[MARMAM] new publication on Cuvier's beaked whale natural marking

massimiliano rosso massimiliano.rosso at cimafoundation.org
Mon Jul 4 01:24:40 PDT 2011


Please post to MARMAM


Dear MARMAM colleagues,

The following paper has been published in African Journal of Marine Science:
Rosso, M., Ballardini, M., Moulins, A., Wurtz, M., Natural markings of Cuvier's beaked whale Ziphius cavirostris in the Mediterranean Sea. African Journal of Marine Science, 33(1), 45-57.
DOI: 10.2989/1814232X.2011.572336

ABSTRACT:
Errors in analysis using natural marks have been recognised since the early development of mark-recapture techniques. In this nine-year study, the mark types present on Cuvier’s beaked whales Ziphius cavirostris in the Mediterranean Sea were categorised in order to assess the reliability of natural marks for long-term photo-identification studies. Mark prevalence, abundance and gain/loss rates among age/sex classes were investigated. Results showed that Cuvier’s beaked whales were extensively marked (96% of population; mean = 48 marks per individual, range 0–169), with up to 10 different mark types. However, only five mark types should be considered reliable: notch, large scar, back indentation, medium scrape and large stripe. Marks caused by intraspecific interaction were the most abundant and prevalent mark types. In high-quality photographs, 71% of the population was reliably marked, but reliable marks were unevenly distributed within the population and their prevalence appeared to be strongly correlated to age and sex of individuals. The gain rate of scrapes that could be used reliably for identification was six times higher in mature males than females of the same age. This was the case for mature as well as immature males, suggesting that aggressive interaction among males may start early in their life, before reaching maturity. This difference between sexes may cause an over-representation of males in a typical photo-identification database, especially among immature individuals.

PDF copy can be downloaded from the journal website: http://www.tandfonline.com/doi/abs/10.2989/1814232X.2011.572336
or you can request a copy by emailing: massimiliano.rosso at cimafoundation.org

Best Regards,

Massimiliano

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Massimiliano Rosso, PhD

Postdoctoral Research Fellow
CIMA Research Foundation
Savona Campus
via Magliotto 2 - 17100 Savona
Italy
+39 019 230 271






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