Female southern right whales Eubalaena australis: Are there reproductive benefits associated with their coastal distribution off South Africa?

Elwen, Simon Harvey; Best, Peter B.

doi:10.3354/meps269289

Cited by 37 publications

(46 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This female preference has been reported also in southern right whales [80], [81], [82] and humpback whales [83], [84]. In mammals, including baleen whales, there is evidence of strong female site fidelity [13], [85] and resulting in genetic divergence such as in grey whale [14]; elephants [74], ungulates [2] and sea lions [86].…”

Section: Discussionsupporting

confidence: 55%

Fine-Scale Population Structure of Blue Whale Wintering Aggregations in the Gulf of California

et al. 2013

View full text Add to dashboard Cite

Population differentiation in environments without well-defined geographical barriers represents a challenge for wildlife management. Based on a comprehensive database of individual sighting records (1988–2009) of blue whales from the winter/calving Gulf of California, we assessed the fine-scale genetic and spatial structure of the population using individual-based approaches. Skin samples of 187 individuals were analyzed for nine microsatellite loci. A single population with no divergence among years and months and no isolation by distance (Rxy = 0.1–0.001, p>0.05) were found. We ran two Bayesian clustering methods using Structure and Geneland softwares in two different ways: 1) a general analysis including all individuals in which a single cluster was identified with both softwares; 2) a specific analysis of females only in which two main clusters (Loreto Bay and northern areas, and San Jose-La Paz Bay area) were revealed by Geneland program. This study provides information indicating that blue whales wintering in the Gulf of California are part of a single population unit and showed a fine-scale structure among females, possibly associated with their high site fidelity, particularly when attending calves. It is likely that the loss of genetic variation is minimized by male mediated gene flow, which may reduce the genetic drift effect. Opportunities for kin selection may also influence calf survival and, in consequence, have a positive impact on population demography in this small and endangered population.

show abstract

Section: Discussionsupporting

confidence: 55%

Fine-Scale Population Structure of Blue Whale Wintering Aggregations in the Gulf of California

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Our results indicate that mother-calf social condition is mainly a function of the depth in which the pair moves, which is concordant with the belief that water depth would be a major constraint for the association of mother-calf pairs with others whales since shallow waters limit the movements of courting males within the water column (Smultea 1994, Ersts & Rosenbaum 2003. Avoiding deep waters where the mother-calf pair is easily joined by males would have a positive impact on the offspring survival, as seen in right whales Eubalaena australis off South Africa, where the stranding rate of neonates increased in areas dominated by non-cow individuals (Elwen & Best 2004). The authors suggested this could be caused by inexperienced mothers failing to avoid those sites or their inability to deal with harassment by males.…”

Section: Discussionsupporting

confidence: 69%

“…While avoiding the highest breeding activities and aggression by adult whales in the afternoon could be a plausible explanation for such diurnal movements (see Helweg & Herman 1994, Smultea 1994, Ersts & Rosenbaum 2003, the PCA showed also a positive correlation between time of day and wind speed, which suggests that mother-calf pairs approach the coast more often in afternoon hours off Salinas to avoid rough seas. Coastal protected waters may provide shelter to mother-calf pairs during rough seas helping to save energy (Whitehead & Moore 1982, Elwen & Best 2004. Alternatively, such a difference could be attributed to smaller quieter MC groups that would be harder to see in the rougher waters offshore in the afternoon.…”

Section: Discussionmentioning

confidence: 99%

“…Dawbin 1966, Winn et al 1975, Glockner & Venus 1983, Smultea 1994, Ersts & Rosenbaum 2003, Morete et al 2007. It is unclear, however, what social and environmental conditions motivate the segregation of females and calves within the shallowest zones of their winter distribution, but it may be in response to ecological and social pressures such as predation risk (Chittleborough 1953, Herman & Antinoja 1977, harassment by males (Chittleborough 1958, Smultea 1994, Craig et al 2002, Cartwright & Sullivan 2009 and energy conservation (Whitehead & Moore 1982, Elwen & Best 2004.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Distribution and behaviour of humpback whale mother–calf pairs during the breeding season off Ecuador

Félix¹,

Botero‐Acosta²

2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Data on distribution and behaviour of mother-calf pairs of humpback whales Megaptera novaeangliae obtained during the breeding season (June to October) off Ecuador were analysed. The study was carried out between 2001 and 2009 aboard whale-watching boats. A total of 187 groups containing mother-calf pairs were recorded: 124 pairs alone (MC), 44 with an escort whale (MCE) and 18 with 2 or more whales (MC + n). Five environmental variables were used to assess mother-calf distribution with a principal component analysis (PCA). Two variables, depth and time of day, were sufficient to explain heterogeneity. Average depths increased significantly with group size from MC to MC + n groups (p < 0.001), showing that mother-calf social condition would be a function of the depth at which they moved. MC groups were distributed in shallower waters during afternoon hours (p = 0.035), indicating a preference for shelter areas when sea conditions worsened. The proportion of the 3 female-calf group classes remained fairly constant during the season. In 2 MCE groups, the same escort accompanied the pair after 1 and 4 d, indicating some level of stability and/or guarding behaviour. Twenty resightings of 14 different mother-calf groups were recorded, 90% of resightings occurred within 10 d, showing low site fidelity. In coastal waters, a lower proportion of mother-calf pairs was associated with competitive groups than in other breeding areas located in oceanic archipelagos. This is probably because whales breeding in continental shores do not have to enter oceanic waters when moving between sites within the breeding area. Coastal distribution exposes mother-calf pairs to a greater extent than other age classes to anthropogenic activities in coastal waters, which must be taken into account when considering coastal management.

show abstract

“…sea otters, Riedman et al 1994; polar bears, Atkinson & Ramsay 1995; southern right whales, Elwen & Best 2004). Such a relationship may represent older, more experienced females retaining a higher position in the social hierarchy and thus being exposed to better mating opportunities (Côtè & Festa-Bianchet 2001).…”

Section: Introductionmentioning

confidence: 99%

Factors influencing heterogeneity in female reproductive success in a Critically Endangered population of bottlenose dolphins

Brough

Henderson²,

Guerra³

et al. 2016

Endang. Species. Res.

View full text Add to dashboard Cite

For threatened species or populations, variation in reproductive success among females may be explicitly linked with vulnerability to extinction. Thus, an understanding of factors that may cause variability in reproductive success is important. The population of bottlenose dolphins in Doubtful Sound, New Zealand, has a recent history of rapid population decline and low calf survival rates. A previous study has shown high variability in calf survival among multiparous females. This study addresses the factors that seem most important in explaining variation in calf survival and thus reproductive success among females in this population. Reproductive data were sourced from a long-term photo-identification dataset, which allowed tracking the fate of 49 calves born into the population between 1995 and 2012. General linear mixed models combined with model averaging were used to assess how birth timing, maternal size, age and potential anthropogenic impacts contributed to variation in calf survival. Models show that a female's size and her ability to give birth at an optimum time in the calving season are significant predictors of calf survival to an age of 1 and 3 yr. This is the first study to demonstrate how birth timing and mother size are correlated with female reproductive success in a cetacean species. These results confirm the importance of demographic stochasticity and reproductive heterogeneity in small, threatened marine mammal populations.

show abstract

Female southern right whales Eubalaena australis: Are there reproductive benefits associated with their coastal distribution off South Africa?

Cited by 37 publications

References 16 publications

Fine-Scale Population Structure of Blue Whale Wintering Aggregations in the Gulf of California

Fine-Scale Population Structure of Blue Whale Wintering Aggregations in the Gulf of California

Distribution and behaviour of humpback whale mother–calf pairs during the breeding season off Ecuador

Factors influencing heterogeneity in female reproductive success in a Critically Endangered population of bottlenose dolphins

Contact Info

Product

Resources

About