Post by Rr on Mar 24, 2018 17:42:51 GMT -8
The Deer
Deer Anatomy
Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, mule deer such as black-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species (except the Chinese water deer) and also female reindeer grow and shed new antlers each year.
General Information on the Deer
Deer weights generally range from 30 to 300 kilograms, though the smallest species, the Northern Pudú, averages 10 kilograms and the largest, the moose, averages 431 kilograms. They generally have lithe, compact bodies and long, powerful legs suited for rugged woodland terrain. Deer are also excellent jumpers and swimmers. Deer are ruminants, or cud-chewers, and have a four-chambered stomach. The teeth of deer are adapted to feeding on vegetation, and like other ruminants, they lack upper incisors, instead having a tough pad at the front of their upper jaw. Some deer, such as those on the island of Rùm, do consume meat when it is available.
Skeleton and Muscles
The Chinese water deer, tufted deer, and muntjac have enlarged upper canine teeth forming sharp tusks, while other species often lack upper canines altogether. The cheek teeth of deer have crescent ridges of enamel, which enable them to grind a wide variety of vegetation. Nearly all deer have a facial gland in front of each eye. The gland contains a strongly scented pheromone, used to mark its home range. Bucks of a wide range of species open these glands wide when angry or excited. All deer have a liver without a gallbladder. Deer also have a tapetum lucidum, which gives them sufficiently good night vision.
Antlers
With the exception of the Chinese Water Deer, which have tusks, all male deer have antlers. Sometimes a female will have a small stub. The only female deer with antlers are reindeer (caribou). Antlers grow as highly vascular spongy tissue covered in a skin called velvet. Before the beginning of a species' mating season, the antlers calcify under the velvet and become hard bone. The velvet is then rubbed off leaving dead bone which forms the hard antlers. After the mating season, the pedicle and the antler base are separated by a layer of softer tissue, and the antler falls off.
During the mating season, bucks use their antlers to fight one another for the opportunity to attract mates in a given herd. The two bucks circle each other, bend back their legs, lower their heads, and charge.
Each species has its own characteristic antler structure – for example white-tailed deer antlers include a series of tines sprouting upward from a forward-curving main beam, while fallow deer and moose antlers are palmate, with a broad central portion. Mule deer and black-tailed deer, species within the same genus as the white-tailed deer, instead have bifurcated (or branched) antlers—that is, the main beam splits into two, each of which may split into two more. Young males of many deer, and the adults of some species, such as brocket deer and pudus, have antlers which are single spikes.
Behaviour (Social, Reproductive, Feeding)
Social and Reproductive
Nearly all cervids are so-called uniparental species: the fawns are only cared for by the mother. A doe generally has one or two fawns at a time (triplets, while not unknown, are uncommon). The gestation period is anywhere up to ten months for the European roe deer. Most fawns are born with their fur covered with white spots, though in many species they lose these spots by the end of their first winter. In the first twenty minutes of a fawn's life, the fawn begins to take its first steps. Its mother licks it clean until it is almost free of scent, so predators will not find it. Its mother leaves often, and the fawn does not like to be left behind. The fawn stays hidden in the grass for one week until it is strong enough to walk with its mother. The fawn and its mother stay together for about one year. A male usually never sees his mother again, but females sometimes come back with their own fawns and form small herds.
Feeding
Deer are selective feeders. They are usually browsers, and primarily feed on leaves. They have small, unspecialized stomachs by ruminant standards, and high nutrition requirements. Rather than attempt to digest vast quantities of low-grade, fibrous food as, for example, sheep and cattle do, deer select easily digestible shoots, young leaves, fresh grasses, soft twigs, fruit, fungi, and lichens.
Subspecies of Deer
The deer family has roughly 62 species. The family Cervidae is organized as follows:
Subfamily Cervinae
Tribe Muntiacini
Genus Muntiacus
Southern Red Muntjac, Reeves's Muntjac, Hairy-fronted Muntjac, Fea's Muntjac, Bornean Yellow Muntjac, Roosevelt's muntjac, Gongshan muntjac, Giant Muntjac, Truong Son Muntjac, Leaf Muntjac, Sumatran Muntjac, Pu Hoat Muntja
Genus Elaphodus
Tufted Deer
Tribe Cervini
Genus Dama
Fallow Deer, Persian Fallow Deer
Genus Axis
Chital Deer
Genus Rucervus
Barasingha
Genus Panolia
Eld's Deer
Genus Elaphurus
Père David's Deer
Genus Hyelaphus
Hog Deer, Calamian Deer, Bawean Deer
Genus Rusa
Sambar, Sunda Sambar, Philippine Sambar, Philippine Spotted Deer
Genus Cervus
Red Deer, American Wapiti, Sika Deer, Thorold's Deer
Subfamily Capreolinae
Tribe Capreolini
Genus Alces
Moose
Genus Capreolus
European Roe Deer, Siberian Roe Deer
Genus Hydropotes
Chinese water deer
Tribe Rangiferini
Genus Rangifer
Caribou/Reindeer
Genus Hippocamelus
Taruca, South Andean Deer
Genus Mazama
Red Brocket, Small Red Brocket, Merida Brocket, Dwarf Brocket, Gray Brocket, Pygmy Brocket, Amazonian Brown Brocket, Yucatan Brown Brocket, Little Red Brocket, Central American Red Brocket
Genus Blastocerus
Marsh Deer
Genus Ozotoceros
Pampas deer
Genus Pudu
Northern Pudú, Southern Pudú
Genus Odocoileus
White-tailed deer, Key deer, Mule deer
The horse is a herd animal and needs to be able to communicate with other members of the herd in order to convey emotions such as fear, and to establish a hierarchy of dominance without resorting to violence.
Contentment can be shown by high head and tail carriage, and more extravagant movements. A horse could show impatience by nudging with its muzzle or by stamping its feet. Annoyance and anger can be signified by horses flattening their ears backwards, baring teeth and biting. A sign of aggression would be for a horse to show the whites of its eyes, and to approach in order to kick or to bit. This is unusual, as horses tend to be flight, rather than fight, creatures. A frightened horse might also show the whites of its eyes, but is more likely to back of or run away.
In contrast to signals of aggression within a herd, there are also signs of friendship. Mares and foals nudge and nuzzle each other during nursing or for comfort, and mutual grooming, when two horses nibble at each other, is often seen.
Horses also have a variety of methods of vocal communication. Vocal noises include a squeal or scream which usually denotes a threat by a stallion or mare. Nickers are low-pitched and quiet. A stallion will nicker when courting a mare; a mare and foal nicker to each other; and domestic horses nicker for food. Neighs or whinnies are the most familiar: high pitched, drawn out sounds that can carry over distances. Horses whinny to let others know where they are and to try to locate a herd mate. They also respond to each other’s whinnies even when out of sight.
Blowing is a strong, rapid expulsion of air resulting in a high pitched whooshing” sound, which usually is a sign of alarm used to warn others. Snorting is a more passive, shorter lower pitched version of blowing and is usually just a result of objects entering the nasal passage, but can also be used to signal excitement.
Deer Anatomy
Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, mule deer such as black-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species (except the Chinese water deer) and also female reindeer grow and shed new antlers each year.
General Information on the Deer
Deer weights generally range from 30 to 300 kilograms, though the smallest species, the Northern Pudú, averages 10 kilograms and the largest, the moose, averages 431 kilograms. They generally have lithe, compact bodies and long, powerful legs suited for rugged woodland terrain. Deer are also excellent jumpers and swimmers. Deer are ruminants, or cud-chewers, and have a four-chambered stomach. The teeth of deer are adapted to feeding on vegetation, and like other ruminants, they lack upper incisors, instead having a tough pad at the front of their upper jaw. Some deer, such as those on the island of Rùm, do consume meat when it is available.
Skeleton and Muscles
The Chinese water deer, tufted deer, and muntjac have enlarged upper canine teeth forming sharp tusks, while other species often lack upper canines altogether. The cheek teeth of deer have crescent ridges of enamel, which enable them to grind a wide variety of vegetation. Nearly all deer have a facial gland in front of each eye. The gland contains a strongly scented pheromone, used to mark its home range. Bucks of a wide range of species open these glands wide when angry or excited. All deer have a liver without a gallbladder. Deer also have a tapetum lucidum, which gives them sufficiently good night vision.
Antlers
With the exception of the Chinese Water Deer, which have tusks, all male deer have antlers. Sometimes a female will have a small stub. The only female deer with antlers are reindeer (caribou). Antlers grow as highly vascular spongy tissue covered in a skin called velvet. Before the beginning of a species' mating season, the antlers calcify under the velvet and become hard bone. The velvet is then rubbed off leaving dead bone which forms the hard antlers. After the mating season, the pedicle and the antler base are separated by a layer of softer tissue, and the antler falls off.
During the mating season, bucks use their antlers to fight one another for the opportunity to attract mates in a given herd. The two bucks circle each other, bend back their legs, lower their heads, and charge.
Each species has its own characteristic antler structure – for example white-tailed deer antlers include a series of tines sprouting upward from a forward-curving main beam, while fallow deer and moose antlers are palmate, with a broad central portion. Mule deer and black-tailed deer, species within the same genus as the white-tailed deer, instead have bifurcated (or branched) antlers—that is, the main beam splits into two, each of which may split into two more. Young males of many deer, and the adults of some species, such as brocket deer and pudus, have antlers which are single spikes.
Behaviour (Social, Reproductive, Feeding)
Social and Reproductive
Nearly all cervids are so-called uniparental species: the fawns are only cared for by the mother. A doe generally has one or two fawns at a time (triplets, while not unknown, are uncommon). The gestation period is anywhere up to ten months for the European roe deer. Most fawns are born with their fur covered with white spots, though in many species they lose these spots by the end of their first winter. In the first twenty minutes of a fawn's life, the fawn begins to take its first steps. Its mother licks it clean until it is almost free of scent, so predators will not find it. Its mother leaves often, and the fawn does not like to be left behind. The fawn stays hidden in the grass for one week until it is strong enough to walk with its mother. The fawn and its mother stay together for about one year. A male usually never sees his mother again, but females sometimes come back with their own fawns and form small herds.
Feeding
Deer are selective feeders. They are usually browsers, and primarily feed on leaves. They have small, unspecialized stomachs by ruminant standards, and high nutrition requirements. Rather than attempt to digest vast quantities of low-grade, fibrous food as, for example, sheep and cattle do, deer select easily digestible shoots, young leaves, fresh grasses, soft twigs, fruit, fungi, and lichens.
Subspecies of Deer
The deer family has roughly 62 species. The family Cervidae is organized as follows:
Subfamily Cervinae
Tribe Muntiacini
Genus Muntiacus
Southern Red Muntjac, Reeves's Muntjac, Hairy-fronted Muntjac, Fea's Muntjac, Bornean Yellow Muntjac, Roosevelt's muntjac, Gongshan muntjac, Giant Muntjac, Truong Son Muntjac, Leaf Muntjac, Sumatran Muntjac, Pu Hoat Muntja
Genus Elaphodus
Tufted Deer
Tribe Cervini
Genus Dama
Fallow Deer, Persian Fallow Deer
Genus Axis
Chital Deer
Genus Rucervus
Barasingha
Genus Panolia
Eld's Deer
Genus Elaphurus
Père David's Deer
Genus Hyelaphus
Hog Deer, Calamian Deer, Bawean Deer
Genus Rusa
Sambar, Sunda Sambar, Philippine Sambar, Philippine Spotted Deer
Genus Cervus
Red Deer, American Wapiti, Sika Deer, Thorold's Deer
Subfamily Capreolinae
Tribe Capreolini
Genus Alces
Moose
Genus Capreolus
European Roe Deer, Siberian Roe Deer
Genus Hydropotes
Chinese water deer
Tribe Rangiferini
Genus Rangifer
Caribou/Reindeer
Genus Hippocamelus
Taruca, South Andean Deer
Genus Mazama
Red Brocket, Small Red Brocket, Merida Brocket, Dwarf Brocket, Gray Brocket, Pygmy Brocket, Amazonian Brown Brocket, Yucatan Brown Brocket, Little Red Brocket, Central American Red Brocket
Genus Blastocerus
Marsh Deer
Genus Ozotoceros
Pampas deer
Genus Pudu
Northern Pudú, Southern Pudú
Genus Odocoileus
White-tailed deer, Key deer, Mule deer
The horse is a herd animal and needs to be able to communicate with other members of the herd in order to convey emotions such as fear, and to establish a hierarchy of dominance without resorting to violence.
Contentment can be shown by high head and tail carriage, and more extravagant movements. A horse could show impatience by nudging with its muzzle or by stamping its feet. Annoyance and anger can be signified by horses flattening their ears backwards, baring teeth and biting. A sign of aggression would be for a horse to show the whites of its eyes, and to approach in order to kick or to bit. This is unusual, as horses tend to be flight, rather than fight, creatures. A frightened horse might also show the whites of its eyes, but is more likely to back of or run away.
In contrast to signals of aggression within a herd, there are also signs of friendship. Mares and foals nudge and nuzzle each other during nursing or for comfort, and mutual grooming, when two horses nibble at each other, is often seen.
Horses also have a variety of methods of vocal communication. Vocal noises include a squeal or scream which usually denotes a threat by a stallion or mare. Nickers are low-pitched and quiet. A stallion will nicker when courting a mare; a mare and foal nicker to each other; and domestic horses nicker for food. Neighs or whinnies are the most familiar: high pitched, drawn out sounds that can carry over distances. Horses whinny to let others know where they are and to try to locate a herd mate. They also respond to each other’s whinnies even when out of sight.
Blowing is a strong, rapid expulsion of air resulting in a high pitched whooshing” sound, which usually is a sign of alarm used to warn others. Snorting is a more passive, shorter lower pitched version of blowing and is usually just a result of objects entering the nasal passage, but can also be used to signal excitement.