Speothos venaticus (Lund, 1842)

Voss, Robert S. & Fleck, David W., 2017, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 2: Xenarthra, Carnivora, Perissodactyla, Artiodactyla, And Sirenia, Bulletin of the American Museum of Natural History 2017 (417), pp. 1-1 : 1-

Speothos venaticus (Lund, 1842)

Figures 12B , 13B

VOUCHER MATERIAL: None.

OTHER INTERFLUVIAL RECORDS: Choncó ( Amanzo, 2006), Río Yavarí-Mirím (Salovaara et al., 2003), San Pedro (Valqui, 1999).

IDENTIFICATION: Bush dogs are unmistakable in external appearance ( Emmons, 1997), so sight

records from competent observers are reliable evidence for local occurrence.

ETHNOBIOLOGY: The bush dog has only one name, achu kamun. The term achu (“red howler monkey”) is used as a modifier of the term kamun (“feline/canine”) based on the similarity in pelage coloration of bush dogs and howler monkeys.

Bush dogs are not eaten. The Matses often comment that they would seem to make nice pets, but they almost never raise them due to the belief that they will make children fall ill. One informant knew of a single case in which a woman found a bush dog pup and raised it; when it became an adult it hunted together with Matses hunting dogs.

The spirits of bush dogs can make children ill when a Matses looks at a bush dog or kills one. If a hunter does so, he will collect medicinal plants to bathe his children with, to prevent them from becoming ill. Among the symptoms of being made ill by a bush dog (or a feline or other wild canine) are a high fever and intense thirst.

MATSES NATURAL HISTORY: The head and forequarters of bush dogs are orangeish. Their tails and hindquarters are black or blackish. Bush dogs are smaller and fatter than domestic dogs.

Bush dogs are more commonly encountered than short-eared dogs (but there are many Matses who have never seen one). They are found in all types of habitats.

They den together in hollow logs or in large holes in hillsides. Sometimes they dig depressions in the ground to sleep there one night.

Bush dogs are diurnal. They hunt as a group searching for the spoor of their prey. They search for pacas, sniffing for their scent along large or small streams. When they find paca spoor, all the members of the pack begin to follow it. When one dog finds the paca’s burrow, it calls the other dogs. A large male dog enters the burrow. The paca then dashes out of one of the other exits of its burrow, and all the dogs chase it down, barking. The paca typically goes to a stream, follows it to a deep bend, plunges in, and holds its breath underwater. The bush dogs arrive and the leader barks out orders for the others in the pack to surround the deep stream bend ready to pounce on the paca when it comes out. While some wait upstream, others downstream, and some on the bank above the stream bend, one or two of the bush dogs plunge into the water and feel around for the paca underwater. When one of the dogs touches it underwater, the paca emerges and flees to a shallow section of the stream, where the waiting dogs pounce on it. They kill it together, biting its neck and other vital parts, and they eat it together after pulling it to the bank. They eat every part of it.

When bush dogs find a greater long-nosed armadillo in its burrow, one of them enters the burrow, follows the armadillo into its retreat tunnel, kills it, and drags it out of the burrow to eat it with the other bush dogs. When they find a nine-banded long-nosed armadillo in a leaf nest on the ground, they surround the nest, and one of the bush dogs jumps on it (to make the armadillo come out). The other dogs then pounce on the armadillo and kill it, or they may have to chase it down to kill it.

When bush dogs find an agouti, they chase it down barking until it seeks refuge in a hollow log or a hole in the ground. Then, one of the dogs goes into the hole while the others wait at the opening. If the log or the hole in the ground has more than one opening, one dog goes into each hole. Then they kill the agouti in the log or hole, or they kill it as it exits. Bush dogs rest after eating, lying in a dry spot for a while, before hunting again. Or they may first drink water at a stream.

Bush dogs travel in packs of three to eight individuals; five is the typical size of a pack. The pack has a male leader. Both males and females hunt.

(The Matses do not know of any animal that eats bush dogs, although they imagine a jaguar would do so.)

Bush dog barks are more high-pitched than those of domestic dogs.

Bush dogs eat pacas, long-nosed armadillos, agoutis, acouchies, and spiny rats. They do not eat larger mammals like peccaries. They also eat whitethroated tinamous, smaller species of tinamous, wood-quails, and other terrestrial birds. They dig jungle frogs out of their burrows to eat them.

REMARKS: Bush dogs have long been something of a zoological enigma, with their small size, highly developed social behavior, hypercarnivorous dentition, absurdly short legs, partially webbed feet, diurnal activity, and a remarkable ability to swim underwater (Sheldon, 1992; Beisiegel and Zuercher, 2005). This odd combination of traits seems all the more extraordinary by comparison with those of closely related Chrysocyon brachyurus (the maned wolf; Perini et al., 2010), a much larger, solitary, omnivorous, long-legged, crepuscular/nocturnal, and strictly nonaquatic species. Attempts to explain bush dog morphobehavioral traits have included seemingly implausible suggestions that packs of these diminutive, dachshundlike animals can run down and kill much larger prey (e.g., peccaries, deer, and even tapirs; Zuercher et al., 2004); that their short legs and hypercarnivorous dentition are the nonadaptive consequence of phyletic dwarfing (Wayne and O’Brien, 1987); that their partially webbed feet are somehow useful for walking on soft soil near streams ( Beisiegel and Zuercher, 2005); and that they might cache their food underwater (Kleiman, 1972). A defining aspect of the literature on this species is that most information about diet and behavior is derived from captive studies; few biologists have seen bush dogs alive in the wild for more than a few minutes at a time (e.g., Deutsch, 1983; Peres, 1991; Strahl et al., 1992; Aquino and Puertas, 1997).

Matses observations about bush dogs—which agree strikingly with reports by Tate (1931) and Cabrera and Yepes (1940) that were also derived from indigenous sources—convincingly account for many unusual aspects of the bush dog phenotype. In particular, their dachshundlike morphology 6 is clearly adaptive for entering burrows or hollow logs to drag or flush their inhabitants (armadillos, pacas, agoutis) to the surface. Their cooperative social behavior and swimming abilities may be especially important for hunting pacas, whose streamside burrows have multiple exits, and whose evasive behavior often includes hiding underwater (Tate, 1931; Cabrera and Yepes, 1940; personal obs.). Although Matses accounts of bush dog hunting behavior include obvious anthropomorphisms, the ambush tactics they describe are plausible in the context of hunting behavior previously reported for other social canids (e.g., wolves and African hunting dogs). From these accounts, and from previously published anecdotes and captive observations, Speothos venaticus seems best characterized as a pack-hunting diurnal predator anatomically and behaviorally specialized to extract medium-sized (ca. 3–12 kg) mammalian prey from burrows, and to pursue escaped prey (especially pacas) into water.

Figures

FIG. 12. Dorsal views of adult skulls of Atelocynus microtis (A, AMNH 98639) and Speothos venaticus (B, AMNH 98560). Both specimens are from northeastern Peru, but neither is from the Yavarí-Ucayali interfluve.

FIG. 13. Ventral views of adult skulls of Atelocynus microtis (A, AMNH 98639) and Speothos venaticus (B, AMNH 98560). Note the absence of M2 in Speothos.