Dear colleagues,
We are excited to announce the following publication:
Kirchner T, Wiley DN, Hazen EL, Parks SE, Torres LG, Friedlaender AS
(2018): Hierarchical foraging of humpback whales relative to the
structure of their prey. Marine Ecology Progress Series 607: 237-250.
https://doi.org/10.3354/meps12789
Abstract: Movement within and between prey patches can influence the
fitness of a predator, and understanding such foraging decisions is an
important topic in ecology. Most research has found sustained foraging
in dense prey patches but has focused on the movement of raptorial
predators that feed on single prey items, or suspension-feeders foraging
on comparatively immobile zooplankton. The goal of this study was to
investigate the fine-scale movement of a suspension-feeding marine
vertebrate species while foraging for mobile prey. Using animal-borne
tags and surface observations, we analyzed the movement of foraging
humpback whales
Megaptera novaeangliae within and among acoustically
detected patches of sand lance
Ammodytes spp. in the water column in the
southern Gulf of Maine, USA. Analyzing data from 9 whales tagged
between 2008 and 2012, we found hierarchical whale foraging movements
that paralleled a complex, hierarchically structured prey landscape. For
7 out of 9 whales, feeding bout scales corresponded to prey patch
scales. For 6 out of 9 whales, movement between sequential feeding
events was not significantly different from distances between
neighboring prey schools. Targeting neighboring schools during
sequential feeding events, as opposed to sustained foraging in
profitable patches, may increase foraging success in marine
suspension-feeders targeting mobile prey, which confirms findings from
many other marine predator taxa feeding on mobile prey species. Our
study presents novel evidence for the high behavioral plasticity of an
intermittent suspension-feeder targeting mobile prey, adapting its
movement to the behavior of its prey and the structure of its prey
field.
Open Access to the article is available at:
https://www.int-res.com/abstracts/meps/v607/p237-250/
Best regards,
Theresa Kirchner, M.S.
Research Assistant
Center for Coastal Studies
Provincetown, Massachusetts, USA
Email: tkirchner at
coastalstudies.org