THE SHOT- EARED DOG

 

The short-eared dog (Atelocynus microtis), also known as the short-eared zorro or small-eared dog,^[2][3] is a unique and elusive canid species endemic to the Amazonian basin.^[1][2] This is the only species assigned to the genus Atelocynus.^[1]

 

Other names

 

The short-eared dog has many names in the local languages where it is endemic, including cachorro-do-mato-de-orelha-curta in Portuguese, zorro de oreja corta ("short-ear fox") in Spanish, nomensarixi in Chiquitano, uálaca in Yucuna, cuachi yaguar in Guarayu, quinamco in Mooré, and achuj in Ninam and Mosetén.^[4]

Other common names in Spanish include zorro ojizarco ("blue-eyed fox"), zorro sabanero ("savannah fox"), and zorro negro ("black fox").

 

Evolution and systematics

 

After the formation of the Isthmus of Panama in the latter part the Tertiary (about 2.5 million years ago in the Pliocene), canids migrated from North America to the southern continent as part of the Great American Interchange. The short-eared dog's ancestors adapted to life in tropical rainforests, developing the requisite morphological and anatomical features. Apart from its superficial resemblance to the bush dog, the short-eared dog seems not to be closely related to any fox-like or wolf-like canid.^[5] It is one of the most unusual canids.^[6]

Two subspecies of this canid are recognized,^[1] A. m. microtis and A. m. sclateri

 

Occurrence and environment

In the Amazon rainforest

The short-eared dog can be found in the Amazon rainforest region of South America (in Brazil, Bolivia, Peru, Colombia, Ecuador and possibly Venezuela).^[1] There is a single report of "three slender, doglike animals" of this species sighted in the Darien region of Panama in 1984 by German biologist Sigi Weisel and a native Embera-nation Panamanian; this rare species' presence in Panama is possible because of "the continuous mass of forest habitat that covers this region".^[3] It lives in various parts of the rainforest environment, preferring areas with little human disturbance. It lives in both lowland forests known as Floresta Amazônica and terra firme forest, as well as in swamp forest, stands of bamboo, and cloud forest.^[7] It is a solitary animal and prefers moving in trees away from human and other animal interactions.^[8]

 

Appearance

The short-eared dog has short and slender limbs with short and rounded ears. It has a distinctive fox-like muzzle and bushy tail. Its paws are partly webbed, helping adapt it to its partly aquatic habitat.^[9]

Its fur ranges from dark to reddish-grey, but can also be nearly navy blue, coffee brown, dark grey, or chestnut-grey to black, and the coat is short, with thick and bristly fur.^[6] It has a somewhat narrow chest, with dark color variation on the thorax merging to brighter, more reddish tones on the abdominal side of the body.

 

Diet

 

This wild dog is mainly a carnivore, with fish, insects, and small mammals making up the majority of its diet. An investigation led in the Cocha Cashu Biological Station in Peru into the proportions of different kinds of food in this animal's diet produced the following results: fish (28%), insects (17%), small mammals (13%), various fruits (10%), birds (10%), crabs (10%), frogs (4%), and reptiles (3%).

 

Reproduction and behavior

 

This species has some unique behaviors not typical to other canids. Females of this species are about one-third larger than males. The excited male sprays a musk produced by the tail glands. It prefers a solitary lifestyle, in forest areas. It avoids humans in its natural environment. Agitated males raise the hairs on their backs.^[10]

The lifespan and gestation period of the short-eared dog are unknown, although sexual maturity is reached at three years of age, relatively late compared to other canid species.^[11]

Threats, survival, and ecological concerns

 

Feral dogs pose a prominent threat to the population of short-eared dogs, as they facilitate the spread of diseases such as canine distemper and rabies to the wild population. The short eared dog suffers greatly from loss of habitat. There is a significant amount of disturbance in formerly remote South American forests, and almost no habitat except where human settlers and prospectors pass daily destroy or expose their dens. Humans also contribute to their extermination by degradation of the species' natural habitat and the general destruction of tropical rainforests.

Manú National Park, Madre de Dios, Peru

 

Status of conservation

The short-eared dog is currently considered near threatened by the IUCN.^[2] No comprehensive ecological and genetic research has been carried out on the species. 

 

 Binomial name

 

 Atelocynus microtis

(Sclater, 1883)

 

 

 

 

 

 

 Short-eared dog range

THE BUSH DOGS

 

The bush dog (Speothos venaticus) is a canine found in Central and South America.^[4][5] In spite of its extensive range, it is very rare in most areas except in Suriname, Guyana and Peru;^[5][7] it was first identified by Peter Wilhelm Lund from fossils in Brazilian caves and was believed to be extinct.^[7] The bush dog is the only living species in the genus Speothos,^[4] and genetic evidence suggests that its closest living relative is the maned wolf of central South America^[8] or the African wild dog.^[9] The species is listed as Near Threatened by the IUCN.

In Brazil it is called cachorro-vinagre ("vinegar dog") or cachorro-do-mato ("bush dog"). In Spanish-speaking countries it is called perro vinagre ("vinegar dog"), zorro vinagre ("vinegar fox"), perro de agua ("water dog"), or perro de monte ("mountain dog").

 

 

Description

 

 

Adult bush dogs have soft long brownish-tan fur, with a lighter reddish tinge on the head, neck and back and a bushy tail, while the underside is dark, sometimes with a lighter throat patch. Younger individuals, however, have black fur over their entire bodies.^[7] Adults typically have a head-body length of 57–75 cm (22–30 in), with a 12.5–15 cm (5–6 in) tail. They have a shoulder height of 20–30 cm (8–12 in) and weigh 5–8 kg (11–18 lb).^[10] They have short legs relative to their body, as well as a short snout and relatively small ears.^[7]

The teeth are adapted for its carnivorous habits. Uniquely for an American canid, the dental formula is 3.1.4.13.1.4.2 for a total of 38 teeth.^[7] The bush dog is one of three canid species (the other two being the dhole and the African wild dog) with trenchant heel dentition, having a single cusp on the talonid of the lower carnassial tooth that increases the cutting blade length.^[7] Females have four pairs of teats and both sexes have large scent glands on either side of the anus.^[7] Bush dogs have partially webbed toes, which allow them to swim more efficiently.^[11]

 

Genetics

Speothos has a diploid chromosome number of 74,^[12] and so it is unable to produce fertile hybrids with other canids.^{[citation needed]}

 

Distribution and habitat

 

 Bush dogs are found from Costa Rica^[13] in Central America and through much of South America east of the Andes, as far south as central Bolivia, Paraguay and southern Brazil. They primarily inhabit lowland forests up to 1,900 metres (6,200 ft) elevation,^[7] wet savannas and other habitats near rivers, but may also be found in drier cerrado and open pasture.^[5] The historic range of this species may have extended as far north as Costa Rica where the species may still be found in suitable habitat.^[5][14][15] New, repeated observations of bush dog groups have been recorded in east-central (Barbilla National Park) and south-eastern (La Amistad International Park) Costa Rica, and a substantial portion of the Talamanca Mountains up to 120 km to the north-northwest and at elevations up to 2,119 m.^[16] Very recent fossils dating from 300 A.D. to 900 A.D.(the Late Ceramic Age) have been found in the Manzanilla site on the eastern coast of Trinidad.^[17]

There are three recognised subspecies:^[4][7]

• The South American bush dog (Speothos venaticus venaticus), with a range including southern Colombia and Venezuela, the Guyanas, most of Brazil, eastern Ecuador and Peru, Bolivia, and northern Paraguay.
• The Panamanian bush dog (Speothos venaticus panamensis), with a range including Panama, northern Colombia and Venezuela, western Ecuador.
• The southern bush dog (Speothos venaticus wingei), with a range including southern Brazil and Paraguay, as well as extreme northeastern Argentina. The first camera trap photos of this species in Argentina were obtained in April 2016 from the Selva Paranaense Don Otto Ecological Private Reserve, located in Eldorado Department of the Misiones province of Argentina. ^{[18] [19]}

 

Behavior

 

Bush dogs are carnivores and hunt during the day. Their typical prey are pacas, agoutis, acouchis^[20] and capybaras, all large rodents. Although they can hunt alone, bush dogs are usually found in small packs. The dogs can bring down much larger prey, including peccaries and rheas, and a pack of six dogs has even been reported hunting a 250 kg (550 lb) tapir, where they trailed the animal and nipped at its legs until it was felled. When hunting paca, part of the pack chases it on land and part wait for it in the water, where it often retreats.^[7]

Bush dogs appear to be the most gregarious South American canid species. They use hollow logs and cavities such as armadillo burrows for shelter. Packs consist of a single mated pair and their immediate relations, and have a home range of 3.8 to 10 square kilometres (1.5 to 3.9 sq mi).^[7] Only the adult pair breed, while the other members of the pack are subordinate, and help with rearing and guarding any pups.^[21] Packmates keep in contact with frequent whines, perhaps because visibility is poor in the undergrowth where they typically hunt.^[22] While eating large prey, parents position themselves at either ends of the animal, making it easier for the pups to disembowel it.^[7]

 

Reproduction

Bush dogs with pups

Bush dogs mate throughout the year; oestrus lasts up to twelve days and occurs every 15 to 44 days.^[23] Like many other canids, bush dog mating includes a copulatory tie, during which the animals are locked together.^[23] Urine-marking plays a significant role in their pre-copulatory behavior.^[24][25]

Gestation lasts from 65 to 83 days and normally results in the birth of a litter of three to six pups, although larger litters of up to 10 have been reported.^[7] The young are born blind and helpless and initially weigh 125 to 190 grams (4.4 to 6.7 oz). The eyes open after 14 to 19 days and the pups first emerge from the nativity den shortly thereafter.^[7] The young are weaned at around four weeks and reach sexual maturity at one year.^[26] They can live for up to 10 years in captivity.^[7]

 

Conservation

 

Bush dogs are very little known compared to other canines of the World and their conservation is still in the beginning stages. The species is so uncommon that when bush dog bones were discovered in a cave in 1839, paleontologist Peter Wilhelm Lund thought that they were already extinct.^[1] Luckily, bush dogs are not extinct and studies suggest that bush dogs are able to live in a wide variety of habitats and are a generalist species.

 

Some barriers to bush dog conservation include their dense habitat and very scattered population making them difficult to locate, the need for very large areas not disturbed by humans for the bush dogs to live in because they live and hunt in packs, and their very shy nature. The species is currently listed as Near Threatened by the IUCN because of an estimated 20-25 percent loss in numbers over the latest 12-year period.^[3] The main threats to bush dogs in the wild are in order of most important: habitat loss, including fragmentation, the loss of prey species because of human poaching and diseases that they can get from the domestic dog populations that they come across. The type of habitat loss that is affecting bush dogs the most is clear cutting of trees in the amazon and other good habitats for wood, cattle farming and palm oil. Disease from domestic dogs is slowly becoming a bigger and bigger problem for bush dogs, because of human encroachment they now share more of their habitat than ever with potentially unvaccinated domestic dogs. Hunting of bush dogs is prohibited in most of their range, countries banning the hunting of the species include Colombia, Ecuador, Brazil, French Guiana, Paraguay, Peru, Bolivia, Panama and Argentina. There is nothing that explicitly bans bush dog hunting in the laws of Guyana and Suriname. Another issue is that many of the countries that the bush dog lives in have limited resources in place to enforce the wildlife laws that are made.

Currently scientists are using a number of different methods to try and create a management plan for bush dogs. Traditional camera traps have not worked well in evaluating the species because of how shy they are so scientists have deployed scent-detecting dogs to try and find the bush dogs burrows where they rest at night.^[2] The hope is to be able to collect better data about habitat use of the species, what kind of prey they hunt, and how and when the cubs branch off from the pack. There are protected areas that exist throughout the bush dogs range such as the Yasuni Biosphere Reserve which will theoretically be able to support feeder populations. In good news for the species, as recently as 2020, bush dogs were caught on camera traps in the Talamanca Mountains of Costa Rica suggesting that they may be expanding their range northward and even higher in elevation than previously thought possible. This could mean that if humans put in a concerted effort to try and save bush dogs the species will be able to respond well and keep a steady population or maybe even gain in numbers.

 

 

 

 Binomial name

 

 Speothos venaticus

(Lund, 1842)

 

 

 

 

 

 Bush dog range

 

 

 

 

 

 

THE HYRAX

 

  

 Rock hyrax (Procavia capensis)
Erongo, Namibia

Characteristics

 

0:05

 

 

 

Evolution

 

 

 

 

 

Local and indigenous names

 

Young hyrax on Mount Kenya