Few vessel strikes to sperm whales have been documented, but vessel traffic worldwide is increasing, which increases the risk of collisions. Molecular phylogeny of cetaceans prompts revision of morphological transformations. Chapter contents Book contents. Coda repertoire similarity and clan structure of sperm whale groups from the Pacific between and O'Leary and Geisler, Marine Mammal Science The sperm whale is the most evolutionarily modified of the toothed whales.
Social groups typically consist of 10—12 individuals including at least 1—2 calves Gannier et al. By contrast, results from a survey of a large portion of the western basin from Gibraltar to Sicily and bounded on the north by a line from the Balearics east to Sardinia in Summer indicate a Sperm Whale detection rate roughly eight times that in the Ionian Sea Lewis et al. Odobenus rosmarus Walrus Info. Sperm whale males attain sexual maturity at an average of 12 years of age; females at 9 years. In the Ligurian Sea, known to contain one of the most productive pelagic areas in the Mediterranean, 70 Sperm Whales have been photo-identified across 14 years — of intensive research, suggesting that density there is low. Although the cause of a standing often remains unknown, scientists can sometimes attribute them to factors such as disease, vessel strikes, fishing gear entanglements, pollution exposure, or underwater noise.
Sperm Whale: Physeter macrocephalus - ScienceDirect
Marine mammals are considered to be good indicators for concentrations of metal and pollutant accumulation in the environment due to their long lifespan and in some cases position near the top of marine food webs. The subpopulation experiences an inferred continuing decline in numbers of mature individuals; 3. Supreme Court condemns ruling that enabled internment of Japanese-Americans, but says travel Monitoring sperm whale population abundance, distribution, and habitat use. The joint between upper arm and forearm is immobile, creating an effective paddle.
Echolocation is the ability to assess the environment mostly, detecting obstacles, conspecifics, predators, and prey by emitting sounds and listening to the echoes. In some parts of the eastern basin, social groups of females with immatures and solitary mature males are both found in the same area year-round Frantzis et al. NOAA Fisheries conducts research on the biology, behavior, and ecology of the sperm whale. Engelhaupt, Daniel Thomas Phylogeographyj kinship and molecular ecology of sperm whales Physeter macrocephalus. The position of the external nares on the top of the skull allows cetacean to breathe while keeping the rest of the head underwater. Vessel strikes, Entanglement in fishing gear, Ocean noise, Marine debris, Climate change, Oil spills and contaminants. Female sperm whales reach sexual maturity around 9 years of age when they are roughly 29 feet long.