Chasmaporthetes (SciiFii)

The hunting hyena (Chasmaporthetes americanus), also known as the running hyena, the American hyena, and (by native American Indians) Shunka Warakin, is a species of hyena that originally lived in in North America as an extinct species of Chasmaporthetes during the Pliocene-Pleistocene epochs, living from 4.9 million to 780,000 years ago, and was once extinct, but has since been brought back from extinction by SciiFii and reintroduced to the open woodlands and grasslands across North America to help boost biodiversity. The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative. The hunting hyena is the only hyena to cross the Bering land bridge and made it into the Americas, and it ranges over western and southern United States.

The hunting hyena is one of the so-called "dog-like" hyenas (of which the aardwolf also belongs to), a hyaenid group which, in contrast to the now more common "bone-crushing" hyenas, evolve into slender-limbed, cursorial hunters like canids. Hunting hyenas are distinguished from other species by their thick brown coat, pointed ears, and long tail. They also have a body build and leg design very similar to those of aardwolves (Proteles cristata), but unlike aardwolves, hunting hyenas are built for long-distance running to hunt down prey such as deer, pigs, peccaries, and pronghorns. The hunting hyenas have more robust jaws with stronger teeth than that of aardwolves, allowing it to rip out chunks of flesh from its prey similar to other hyenas as well as predatory canids. Hunting hyenas are shy and primarily diurnal, sleeping in burrows it digs by night.

They have often been mistaken for solitary animals. In fact, they live as monogamous pairs with their young. If their territory is infringed upon, they will chase the intruder up to 400 meters (1,300 ft) or to the border. If the intruder is caught, which rarely happens, a fight will occur, which is accompanied by soft clucking, hoarse barking, and a type of roar. The majority of incursions occur during mating season, when they can occur once or twice per week. When food is scarce, the stringent territorial system may be abandoned and as many as three pairs may occupy a "single territory". The territory is marked by both sexes, as they both have developed anal glands from which they extrude a black substance that is smeared on rocks or grass stalks in 5-millimetre (0.20 in)-long streaks. Hunting hyenas also have scent glands on the forefoot and penile pad. They often mark near termite mounds within their territory every 20 minutes or so. If they are patrolling their territorial boundaries, the marking frequency increases drastically, to once every 50 meters (160 ft). At this rate, an individual may mark 60 marks per hour, and upwards of 200 per night.

A hunting hyena pair may have up to 10 dens, and numerous feces middens, within their territory. When they deposit excreta at their middens, they dig a small hole and cover it with sand. Their dens are usually abandoned aardvark, springhare, or porcupine dens, or on occasion they are crevices in rocks. They will also dig their own dens, or enlarge dens started by springhares. They typically will only use one or two dens at a time, rotating through all of their dens every six months. During the summer, they may rest outside their den during the night, and sleep underground during the heat of the day.

The breeding season varies depending on location, but normally takes place during autumn or spring. In Mexico and Southern United States, breeding occurs in early July. During the breeding season, unpaired male hunting hyenas search their own territory, as well as others, for a female to mate with. Dominant males also mate opportunistically with the females of less dominant neighboring hunting hyenas, which can result in conflict between rival males. Dominant males even go a step further and as the breeding season approaches, they make increasingly greater and greater incursions onto weaker males' territories. As the female comes into oestrus, they add pasting to their tricks inside of the other territories, sometimes doing so more in rivals' territories than their own. Females will also, when given the opportunity, mate with the dominant male, which increases the chances of the dominant male guarding "his" cubs with her. Copulation lasts between 1 and 4.5 hours.

Gestation lasts between 89 and 92 days, producing two to five cubs (most often two or three). They are born with their eyes open, but initially are helpless and weigh around 200–350 g (7.1–12.3 oz). The first six to eight weeks are spent in the den with their parents. The male may spend up to six hours a night watching over the cubs while the mother is out looking for food. After three months, they begin supervised foraging, and by four months are normally independent, though they often share a den with their mother until the next breeding season. By the time the next set of cubs is born, the older cubs have moved on. Hunting hyenas generally achieve sexual maturity at one and a half to two years of age.

The hunting hyena has not seen decreasing numbers and is relatively widespread throughout Mexico and the United States. They are not common throughout their range, as they maintain a density of no more than 1 per square kilometer, if food is abundant. Because of these factors, the IUCN has rated the hunting hyena as Least Concern. In some areas, they are persecuted because of the mistaken belief that they prey on livestock; however, they are actually beneficial to the farmers because they prey on would-be-pests such as deer and rabbits that are detrimental to crops. In other areas, the farmers have recognized this, but they are still killed, on occasion, for their fur. Dogs and insecticides are also common killers of the hunting hyenas.