We would like to announce a new publication: Wade, P. R., R. R. Reeves and S. Mesnick. 2012. Social and Behavioural Factors in Cetacean Responses to Over-exploitation: Are Odontocetes Less ‘Resilient’ than Mysticetes? J. Marine Biology 2012 (doi:10.1155/2012/567276)
The Journal of Marine Biology is Open Access, so the pdf of the article can be found here: http://www.hindawi.com/journals/jmb/2012/567276/ You can also directly request the pdf from me at [email protected]. Abstract: Many severely depleted populations of baleen whales (Mysticeti) have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti). We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete life history. However, an additional factor may be the highly social nature of many odontocetes in which survival and reproductive success may depend on: (a) social cohesion and organization, (b) mutual defence against predators and possible alloparental care, (c) inter-generational transfer of “knowledge”, and (d) leadership by older individuals. We found little evidence of strong recovery in any of the depleted populations examined. Their relatively low potential rates of increase mean that odontocete populations can be over-exploited with take rates of only a few percent per year. Exploitation can have effects beyond the dynamics of individual removals. Four species showed evidence of a decrease in birth rates following exploitation; potential mechanisms include a deficit of adult females, a deficit of adult males, and disruption of mating systems. The evidence for a lack of strong recovery in heavily exploited odontocete populations indicates that management should be more precautionary. Best regards, Paul Wade, Ph.D. National Marine Mammal Laboratory Alaska Fisheries Science Center National Marine Fisheries Service, NOAA Seattle, WA 98115 _______________________________________________ MARMAM mailing list [email protected] https://lists.uvic.ca/mailman/listinfo/marmam
