Amaral, A. R.,Collins, T.,Minton, G.,Baldwin, R.,Willson, A.,Kershaw, Francine,Gray, H.,Findlay, K.,Brownell Jr, R.L.,Rosenbaum, H. C.
Update on Genetic Analyses of Arabian Sea Humpback Whales Technical Report
no. 9, 2016.
Abstract | BibTeX | Tags: Arabian Sea, breeding grounds, feeding grounds, genetics, Gulf of Masirah, Humpback Whale, megaptera novaeangliae, Microsatellite, sexing
@techreport{,
title = {Update on Genetic Analyses of Arabian Sea Humpback Whales},
author = {Amaral, A. R.,Collins, T.,Minton, G.,Baldwin, R.,Willson, A.,Kershaw, Francine,Gray, H.,Findlay, K.,Brownell Jr, R.L.,Rosenbaum, H. C.},
year = {2016},
date = {2016-01-01},
journal = {Working Paper presented to the Scientific Committee of the International Whaling Commission},
number = {9},
pages = {6},
publisher = {IWC},
abstract = {From the 49 new samples, 44 were successfully genotyped at 10 microsatellite loci. We identified 27 males and 17 females. Within this dataset, 7 duplicate samples were found. Five samples representing 3 individuals in the 2015 dataset registered as genotypic matches with animals sampled in the 2004 dataset. An additional 9 samples involving 6 individuals that represent potential matches between the 2015 and 2004 dataset are being reviewed to determine if they represent inter-year recaptures. As the data were generated very recently, further checks to clarify issues with some microsatellite loci will be completed. Six samples failed to amplify consistently for sexing markers and need to be revisited.
Analysis of the combined genotypic dataset will be completed by the end of June/early July 2016. The genotypic matches and sexing data will be incorporated into the Oman Photo-ID database, and used to generate robust updated photo-ID and genotypic mark-recapture estimates of population abundance. These data have also been used to determine or confirm the sex of the 9 satellite tagged whales off the coast of Oman (see SH28), and a significant number of other whales identified photographically off the coast of Oman. This will prove highly valuable if future satellite tagging efforts are undertaken in Oman, as previous tagging work has been significantly male-biased (See SH28), and future tagging should target known females.
Preliminary assessment of the new sexing data (although not yet fully complete) is providing valuable insight into possible difference in habitat use between the two primary study sites off the coast of Oman (see Figure 1). Minton et al. (2011) documented a heavy bias toward males in Dhofar and a ratio near parity in the Gulf of Masirah. These results were based on the total number of photographic captures of known sex individuals. The combination of new and old sexing information allows for a more nuanced examination of this phenomenon: the male-female ratio based on individual whales for which sex was determined in each study site (regardless of how frequently they were observed) is 2:1 in Dhofar (n=30), whilst in the Gulf of Masirah this ratio is slightly biased toward females, with 45% of individuals of known sex observed in that study area being male, and 55% female (n=49). More detailed analysis of these sexing data in relation to survey effort and photographic identification data will yield further important insights into habitat use, behaviour, and social interactions, critical for the conservation of this population.},
keywords = {Arabian Sea, breeding grounds, feeding grounds, genetics, Gulf of Masirah, Humpback Whale, megaptera novaeangliae, Microsatellite, sexing},
pubstate = {published},
tppubtype = {techreport}
}
From the 49 new samples, 44 were successfully genotyped at 10 microsatellite loci. We identified 27 males and 17 females. Within this dataset, 7 duplicate samples were found. Five samples representing 3 individuals in the 2015 dataset registered as genotypic matches with animals sampled in the 2004 dataset. An additional 9 samples involving 6 individuals that represent potential matches between the 2015 and 2004 dataset are being reviewed to determine if they represent inter-year recaptures. As the data were generated very recently, further checks to clarify issues with some microsatellite loci will be completed. Six samples failed to amplify consistently for sexing markers and need to be revisited.
Analysis of the combined genotypic dataset will be completed by the end of June/early July 2016. The genotypic matches and sexing data will be incorporated into the Oman Photo-ID database, and used to generate robust updated photo-ID and genotypic mark-recapture estimates of population abundance. These data have also been used to determine or confirm the sex of the 9 satellite tagged whales off the coast of Oman (see SH28), and a significant number of other whales identified photographically off the coast of Oman. This will prove highly valuable if future satellite tagging efforts are undertaken in Oman, as previous tagging work has been significantly male-biased (See SH28), and future tagging should target known females.
Preliminary assessment of the new sexing data (although not yet fully complete) is providing valuable insight into possible difference in habitat use between the two primary study sites off the coast of Oman (see Figure 1). Minton et al. (2011) documented a heavy bias toward males in Dhofar and a ratio near parity in the Gulf of Masirah. These results were based on the total number of photographic captures of known sex individuals. The combination of new and old sexing information allows for a more nuanced examination of this phenomenon: the male-female ratio based on individual whales for which sex was determined in each study site (regardless of how frequently they were observed) is 2:1 in Dhofar (n=30), whilst in the Gulf of Masirah this ratio is slightly biased toward females, with 45% of individuals of known sex observed in that study area being male, and 55% female (n=49). More detailed analysis of these sexing data in relation to survey effort and photographic identification data will yield further important insights into habitat use, behaviour, and social interactions, critical for the conservation of this population.
Analysis of the combined genotypic dataset will be completed by the end of June/early July 2016. The genotypic matches and sexing data will be incorporated into the Oman Photo-ID database, and used to generate robust updated photo-ID and genotypic mark-recapture estimates of population abundance. These data have also been used to determine or confirm the sex of the 9 satellite tagged whales off the coast of Oman (see SH28), and a significant number of other whales identified photographically off the coast of Oman. This will prove highly valuable if future satellite tagging efforts are undertaken in Oman, as previous tagging work has been significantly male-biased (See SH28), and future tagging should target known females.
Preliminary assessment of the new sexing data (although not yet fully complete) is providing valuable insight into possible difference in habitat use between the two primary study sites off the coast of Oman (see Figure 1). Minton et al. (2011) documented a heavy bias toward males in Dhofar and a ratio near parity in the Gulf of Masirah. These results were based on the total number of photographic captures of known sex individuals. The combination of new and old sexing information allows for a more nuanced examination of this phenomenon: the male-female ratio based on individual whales for which sex was determined in each study site (regardless of how frequently they were observed) is 2:1 in Dhofar (n=30), whilst in the Gulf of Masirah this ratio is slightly biased toward females, with 45% of individuals of known sex observed in that study area being male, and 55% female (n=49). More detailed analysis of these sexing data in relation to survey effort and photographic identification data will yield further important insights into habitat use, behaviour, and social interactions, critical for the conservation of this population.