Episode 310: The Crab-Eating Fox

Published: Jan. 9, 2023, 7 a.m.

b"Thanks to Dean for this week's suggestion, the crab-eating fox!\\n\\nFurther reading:\\n\\nJaguars could prevent a not-so-great American biotic exchange\\n\\nThe crab-eating fox is not actually a fox:\\n\\n\\n\\nShow transcript:\\nWelcome to Strange Animals Podcast. I\\u2019m your host, Kate Shaw.\\nI\\u2019m happy to report that I\\u2019m feeling healthy and testing negative for covid now. Even my lingering cough has pretty much cleared up! I hope you\\u2019re healthy too. Anyway, this week let\\u2019s learn about an unusual animal suggested by Dean, the crab-eating fox.\\nThe crab-eating fox lives in parts of South America east of the Andes Mountains. It likes forests and open woodlands, and sometimes lives in savannas too although it prefers areas with a lot of tree cover and rivers. It\\u2019s a fairly small animal that rarely weighs more than 18 pounds, or 8 kg, and stands about 16 inches tall at the shoulder, or 40 cm. It has a thick coat that\\u2019s mostly gray or brown with reddish ears and paws, black markings on the ears, tail, and legs, and a black stripe down its spine. It also has a bushy tail and a relatively short muzzle.\\nThere are two important questions we need to answer about the crab-eating fox. First, does it actually eat crabs? Second, is it actually a fox?\\nThe crab-eating fox does indeed eat crabs, although it\\u2019s an omnivore and will eat pretty much anything it can find. This includes insects, eggs, fruit, carrion, and small animals of various kinds, especially rodents. But during the wet season, when it rains a whole lot and rivers flood and ebb repeatedly, the crab-eating fox eats a whole lot of crabs and other crustaceans.\\nThe crab-eating fox is not, in fact, a fox. It\\u2019s definitely related to foxes, since it\\u2019s a canid and the family Canidae includes foxes as well as wolves, dogs, coyotes, and all their relations, and it looks like a fox. It\\u2019s the only member of its own genus, but it\\u2019s grouped together with some other South American canids that look like foxes but are more closely related to wolves. But they\\u2019re not all that closely related to either foxes or wolves. Another member of this group is the maned wolf, the one with super long legs, which we talked about most recently in episode 167.\\nScientists think that the crab-eating fox\\u2019s closest relation is another South American canid called the short-eared dog, which we talked about in episode 195. Unlike the crab-eating fox, the short-eared dog likes heavy forests and lives in the Amazon rainforest. We know so little about it that researchers sometimes refer to it as the ghost dog.\\nThe crab-eating fox is nocturnal and spends most of the daytime sleeping in a den. Sometimes it makes a den by burrowing into thick grass, sometimes it will dig a burrow, but it prefers to find a den made by another animal and move into it if it\\u2019s empty. It may have several dens in its territory, which it often shares with its mate. Both parents help take care of the babies, and a female may have two litters a year.\\nI\\u2019m happy to report that the crab-eating fox is not endangered. It\\u2019s doing just fine in most places. It\\u2019s an adaptable, intelligent animal, which helps it thrive in a changing environment the same way coyotes do in North America. In fact, it fills the same ecological niche in South America that the coyote fills in North America, and this has led to a really weird potential problem.\\nThe crab-eating fox is native to South America, but it has been spreading northward into Central America. Likewise, the coyote is native to North America, but it has been spreading southward into Central America. Neither species likes thick forested areas, but as more rainforests are cleared for agriculture and housing, people have inadvertently made a sort of corridor for both species. Having people around doesn\\u2019t bother either the crab-eating fox or the coyote. Coyotes have made it as far south as Panama, almost to South America.\\nIf this continues, with crab-eating foxes migrating north and coyotes migrating south in ever gre..."