Skip to main content
WCS
Menu
Library
Library Catalog
eJournals & eBooks
WCS Research
Archives
Research Use
Finding Aids
Digital Collections
WCS History
WCS Research
Research Publications
Science Data
Services for WCS Researchers
Archives Shop
Bronx Zoo
Department of Tropical Research
Browse By Product
About Us
FAQs
Intern or Volunteer
Staff
Donate
Search WCS.org
Search
search
Popular Search Terms
WCS History
Library and Archives
Library and Archives Menu
Library
Archives
WCS Research
Archives Shop
About Us
Donate
en
fr
Title
South American sea lions (Otaria flavescens) avoid killer whale (Orcinus orca) predation
Author(s)
Vila A.R., Campagna C., Iniguez M., Falabella V.
Published
2008
Publisher
Aquatic Mammals
Published Version DOI
https://doi.org/10.1578/AM.34.3.2008.317
Abstract
South American sea lions (Otaria flavescens) are predictably preyed on by killer whales (Orcinus orca) at their breeding colonies in Peninsula Valdés, Argentina. Captures occur in shallow waters along the coastline. Killer whales strand in the surf where sea lion pups practice their swimming skills. Being slow and apparently unaware of danger (nonvigilant), pups are the most vulnerable prey (87% of captures). Adult sea lions escaped most attacks by increasing their swimming speed, changing directions swiftly, grouping, and hauling out of the water. In our observations, predator avoidance behaviours were contextual and based on the presence of killer whales and the degree of risk in the areas used by sea lions during their movements between rookeries. Swimming speed increased in sites where the risk of predation was highest and when killer whales were present. Vigilance and escape manoeuvres were recorded at these dangerous sites, characterized by deeper water and a sloping beach, which allowed the killer whales to strand or approach the coast safely. Predictability of the killer whales in space and time facilitates the South American sea lions in developing a reliable antipredation behaviour. Killer whales become more proficient at being predators, and adult sea lions become better at avoiding being preyed upon as they accumulate experience. The inexperience of the sea lion pups is the currency that sustains the killer whale's high rate of take.
Keywords
antipredator defense; breeding population; feeding behavior; interspecific interaction; pinniped; predation; predation risk; swimming behavior; whale; Argentina; Chubut; South America; Valdes Peninsula; Orcinus orca; Otaria byronia; Otariidae
Access Full Text
A full-text copy of this article may be available. Please email the
WCS Library
to request.
Back
PUB11947