Short-Eared Dog Facts

Short-Eared Dog Profile

South America has more canid species than any other place on Earth. And that’s because until very recently in evolutionary terms, it had no dogs at all. Around 2.5 million years ago, South America finally joined up with North America, and one of the greatest exchanges of wildlife began. 

Migrating down from the North came the ancestor of all canid species now found in the South. This ancestor branched out into a multitude of niches, evolving to become all the species we see today.

One of the most elusive and under-researched is the short-eared dog. This unique canid is also known as small-eared dog, or short-eared zorro, and is native to the Amazonian basin.

Short-eared-dog facts
Photo credit: © Galo Zapata Ríos (

Short-Eared Dog Facts Overview

Habitat: Tropical forest, wetlands
Location: Brazil, Peru, Ecuador and Colombia
Lifespan: 11 years
Size: Up to a meter long
Weight: Around 10kg 
Colour: Brown-black, with reddish-brown underneath
Diet: Mostly fruit and fish, also mammals, marsupials, rodents, frogs
Predators: Ocelots, Jaguars, Pumas
Top Speed: Unknown
No. of Species: 1
Conservation Status: Near Threatened (IUCN)

Short-eared dogs are very funny-shaped animals, which made them hard to categorize for a long time just by looking at them. They don’t appear to be closely related to any fox-like or wolf-like canid

And even looking at them wasn’t easy, as they’re some of the most elusive canids known. They call home the rainforests of Brazil, Bolivia, Colombia, Ecuador, Peru and Venezuela.

Luckily, a habituated specimen was able to teach us a lot about his kind, but there’s still so much to learn in order to protect this mystery carnivore. 

The short-eared dog is currently considered near threatened by the IUCN, due to loss of habitat, disease, threat from feral dogs and humans.

Interesting Short-Eared Dog Facts

1. Flag-tailed wild dogs

These canids have a bunch of common names, some more accurate than others, and it was a while before researchers knew exactly what they were looking at. 

What’s left of the dog family, or Canidae, is branched into two tribes, the Vulpine, including all the foxes, and the Canini, which contains all the dogs (These aren’t to be confused with the Iceni tribe, who were responsible for making trouble for the Roman colonisers in Britain in the 0040s).

This strange-looking animal sort of resembles a marsupial than either of these canids and is locally known as the short-eared zorro, which is a type of fox. It’s also known as the “flag-tailed wild dog” on account of its interesting tail flare. 

And this is the most accurate because Atelocynus microtis is definitely a species of dog. It’s the only member of its genus in the Canini tribe, and one of the least understood of all 19 dog species. 

Short Eared Dogs
Photo credit: © jono_irvine (

2. They’re a mystery! 

This lack of research means we don’t really know all that much about it. Even locals consider them rare and elusive, and researchers have an even harder time figuring out how to study them. 

Very little behavioural information for this species comes from wild sightings, and most of what we know comes from a handful of captive specimens, and a pair of research papers from the ‘80s. 

From a couple of pieces of information – namely, local sightings and a third eyelid found on the dog – it’s inferred that this is a partially aquatic animal. There’s also a fair amount of fish remains in its poop, which does back this up. 

They appear to be solitary, and while 95% of observations have been made in the daytime, this doesn’t tell us much other than about the diurnal nature of the observers.

Communication is unknown, lifespan in captivity may not reflect that of wild animals, and overall, the species is a bit of a mystery. 1

3. Males are smaller

One thing that stands out in the species is the sexual dimorphism, which is the reverse of most mammal species, in that the males are smaller than the females. 

However, from a captive pair, it appears the little guy is still dominant over the female, despite the size discrepancy of around one-third, though this might not be typical.  

The males may maintain this dominance on account of them being generally unpleasant to get close to. 

4. They have a leaky anus

When excited, the male sprays a musk from the base of its tail. When agitated, it also raises the hairs on its neck, and puffs up the end of its bushy tail, which is what gave it the nickname “flag-tailed wild dog”. 

The anal secretions are said to produce a strong, musky odour, which doesn’t appear to be present in the female, and its role doesn’t appear to be well understood yet. 

The rest of what we understand comes mostly from a single animal, named Oso. 

5. Much of what we know is from a single individual, ‘Oso’

We can thank explorer and researcher Renata Leite Pitman for the majority of modern information on this species, as she has been involved in collating and tracking several wild individuals in recent decades. 

One of her projects was Oso, an orphaned (or likely more accurately, “dog-napped”) wild specimen that was brought up in captivity on a farm among domestic dogs. 

Oso was obtained by Pitman, along with the permits for her research, and the pair teamed up to figure out exactly what a short-eared dog is and does. Oso was taken on walks in the wild to figure out what his favourite food was. He was brought among females, to see what short-eared dog flirting looks like, and let loose to see how he related to other species.

What Pitman and her team discovered was that Oso’s notably small balls were a product of his age. 2

Short-eared dog laying down
Photo credit: © Diego Naranjo (

6. They are late bloomers

From the experiments, the team discovered that short-eared dogs don’t reach sexual maturity until three years of age, which is very old for a dog. This was only realized when Oso’s testicles finally descended, and he started making strange noises.

His vocalisations changed and began to resemble the calls of an owl. When these calls were recorded and played back in the forest, the local female showed up right away.

In 2010, Oso was released with a tracker back into the wild and was followed for three years before his collar ran out of battery.

In that short time, he gave Pitman and the rest of us valuable information about his species.

7. They depend on armadillos 

Being such small animals, they’re at risk of predation by the larger dangers in the Amazon. Jaguars, pumas, and even ocelots can be a danger to a short-eared dog, and the poor little canids don’t have a lot of power to defend themselves with, either. 

So, they hide. And part of their ecology is a strong relationship with armadillos. This is likely a very one-sided relationship, in which the dog hides in the burrow of the armadillo, and leaves nothing of value behind. 

One dog was recorded using up to 13 of these burrows, so they’re clearly important. The dogs spend about two hours hiding in armadillo burrows, then they spend about two hours walking about, eating, mostly, fruit. 

Males are very defensive of their burrows and females will leave their pups in one at around six months of age. 

8. They’re elusive and threatened

These shy animals are rare. It’s thought that this species is possibly the rarest of all South American carnivores, with an estimated 15,000 individuals. 

Being both shy and rare makes them a huge hassle to study, and this therefore makes their conservation difficult.

We can safely assume habitat loss is a threat to the species, but other threats come with human encroachment. 

Short Eared Dogs in Rainforest
Photo credit: © jono_irvine (

9. Domestic dogs are a problem

Hunters bring domestic dogs with them into the forest, and while direct attacks aren’t always a threat, the diseases the dogs bring with them are. 

Distemper and parvovirus in particular have been introduced into the short-eared dog population and could be devastating to the species. 

In response to this, vaccination programs are underway to provide the local domestic dog populations with the vaccines required to create a buffer between the short-eared dogs and the viruses. 3

Short-Eared Dog Fact-File Summary

Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae 
Subfamily: Caninae
Tribe: Canini
Genus: Atelocynus
Species: Atelocynus Microtis

Fact Sources & References

  1. Annalisa Bert (1986), “Atelocynus microtis”, Oxford Academic.
  2. Short-eared dog? Uncovering the secrets of one of the Amazon’s most mysterious mammals”, Mongabay.
  3. Atelocynus microtis short-eared dog”, Animal Diversity Web.