By angela mangano
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)
Biogeographic Regions:
indian ocean (native 
); pacific ocean (native ).
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, Leatherwood, and Webber, 1993)
These animals are found in the following types of habitat:
temperate .
Physical Description
(5189.8 lbs)
(6.56 to 15.42 ft)
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, Leatherwood, and Webber, 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)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: male larger.
Reproduction
summer and autumn
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)
Key reproductive features:
seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
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, Leatherwood, and Webber, 1993; Reeves et al., 2002)
Home Range
No information is available.
Key behaviors:
natatorial ; motile ; solitary .
Food Habits
Mesoplodon bowdoini feeds in deep waters primarily on squid. When squid are not available fish become a secondary source of food. (Jefferson, Leatherwood, and Webber, 1993)
Primary Diet:
carnivore (piscivore , molluscivore ).
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)
- None known
- None known
- None known
Economic Importance for Humans: Negative
There are no known adverse affects of M. bowdoini on humans.
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)
Conservation Status
IUCN Red List: [link]:
Data Deficient.
US Federal List: [link]:
No special status.
CITES: [link]:
No special 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. (U.S. Department of the Interior, 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.
angela mangano (author), University of Michigan. Phil Myers (editor, instructor), Museum of Zoology, University of Michigan.
