Post by rock on May 20, 2019 16:57:24 GMT 5
spotted hyena-Crocuta crocuta
The spotted hyena (Crocuta crocuta), also known as the laughing hyena or tiger wolf, is a species of hyena native to Sub-Saharan Africa. It is listed as Least Concern by the IUCN on account of its widespread range and large numbers estimated at 10,000 individuals. The species is however experiencing declines outside of protected areas due to habitat loss and poaching. The species may have originated in Asia, and once ranged throughout Europe for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, its rounded ears, its less prominent mane, its spotted pelt, its more dual purposed dentition, its fewer nipples and the presence of a pseudo-penis in the female. It is the only mammalian species to lack an external vaginal opening. The spotted hyena is the most social of the Carnivora in that it has the largest group sizes and most complex social behaviours. Its social organisation is unlike that of any other Carnivore, bearing closer resemblance to that of cercopithecine primates (baboons and macaques) with respect to group-size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, the social system of the spotted hyena is openly competitive rather than cooperative, with access to kills, mating opportunities and the time of dispersal for males depending on the ability to dominate other clan-members. Females provide only for their own cubs rather than assist each other, and males display no paternal care. Spotted hyena society is matriarchal; females are larger than males, and dominate them. The spotted hyena is a highly successful animal, being the most common large carnivore in Africa. Its success is due in part to its adaptability and opportunism; it is both an efficient hunter and a scavenger, with the capacity to eat and digest skin, bone and other animal waste. In functional terms, the spotted hyena makes the most efficient use of animal matter of all African carnivores. The spotted hyena displays greater plasticity in its hunting and foraging behaviour than other African carnivores; it hunts alone, in small parties of 2-5 individuals or in large groups. During a hunt, spotted hyenas often run through ungulate herds in order to select an individual to attack. Once selected, their prey is chased over long distance, often several kilmoetres, at speeds of up to 60 km/h. The spotted hyena is the largest extant member of the Hyaenidae. Adults measure 95.0—165.8 cm in body length, and have a shoulder height of 70.0-91.5 cm. Adult male spotted hyenas in the Serengeti weigh 40.5—55.0 kg (89—121 lb), while females weigh 44.5—63.9 kg (98—141 lb). Spotted hyenas in Zambia tend to be heavier, with males weighing on average 67.6 kg (149 lb), and females 69.2 kg (153 lb). Exceptionally large weights of 81.7 kg (180 lb) and 86 kg (190 lb) are known.
american cheetah-Miracinonyx trumani
The American cheetah is either of two feline species of the extinct genus Miracinonyx, endemic to North America during the Pleistocene epoch (2.6 million to 11,000 years ago) and morphologically similar to the modern cheetah (Acinonyx jubatus).
These cats were originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.
The two species commonly identified are M. inexpectatus and M. trumani. Sometimes, a third species, M. studeri, is included, but it is more often listed as a junior synonym of M. trumani.
Both species are similar to the modern cheetah, with faces shortened and nasal cavities expanded for increased oxygen capacity, and legs proportioned for swift running.
However, these similarities may not be inherited from a common ancestor, but may instead result from either parallel or convergent evolution.
These were larger than a modern cheetah and similar in size to a modern northern cougar. Body mass was typically around 70 kg (150 lb), with a head-and-body length of 170 cm (67 in), tail length around 92 cm (36 in), and shoulder height of 85 cm (33 in). Large specimens could have weighed more than 95 kg (209 lb).
Research into the American cheetah has been contradictory. The veracity of the origin of the modern cheetah is also debated; however, Miracinonyx is believed to have evolved from cougar-like ancestors, regardless of whether in the Old World or the New World.
M. trumani was the animal morphologically most similar to true cheetahs. Living on the prairies and plains of western America, it was probably a predator of hoofed plains animals, such as the pronghorn.
In fact, predation by Miracinonyx is thought to be the reason pronghorns evolved to run so swiftly, their 60-mph top speed being much more than was needed to outrun extant American predators, such as cougars and gray wolves.
American cheetah died out around 11,000 years ago. Its extinction coincides with the disappearance of many North American mammals, but what factors ultimately led to the demise of this feline are more of a mystery.
Climate change was obviously a factor, and the loss of some of its prey species may also
have been important. It is possible that such a specialist cat really felt the squeeze of climate change and the effect it had on its environment.
The spotted hyena (Crocuta crocuta), also known as the laughing hyena or tiger wolf, is a species of hyena native to Sub-Saharan Africa. It is listed as Least Concern by the IUCN on account of its widespread range and large numbers estimated at 10,000 individuals. The species is however experiencing declines outside of protected areas due to habitat loss and poaching. The species may have originated in Asia, and once ranged throughout Europe for at least one million years until the end of the Late Pleistocene. The spotted hyena is the largest member of the Hyaenidae, and is further physically distinguished from other species by its vaguely bear-like build, its rounded ears, its less prominent mane, its spotted pelt, its more dual purposed dentition, its fewer nipples and the presence of a pseudo-penis in the female. It is the only mammalian species to lack an external vaginal opening. The spotted hyena is the most social of the Carnivora in that it has the largest group sizes and most complex social behaviours. Its social organisation is unlike that of any other Carnivore, bearing closer resemblance to that of cercopithecine primates (baboons and macaques) with respect to group-size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, the social system of the spotted hyena is openly competitive rather than cooperative, with access to kills, mating opportunities and the time of dispersal for males depending on the ability to dominate other clan-members. Females provide only for their own cubs rather than assist each other, and males display no paternal care. Spotted hyena society is matriarchal; females are larger than males, and dominate them. The spotted hyena is a highly successful animal, being the most common large carnivore in Africa. Its success is due in part to its adaptability and opportunism; it is both an efficient hunter and a scavenger, with the capacity to eat and digest skin, bone and other animal waste. In functional terms, the spotted hyena makes the most efficient use of animal matter of all African carnivores. The spotted hyena displays greater plasticity in its hunting and foraging behaviour than other African carnivores; it hunts alone, in small parties of 2-5 individuals or in large groups. During a hunt, spotted hyenas often run through ungulate herds in order to select an individual to attack. Once selected, their prey is chased over long distance, often several kilmoetres, at speeds of up to 60 km/h. The spotted hyena is the largest extant member of the Hyaenidae. Adults measure 95.0—165.8 cm in body length, and have a shoulder height of 70.0-91.5 cm. Adult male spotted hyenas in the Serengeti weigh 40.5—55.0 kg (89—121 lb), while females weigh 44.5—63.9 kg (98—141 lb). Spotted hyenas in Zambia tend to be heavier, with males weighing on average 67.6 kg (149 lb), and females 69.2 kg (153 lb). Exceptionally large weights of 81.7 kg (180 lb) and 86 kg (190 lb) are known.
american cheetah-Miracinonyx trumani
The American cheetah is either of two feline species of the extinct genus Miracinonyx, endemic to North America during the Pleistocene epoch (2.6 million to 11,000 years ago) and morphologically similar to the modern cheetah (Acinonyx jubatus).
These cats were originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.
The two species commonly identified are M. inexpectatus and M. trumani. Sometimes, a third species, M. studeri, is included, but it is more often listed as a junior synonym of M. trumani.
Both species are similar to the modern cheetah, with faces shortened and nasal cavities expanded for increased oxygen capacity, and legs proportioned for swift running.
However, these similarities may not be inherited from a common ancestor, but may instead result from either parallel or convergent evolution.
These were larger than a modern cheetah and similar in size to a modern northern cougar. Body mass was typically around 70 kg (150 lb), with a head-and-body length of 170 cm (67 in), tail length around 92 cm (36 in), and shoulder height of 85 cm (33 in). Large specimens could have weighed more than 95 kg (209 lb).
Research into the American cheetah has been contradictory. The veracity of the origin of the modern cheetah is also debated; however, Miracinonyx is believed to have evolved from cougar-like ancestors, regardless of whether in the Old World or the New World.
M. trumani was the animal morphologically most similar to true cheetahs. Living on the prairies and plains of western America, it was probably a predator of hoofed plains animals, such as the pronghorn.
In fact, predation by Miracinonyx is thought to be the reason pronghorns evolved to run so swiftly, their 60-mph top speed being much more than was needed to outrun extant American predators, such as cougars and gray wolves.
American cheetah died out around 11,000 years ago. Its extinction coincides with the disappearance of many North American mammals, but what factors ultimately led to the demise of this feline are more of a mystery.
Climate change was obviously a factor, and the loss of some of its prey species may also
have been important. It is possible that such a specialist cat really felt the squeeze of climate change and the effect it had on its environment.
