Hauling-out is the behaviour

Ethology

Ethology is the scientific study of animal behavior, and a sub-topic of zoology....

 associated with pinniped

Pinniped

Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

s (true seals, sea lions, fur seals and walruses), of temporarily leaving the water between periods of foraging activity for sites on land or ice. Hauling-out is necessary in seals for mating (with the exception of the Baikal Seal) and giving birth (though a distinction is generally made between reproductive aggregations, termed "rookeries", and non-reproductive aggregations,termed "haul-outs"). Other benefits of hauling-out may include predator avoidance, thermal regulation, social activity, parasite reduction and rest.

There is much variety in haul-out patterns between different seal species. Haul-out sites may be segregated by age and sex within the same species. Many species of pinniped have only a few localized rookeries where they breed, but periodically occupy hundreds of haul-out sites throughout the range. For example, the Australian Fur Seals breed on only nine islands in Bass Strait

Bass Strait

Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland, specifically the state of Victoria.-Extent:The International Hydrographic Organization defines the limits of the Bass Strait as follows:...

 but also occupy up to 50 haul-out sites in south-east Australian waters, and Steller sea lions have around 50 rookeries throughout their range, but several hundred haul-out sites.