Noctule bats locate tree roosts faster by eavesdropping on the echolocation calls of conspecifics. Increasing evidence suggests that echolocation is important not only for orientation and finding prey, but also for communication.

This paper presents a method to detect and classify odontocete echolocation clicks as well as to estimate the number of animals that are vocalizing. A transient detector using the Page test [1-3] is used to extract the clicks: the click time, the click duration, the click amplitude and the spectral information of the clicks are extracted. A probability distribution over the species is assigned ...

Brucella infections have recently been recognized in seals, sea lions, walruses, dolphins, porpoises, whales and an otter. This organism appears to be widespread in marine mammals, and has probably been endemic in these populations for a long time. The clinical significance is uncertain. A few infections have been associated with placentitis/abortions, neonatal mortality, meningoencephalitis, a...

Many odontocete groups have developed enlarged facial crests, although these crests differ in topography, composition and function. The most elaborate crests occur in the South Asian river dolphin (Platanista gangetica), in which they rise dorsally as delicate, pneumatized wings anterior of the facial bones. Their position wrapping around the melon suggests their involvement in sound propagatio...

Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55-60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although ceta...

A critical analysis of the numerous works on dolphin swimming shows that several uncertainties led to incorrect conclusions concerning the estimates of dolphin drag coefficients. Original results on dolphin kinematics and hydrodynamics indicate the existence of a drag-reduction mechanism, caused by the formation of a negative pressure gradient along the body during active swimming. The mathemat...

The biosonar system of dolphins and porpoises has been studied for about 5 decades and much has been learned [Au, W. W. L. (1993). The Sonar of Dolphins (Springer, New York)]. Most experiments have involved human-made targets; little is known about odontocetes' echolocation of prey. To address this issue, acoustic backscatter from Atlantic cod (Gadus morhua), gray mullet (Chelon labrosus), poll...

Last Updated: July 28, 2009 Importance Brucella infections have recently been recognized in seals, sea lions, walruses, dolphins, porpoises, whales and an otter. This organism appears to be widespread in marine mammals, and has probably been endemic in these populations for a long time. The clinical significance is uncertain. A few infections have been associated with placentitis/abortions, neo...

Understanding the solubility of nitrogen gas in tissues is a crucial aspect of diving physiology, especially for air-breathing tetrapods. Adipose tissue is of particular interest because of the high solubility of nitrogen in lipids. Surprisingly, nothing is known about nitrogen solubility in the blubber of any marine mammal. We tested the hypothesis that N(2) solubility is dependent on the lipi...

Brucella infections have recently been recognized in seals, sea lions, walruses, dolphins, porpoises, whales and an otter. This organism appears to be widespread in marine mammals, and has probably been endemic in these populations for a long time. The clinical significance is uncertain. A few infections have been associated with placentitis/abortions, neonatal mortality, meningoencephalitis, a...