Short-finned Pilot Whale - Globicephala macroryhynchus

Short-finned Pilot Whale
Globicephala macrorhynchus

Other Names: Pothead Whale, Shortfin Pilot Whale, Pacific Pilot Whale

Habitat: Inshore and offshore

Status: Common

Population: Unknown

Threats: Hunting/whaling and entanglement in fishing nets

Group Size: 10-30, several hundred sometimes together (rare)

Fin Position: Far forward of center

Newborns: 4 ž-6 ź ft (1.4-1.9 m), 135 lb. (60 kg)

Adults:12-21 ˝ ft (3.6-6.5 m), 1-4 tons

Diet: Squid or octopus, and occasionally fish

Teeth: 14-18 on top, 14-18 on bottom

Description

Dorsal fin:

- very broad base
- dorsal fin shape varies according to sex and age
- rounded tip
- concave trailing edge

Flukes:

- flukes may be lifted above surface before a long dive
- concave trailing edges
- distinct notch in middle
- sharply pointed tips

Flippers:

- long, slender, sickle-shaped flippers positioned close to head
- flipper 14-19% of body length
- gently curved edge

Other characteristics:

- bulbous head (more pronounced in older males)
- gray or white diagonal stripe behind each eye (variable)
- gray or white cape (variable)
- adult males may be heavily scarred
- slender body becomes more robust with age
- thickened tail stock
- jet black or dark gray color can appear chocolate brown in certain lights (calves are paler or browner)
- gray or off-white belly patch variable and less vivid than on Long-finned Pilot Whale
- W-shaped grayish white patch on throat
- mouth slants upward

Behavior

- entire pods sometimes seen logging, allowing close approach by boats
- lobtailing and spyhopping are sometimes observed
- may surf on ocean swells
- rarely breaches
- feeds mostly at night, when dives may last for 10 minutes or more
- strong blow may be visible in calm weather
- strongly arches tail stock before a long dive
- calves throw entire head out of water when surfacing to breathe; adults usually show only the top half (though they sometimes porpoise, lifting most of body out of water, when traveling fast or accelerating)

Distribution

- tropical, subtropical, and warm temperate oceans around the world
- widely distributed, although exact range is unknown because of confusion with Long-finned Pilot Whale
- more tropical than the Long-finned Pilot Whale, but there is some overlap in range
- several distinct populations may be different species (2 populations off Japan appear to be genetically distinct)
- generally nomadic, with no fixed migrations, but some north-south movements are related to prey movements or incursions of warm water
- inshore-offshore movements are determined by spawning squid (outside squid season usually found offshore)
- some populations are present year-round, such as in Hawaii and the Canary Islands
- prefers deep water: look at the edge of the continental shelf and over deep submarine canyons
- susceptible to mass strandings

e-mail questions, comments, and/or suggestions to
wcrc@sci.tamucc.edu

Internet Coordinator: Candice Orca Mottet

e-mail questions, comments, and/or suggestions to wcrc@sci.tamucc.edu

e-mail questions, comments, and/or suggestions to
wcrc@sci.tamucc.edu