiparous females who had previously lost calves. A mean interbirth interval (IBI) of 3.80 years (n = 110) and mean fecundity of 0.16 was estimated for the population. Calf loss resulted in shortened IBIs, whilst longer IBIs were observed in females assumed to be approaching reproductive senescence. Maternal age and size, breeding experience, dominance, individual associations, group size and other social factors, were all concluded to influence reproductive success (RS) in this population. Some females are likely more important than others for the future viability of the population. Consequently, a better knowledge of the demographic groups containing those females showing higher reproductive success would be highly desirable for conservation efforts aimed at their protection.
Item ID: | 51122 |
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Item Type: | Article (Research - C1) |
ISSN: | 1932-6203 |
Additional Information: | This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
Date Deposited: | 11 Oct 2017 07:39 |
FoR Codes: | 31 BIOLOGICAL SCIENCES > 3109 Zoology > 310901 Animal behaviour @ 100% |
SEO Codes: | 97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 100% |
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