scholarly journals Abundance of humpback whales in Oceania using photo-identification and microsatellite genotyping

2012 ◽  
Vol 453 ◽  
pp. 249-261 ◽  
Author(s):  
R Constantine ◽  
JA Jackson ◽  
D Steel ◽  
CS Baker ◽  
L Brooks ◽  
...  
Keyword(s):  
Humpback Whales ◽  
Microsatellite Genotyping ◽  
Photo Identification

A longitudinal study of humpback whales in Irish waters

2015 ◽  
Vol 96 (4) ◽  
pp. 877-883 ◽  
Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
North Atlantic ◽  
Spatial Scales ◽  
Humpback Whales ◽  
Migratory Species ◽  
The Public ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
Eastern North Atlantic

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

Advanced image recognition: a fully automated, high-accuracy photo-identification matching system for humpback whales

2021 ◽  
Author(s):  
Ted Cheeseman ◽  
Ken Southerland ◽  
Jinmo Park ◽  
Marilia Olio ◽  
Kiirsten Flynn ◽  
...  
Keyword(s):  
Image Recognition ◽  
High Accuracy ◽  
Humpback Whales ◽  
Photo Identification

scholarly journals Abundance and survival estimates of the southeastern Pacific humpback whale stock from 1991–2006 photo-identification surveys in Ecuador

2020 ◽  
pp. 301-307 ◽  
Author(s):  
Fernando Félix ◽  
Cristina Castro ◽  
Jeffrey L. Laake
Keyword(s):  
Annual Variation ◽  
Humpback Whales ◽  
Collaborative Effort ◽  
Transient Effect ◽  
Photo Identification ◽  
Migration Timing ◽  
Open Population ◽  
Southeastern Pacific ◽  
Capture Recapture ◽  
Wintering Areas

Southeastern Pacific humpback whales (Breeding Stock G) breed along the northwestern coast of South America and farther north up to CostaRica. Photo-identification surveys conducted aboard whalewatching vessels during the migration/breeding season from June to September between1991 and 2006 off the coast of Ecuador (2°S, 81°W) have produced a database of 1,511 individual whales. Comparisons of photographs produced190 between-year re-sightings of 155 individual whales. Closed and open capture-recapture models were used to estimate abundance and survival.The best estimate of abundance in 2006 with the Chapman modified-Petersen was 6,504 (95% CI: 4,270–9,907; CV = 0.21). Abundance estimatesfrom open population models were considerably lower due to heterogeneity in capture probability which produced a ‘transient’ effect. Our bestestimate of true survival was 0.919 (95% CI: 0.850–0.958). Heterogeneity most likely occurred from inter-annual variation in sampling and unknownstructure and variation in the migration timing and corridor. A more extensive collaborative effort including other wintering areas further north aswell as integrating breeding-feeding data will help to reduce heterogeneity and increase precision in abundance and survival estimates.

Killer whales (Orcinus orca) in Angolan and Gulf of Guinea waters, tropical West Africa

2010 ◽  
Vol 90 (8) ◽  
pp. 1601-1611 ◽  
Author(s):  
Caroline R Weir ◽  
Tim Collins ◽  
Inês Carvalho ◽  
Howard C. Rosenbaum
Keyword(s):  
Group Size ◽  
Orcinus Orca ◽  
Humpback Whales ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Killer Whales ◽  
External Appearance ◽  
Tropical Waters ◽  
Photo Identification ◽  
Mola Mola

Killer whales Orcinus orca are considered to be relatively uncommon in tropical waters. Few sightings have been reported from the west coast of Africa due to a paucity of survey coverage. We present data on 32 killer sightings from tropical waters off Angola (N = 18), Gabon (N = 7), São Tomé (N = 6) and Cameroon (N = 1), comprising a combination of dedicated survey sightings (N = 21) and reliable anecdotal records (n = 11). Killer whales were reported from coastal waters, the shelf edge and deep, oceanic areas. Sightings indicate a probable year-round occurrence of killer whales within the region. Mean group size was 5.6 animals. There was no difference in group size between sightings in waters >200 m deep and those on the continental shelf. No photo-identification matches were found between Angola, Gabon and São Tomé. Re-sightings of two individuals occurred annually in São Tomé during 2002–2004. Killer whales had external appearance consistent with the Type A nominate species form. Antagonistic encounters were recorded between killer whales and humpback whales Megaptera novaeangliae off Angola, Gabon and Cameroon, and with sperm whales Physeter macrocephalus off Angola. Predation on ocean sunfish Mola mola was recorded in São Tomé, and possible predation on sharks was recorded twice in Gabon.

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.

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

scholarly journals Long term trends in abundance of humpback whales in Hervey Bay, Australia

2020 ◽  
pp. 237-241
Author(s):  
Paul H. Forestell ◽  
Gregory D. Kaufman ◽  
Milani Chaloupka
Keyword(s):  
Intrinsic Rate ◽  
Seasonal Abundance ◽  
Humpback Whales ◽  
Population Increase ◽  
Type Model ◽  
Photo Identification ◽  
Abundance Estimates ◽  
Antarctic Waters ◽  
Long Term Trends

Seasonal abundance estimates of humpback whales resident during the austral winter in Hervey Bay, Queensland, Australia between 1987 and 2007were obtained from a capture-mark-recapture study using photo-identification images of 3,155 individual whales. Hervey Bay is a major southboundstopover site for Breeding Stock E humpback whales returning to Antarctic waters from over-wintering in the vicinity of the Great Barrier Reef.Annual survival, recapture and abundance estimates were derived using a Cormack-Jolly-Seber modelling approach and a Horwitz-Thompson typeabundance estimator. The best-fit model was a 2-ageclass Brownie-Robson type model that estimated apparent annual survival for the non-transientwinter stopover ageclass at approximately 0.945 (95% confidence interval: 0.929–0.957). Apparent annual abundance of winter stopover humpbackwhales in Hervey Bay was estimated to have increased significantly over the past 21 years at ca. 13.4% per annum (95% CI 11.6–15.2). The mostrecent Hervey Bay winter stopover population (2007) was estimated to comprise ca. 6,246 post-yearlings (95% CI 5,011–7,482). This estimatedrate of population increase is similar to estimates for other surveys along the east Australian coast but significantly higher than the intrinsic rate ofincrease (rmax) estimated recently for several recovering Southern Hemisphere humpback whale stocks based on the feeding ground sampling.

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.

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