Condors remained plentiful along the West Coast for thousands of years until Europeans began settling the region in the late 1700s. "In 1806, Lewis and Clark found large condors feeding on whale carcasses near the mouth of the Columbia River in Oregon," Chamberlain notes. "But huge sealing and whaling industries started around that time, and the large seal rookeries and whale carcasses quickly disappeared. So the condors were once again stuck without a food source. Our isotopes show that the disappearance of the marine mammals coincided with the arrival of the large Spanish missions with their cattle, which they raised largely for tallow and leather. Many thousands of cattle were brought here, so the condors switched their whole diet to cattle."
The large cattle ranches disappeared within a few decades, once leaving the condors without a reliable food source. "After the cattle were gone, condors starting getting rarer and hence more valuable as collector's items," Chamberlain says. "So people started shooting them for their feathers and stealing the eggs. That pushed them right to the brink of extinction until they hardly had any food left."
By the 1980s, only two-dozen condors remained in the wild, prompting the U.S. Fish and Wildlife Service to take the controversial step of rounding up the entire population and placing them in a captive-breeding program for future release.
"The decline of the condor was all man-induced," Chamberlain notes. "The megafauna are wiped out by early Ice Age humans, so the condors have to feed on marine carcasses along the coast. Then people come over again and killed seals, whales and sea lions, so the condors had to feed on cattle. Then we change our ranching practices s