Hyperoodon ampullatusnorthern bottlenose whale

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Geographic Range

The range of Hyperoodon ampullatus (the northern bottlenose whale) extends from the polar ice of the North Atlantic southwest to Long Island Sound and southeast to the Cape Verde Islands. (MacDonald, 1987; Minasian, et al., 1984)

Habitat

H. ampullatus is most commonly found in waters at least 1000m deep and often forages at or near the north atlantic ice shelf in sheltered embayments during the spring and summer. (Reeves, et al., 1993)

Physical Description

Individuals of this species can reach up to 9.8m in length, but most are around 6.7-7.6m at the age of sexual maturity (7-14 years). They are sexually dimorphic, with males being up to 25% larger than females. The size of individuals in the Gully population (off Nova Scotia) is believed to be some 0.7m shorter than that of other Northern bottlenose whales. Individual whales may live up to 37 years (Herman 1980, MacDonald 1987, Whitehead et al. 1997a).

Northern bottlenose whales are varied in color, ranging from greenish-brown to chocolate and gray. Individuals may be blotted with patches of grayish-white and coloration is generally lighter on the flanks and underbelly, fading to a white or cream color. Young calves are generally chocolate colored in appearance (Evans 1987, Tinker 1988).

The body is long, robust and cylindrical and the beak is short, resembling a bottle in shape. Both sexes have large, protruding melons that are often vertical anteriorly in older animals and turn yellowish-white with age in males. The melon of the female is not as prominent as that of the male.The posteriorly-curved dorsal fin is 30-38cm in height and is located at a distance of 1/3 the total body length from the tail. The tail fluke lacks a medial notch and the flippers are small and pointed (Minasian et al. 1984, Tinker 1988).

The dentition of the species is highly reduced, with males possessing one or occasionally two pairs of short teeth in the tip of the lower jaw. These teeth never erupt in females, may never fully erupt in males, and often fall out with age (Minasian et al. 1984). (Herman, 1980; MacDonald, 1987; Whitehead, et al., 1997a)

  • Sexual Dimorphism
  • male larger
  • Range mass
    5800 to 7500 kg
    12775.33 to 16519.82 lb
  • Range length
    9.8 (high) m
    32.15 (high) ft

Reproduction

The mating system of Hyperoodon ampullatus is believed to be polygynous, with a single mature male associating with a group of females during the mating season.

Females become sexually mature at a length of 6.7-7m (8-14 years) and males reach maturity at 7.3-7.6m (7-9 years) (Evans 1987, MacDonald 1987, Minasian et al. 1984).

Mating occurs in spring and early summer and calves are born from April to June. Data from the Gully population near Nova Scotia indicates that the mating and calving period for this population may be from June to August. The gestation period for all Northern bottlenose whales is around twelve months and females exhibit a calving interval of two to three years. (Whitehead et al. 1997a, MacDonald 1987, Reeves et al. 1993, Tinker 1988).

  • Breeding interval
    Females exhibit a calving interval of two to three years
  • Breeding season
    Mating occurs in spring and early summer
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    12 months
  • Average gestation period
    365 days
    AnAge
  • Average weaning age
    12 months
  • Range age at sexual or reproductive maturity (female)
    8 to 14 years
  • Range age at sexual or reproductive maturity (male)
    7 to 9 years

Calves are around 3.5m in length at birth and weaning occurs at around one year of age.

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

Lifespan/Longevity

Behavior

Northern bottlenose whales are generally found in groups of four to ten individuals, although group size may occasionally number as many as 25 individuals. Whalers observed that adult males sometimes travel separately from females and young males, and that this behavior occurs most commonly before and during the yearly migration. Data collected from The Gully population near Nova Scotia indicates that there may be long-term companionships between a small proportion of males and females (Harrison and Bryden 1988, Minasian et al. 1984, Reeves et al. 1993).

Hyperoodon ampullatus is generally migratory, spending the spring and early summer in the more northern latitudes and migrating south for the winter, and consists of at least two distinct populations. The larger population summers off Cape Chidley and across the mouth of the Hudson Straight to the mouth of Cumberland Sound along the 1000m depth contour and is widely distributed. The smaller population summers in a 20km x 8km area near the entrance of The Gully off the coast of Nova Scotia. Studies of The Gully population indicate that this population is likely non-migratory, remaining near Sable Island throughout the year. Strandings of Hyperoodon ampullatus off the coast of Europe in early fall indicate that many Northern bottlenose whales migrate to more southernly latitudes beginning in July (Reeves et al. 1993, Whitehead et al.1997a, Whitehead et al. 1997b).

These whales emit powerful ultrasonic clicks as well as low-intensity sounds which are audible to humans. Ultrasonic sounds are amplified in the melon and may serve in the echolocation of prey, especially in deep or murky water where there is little light penetration. Unlike other beaked whales, H. ampullatus is not prone to mass beachings (Evans 1987, MacDonald 1987, Reeves et al. 1993, Simmons and Hutchinson 1996).

Although the species' surface behavior is variable, H. ampullatus freqently approaches sluggish ships and may circle around them for an hour or more. This behavior, coupled with the tendancy for group members to aid an injured individual, made the Northern bottlenose whale a favorite target of whaling vessels (Harrison and Bryden 1988, Minasian et al. 1984, Reeves et al. 1993).

Communication and Perception

Food Habits

Hyperoodon ampullatus feeds primarily on squid (e.g. Gonatus fabricii), although sea cucumbers (Holothuroidea), herring (Clupea harrengus), cuttlefish (Sepiidae), sea stars (Asteroidea), and other benthic invertebrates supplement the diet. Utilizing a feeding method similar to that of Physeter catodon (the sperm whale), northern bottlenose whales make deep, sustained dives to capture prey. Dives last up to 70min and diving depths range from 80 to 800m with a maximum recorded dive depth of 1453m. Breathing intervals of 10min are common between deep dives and individuals frequently resurface in close proximity to where a dive began (Herman 1980, Hooker and Baird 1999, Minasian et al. 1984, Reeves 1993, Walker 1975).

  • Animal Foods
  • fish
  • mollusks
  • aquatic crustaceans
  • other marine invertebrates

Economic Importance for Humans: Positive

The Northen bottlenose whale was hunted for centuries for the spermaceti oil contained in its head and as a souce of food for native peoples. Scottish, English, and Norwegian whalers hunted H. ampullatus commercially from the mid-1800's until 1973. Because of its behavior of approaching large vessels and defending injured group members, whalers found Northern bottlenose whales easy to hunt. This whale's behavior and the fact that the spermaceti oil contained in its head was of almost equal quality to that of the Sperm whale resulted in overhunting and gross reductions in Northern bottlenosed whale populations around the turn of the century (Bloch et al. 1996, Reeves et al. 1993).

Conservation Status

The IUCN relieved Hyperoodon ampullatus of its "vulnerable" listing in 1991, an currently lists it as "Lower Risk, subjec to continued conservation." COSEWIC (Committee on the Status of Endangered Wildlife in Canada) assigned the species to its "vulnerable" category in 1996. Though not listed under the U.S. Endangered Species Act, trade in northern bottlenose whales is restricted by CITES, the species is included in Appendix I. These whales have not been hunted commercially since 1973. (Elderkin, August 20,1998; Reeves, et al., 1993; Simmonds and Hutchinson, 1996)

Other Comments

Of all the Ziphiidae, Hyperoodon ampulatus is the most well-known and researched. It is closely related to H. planifrons, which inhabits the oceans of the southern hemisphere, and the two may have diverged only a few thousand years ago. Both species are very similar in external appearance, with H. ampullatus being slightly larger. The two species can be differentiated based on geographic distribution and the flatter maxillary crests of H. planifrons (Collete Hendricks 1997, Reeves 1993).

The early Miocene of Australia yields the first fossil evidence of Ziphiids, one of the most primitive families of whales (MacDonald 1987, Vaughn et al. 2000).

Contributors

Gerhard Mundinger (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Atlantic Ocean

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.

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.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

iteroparous

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).

migratory

makes seasonal movements between breeding and wintering grounds

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).

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polygynous

having more than one female as a mate at one time

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

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

social

associates with others of its species; forms social groups.

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

Animal Diversity WebHyperoodon planifrons [Southern bottlenose whale]1997http://animaldiversity.ummz.umich.edu/accounts/hyperoodon/h._planifrons.htmlOctober 13, 1999

Bloch, D., G. Desportes, M. Zachariassen, I. Christensen. 1996. The northern bottlenose whale in the Faroe Islands, 1584-1993. Journal of Zoology (London), 239: 123-140.

Elderkin, M. August 20,1998. "Nova Scotia species at risk with official COSEWIC status" (On-line). Accessed October 13,1999 at http://www.gov.ns.ca/NATR/wildlife/endngrd/specie98.htm.

Evans, P. 1987. Whales & Dolphins. New York, New York: Facts on File Publications.

Harrison, S., D. Bryden. 1988. Whales, Dolphins and Porpoises. New York, New York: Facts on File Publications.

Herman, L. 1980. Cetacean Behavior: Mechanisms and Functions. Malabar, Florida: Robert E. Krieger Publishing Company.

Hooker, S., R. Baird. 1999. Deep-diving behaviour of northern bottlenose whales, Hyperoodon ampullatus (Cetacea: Ziphiidae). Proceedings of the Royal Society, London. B., 266: 671-676.

MacDonald, D. 1987. The Encyclopedia of Mammals. New York, New York: Facts on File Publications.

Minasian, S., K. Balcomb, L. Foster. 1984. The World's Whales. Washington, D.C.: Smithsonian Books.

Reeves, R., E. Mitchell, H. Whitehead. 1993. Status of the Northern Bottlenose Whale, Hyperoodon ampullatus. The Canadian Field-Naturalist, 107: 490-508.

Simmonds, M., J. Hutchinson. 1996. The Conservation of Whales and Dolphins. New York, New York: John Wiley & Sons.

Tinker, W. 1988. Whales of the World. New York, New York: E.J. Brill.

Vaughn, T., J. Ryan, N. Czaplewski. 2000. Mammalogy, 4th Edition. Fort Worth, Texas: Saunders College Publishing.

Walker, E. 1975. Mammals of the World. Baltimore, MD: Johns Hopkins University Press.

Whitehead, H., A. Faucher, S. Gowans, S. McCarrey. 1997a. Status of the Northern Bottlenose Whale, Hyperoodon ampullatus, in The Gully, Nova Scotia. The Canadian Field-Naturalist, 111: 287-292.

Whitehead, H., S. Gowans, A. Faucher, S. McCarrey. 1997b. Population Analysis of Northern Bottlenosed Whales in The Gully, Nova Scotia. Marine Mammal Science, 13: 173-185.