Population Bottleneck

1. Population Bottleneck

2. Population or genetic 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

3. Recovery or

4. Northern Elephant Seal • 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.

5. Wisent (European Bison) • 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.

6. American 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 .

7. Other species with low population numbers and limited genetic diversity. • Giant Panda • Greater Prairie Chicken • Cheetah • Some purebred dogs and cats

8. Black Footed Ferret • 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.

9. Ferrets eat prairie dogs

10. Predators of Ferrets