Ears Wide Open

New Studies Reveal Blue Whales Regional Dialects, Behavior - Two studies at Scripps Institute of Oceanography have shed new light on the acoustic communication of blue whales. In one, researchers identified specific regional dialects that suggest the extent of sub-populations of the whales. Some populations, such as along the east coast of North America, are fairly concentrated in one area, while others, including one that ranges across much of the North Pacific, are more wide-spread. The paper suggests that the stock structures of blue whales, traditionally based on International Whaling Commission boundaries, should instead be reconstructed based on song, which would more accurately represent their true population distributions. A second new study has, for the first time, corelated the sex and behaviors that are associated with several well-known blue whale calls. "This is the first study that has been able to study the calls by directly observing the animal while it is calling and gathering key information such as depth and body orientation—getting a sense of what the animal is doing underwater," said researcher Erin Oleson. "Once you understand the context of specific types of sounds, then you can use those sounds to infer something about what they are doing when you are not there to actually see them doing it." Source: Scripps Press Release, 2/27/07 [READ PRESS RELEASE]

Deep Sea Vents Offer Clues in Sound - A new approach to studying the flow patterns of deepsea vents, using sound recording, has produced some intriguing results. University of Washington researcher Timothy Crone places hydrophones near two vents and found a varying rubbling noise that could be caused by changes in flow volume or mixing of different fluids. Crone's recorders also picked up more resonant tones, which could be produced in the same way jug band members produce sound by blowing across the mouths of their jugs, causing the air inside the jug to resonate and produce a deep tone. Source: UWashington Press Release/Eurekalert, 2/7/07 [READ PRESS RELEASE] [VIDEO WITH TONES] [READ PAPER]

Recordings Eavesdrop on Orca Predation of Fur Seals - Fur seal populations have been in decline off the Alaskan coast, and biologists have suspected orcas may be playing a large part. However, catching them in the act of hunting seals has been difficult, since much activity occurs below the surface or at night. A pilot project by University of Alaska PhD candidate Kelly Newman has returned a surprising wealth of new insight. Newman deployed an autonomous recording system that listened in on activity several miles offshore for twenty days. On the very first hour of recording, and on nineteen of the days it was in the field, orcas were heard, most often in the wee hours of the night, with 2am the most active time. The recordings belie the violence in the water. From silence, the sensitive recorder picks up a thump, a pause, another thump, then whale calls, sort of a high-pitch warble. It's the sound of a silent killer whale ramming a seal, flopping on it or even throwing it in the water, then a summons to eat. Source: Alaska Daily News, 2/6/07 [READ ARTICLE]

Especially Interesting Websites from Research Institutions

Voices in the Sea - A beautiful Flash presentation of information on several families of cetaceans, including dolphins, beaked whales, blue whales, and humpbacks. Includes short videos of Scripps Institute of Oceanography researchers introducing each family, and sound files. [WEBSITE]

Mapping Anthropogenic Noise in the Sea - A project of the Woods Hole Marine Policy Center, this site includes background on ocean noise sources and a first multi-layer GIS map charting noise sources in the Stellwagen Bank National Marine Sanctuary off the coast of Boston and Cape Cod. [WEBSITE] [STELLWAGEN MAP PAGE]

Megalithic Sound and Landscape - From Dr. Aaron Watson, University of Reading Department of Archaeology, who documents the acoustic properties of neolithic sites, including stone circles and underground passages. [WEBSITE] [RELATED WEBSITE]

Jayne Yack Insect Neuroethology Lab - A wonderful introduction to hearing and use of sound by insects. Yack's team at Carleton University in Ottowa has discovered at least 14 different hearing mechanisms in insects, as well as 20 caterpillars that use sound. [WEBSITE]

Discovery of Sound in the Sea - An amazing University of Rhode Island site with detailed sections on the Physics of sound, Ways that humans use sound (including data transmission), Ways that animals use sound, Teachers resources, including little stories about sounds heard by animals, Page of links to online sound files, Their own sound files, All kinds of technologies tha make noise, Profiles of several scientists, including interviews. [WEBSITE]