A rare observation of group prey processing in wild leopard seals (Hydrurga leptonyx)
Cooperative feeding is often observed among predators with strong social bonds; however, it is unexpected in solitary predators. During 2016, several mass predation events were witnessed in St Andrews Bay and Right Whale Bay, South Georgia, where up to 36 leopard seals (Hydrurga leptonyx) were seen feeding together at king penguin (Aptenodytes patagonicus) colonies. Three post-mortem prey-processing events were observed where two leopard seals actively fed on the same carcass in an unusual display of tolerance for a species where anti-social behaviour is the norm. The seals were observed repeatedly tearing adult king penguins between themselves, while floating alongside each other at the surface of the water. This is the first record of co-feeding in this difficult-to-study species; however, it is expected that the behaviour is rare within the population. We propose that the high density of predators combined with the readily available prey, makes it costlier to defend a kill than it is to tolerate kleptoparasitism. It is unclear whether this behaviour shows cooperative feeding, which would likely enable more efficient prey processing: by holding the prey in their jaws, each seal provides an anchor on the prey that others can pull against to stretch and tear it.
KeywordsCooperation Foraging behaviour Leopard seal Predation Kleptoparasitism Social behaviour
The authors thank Sophie Lanfear (Producer, Silverback Films) for continued support for this manuscript, sourcing leopard seal footage and for liaising with Silverback. This paper would not be possible without Silverback Films and the film crew’s hard work on the ground. Contact with the film crew was initially established through the British Antarctic Survey. The authors also thank Silke Cleuren, William Parker and Kathryn Pack for critically reading the drafts of this manuscript. They also thank the two reviewers and editor who greatly improved the manuscript during the peer-review process.
The manuscript was devised and drafted by JR and DH. Footage was analysed by JR. Photography of solitary predation events was provided by JR. In situ behavioural observations, additional footage and accounts were provided by DP. AE provided critical feedback on the manuscript. All authors contributed to this manuscript and provided comments on drafts.
No funding was utilised for this manuscript.
Compliance with ethical standards
Conflict of interest
We declare that there are no competing interests associated with this work.
Research involving with animal rights
All observations were made under permit of the South Georgia & South Sandwich Islands Government. Drone footage was obtained under Regulated Activity Permit 2016/031 by licensed pilots. Additional images were taken by JRR under Regulated Activity Permit 2015/013.
Permission to carry out fieldwork
All fieldwork and data collection were authorized by South Georgia & South Sandwich Islands Government under Regulated Activity Permits 2016/031 and 2015/013.
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