雅思阅读精选：加州小狐狸的"绝处逢生"_雅思英语阅读

雅思阅读精选：加州小狐狸的"绝处逢生"

　　Its probably the best known example of island dwarfism, Coonan said.

　　On the islands, the smaller foxes quickly differentiated into six new subspecies. Free from predators, they thrived until until the 1990s, when golden eagles arrived.

　　Historically, golden eagles never bred on the Channel Islands, but some do occasionally make the 25-mile trek from the California mainland.

　　In previous times, golden eagles arriving on the Channel Islands would have likely been chased off by bald eagles, which are intensely territorial. But the Channel Islands bald eagles had been decimated decades earlier by the insecticide DDT, Coonan explained. From the 1940s to about the 1970s, chemical companies discharged millions of pounds of DDT into the ocean, where it contaminated the bald eagles marine food supply.

　　In the 90s, golden eagles were drawn to Santa Cruz Island by its burgeoning feral pig population. The descendents of domestic farm animals brought to the island in the 1850s, the pigs provided a steady food source for the raptors.

　　What the golden eagles were really depending on were the pigs. The foxes were kind of an ancillary snack, said Kate Faulkner, chief of natural resources management for Channel Islands National Park.

　　The loss of bald eagles, the arrival of golden eagles, and the islands thriving feral pig population created a perfect storm of events that nearly doomed the island foxes, Coonan said.