scholarly journals Photo-identification of individual Southern Hemisphere humpback whales (Megaptera novaeangliae) using all available natural marks:

2020 ◽  
Vol 21 (1) ◽  
pp. 71-83
Author(s):  
Wally Franklin ◽  
Trish Franklin ◽  
Peter Harrison ◽  
Lyndon Brooks
Keyword(s):  
Poor Quality ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Parameter Estimates ◽  
Photo Identification ◽  
Dorsal Fin ◽  
Matching Process ◽  
Lateral Body ◽  
Logistic Mixed Effects Model ◽  
Natural Marks

Misidentification errors in capture-mark recapture studies of humpback whales (Megaptera novaeangliae) related to poor quality of photographs as well as changes in natural marks can seriously affect population dynamics parameter estimates and derived estimates of population size when using sophisticated modelling techniques. In this study we used an innovative photo-identification matching system to investigate and examine the long-term stability and/or changes in natural marks on ventral-tail flukes, dorsal fin shapes and lateral body marks from a sample of 79 individual humpback whales, resighted in 2 to 11 years over timespans ranging from 2 to 21 years. A binary logistic mixed effects model, on a pair-matched sample of the 79 individual whales, found no significant differences in the proportions of ventral-tail fluke marks, dorsal fin shapes and lateral body marks, that displayed changes in primary and/or secondary characteristics over years (F=0.939, df=1/156, p =0.334). The results of this study substantiate the value and reliability of using primary and secondary natural marks on the ventral-tail flukes, in conjunction with dorsal fin shapes and secondary lateral body marks as double-tags. This provides a means of maximising observations of individual humpback whales over years, while minimising and managing misidentification errors in the photo-identification matching process, thus significantly improving modelling outcomes.

Possible Sexing Technique for Humpback Whales (Megaptera novaeangliae)

1980 ◽  
Vol 37 (12) ◽  
pp. 2362-2364 ◽  
Author(s):  
V. P. Jurasz ◽  
D. McSweeney ◽  
C. M. Jurasz
Keyword(s):  
Morphological Feature ◽  
Megaptera Novaeangliae ◽  
Pregnant Female ◽  
Humpback Whales ◽  
Reasonable Accuracy ◽  
Southeast Alaska ◽  
Dorsal Fin ◽  
Breeding Grounds

By comparing photographs of humpback whales (Megaptera novaeangliae) photographed at the peak of their arch during a dive, we found some to be smooth and others to be scalloped middorsally caudal to the dorsal fin. Out of 410 photographs taken in southeast Alaska and Hawaii, 66% were found to be smooth and 34% scalloped. All females with calves were smooth. One pregnant female was smooth and only one female who was pregnant was slightly scalloped. One known male was scalloped and one "singer" on the Hawaiian breeding grounds was scalloped. We suggest that the smoothness or scalloping of this region is a morphological feature and can be used with reasonable accuracy to determine sex in humpback whales.Key words: humpback whales, morphology, sex

Dorsal fin scars as indicators of age, sex, and social status in humpback whales (Megaptera novaeangliae)

1988 ◽  
Vol 66 (2) ◽  
pp. 416-420 ◽  
Author(s):  
Kevin Chu ◽  
Sharon Nieukirk
Keyword(s):  
Social Status ◽  
Breeding Season ◽  
Intrasexual Competition ◽  
Megaptera Novaeangliae ◽  
Physical Contact ◽  
Humpback Whales ◽  
Dorsal Fin ◽  
Large Groups

We compared the number of linear marks and the shapes of dorsal fins of different classes of humpback whales during the breeding season. Male humpbacks tend to have more marks than females. Such marks are probably scars resulting from physical contact during intrasexual competition for mates. Not all males have marks; therefore, an unmarked adult humpback could be a male or a female. An adult with many marks is likely a male, however. Differences in the dorsal fins of principal and secondary escorts in large groups of competing males suggest that not all escorts have the same chance of attaining principal escort status. Therefore, male – male competitions in large groups should not necessarily be viewed as contests between equals. Principal escorts showed significantly more of some types of marks than did lone escorts of cows with calves, suggesting that not all lone escorts may retain their position if challenged.

Photo-identification matches of humpback whales (Megaptera novaeangliae ) from feeding areas in Russian Far East seas and breeding grounds in the North Pacific

2017 ◽  
Vol 34 (1) ◽  
pp. 100-112 ◽  
Author(s):  
Olga V. Titova ◽  
Olga A. Filatova ◽  
Ivan D. Fedutin ◽  
Ekaterina N. Ovsyanikova ◽  
Haruna Okabe ◽  
...  
Keyword(s):  
North Pacific ◽  
Russian Far East ◽  
Far East ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
The North Pacific

Site fidelity and movement of humpback whales (Megaptera novaeangliae) in the western Gulf of Alaska as revealed by photo-identification

2017 ◽  
Vol 95 (3) ◽  
pp. 169-175 ◽  
Author(s):  
Briana H. Witteveen ◽  
Kate M. Wynne
Keyword(s):  
Site Fidelity ◽  
Sampling Strategy ◽  
Gulf Of Alaska ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Feeding Site ◽  
Temporal Differences ◽  
Limited Movement ◽  
Photo Identification ◽  
Kodiak Archipelago

We describe feeding-site fidelity in terms of the rate of annual return by individual humpback whales (Megaptera novaeangliae (Borowski, 1781)) to Kodiak Archipelago and Shumagin Islands feeding areas and the rate of exchange between these Gulf of Alaska feeding aggregations. Individual whales were photo-identified in both regions between 1999 and 2015 during vessel surveys, either throughout the feeding season (Kodiak region) or in brief 7- to 10-day windows (Shumagin Islands). Feeding-site fidelity was assessed in terms of individuals’ annual return rate, sighting interval, total number of years sighted, and movement between feeding areas. We found similarly high degrees of site fidelity in both regions and limited movement of individuals between them, suggesting that the Shumagin Islands and Kodiak Archipelago represent distinct feeding aggregations. Results did not appear affected by temporal differences in sampling strategy in these study areas.

PHOTO-IDENTIFICATION OF HUMPBACK WHALES (MEGAPTERA NOVAEANGLIAE) IN NEW ZEALAND WATERS AND THEIR MIGRATORY CONNECTIONS TO BREEDING GROUNDS OF OCEANIA

2007 ◽  
Vol 23 (3) ◽  
pp. 715-720 ◽  
Author(s):  
Rochelle Constantine ◽  
Kirsty Russell ◽  
Nadine Gibbs ◽  
Simon Childerhouse ◽  
C. Scott Baker
Keyword(s):  
New Zealand ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Photo Identification ◽  
Breeding Grounds

Humpback whales, Megaptera novaeangliae (Cetaceaa : Balaenopteridae), in Hervey Bay, Queensland .

1994 ◽  
Vol 21 (3) ◽  
pp. 293 ◽  
Author(s):  
PJ Corkeron ◽  
M Brown ◽  
RW Slade ◽  
MM Bryden
Keyword(s):  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Eastern Coast ◽  
Western Coast ◽  
Photo Identification ◽  
Breeding Grounds ◽  
Pass Through ◽  
The Antarctic ◽  
The Impact ◽  
Final Cohort

Humpback whales, Megaptera novaeangliae, of the Antarctic Area V stock, pass through Hervey Bay, Queensland, during their southward migration. As part of an investigation of the impact of commercial whalewatching in the bay, aerial surveys were conducted during the 1988-90 whalewatching seasons, and a photo-identification project was run over the 1988 season. In 1988,60 pods containing 127 whales were observed. All pods were sighted on the transects in the eastern section of Hervey Bay, so surveys in 1989 and 1990 were confined to this area. In 1989, 223 whales in 121 pods were counted, and in 1990, 105 whales in 60 pods were observed. There was annual variation in the temporal pattern of the migration through Hervey Bay. Pods tended to occur in shallow water close to the western coast of Fraser Island and, on days when several whales were observed in the bay, pods were not distributed in a regular fashion. Mother-calf pods were the final cohort to migrate through the Bay. The recorded sizes of whale pods varied between observation platforms and averaged 1.75-2.81. In all, 100 whales were identified from photographs of natural marks. Most were photographed once only, although individual whales were sighted up to seven times. Of the 34 whales identified on more than one occasion, 24 were observed over a one- or two-day period. Pod sizes and residence times of whales in Hervey Bay resemble those of whales recorded at tropical breeding grounds. However, there are no data suggesting that Hervey Bay is of particular importance to any class of the humpback whale population migrating off the eastern coast of Australia.

The Impact of Missing and Error-Prone Auxiliary Information on Sparse-Matrix Sub-Population Parameter Estimates

Methodology ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 89-99 ◽  
Author(s):  
Leslie Rutkowski ◽  
Yan Zhou
Keyword(s):  
Sparse Matrix ◽  
Small Body ◽  
Auxiliary Information ◽  
Poor Quality ◽  
Quality Data ◽  
Estimation Methods ◽  
Parameter Estimates ◽  
Population Parameter ◽  
Conditioning Model ◽  
The Impact

Abstract. Given a consistent interest in comparing achievement across sub-populations in international assessments such as TIMSS, PIRLS, and PISA, it is critical that sub-population achievement is estimated reliably and with sufficient precision. As such, we systematically examine the limitations to current estimation methods used by these programs. Using a simulation study along with empirical results from the 2007 cycle of TIMSS, we show that a combination of missing and misclassified data in the conditioning model induces biases in sub-population achievement estimates, the magnitude and degree to which can be readily explained by data quality. Importantly, estimated biases in sub-population achievement are limited to the conditioning variable with poor-quality data while other sub-population achievement estimates are unaffected. Findings are generally in line with theory on missing and error-prone covariates. The current research adds to a small body of literature that has noted some of the limitations to sub-population estimation.

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