Population Bottleneck

An event(s) in which a significant percentage of the population is killed or unable to reproduce.

Population bottlenecks reduce the genetic variation and, therefore, the population's ability to adapt to new selective pressures, such as climatic change or shift in available resources

Population or genetic bottleneck

Recovery or

In the 1890’s, their population fell to about 30. Although it now numbers in the hundreds of thousands, the potential for bottlenecks within colonies remains. Dominant bulls are able to mate with a large number of females — sometimes as many as 100. With so much of a colony's offspring descended from just one dominant male, genetic diversity is limited making the species more vulnerable to diseases and genetic mutations.

Northern Elephant Seal

Heaviest wild land animal in Europe.Hunted to almost extinction in the wild in the

early 20th century. In the 1920’s they were re-introduced in

some eastern European countries where their numbers are increasing.

Wisent (European Bison)

The population of American bison (Bison bison) fell due to overhunting, nearly leading to extinction around the year 1890, though it has since begun to recover .

American Bison

YearAmericanbison (est)

Before 1492 60,000,000

1890 750

2000 360,000

Giant Panda

Greater Prairie Chicken

Cheetah

Some purebred dogs and cats

Other species with low population numbers and limited genetic diversity.

North America’s rarest mammal. First discovered in 1851. The species declined

through the 1900’s due to decreasing prairie dog populations and the plague.

Declared extinct in 1979. In 1981 a dog in Wyoming brought a dead black

footed ferret to his owner. A captive breeding program was started to

increase the population.There are over 1000 mature ferrets living in the

wild with four self sustaining populations.

Black Footed Ferret

Ferrets eat prairie dogs

Predators of Ferrets