Socio-sexual signals and reproduction in mammals

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Whale rescue dilemma
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Cetaceans
Descendants of land-living mammals Related to
hoofed animals Entered the water roughly 50
million years ago
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Order Cetacea
Suborder Mysticeti baleen whales Family
Balaenidae Right Whales Family Balaenopteridae
Rorquals Family Eschrichtiidae Gray Whale Family
Neobalaenidae Pygmy Right Whale Suborder
Odontoceti toothed whales Family Delphinidae
oceanic dolphins Family Monodontidae Narwhal and
Beluga Family Phocoenidae Porpoises Family
Physeteridae Sperm Whale Family Kogiidae Dwarf
and Pygmy Sperm Whales Family Ziphidae Beaked
Whales Superfamily Platanistoidea river
dolphins Family Iniidae Boto Family Lipotidae
Baiji Family Platanistidae Ganges and Indus
River Dolphin Family Pontoporiidae La Plata
River Dolphin
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Order Cetacea
Suborder Mysticeti baleen whales Family
Balaenidae Right Whales Family Balaenopteridae
Rorquals Family Eschrichtiidae Gray Whale Family
Neobalaenidae Pygmy Right Whale Suborder
Odontoceti toothed whales Family Delphinidae
oceanic dolphins Family Monodontidae Narwhal and
Beluga Family Phocoenidae Porpoises Family
Physeteridae Sperm Whale Family Kogiidae Dwarf
and Pygmy Sperm Whales Family Ziphidae Beaked
Whales Superfamily Platanistoidea river
dolphins Family Iniidae Boto Family Lipotidae
Baiji Family Platanistidae Ganges and Indus
River Dolphin Family Pontoporiidae La Plata
River Dolphin
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Pilot Whales

• 3.5 to 5 m long, 1.5 and 3 tons, for female and
  male
• Males live for about 45 years and female about 60
  years
• Polygamous
• Very social, family animals
• May travel in groups of up to 100, one animal
  acting as leader
• World population is unknown (at least few
  100,000)
• Feed on squids and fish
• Feeding dives may last for 10 minutes or more
• Can dive to depths of 600m but most dives are 30
  - 60m

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Distribution of Pilot whales
Green Long-finned - Blue Short-finned
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Distribution of Long-finned Pilot Whales
Globicephala melas
http//www.environment.gov.au/cgi-bin/sprat/public
/publicspecies.pl?taxon_id59282
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Stranding of Long-finned Pilot Whales
http//aadc-maps.aad.gov.au/aadc/whales/species_si
ghtings.cfm?taxon_id59282
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Stranding in Tasmania - 2003

• Over 100 pilot whales
• Very few rescued

Photos The Age
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Difficult to rescue

• Skin needs to be maintained wet
• Heavy
• Cannot be towed
• They beached themselves again again

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Dilemma

• What would you do?
• - do nothing
• - euthanise the whales
• - try to save them

• Which animals would you save first?
• - adult male - adult female
• - pregnant
• - young

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Scientific interest

• Blood samples
• Tissue samples
• For DNA parenting, recording
• Understand the cause of stranding

Would you agree for the scientists to take
samples from all the whales?
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Whaling

• Pilot Whales have also been hunted for many
  centuries
• In the mid-1980s 2,300 animals killed annually
• By the 1990s Decrease to about 400/year

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Make use of the animals?

• Limited success of the rescue
• Whalers
• Euthanasia
• Process of meat and fat
• Money to finance the rescue

Would you agree for the company to euthanise the
remaining whales and process them?
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Possible explanations for stranding

• Sick or infested with parasites
• Internal compass may be malfunctioning due to
  pollutants or naturally occurring ionic minerals
  in the water.
• Simply be confused
• Leader beached itself and all the pod follows
• accidental or a purposeful effort on the part of
  the whales?

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Human responsibility?
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Scenario 1
Internal compass may be malfunctioning due to
sonar testing by the Navy
The leader strands itself and all members of the
pod follow
If you knew that the whales beached themselves
because of human activities, would you have taken
the same decision?
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Scenario 2
Genetic defect leading to heart defect
The leader strands itself and all members of the
pod follow
If you knew that the whales beached themselves
because of a genetic defect and following a
natural process, would you have taken the same
decision?
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Blue whales
Balaenoptera musculus
Listed as Endangered on IUCN Red list
Adult size 24-27 m Adult weight up to 136 tons
Photo Univ. Texas
Photo NOAA Yr. of the Ocean
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Distribution of Blue whales
http//www.environment.gov.au/cgi-bin/sprat/public
/publicspecies.pl?taxon_id39
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Stranding of Blue Whales
http//aadc-maps.aad.gov.au/aadc/whales/species_si
ghtings.cfm?taxon_id36
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Scenario

• A Blue whale is seen off Tasmania
• Wounded after being attacked by a killer whale
• - its natural predator
• Listed as Endangered on the IUCN red list
• What would you do?
• do nothing
• euthanise the whale
• try to save it