Endangered+Species+(Arctic+Tundra)

The polar grasslands biome contains a plethora of threatened species, such as the polar bear, arctic fox, and arctic wolf, but only a few species that are actually classified as endangered. Two of these species are the Eskimo curlew, also known as the prairie pigeon, and the arctic peregrine falcon.


 * Eskimo Curlew:** The Eskimo curlew is a migratory arctic bird that breeds in the grassy meadows of the polar grasslands during the summers and migrates to warmer semi-desert areas in the winter. It migrates to South America during the winter and returns to the arctic tundra to breed during the summer. The Eskimo curlew nests by digging holes in dry areas of the polar grasslands, and lays a set of 4 eggs per year that hatch in the summer. Its main food source is the rocky mountain grasshopper--it feeds primarily on its egg cases and insect nymphs. It is a medium-sized bird with a long, thin, beak that curves downward, long blue-grey legs, large wings, and a brown feather coat with black v-shaped markings.

The Eskimo curlew is a critically endangered species, estimated to have less than 50 individuals remaining in the wild. The last sighting of the Eskimo curlew occurred in the early 1960s. Between 1870-1890, unrestricted hunting caused the Eskimo curlew to decline dramatically. Today, the main threat to the Eskimo curlew is habitat loss. Its former breeding grounds in the polar grasslands have been taken over by a similar bird species, the Whimbrel, and its grassland winter habitats in South America have largely been converted to tree plantations. In 1994, only 4% of the Eskimo curlew's habitat on their northern migration route remained. The severe decline of the Eskimo curlew's habitat has most significantly influenced their decline. (J1) (J2)




 * Arctic Peregrine Falcon:** The arctic peregrine falcon is currently a threatened species, but was on the endangered species list for several decades. It is a migratory bird species that spends the harsh arctic winters in Central and South American countries such as Cuba and Mexico, and nests in the polar grasslands of Alaska, Canada, and Greenland in the summer. It is the palest and smallest of three species of peregrine falcon, with a slate-colored back and a white breast (J4). They breed in small nests in rocky areas of the tundra. Their main sources of food are mice and lemmings, although they will sometimes eat sparrows and other small birds (J3).

The largest decline of arctic peregrine falcons occurred in the 1950s due to high levels of the pesticide DDT and its breakdown product DDE. These pesticides caused death and reduced reproduction of arctic peregrine falcons and other birds of prey. DDE prevented normal calcium deposition in eggshells, causing eggs to frequently break before hatching, limiting the population of arctic peregrine falcons from growing. By the 1970s, arctic peregrine falcons had experienced nearly an 80% decline. However, as the use of DDT and other harmful pesticides was restricted, the arctic peregrine falcon population slowly increased. Its population size, reproductive rates, and eggshell conditions began to improve. Thus, it was reclassified from an endangered species to a threatened species in 1994 (J5). (J6)

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