A study finds that both long-term memory and resource tracking influence blue whale migratory behaviors. Many migrant species track waves of high-quality food sources across landscapes. Although there is extensive research on terrestrial migration patterns, the migratory behaviors of marine animals have not been extensively explored. To determine what drives blue whale migration patterns, Briana Abrahms and colleagues combined 10 years of data on daily blue whale movements collected from satellite tags with satellite-based phytoplankton measurements in the California Current Ecosystem. The timing of whale movements was compared to the timing of the spring phytoplankton bloom, which drives a coast-wide wave of krill, the whales' primary prey. The authors report that the whales almost perfectly matched their migration to the historical average timing of the krill wave. Moreover, the whales preferentially foraged in areas with lower immediate food availability but higher and more predictable long-term productivity, compared with areas where they did not forage. The findings indicate that blue whales enhance their ability to track krill by remembering the locations of stable, high-quality foraging sites, but the whales' reliance on memory could hamper adaptations to novel ecosystem conditions.
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Article #18-19031: "Memory and resource tracking drive blue whale migrations," by Briana Abrahms et al.
MEDIA CONTACT: Briana Abrahms, NOAA Southwest Fisheries Science Center, Monterey, CA; tel: 425-890-5603; email: < briana.abrahms@noaa.gov >
Proceedings of the National Academy of Sciences