Environmental Science · Ecology
Humpback whales in Monterey Bay fed more frequently when California sea lions were present. The whales appeared to spend less time searching and approaching prey, while the effort and movement of individual lunges showed no detectable increase.
Humpback and fin whales often move into killer whales’ herring-hunting groups in northern Norway, feeding on dense patches that the killer whales have gathered. The intrusions can end killer whale hunts, while whale-watching tourism adds further disruption to feeding.
Large groups of mahi-mahi may interfere with striped marlin hunting at shared prey schools, causing the marlin to abandon a hunt. The study also found that smaller numbers of mahi-mahi may increase the marlin’s net captures.
Satellite tracking of 21 southern right whales from Aotearoa New Zealand found that they used one of two routes to reach shared summer feeding grounds. The results suggest the whales may balance faster travel against lower energy costs, while adjusting their route as individuals.
Japanese bent-winged bats adjusted their echolocation frequencies in response to sounds that could interfere with their calls. A mathematical model and a two-dimensional group simulation indicate that this self-organized behavior can reduce potential misdetections across a flying group.
A study of juvenile white sharks off New South Wales, Australia, found that sharks tagged together in the same place tended to return to the nursery area and be detected near one another in later years. The overall pattern did not show clear non-random association, leaving the extent of social behavior uncertain.
Herring supplied more than half of the estimated annual energy needs of non-reproductive and pregnant female humpback whales, as well as juvenile and adult males, in an eastern British Columbia feeding ground. Juvenile and lactating females obtained between 25% and 50% of their estimated needs from herring.
Researchers report the first documented case of a humpback whale attending to a stillborn calf after its death. The female stayed close, repeatedly interacted with the calf and did not try to lift it to the surface.
A study mapped where gillnet fisheries and 13 cetacean species occur in Brazil’s Santos Basin. Guiana dolphins, franciscanas and bottlenose dolphins showed the greatest spatial overlap with the fisheries, highlighting areas for bycatch monitoring and management.
