Apparently they’ve been having a whale of a time
Southern Right whale population has seen a baby boom with a whopping 661 new calves spotted in SA waters
Scientists are baffled by an apparent whale baby boom off the South African coastline, with triple last year’s number of calving Southern Right whales recorded last week during an aerial count conducted by the Mammal Research Institute.
A record number of 1,347 Southern Right whales were counted between Cape Infanta and Hermanus, of which 661 were calves. The figure is all the more surprising considering last year’s aerial count recorded just 215 calves.
Researchers believe the sudden baby boom could be related to a shift in whale calving interval, from an average three years to between four and five years. “Some data analysis showed a shift in calving interval, and this is very likely due to food availability,” explained Els Vermeulen, research manager of the Mammal Research Institute’s Whale Unit which conducts annual photographic and counting whale surveys.“Last year’s (very low) statistics predicted that there would likely be a massive baby boom – because all the females not calving last year had to calf at some point,” Vermeulen said. However the huge leap in numbers was unexpected.
Southern Rights typically visit SA’s sandy protected bays that serve as convenient “swimming pools” both to mate and rear their young.
The latest figures suggest Southern Rights still feel right at home in SA’s territorial waters: “I was obviously very pleased to see so many whales given the low number of whales counted in the last few years,” said gyrocopter pilot Jean Tresfon who conducted the last week’s counting survey.“The scientists were expecting an upsurge in numbers due to the delayed calving of females in previous years and had a graph forecasting a big jump in the numbers of whales for 2017/18 but I don't think any of us expected quite this many.”
Vermeulen said annual whale surveys began 39 years ago and currently included both counting and photo ID surveys. She said researchers planned to match recent survey results with relevant stock assessments of whales’ preferred prey, krill, to investigate a possible link between calving cycle and food availability.
Researchers plan a follow-up survey in three weeks time, and will conduct a supplementary annual photo-identification aerial survey in October between Nature’s Valley and Muizenberg.