Blainville's beaked whales are thought to have the widest range of all species in their genus Mesoplodon. This cosmopolitan species occurs in every ocean with exception of the Arctic. Blainville's beaked whales prefer tropical and warm temperate waters, and their distribution may vary with the movements of warm-water currents. In the Western Atlantic, their range stretches from the Gulf of Mexico and the Caribbean Sea to Nova Scotia. A number of strandings have been reported from Florida to Nova Scotia, and also in Puerto Rico. In the eastern Atlantic, they have been recorded off the coasts of Spain, the Netherlands, Portugal, the United Kingdom, and the Canary Islands. The farthest north they have been recorded in the eastern Atlantic is Aberaeron, Wales. In the Pacific, Blainville's beaked whales range from California to Taiwan. Records of strandings and sightings in the Pacific include the Line Islands, the Philipines, the mainland coast of China, Japan, the Ryukyu Islands, Midway, the Cook Islands, the Solomon Islands, New Caledonia, and the Hawaiian Islands. There are few records of Blainville's beaked whales in the Indian Ocean, likely due to a low observation effort. They have been recorded in Seychelles, Nicobar Islands, and the Maldives. Strandings have also been reported on the island of Mauritius in the southwest Indian Ocean. (Baird, et al., 2009; Ballance, et al., 2001; Borsa and Robineau, 2005; Claridge, 2006; Herman, et al., 1994; Hevia, et al., 2011; Mead, 1989; Pastene, et al., 2006; Reeves, et al., 2002; Rosario-Delestre, et al., 1999; Schorr, et al., 2009; Waring, et al., 2009)
Blainville's beaked whales seem to prefer warm temperates and tropical waters, avoiding the Arctic and Antarctic Oceans. They prefer water temperatures from 10°C to 32°C. Preferred depths range from 700 to 1000 meters, often alongside much deeper waters. They seem to favor areas that are topographically diverse. Along with temperature, depth, and topography, their habitat is dependent on the level of productivity in the water. Blainville's beaked whales were once thought to avoid coastal regions and shallow waters, however, recent studies suggest that they seem to be more pelagic than other species of beaked whales and are the most frequently spotted of all beaked whales near tropical islands. (Baird, et al., 2006; Baird, et al., 2009; Claridge, 2006; Mead, 1989; Reeves, et al., 2002)
Blainville's beaked whales have long and narrow bodies, similar to the other species in the genus Mesoplodon. Their fusiform bodies are widest near the middle and taper at each end. They weigh 820 to 1,030 kg and have an estimated lengths of 4.5 to 4.6 m. The longest recorded length was a female with a length of 4.7 meters. At birth, they are roughly 2 m long and weigh around 60 kg. (Besharse, 1971; Jefferson, 1993; Mead, 1989; Raven, 1942; Reeves, et al., 2002)
Blainsville's beaked whales have a moderately flat melon, somewhat long beak, thick rostrum, a small falcate dorsal fin located roughly two-thirds down the back, and a pair of throat grooves found under the lower jaw. Their blowhole tends to be semi-circular with the open side aimed toward its head. Blainville's beaked whales are dark bluish gray color on the dorsal and lateral regions and lighter gray on the ventral side. They are very difficult to distinguish from other members of their genus because they are so similar in appearance. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011; Besharse, 1971; Jefferson, 1993; Mead, 1989; Raven, 1942; Reeves, et al., 2002)
Males have a heavily arched rear half of their lower jaw, unlike juveniles and females. Males also have large teeth that project out from the lower jaw and rise above the upper jaw. Single-stalked barnacles often bind to these exposed teeth in small clusters. Females and juveniles also have teeth, but they are not easily seen because they are beneath the tissue of the gum within the mouth. Males often have scars present on their bodies, which studies suggest result from competing with each other for access to females. (Besharse, 1971; Jefferson, 1993; Mead, 1989; Raven, 1942; Reeves, et al., 2002)
Fighting among males for access to females is believed to be common, as numerous long narrow scars are found on males. These are likely caused by the large, tusk-like teeth of males. Studies suggest they form harems, which consist of several females and a single dominant male. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011)
Knowledge about reproduction habits of Blainville's beaked whales is very scarce. The estimated age of sexual maturity is 9 years. Mature females give birth to a single calf. Newborn calves are estimated to weigh around 60 kg and measure 1.9 to 2.6 m in length. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011)
Little is known about parental investment in this species, but female whales typically nurse calves. There is little parental investment in this species.
The lifespan of Blainville's beaked whales is unknown. (Jefferson, 1993)
Little is known about the Blainville's beaked whales' social behavior. They are difficult to research because they flee from humans and their blow at the surface of the water is not very noticeable. They are typically found individually or in social groups averaging 3 to 7 individuals, but on occasion as many as 12. Due to the lack of research, it is unclear whether these groups are composed of different ages and sexes or if they are segregated. Some research suggests that adult populations are possibly grouped into harems. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011; Baird, et al., 2006; Claridge, 2006)
Like other beaked whales, Blainville's beaked whales are deep divers that feed on prey in deep water. They typically dive down 500 to 1000 m, and stay underwater for 20 to 45 minutes. Dives lasting longer than 50 minutes and reaching depths around 1400 m have been recorded. In dives deeper than 800 m, descent rates are faster than ascent rates. In dives that are 100 to 600 m deep, descent and ascent rates are similar. Dives are performed during both the day and at night. Migration habits are unknown. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011; Baird, et al., 2006; Claridge, 2006)
Size of home ranges of Blainsville's beaked whales is unknown.
Blainville's beaked whales use echolocation to locate prey on deep dives. They produce two types of clicking sounds, each associated with a specific foraging phase. Search clicks, between 0.2 and 0.4 seconds, are sent during their diving phase in search of prey. Short burst clicks are buzz clicks emitted while capturing prey. (Johnson, et al., 2006)
Most of the information on the food habits of Blainville's beaked whales is collected from the stomach contents of stranded individuals. The primary prey is thought to be cephalopods (Cephalapoda), as they eat armhook squid (Gonatidae), glass squid (Cranchiidae), and cock-eyed squid (Histioteuthidae). However, they most likely consume a significant quantity of other fish and invertebrates. (MaCleod, et al., 2003; Reeves, et al., 2002)
There are no records of any predation of Blainville's beaked whales. (Mead, 1989)
Blainsville's beaked whales prey on cephalopods, but are not known to be eaten by any other animals. Barnacles (Cirripedia) attach themselves to the tusk-like teeth of males.
Blainville's beaked whales are sometimes hunted by small cetacean hunters in various locations. Occasionally, they are also taken accidentally by Japanese tuna boats. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011)
There are no known negative impacts of Blainsville's beaked whales on humans.
The IUCN Red List classifies Blainsville's beaked whales as "Data Deficient," meaning that there is insufficient information to determine the stability of their population or its trend. However, they appear to be fairly common in most warm waters, and are the most common of all the whales in their genus (Mesoplodon). Current threats include accidental and intentional hunting and ingesting pollution. Confusion by military sonar has caused them to wash up on beaches in large numbers. They may also be affected by climate change, but the potential impacts are not yet certain. ("Blainville's Beaked Whale (Mesoplodon densirostris)", 2011; Mead, 1989)
Michael Quinones (author), University of Wisconsin-Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, Alecia Stewart-Malone (editor), University of Wisconsin-Stevens Point, Catherine Kent (editor), Special Projects.
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.
The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.
found in the oriental region of the world. In other words, India and southeast Asia.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
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