Australia's last great whale haven.pdf - Ningaloo Atlas

November 2011 Appendix 1 – Species Profiles
63
Short-finned pilot whale
Family
Delphinidae
Distribution and migration
Tropical (22–32°C) to temperate (10–22°C) oceanic
waters, approaching coastal seas. Stranding events
recorded from all states and the Northern Territory.
Not well surveyed within Australian waters,
distribution primarily assumed from incidental sightings,
plus beach-cast animals, for all areas. Generally nomadic,
with no known migration patterns. Short-term
north-south and inshore-offshore movements
presumably related to prey movements or incursions
of warm water. May be found in significantly shallower
water during winter (depth 375m) than summer (800m).
Diet and behaviour
Feed mainly on squid, cuttlefish, octopus and some fish.
Distribution and movements of short-finned pilot whales
appear to be regulated by prey availability. In particular,
inshore-offshore movements are probably determined
by the timing of squid spawning (found inshore during
squid season). May feed on vertically migrating prey,
with deep dives at dusk and dawn following prey
migrations, and near-surface foraging at night.
The deepest dives recorded (typically 600–800m
for a maximum of 27 minutes) during the day.
Information from the NW Region
Seen in offshore waters surrounding Browse Island,
and from Cape Londonderry to the Lacepede Islands.
Scientific Name
Globicephala macrorhynchus
Habitat
Prefer deep water and occur mainly at the edge of the
continental shelf, and over deep submarine canyons.
May also approach coastal seas. Outside Australia,
seasonal inshore and offshore movements of known
groups occur, apparently in response to abundance
and spawning of prey.
Reproduction
Sexual maturity: 14.6 years, 4.0–5.0m (males),
9 years, 2.9–3.6m (females). Maximum age: 46 years
(males), 63 years (females). Mass strandings occur.
Gestation: 14.9 months, birth weight and length:
55kg and 1.4m. Weaning occurs at approximately
two years, suckling may continue for up to 15 years,
suggesting complex social structure. Females breed for
an average of 24 years, produce an average 4–5 calves.
Mating occurs all year round, resulting in a diffusely
seasonal calving period, with peaks in spring and autumn
in the southern hemisphere. Mating system is polygynous.
No calving areas are known for Australian waters.
Population status
No population estimates available for Australian waters,
generally considered to be in relatively high abundance.
No population trends can be calculated due to a paucity
of survey data.
Sources: Bannister et al. 57 , Culik 61 , DEWR 93, 94 , DSEWPaC 101 , Jefferson et al. 114 , Kasuya and Marsh 115 ,
McPherson and Nishida 134 , Mintzer et al. 144 , Perrin and Reilly 17 , Ross 57