title: Mother knows best: occurrence and associations of resighted humpback whales suggest maternally derived fidelity to a Southern Hemisphere coastal feeding ground.
abstract: Site fidelity is common among migratory cetaceans, including humpback whales (Megaptera novaeangliae). In the Northern Hemisphere it has been found that fidelity to humpback whale feeding grounds is transferred maternally but this has never been shown for the species in the Southern Hemisphere. We examined this in a unique feeding area off west South Africa using resighting data of 68 individually identified humpback whales by means of photographic (tail flukes and dorsal fins) and/or molecular methods (microsatellite genotyping) over an 18 year span. We found short-term association patterns and recurrent visits typical of other feeding grounds. Males and females had different seasonality of attendance. Significant female-dominated presence corresponded to timing of an expected influx of females on their southward migration from the breeding ground: firstly non-nursing (possibly pregnant) females in mid-spring, and mothers and calves in mid-to late summer. The potential benefit of this mid-latitude feeding area for females is illustrated by a record of a cow with known age of at least 23 years that produced calves in three consecutive years, each of which survived to at least six months of age: the first record of successful post-partum ovulation for this species in the Southern Hemisphere. We recorded association of a weaned calf with its mother, and a recurring association between a non-lactating female and male over more than two years. Moreover, three animals first identified as calves returned to the same area in subsequent years, sometimes on the same day as their mothers. This, together with numerous Parent-Offspring relations detected genetically among and between resighted and non-resighted whales is strongly suggestive of maternally derived site fidelity at a small spatial scale by a small sub-population of humpback whales.
authors.affiliation: Mammal Research Institute, University of Pretoria, Pretoria, South Africa ; Sustainability Research Unit / South African National Parks, Nelson Mandela Metropolitan University (George Campus), George, South Africa.
authors.forename: Jaco
authors.initials: J
authors.lastname: Barendse
authors.affiliation: Mammal Research Institute, University of Pretoria, Pretoria, South Africa.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Best
authors.affiliation: Ocean Giants Program, Wildlife Conservation Society, Bronx, New York, United States of America ; Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, United States of America ; Faculdade de Ciências do Mar e Ambiente, Universidade do Algarve, Campus Gambelas, Faro, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Carvalho
authors.affiliation: Ocean Giants Program, Wildlife Conservation Society, Bronx, New York, United States of America ; Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York, United States of America ; Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Cristina
authors.initials: C
authors.lastname: Pomilla
mesh_terms: D000818:Animals; D005260:Female; D050640:Humpback Whale / Q000502:physiology*; D008297:Male; D012621:Seasons