Biology 1229

Extinction II:The bad news

The four horsemen of the extinction crisis I: Habitat destruction

Spoon-billed sandpiper Jamaican blackbird

Jamaican BlackbirdNesospar nigerrimus ‘wildpine sergeant’Endemic to Jamaica2000-10000 remainingMature montane, elfin and mist

forest at high elevations

Blue and John Crow Mountains National Park800 km2 of habitat protectedOngoing surveys to establish

basic population biology of species

Blue Mountain coffee ~$30/pound…

Spoon-billed sandpiperEurynorhynchus pygmeusSmall wading birdMigratory1000 – 2500 remainingBreeds annually

1 clutch + ‘replacement clutch’ 14 % fledging rate

Saemangeum, South Korea Dammed in

2006 after lengthy legal battle

Spoon-billed sandpiperThreats

Habitat destruction Breeding habitat Staging grounds Winter habitat

Predation at breeding grounds Dogs Arctic foxes

Predation at wintering grounds hunting

The four horsemen of the extinction crisis II: Overkill

Example: (some) fisheriesExample: Bushmeat

Fisheries as overkill…

Fish

Invertebrates

BushmeatThe practice of

eating wild animals aka ‘game’A serious problem,

particularly in West Africa

Mountain GorillaGorilla beringeiCritically

endangeredCentral Africa, e.g.

DRC~700 left

None in captivityPopulation rising in

2002

Virunga MountainsDRC/Rwanda/Uganda380 gorillas, population

increasingDian Fossey

Gorillas and bushmeat 2007 Civil war in DRC leads to massive

displacement, need for food and many people with guns designed for killing large primates

Park rangers and anti-poaching patrols attacked Most rangers now pulled out of area

5 gorillas found shot dead in September

Many more in bushmeat trade

Western lowland gorillaDouble Whammy

Bushmeat Ebola

The four horsemen of the extinction crisis III: Invasive species

Mammals in New Zealand

Pre-human New Zealand3 species of land mammalsAll predators were birds

Good vision, poor sense of smell Many flightless birds

Then humans arrived…Kiore

House mouse

Ship rat

Norway rat

Feral cat

Feral pig

Sto

at

ferret

weasel

Bru

sh

-tailed

possu

m

European hedgehog

New Zealand extinctions since European settlement57 land birds extinct since

human arrival19 since Europeans arrived

Stephen’s Island wren Xenicus lyalli

"there is very good reason to believe that the bird is no longer to be found on the island, and, as it is not known to exist anywhere else, it has apparently become quite extinct. This is probably a record performance in the way of extermination." The Press 16 March 1895

Still endangered due (mainly) to predation Australasian Bittern Brown Kiwi Kokako New Zealand Dotterel Forbes’s parakeet Malherbe’s parakeet Chatham Island Oystercatcher Black Stilt Yellowhead Kaka Black Robin Kakapo + numerous seabirds, invertebrates, frogs and

reptiles

The four horsemen of the extinction crisis IV: Climate change

Polar bear

Polar BearUrsus maritimusLarge carnivore

Eats mainly seals Other terrestrial organisms will do

Sexually dimorphicSemi-aquaticArctic species

Polar bears are semi-marineHunt mainly on sea iceSwim well (but not indefinitely!)

Climatic changes affecting polar bearsSea ice

Decreased extent Longer swims – for the first time, polar bears are

being found drowned

Timing of ice formation and breakup

Results in mums in poorer condition and thus less reproduction

Prey availability Increased human-bear interactions