Photo-identification of sperm whales in the north-western Mediterranean Sea: an assessment of natural markings

Photo-identification is an important, non-invasive tool that can be used to obtain data about cetacean population dynamics that are essential for proper environmental management. A standardized protocol is crucial for obtaining optimal results, particularly for long-lived and highly migratory species such as sperm whales (Physeter macrocephalus) but also to study resident populations. Photo-identification of individuals using natural marks has been widely used to study sperm whales in the Mediterranean Sea. However, the prevalence of the marks used for identification is unknown. Thus, the goal of this study was to identify which mark types are most useful for identifying individual sperm whales. A photo-identification catalogue of sperm whales from the north-western Mediterranean Sea was produced and examined to determine the most frequent mark types present on whales in the study area. Mark types and their distribution were described, prevalence and the size of each mark type were calculated, variability in visibility was investigated, and gain and loss rates were analysed. Analysis of natural pigmentation may characterize sperm whale flanks in this study area as the best and most convenient element on which matching technique can be based. Indeed, this technique led to the identification of 97% of photographed individuals. Copyright © 2014 John Wiley & Sons, Ltd.

[1]  H. Whitehead,et al.  Regional and group-level differences in fluke markings and notches of sperm whales , 1998 .

[2]  H. Whitehead,et al.  Heterogeneous social associations within a sperm whale, Physeter macrocephalus, unit reflect pairwise relatedness , 2008, Behavioral Ecology and Sociobiology.

[3]  Georgina M. Mace,et al.  Assessing Extinction Threats: Toward a Reevaluation of IUCN Threatened Species Categories , 1991 .

[4]  Hal Whitehead,et al.  AN ASSESSMENT OF CHANGES WITH TIME IN THE MARKING PATTERNS USED FOR PHOTOIDENTIFICATION OF INDIVIDUAL SPERM WHALES, PHYSETER MACROCEPHALUS , 1995 .

[5]  H. Whitehead,et al.  Past and Distant Whaling and the Rapid Decline of Sperm Whales off the Galápagos Islands , 1997 .

[6]  H. Whitehead,et al.  Social structure and mating system of sperm whales off northern Chile , 2004 .

[7]  N. Jaquet,et al.  Distribution and relative abundance of sperm whales in relation to key environmental features, squid landings and the distribution of other cetacean species in the Gulf of California, Mexico , 2002 .

[8]  H. Whitehead,et al.  Behavioural evidence for social units in long-finned pilot whales , 2003 .

[9]  H. Whitehead,et al.  Nicks and notches of the dorsal ridge: Promising mark types for the photo-identification of narwhals , 2009 .

[10]  Scott K. Anderson,et al.  TEMPORAL VARIABILITY IN FEATURES USED TO PHOTO‐IDENTIFY HUMPBACK WHALES (MEGAPTERA NOVAEANGLIAE) , 2000 .

[11]  R. Huele,et al.  PHOTO-IDENTIFICATION OF SPERM WHALES AT BLEIK CANYON, NORWAY , 2001 .

[12]  N. Jaquet,et al.  Sperm whales in the Gulf of California: Residency, movements, behavior, and the possible influence of variation in food supply , 2003 .

[13]  H. Lotze,et al.  Loss of Large Predatory Sharks from the Mediterranean Sea , 2008, Conservation biology : the journal of the Society for Conservation Biology.

[14]  E. Slooten,et al.  Abundance and seasonal residence of sperm whales at Kaikoura, New Zealand , 1995 .

[15]  A. Gannier,et al.  Movements of sperm whale in the western Mediterranean Sea: preliminary photo-identification results , 2007, Journal of the Marine Biological Association of the United Kingdom.

[16]  R. Reeves,et al.  The status and distribution of cetaceans in the Black Sea and Mediterranean Sea , 2006 .

[17]  H. Whitehead,et al.  Sperm whale social units : variation and change , 1998 .

[18]  K. Schneider,et al.  Epidermal diseases in bottlenose dolphins: impacts of natural and anthropogenic factors , 1999, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[19]  S. Airoldi,et al.  Inter-basin movements of Mediterranean sperm whales provide insight into their population structure and conservation , 2011 .

[20]  H. Whitehead,et al.  Observations on the composition and behaviour of groups of female sperm whales near the Galapagos Islands , 1989 .

[21]  H. Whitehead,et al.  PHOTOGRAPHIC IDENTIFICATION OF NORTHERN BOTTLENOSE WHALES (HYPEROODON AMPULLATUS): SOURCES OF HETEROGENEITY FROM NATURAL MARKS , 2001 .

[22]  H. Whitehead,et al.  THE USE OF NATURAL MARKINGS IN STUDIES OF LONG‐FINNED PILOT WHALES (GLOBICEPHALA MELAS) , 2007 .

[23]  Luke Rendell,et al.  Who Cares? Between-group variation in alloparental caregiving in sperm whales , 2009 .

[24]  M. Rosso,et al.  Natural markings of Cuvier's beaked whale Ziphius cavirostris in the Mediterranean Sea , 2011 .

[25]  H. Whitehead.  DIRECT ESTIMATION OF WITHIN-GROUP HETEROGENEITY IN PHOTO-IDENTIFICATION OF SPERM WHALES , 2001 .

[26]  H. Whitehead,et al.  Photo-Identification: A Reliable and Noninvasive Tool for Studying Pink River Dolphins (Inia geoffrensis) , 2011 .

[27]  E. Slooten,et al.  Social structure and residency in aggregations of male sperm whales , 2002 .

[28]  Brian D. Smith,et al.  Dolphins, whales and porpoises : 2002-2010 conservation action plan for the world's cetaceans , 2003 .