The elusive short-eared dog is a solitary, semi-aquatic enigma of the Amazon rainforest

Nature · Published 3 October 2026 Swipe more like this →

In short: Deep in the Amazon basin lives the short-eared dog, a rare canid that defies typical pack behavior. With partly webbed paws and a mysterious, solitary lifestyle, this animal remains one of the most unusual members of its family, avoiding human contact while navigating the dense, remote tropical rainforests of South America.

The short-eared dog, or Atelocynus microtis, is the sole member of its genus. While it bears a superficial resemblance to the bush dog, genetic research identifies the crab-eating fox as its closest living relative. These canids are products of the Great American Interchange, having migrated from North America to South America following the formation of the Isthmus of Panama roughly 2.5 million years ago. Genomic studies suggest that the subtribe Cerdocyonina, to which this species belongs, began diversifying between 3.5 and 3.9 million years ago.

Physically, the species is highly adapted to its environment. It possesses short, rounded ears, a fox-like muzzle, and a narrow chest. Its paws are partially webbed, a feature that aids its movement in the swampy, aquatic-adjacent habitats it frequents. The animal’s coat is thick and bristly, ranging in color from dark grey and chestnut to nearly navy blue. Interestingly, the species exhibits reverse sexual dimorphism, with females being approximately one-third larger than their male counterparts. Sexual maturity is reached at three years of age, a notably late milestone compared to other canids.

The short-eared dog is a shy, solitary carnivore that feeds primarily on fish, insects, and small mammals. It is notoriously difficult to study, as it prefers to remain under dense tree cover and actively avoids human interaction. Because of this, much of its life history—including its lifespan and gestation period—remains unknown. The species is currently classified as near threatened by the IUCN. Its survival is increasingly precarious due to habitat destruction and the spread of diseases, such as rabies and canine distemper, transmitted by feral dogs encroaching on formerly remote forest regions.

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