This errata version corrects a species identification error in the original (removed by the authors and journal) publication, which incorrectly identified a group of false killer whales (Pseudorca crassidens) as melonheaded whales (Peponocephala electra). This is not the first time that a “blackfish” misidentification has occurred in print (Baird, 2010). For example, Watkins et al. (1997) reported on observations and acoustics of putative melon-headed whales, but reported sighting details (small group size and many individuals with “scratches and scars”) that are more typical of pygmy killer whales (Feresa attenuata). An examination of photos provided by the authors of that paper revealed that they were in fact pygmy killer whales. These misidentifications illustrate the value in having species experts confirm species identity from photographs of these species, particularly when documented in new areas or when researchers have limited prior experience with these species. All three overlap in their range(s) in tropical waters and are grossly similar in appearance (along with short-finned pilot whales [Globicephala macrorhynchus]), although can be discriminated based on a number of features, including body proportions (e.g., relative size of the dorsal fin in relation to overall body length), dorsal fin shape, flipper shape, and head shape (Jefferson et al., 2015). Some guidance for identifying these four species from lateral above-water photographs can be found in Yahn et al. (2019), as well as in the aerial-drone photographs presented in the images on the following page (Figure 1). Distinguishing species from aerial still images is not necessarily straightforward, however, as distortion created by the water can change the shape (e.g., making flippers with rounded tips appear pointed, or vice versa, or making a rounded head appear pointed). Body proportions, in particular the relative length of the back from the anterior insertion of the dorsal fin to the blowhole in comparison to the length of the dorsal fin base, can be used to discriminate false killer whales and short-finned pilot whales from each other and from the other two species (Figure 1), although it is important to note that body proportions can vary with age and sex (Yahn et al., 2023).
Citation:
Baird, R.W., and T.A. Jefferson. 2024. Errata Note: Common Cetacean Species Misidentifications. Aquatic Mammals 50(3): 179-180. doi: 10.1578/AM.50.3.2024.179
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Errata Note: Common Cetacean Species Misidentifications