Identification of Humpback Whales by Fluke Photographs

Katona, Steven K.; Baxter, B; Brazier, Oliver; Kraus, Scott D.; Perkins, Judy S.; Whitehead, Hal

doi:10.1007/978-1-4684-2985-5_2

Cited by 177 publications

(142 citation statements)

References 8 publications

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“…Standardized sampling protocols for locating groups of whales, systematically covering groups once located and maximizing the chances of successfully sampling each individual were used in all areas as described by Smith et al (1999). Individual animals were identified from photographs of natural markings on the ventral surface of the flukes (Katona et al, 1979). Because the quality of photographs can influence the ability of observers to identify re-sightings (Stevick, Palsbøll et al, 2001), the rate of re-sighting was calculated using only photographs of whole flukes of quality categories 3+ or better as described by Friday et al (2000).…”

Section: Methodsmentioning

confidence: 99%

Segregation of migration by feeding ground origin in North Atlantic humpback whales (Megaptera novaeangliae)

et al. 2003

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Results from a large-scale, capture-recapture study of humpback whales Megaptera novaeangliae in the North Atlantic show that migration timing is influenced by feeding ground origin. No significant differences were observed in the number of individuals from any feeding area that were re-sighted in the common breeding area in the West Indies. However, there was a relationship between the proportion (logit transformed) of West Indies sightings and longitude (r 2 = 0.97, F 1,3 = 98.27, P = 0.0022) suggesting that individuals feeding farther to the east are less likely to winter in the West Indies. A relationship was also detected between sighting date in the West Indies and feeding area. Mean sighting dates in the West Indies for individuals identified in the Gulf of Maine and eastern Canada were significantly earlier than those for animals identified in Greenland, Iceland and Norway (9.97 days, t 179 = 3.53, P = 0.00054). There was also evidence for sexual segregation in migration; males were seen earlier on the breeding ground than were females (6.63 days, t 105 = 1.98, P = 0.050). This pattern was consistently observed for animals from all feeding areas; a combined model showed a significant effect for both sex (F 1 = 5.942, P = 0.017) and feeding area (F 3 = 4.756, P = 0.0038). The temporal difference in occupancy of the West Indies between individuals from different feeding areas, coupled with sexual differences in migratory patterns, presents the possibility that there are reduced mating opportunities between individuals from different high latitude areas.

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Section: Methodsmentioning

confidence: 99%

Segregation of migration by feeding ground origin in North Atlantic humpback whales (Megaptera novaeangliae)

et al. 2003

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“…1) in the winter breeding and calving seasons (July to September) from 1995 to 2001 (see Garrigue et al 2001). Individual humpback whales were identified from photographs of the unique markings on the ventral surface of their tail flukes (photo-identification, Katona et al 1979), as well as using microsatellite genotypes (see below). For the purposes of the present study, some sighting records reported previously were deleted from the catalogue (e.g.…”

Section: Field Collection and Photographic Identificationmentioning

confidence: 99%

Organismal and 'gametic' capture-recapture using microsatellite genotyping confirm low abundance and reproductive autonomy of humpback whales on the wintering grounds of New Caledonia

Garrigue¹,

Dodémont²,

Steel³

et al. 2004

Mar. Ecol. Prog. Ser.

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The abundance and reproductive autonomy of humpback whales from the New Caledonia (South Pacific) wintering grounds were investigated using capture-recapture models and paternity inference based on nuclear microsatellite genotyping, mitochondrial DNA sequencing, molecular sex identification and photographs of natural markings (photo-identification). The analyses included records of 213 individuals (excluding 16 calves used in paternity inference) identified by genotypes (9 loci), and 210 identified by fluke photographs, collected from 1995 to 2001. By comparing records of 175 individuals identified using both genotypes and photographs, a small number of errors were detected (and corrected) in the photo-identification catalogue and in the field and laboratory notes of the genotypes. Using the weighted mean of the Petersen capture-recapture model, the estimate of abundance based on genotyping (N = 533, CV = 0.15) was larger than the estimate based on photo-identification (N = 327, CV = 0.11). Sex-specific estimates of abundance based on genotypes were similar for males and females although the variance of the female estimate was greater than the male (N f = 248, CV = 0.30; N m = 288, CV = 0.18, respectively). The paternity of 5 calves from 16 sampled cow/calf pairs was inferred from the total sample of 133 non-calf males (one offspring each). The 16 sampled cow/calf pairs and the 5 inferred paternities were used for an alternate 'gametic recapture' estimate of male abundance. This gametic recapture estimate (N m = 379, CV = 0.30) was similar to the sex-specific estimate based on the organismal recapture using a 2-sample model (N m = 382, CV = 0.22). The close agreement of the organismal and gametic recapture estimates support the assumption that this humpback whale wintering ground represents an autonomous population unit that is relatively closed to demographic and reproductive interchange. The current low abundance of the New Caledonian breeding unit highlights the slow recovery of this and some other regional populations in the Southern Hemisphere following intensive 20th century commercial and illegal whaling.

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“…Katona et al 1979). Photo-identification studies of humpback whales in the North Pacific have revealed much about migrations, population structure and abundance (e.g.…”

Section: Introductionmentioning

confidence: 99%

Geographic variation in killer whale attacks on humpback whales in the North Pacific: implications for predation pressure

Steiger¹,

Calambokidis²,

Straley³

et al. 2008

Endang. Species. Res.

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We examined the incidence of rake mark scars from killer whales Orcinus orca on the flukes of humpback whales Megaptera novaeangliae throughout the North Pacific to assess geographic variation in predation pressure. We used 3650 identification photographs from 16 wintering or feeding areas collected during 1990 to 1993 to determine conservative estimates in the percentage of whales with rake mark scarring. Dramatic differences were seen in the incidence of rake marks among regions, with highest rates on wintering grounds off Mexico (26 vs. 14% at others) and feeding areas off California (20 vs. 6% at others), 2 areas between which humpback whales migrate. Although attacks are rarely witnessed, the prevalence of scars demonstrates that a substantial portion of animals are attacked, particularly those that migrate between California and Mexico. Our data also suggest that most attacks occur at or near the wintering grounds in the eastern North Pacific. The prevalence of attacks indicates that killer whale predation has the potential to be a major cause of mortality and a driving force in migratory behavior; however, the location of the attacks is inconsistent with the hypothesis that animals migrate to tropical waters to avoid predation. Our conclusion is that, at least in recent decades, attacks are made primarily on calves at the wintering grounds; this contradicts the hypothesis that killer whales historically preyed heavily on large whales in highlatitude feeding areas in the North Pacific.

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Identification of Humpback Whales by Fluke Photographs

Cited by 177 publications

References 8 publications

Segregation of migration by feeding ground origin in North Atlantic humpback whales (Megaptera novaeangliae)

Segregation of migration by feeding ground origin in North Atlantic humpback whales (Megaptera novaeangliae)

Organismal and 'gametic' capture-recapture using microsatellite genotyping confirm low abundance and reproductive autonomy of humpback whales on the wintering grounds of New Caledonia

Geographic variation in killer whale attacks on humpback whales in the North Pacific: implications for predation pressure

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