Photo-identification Catalogue of Western Gray Whales 1994-2001
Alexander M. Burdin and David W. Weller
Individual identification is a powerful aid to studying wildlife, including whales. The ability to recognize individual whales makes it possible to estimate abundance, survivorship and aspects of reproduction such as age at sexual maturity and birth intervals. Repeated observations of known individuals can also be used to determine between location
movement patterns, site fidelity, health and body condition and, in some cases, whether and how often they have been struck by vessels, entangled in fishing gear and attacked by killer whales. The greatest value of photo-identification methods comes as a result of studies using long time series of data. As data accumulate, estimates of abundance and trends become more accurate and precise and our understanding of other features of population dynamics (e.g. birth rates) improves.