G.4 Conservation of Biodiversity

ExtinctionHas always been part of

evolution!!!Those species that are best

adapted to their environment survive to reproduce

Those which are not, dieImpacts of humans have greatly

accelerated the rate of species extinction in the world!

Reasons for Extinction

OverexploitationHabitat LossIntroduced speciesPollutionLoss of genetic variationCatastrophic Disturbances

Passenger PigeonFound in North

AmericaIn 1800’s the

population was in the billions

Last survivor died in captivity in 1944 in the Cincinatti Zoo

Causes:Produce only 1 egg/yearHabitat loss due to farmingFed on chestnuts, acorns,

and beech nutsUsed for shooting practiceHunted for feathers (for

hats) and meat

Carolina ParakeetFound in Northern US

and Southern Canada from the east coast to the midwest

Nest in hollow treesExtinct in the wild

since 1900

Causes:Nesting trees cleared

for farming and fuel in the mid 1800’s

Introduction of honey bee from Europe lead to competition = demise of the parakeet

Feathers used in hatsParakeets kept as pets

Great AukA flightless bird found

in North America, Europe, and the north Atlantic

The last mating pair died in 1844

Causes:• Only have 1 egg/year• Slaughtered for food

and bait by fisherman• Killed for the feather

industry (down for bedding)

Should Panda’s be left to go extinct?British scientists

Packham and Wright think it is at least something that should be considered

http://www.youtube.com/watch?v=W4nFwAvZ0OI

ConservationNature ReservesAreas of aquatic or terrestrial ecosystems

that have been protected in order to conserve biodiversity or unique species.

Conservation can be attempted by setting aside land for restricted access and controlled use.

These include small nature reserves and larger parks (ie – Algonquin Provincial Park)

Features that promote conservation of biodiversity1) Edge EffectsThe ecology at the edge of an ecosystem is

different than at the centreWhen habitat’s are fragmented the relative

proportion that occurs at a boundary increases

There could be a change in microclimate that can reduce appropriate habitats

Can open up species for greater predation

Features that promote conservation of biodiversity2) SizeSingle large sites are preferred over

several small sitesLarge sites can support larger

populations, have more niches and more resources

Smaller habitats have more edge area putting more organisms at greater risk

Features that promote conservation of biodiversity3) Habitat CorridorsHabitats can be fragmented by developed land

(farming, housing, etc…) or roadsCorridors connect otherwise isolated habitatsWildlife can travel between the habitats in

corridorsCan include greenbelts or tunnels under roads

Active Management TechniquesEffective management is the key to keeping

the diversity of a nature reserve. This is accomplished by:Restoration of the land to its natural stateRecovery of threatened species by restoring

their habitatRe-introductions of native species Removal of invasive speciesProtection against development and pollutionFunding and increasing public awareness

In Situ ConservationWithin the original habitatHabitat preservation - Nature reserves

help endangered species by maintaining their habitat and preventing competition from invasive species.

Long term management strategy

Ex Situ ConservationOften used as a last resort if a species cannot

be kept in its natural habitat safely or the population if incredibly small

Captive breeding Zoo’s and wildlife refugesTechniques include:

artificial insemination embryo transfer to a surrogate cryogenics

Peregrine FalconReason for decline: DDT and related

pesticidesBy the time DDT was banned in 1972 the

population in Eastern North America was gone

Populations from other parts of the country were used to establish captive breeding an re-introduce the population

Gray WolfYellowstone National ParkTwo packs from Canada were reintroduced in

1995 and 1996By 2002, 16 packs and more than 200 wolves

were in the park

Botanical Gardens – cultivation, breeding, and research

Seed Banks – Seeds are kept in cold, dark conditions that prevent the seeds from germinating. Seeds from plants from all over the world are stored in seed banks.