Researchers have observed behavior in the wild that may provide essential insights into the reproduction of the endangered whale shark.
For the first time, researchers have managed to observe behaviors in natural settings that could shed light on the reproductive practices of the endangered whale shark.
There is limited knowledge regarding the pre-mating actions of this elusive species, and given its endangered status, the urgency to understand these behaviors has never been greater.
From 2009 to 2024, annual research expeditions have been conducted at Ningaloo Reef, a World Heritage Site located in the northwestern coastal area of Western Australia, specifically during May, which is the peak season for whale shark aggregations.
During the expedition in 2024, the research team observed and documented a sexually mature male whale shark following and biting a smaller female whale shark.
The team consisted of PhD candidate Christine Barry from Murdoch University’s Harry Butler Institute and the Australian Institute of Marine Science, along with her supervisor, Dr. Mark Meekan from The University of Western Australia.
In a paper published in Frontiers in Marine Science, Ms. Barry discusses the significance of these findings.
“Following and biting are typical mating behaviors observed in various species within the same subclass of cartilaginous fish that includes whale sharks,” Ms. Barry noted.
“These observations align with earlier reports from fishers who described similar behaviors exhibited by sexually mature males towards females at different aggregation locations.”
While the interaction that was observed did not likely lead to actual mating, Ms. Barry indicated that the observed behaviors suggest that the mating patterns of whale sharks are similar to those seen in numerous shark species.
The availability of these observations not only broadens researchers’ knowledge of whale shark mating behaviors but also sheds light on sex ratios reported in whale shark populations across various coastal gathering spots.
“At Ningaloo Reef, and in many global aggregation areas, the male-to-female ratio is about 1 female for every 3 males,” Ms. Barry explained.
“This may provide one explanation for why female whale sharks tend to avoid these aggregation sites. For juvenile females in particular, the energetic costs associated with unwanted attention from males could be a significant factor contributing to the pronounced male bias.”
This research paves the way for conservation initiatives and further studies focused on the repopulation and protection of this species. Ms. Barry, along with her PhD supervisor Dr. Adrian Gleiss, a senior lecturer at Murdoch University’s School of Environmental and Conservation Sciences, have been leading efforts in whale shark research.
Their work has included valuable insights into the effects of tourism on whale sharks and the natural predation of baitfish associated with whale sharks in Ningaloo Reef. ENDS
