3.3 What makes a species prone to extinction

Influence on risk of extinction Factor Influence on risk of extinction 1 2 3 4 5 6 7

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Small population size or declining #s. Low genetic diversity. Small pop. Less chance of survival if conditions change May have small gene pool and be unable to adapt (cheetah) More inbreeding occurs causing genetic issues Large predators and extreme specialist are commonly in this category Unfortunately today there are right around 10,000 cheetahs left in the wild; possibly even less. According to The Cheetah Conservation in South Africa, a few decades ago cheetahs were predicted to be extinct by the year 2013. Thankfully there are still cheetahs alive to this day!

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Specialized feeders or niche requirements When dependent on one resource for survival species become at risk Some orchids rely on a single insect Giant pandas depend exclusively on bamboo (2,000 left)

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Low Reproductive potential Species which reproduce slowly at great risk Elephants live long time and have low reproductive rate and are more vulnerable Slower reproduction = difficulties sustaining and restoring pop. #s

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Behavior Flightless birds like dodo and the elephant bird evolved in places w/o humans. They were not afraid and were easily killed Whales and elephants have close bonds with one another they remain with dying members of their group & put themselves in danger Flocks and herds rely on each other. Isolated or smaller groups become vulnerable

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Large body/top predators Top predators more at risk. #s of species at end of a food chain are lower than other species. 10% rule Reduction in prey lower on food chain can have serious risks

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Narrow geographical range Limited range = more at risk than widely distributed species Place becomes damaged or destroyed they will have to be moved to zoos or reserves for survival Because of ongoing and potential loss of their sea ice habitat resulting from climate change, polar bears were listed as a threatened species in the US under the Endangered Species Act in May 2008. Spoon billed Sand piper limited to small area in Russia 200 left

Factors that make species more or less vulnerable to extinction Influence on risk of extinction Valued resources Species valued for parts are hunted (elephant = ivory, sperm whale = oil, emu = feathers) Due to their highly shiny and luxuriant fur, the marten’s pelts were and still are highly desired. Now, strict hunting laws are in place to ensure the survival of the marten. This African elephant has what are believed to be the biggest tusks among elephants at Kenya's Samburu National Reserve. Illegal poaching of some 30,000 elephants a year for their ivory tusks threatens the animals with extinction.