Mesoplodon bowdoiniAndrew's beaked whale

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Geographic Range

Mesoplodon bowdoini, also known as Andrew's beaked whales, can be found in cool temperate water such as the Indo-Pacific Ocean. The waters around New Zealand and off the southern coast of Australia are home to this whale. ("The Toothed Whales", 1975)

Habitat

These animals prefer to forage at depths below the 1000 meter line. This is possibly due to the distribution of squid and other food sources not yet identified. The great depths to which these mammals travel can result in dives that last longer then 45 minutes. (Jefferson, et al., 1993)

Physical Description

There have been very few sightings of this whale due to its spending little time on the surface. Of the roughly 35 specimens studied, the following is specific to M. bowdoini: indiviuals weigh 2.6 tons at their maximum and at birth the average length is approximately 2 meters. Females grow to an average of 4.6 m., with males growing slightly longer to 4.8 m. The color of males ranges from dark grayish-blue to black, except for the "beak", the tip of the rostrum and lower jaw, which are white in color. Females have more of an off-white beak. (Baker, 2001; Jefferson, et al., 1993; Reeves, et al., 2002)

Andrew's whale females or young are distinguished from other Mesoplodon species by their heads, which have a small melon and as a result, slants down dramatically from the body. Also, females and young have short, thick beaks. The dorsal fin of this species is rather small for its body size. This fin is found in the middle of the back, and it is triangular and blunt tipped. (Reeves, et al., 2002)

The teeth of males are helpful in identification. Males have two teeth located in the lower jaw within a set of sockets in the middle of the beak. Females also contain these teeth, but they are not visible since they do not erupt through to the surface. (Baker, 2001; Culik, 2003)

  • Sexual Dimorphism
  • male larger
  • Average mass
    2359 kg
    5196.04 lb
  • Range length
    2 to 4.7 m
    6.56 to 15.42 ft

Reproduction

Due to the lack of scarring in M. bowdoini investigators believe that there is no physical competition for partners. Little is known about the mating system of this species. ("The Toothed Whales", 1975)

The only information on the reproductive system of M. bowdoini is from occasional observations of young. The calving season occurs during the summer and autumn. (Reeves, et al., 2002)

  • Breeding season
    summer and autumn

No specific information is available. As mammals, females nurse their young.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female

Lifespan/Longevity

No information available.

Behavior

Little is known about the behavior of this whale. Andrew's beaked whales are slow, sluggish marine mammals. Beaked whales have "flipper pockets," which allow the flippers to be tucked away to reduce drag when swimming. M. bowdoini spends little time at the surface, making individulas more difficult to identify or find. When spotted, these whales are generally alone and if in a group it is with no more then 6 others. (Jefferson, et al., 1993; Reeves, et al., 2002)

Home Range

No information is available.

Communication and Perception

No information is known.

Food Habits

Mesoplodon bowdoini feeds in deep waters primarily on squid. When squid are not available fish become a secondary source of food. (Jefferson, et al., 1993)

  • Animal Foods
  • fish
  • mollusks

Predation

No information is known about predation.

Ecosystem Roles

Mesoplodon bowdoini affects the environment by feeding on squid and occasionally fish, which may affect their populations. No relationships with other marine animals are known. ("The Toothed Whales", 1975)

Species Used as Host
  • None known
Mutualist Species
  • None known
Commensal/Parasitic Species
  • None known

Economic Importance for Humans: Positive

There are no known positive affects of M. bowdoini on humans. These animals are not significant to the whaling industry. (Reeves, et al., 2002)

Economic Importance for Humans: Negative

There are no known adverse affects of M. bowdoini on humans.

Conservation Status

M. bowdoini is protected under the 1972 Marine Mammal Protection Act(MMPA). This established an end to the hunting, harassing, capture or killing of marine mammals in US waters and by US citizens. MMPA also extended the ban on the importation of marine mammals or their products into the country. ("Marine Mammal Protection Act", 2003)

Other Comments

This animal is very similar to many other beaked whales. Due to their lack of surface time and strandings, these whales are very poorly known.

Contributors

Matthew Wund (editor), University of Michigan-Ann Arbor.

angela mangano (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Pacific Ocean

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.

World Map

bilateral symmetry

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

endothermic

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.

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

piscivore

an animal that mainly eats fish

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

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).

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

U.S. Department of the Interior. 2003. "Marine Mammal Protection Act" (On-line). Minerals Management Service Environmental Program. Accessed March 09, 2004 at http://www.mms.gov/eppd/compliance/mmpa/.

1975. The Toothed Whales. Pp. 457, 496 in B Grzimek, J Liebig, eds. Grzimek's Animal Life Encyclopedia, Vol. Mammals II, Second Edition. New York: Van Nostrand Reinhold Company.

Baker, A. 2001. Status, relationships, and distribution of Mesoplodon bowdoini Andrews, 1908 (Cetacea: Ziphiidae). Marine Mammal Science, 17(3): 473-493.

Culik, B. 2003. "Convention of Migratory Species (CMS)" (On-line). Mesoplodon bowdoini Andrews, 1908. Accessed October 07, 2004 at http://www.cms.int/reports/small_cetaceans/data/m_bowdoini/m_bowdoini.htm.

Jefferson, T., S. Leatherwood, M. Webber. 1993. FAO Species Identification Guide: Marine Mammals of the World. Rome, Italy: Food and Agriculture Organization.

Reeves, R., B. Stewart, P. Clapham, J. Powell. 2002. Sea Mammals of the World. London: A & C Black.