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Cetacean Behaviour
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Cetacean social behaviour
Hard to study
Define size and shape of
community Limited idea of sociability
Artificial notions
Animals traveling alone mayhave members of a larger
social unit
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Examples of social units
Grey whale: not very social
migrate in pods =2-5
form larger units in coldwater feeding areas and
calving lagoons
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Examples of social units
Blue whale: travel in close nit groups of 2-4 Larger herds in feeding areas
Fin Whales: travel in herds of 3-20
High # when feeding on krill
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Examples of social units
Minke whales: roam alone or in groups of 2some times congregate at edge of pack ice to
feed
Humpback whales : pods of 2-3
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Definitions
Pod: group of whales, dolphins, or
porpoise which can be quite complex
(Some only form pods for short times)
Breaching: leap from water and fall
back with a splash ( reason unknown)
36 ft whale 17 miles/hr
swim parallel to surface than raises fluke
and tilts upward
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Definitions
Spy hopping : whales or dolphins raisetheir heads out of the water for short
periods of time (take a look around)
Lobtailing or tail slapping: raise flukes
and forcefully slaps the water
can be heard for 7rl miles common in humpbacks, grey & right
whale
aggression or warning display
(communication)
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Definitions
Flipper slapping: whale lies on its
side and and lifts its pectoral
fins out of the water and slaps it
down creating a cracking noise
Bowriding: dolphins place
themselves in the wave created
by boats
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Definitions
Logging : whale lies still or near the surface for
an extended period of time
Believed to be a resting behaviour or maybe
sleeping
catnaps with brain function
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Baleen whales
Less social than odontocetes; form loose
aggregations
Seasonal breeding aggregations with intense
social activity
Often in small pods (less than 12)
Some work cooperatively to feed
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Baleen whales
Song
Tropics: male humpbacks sing loud and long andrepeat units of song that last 2-20 min
Song use: declare territory or lure females or both
Theory: song length shows males strength & Advertisemating ability
Next winter: sing version of song from last season withmodifications ( pick up from last year)
Usually Stop singing after breeding
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Odontocetes
Complex social structure fromsolitary beaked whales - true
oceanic dolphins pods
Organization depends on where
they live Ex. River dolphin: single or small
groups
Near shore= small pods
Oceanic= large schools (100s- 1000s)
e.g. spinner and spotted dolphin
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Odontocetes
Many dolphin pods = females and their
offspring
Often both subadult males and females leavegroups but females return when they bear 1st
calf
Males buddy up, and travel outside of female
home range, joining females to mate
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Odontocetes
3 types of societies
1. Nuclear group- single adult males with females
2. Nursery groups- adult females and their young
3. Bachelor group variable # of adult and subadult
males
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Faroe Island Pilot Whales
Males in pods are not the fathers of pod calf's
Males and females never leave mothers pod therefore 2 or
more pods converge for brief matting's ( limits inbreeding )
Males are larger than females and have a more bulbous head
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Faroe Island Pilot Whales
Grandmothers
Post reproductive females that are still lactating
B
aby sitters Pilot whales are deep feeders therefore they may be
feeding calves that cant dive while mothers feed
Only other group of whales that do this is the sperm
whale
Not all grandmothers lactate
Repository of cultural information e.g. locations of
feeding grounds (long term memory of specific
feeding grounds)
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Sperm whales
Sexualy dimorphic, deep divers
Females: 40 ft
Males: 60 ft and 3X the weight
Essentially a matriarchal system
Nursery group or schools: stable groups of 10-
20 mothers, nursing young and immature
calves of both sex (tropical and temperate)
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Sperm whales
Mature males leave group and form Bachelor
pods At 20-25 yrs males are solitary or in pairs
In autumn fully grown males return to warmer
waters to mate (move from one nursery groupto another ~ 6hrs)
Harem: Nursery schools with a visiting bull
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Social Harmony ?
Care for injured pod members
Most are aggressive at times: establishpecking order
Scars on animals of all ages showing fights
E.g. humpbacks:Males will often escort
females that have recently given birth andmay be ready to mate, and will fight off othermales
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Social Harmony ? beaked whales:
beaked whales: 19 sps ranging from 14-40 ft
Sexualydymorphic : males have pair of large teeth
in lower jaw that erupt at puberty
Males have scars
Many males grow dense bones on their snout for
protection during fights
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Social Harmony ?
E.g. Narwhal :
Sexually dimorphic teeth: males have tusk ~ 9ft
(upper left tooth)
Observed tusk threats or fights with males
Do NOT stab each other
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Social Harmony ? Small toothed
whales
Formal organization
When on the move, small closely related groups will adopt
geometric formation
e.g. wedge shape with dominant animals in the lead andyoung protected at the center
If an unknown is ahead, a dominant individual will investigate
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Social Harmony ? Small toothed
whales
Feeding is less formal
Co-operative hunting and corralling prey
E.g. killer whales = well organized hunting
Organize groups into respiratory units which ensurethat no member is ever breathing alone
Herding of salmon into tight ball and take turnsfeeding
Tilt ice floe (seal)
They appear to remain in contact with each otherthroughout the hunt
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Maternal Behaviour
All cetaceans take great care of offspring
Constant surveillance until weaning
Nursemaids
3 examples of care behaviour
1. daisy formation to protect injured pod member
2.distress, it will place itself danger and/or push injured
member away from danger
3. support so injured can breath
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