Жирафы/Giraffes







Жирафы/Giraffes ЖИРАФ Толковый Словарь Даля ЖИРАФ м. гираф, двукопытное животное Camelopardalis, с низким задом и несообразно долгою шеей Малый энциклопедический словарь Брокгауза и Ефрона Жирафа, (Camelopardalis giraffa), жвачное млекопитающее семейства покатоспинных или жирафовых (Camelopardidae s. Devexa); самое высок. млекопит. (выс. на уровне головы 5-6 м.). Вод. в восточн. Африке, иногда стадами до 40 голов. GIRAFFE The biggest ruminant and the tallest mammal. Very long neck with short, upstanding mane, high shoulders sloping steeply to hindquarters; long legs nearly equal in length. Male wt 2420-4250 lb (1100-1932 kg), shoulder ht 9-11 ft (2.7-3.3 m), top of horns up to 18 ft (5.5 m); Female wt 1540-2600 lb (700 1182 kg), female shoulder ht 2 ft shorter. Head tapers to point; long, prehensile tongue. Horns: solid bone, skin covered; a main pair in both sexes but female's thin and tufted; male's thick and bald on top, up to 5 in (13.5 cm). A median horn and 4 or more smaller bumps in males. Tail hocklength, with long tassel. Color brown to rich chestnut (old males darker, even black), dissected into intricate tapestry by patches and blotches of lighter hair, pattern unique in each giraffe. Scent glands: possible glands on eyelids, nose, lips; adult males have pungent smell. Teats: 4. SUBSPECIES Eight recognized races, the reticulated giraffe (G. c. reticulata) of north Kenya most distinctive its latticework of thin lines separating dark patches is also most unlike the markings of any other mammal. The familiar Masai giraffe (G. c. tippelskirchi) of East Africa has the most irregular pattern. RELATIVES The rare okapi, Okapia johnstoni, confined to a small region within the Congo Basin and only discovered early this century, is a dead ringer for the rainforest ancestor of the giraffe. WHERE IT LIVES Formerly throughout arid and dry savanna zones south of the Sahara, wherever trees occur. Eliminated from most of West African and southern Kalahari range but still reasonably common even outside wildlife preserves. GOOD PLACES TO SEE IT Too numerous to mention; most approachable along traveled roads in the popular national parks. ECOLOGY Equipped to exploit a 6 foot band of foliage beyond reach of all other terrestrial browsers except the elephant. The 18 inch (45 cm) tongue and a modified atlas-axis joint that lets the head extend vertically further increase the height advantage. Giraffes can browse crowns of small trees; big bulls can reach 19 feet, a yard higher than cows. Feed mainly on broad leafed deciduous foliage in the rains and on evergreen species at other seasons; menu includes 100 species but Acacia and Combretum trees are mainstays in most areas. Narrow muzzle and flexible upper lip, along with the prehensile tongue, enable this animal to harvest the most nutritious leaves in the quantity (up to 75 lb, 134 kg per day) necessary to sustain its great bulk. Drinks every 2 to 3 days when water available but also extracts water from green leaves; spends dry season near evergreen vegetation, as along watercourses, dispersing more widely in the rains. ACTIVITY Females spend just over half a 24 hour day browsing, males somewhat less (43%). Night is mostly spent Lying down ruminating, especially hours after dark and before dawn. Bulls spend about 22% of the 24 hours walking, compared to 13% for cows the extra mileage goes into searching for cows in heat. SOCIAL/MATING SYSTEM The giraffe is nonterritorial and sociable, living in loose, open herds. At a given moment a giraffe may be in a herd composed of all males, all females, females and young, or of both sexes and all ages or all alone if it is a mature bull or a cow guarding a new calf. There are no leaders and minimum coordination of herd movements. The fluid nature of giraffe society reflects the need to spend most of its time feeding and to move independently between variably spaced trees, and size that makes it unnecessary to bunch together for mutual security. Also height and excellent eyesight enable giraffes to maintain visual contact at long distances a dozen may be dispersed over 1/2 mi (0.8 km) of savanna and still be in a herd. In fact giraffes rarely cluster together unless they happen to be attracted to the same tree, nervous over the presence of lions, or aggregated in the open. Even at rest, herd members stay over 20 yd apart. As usual, females are more sociable than males and rarely out of sight of other females. Mothers of small calves associate most consistently, at least partly because of a mutual attraction between youngsters that results in creches of up to 9 calves. Average spacing between calves is usually less than 10yd. Males remain in maternal herds until they outgrow their resemblance to females at about 3 years, after which they join bachelor herds. They eventually leave their natal range, whereas females stay put. Home ranges of adults and subadults of the two sexes average 63 miles square in Tsavo NP (163 km square), hut vary enormously from 2 up to 252 miles square (5-654 km square). Once settled, hulls have smaller ranges than cows. HOW IT MOVES A giraffe has just 2 gaits walk and gallop. The long legs and short trunk decree an ambling walk, with the entire weight supported alternately on left and right legs, as in camels. The long neck moves in synchrony to maintain balance. In galloping (top speed 37 mph [60 kph]), forelegs and hind legs work in pairs like a running rabbit's. To drink, a giraffe must either straddle or bend its forelegs. The same is true of the okapi, disproving the idea that the giraffe's extra long neck and legs are the reason. REPRODUCTION Year round, with rainy season conception peak. First pregnant in fourth year, gestation 14 to 14.5 months; minimum interval hetween calves c. 16 months. Males begin competing for matings at 7 years hut continue growing, giving seniors a decided weight and height advantage. Male's head also gains weight with age, through bone deposition the process that creates the extra knobs on an old bull's head enabling a bull to deliver ever heavier blows during contests. Combat is rare, though, as bulls from the same area all know their place in a rank hierarchy established through daily contests while maturing in bachelor herds. By the time a female in estrus is ready to mate, the local alpha male has usually supplanted all lesser rivals without ever coming to blows. OFFSPRING AND MATERNAL CARE If we assume Serengeti giraffes are typical, a cow returns to the same location each time she calves The first week or so a calf lies out half the day and most of the night, carefully guarded by its mother, which usually stays within 11 to 25 yd of her offspring for the first 2 weeks, although mothers may stay over 100 yd from a hidden calf and even leave it alone to go to water. The increased security of a maternity group guarding calves in a creche allows a mother to go further and stay away longer. But calves are rarely left totally unattended; absent mothers usually return before dark to suckle their offspring and stay with them overnight. Although giraffes are weaned as yearlings and nutritionally independent at 16 months, the maternal bond lasts up to 22 months. PREDATORS From 50 to 75% of calves fall prey to lions and spotted hyenas the first months, despite hiding and the mother's determined defense. As adults are too big to be regular prey, a mother will stand over and defend her calf against lions, which run the risk of being kicked to death if they get within striking distance. Females never use their horns, and males only use theirs in contests with peers. HOW THEY COMMUNICATE The idea that giraffes are mute is a myth. Though normally silent, calves bleat and make a mewing call, cows seeking lost calves bellow, and courting bulls may emit a raucous cough. Giraffes also give alarm snorts, and moaning, snoring hissing, and flutelike sounds have been reported. GIRAFFE BEHAVIOR GiUIDE Expect to see and hear Usual context and meaning Male Advertising Dominance Male A big hull walking confidendy in the erect posture, head high, or urine" testing males.Observe behavior of other bulls toward such an animal especially whether they discreedy move out of his path. Aggression CHALLENGE TO SPAR OR FIGHT Males only. Females, do not spar or fight. 1. Challenger makes nonchalant approach, stands facing opponent in erect posture. Probable winner of a sparring contest can be foretold if one stands more erect or is taller than the other. 2. If opponent responds in kind, they have a confrontation. 3. They move stiff legged into parallel posinon, or 4. March in step with necks horizontal, looking straight ahead. 5. They rub heads and necks and twine necks or lean against one another, ears flapping (low intensity), with pauses while gazing into distance. Assessing opponent's weight. 6. Contestants aim blows at rump, flanks, or neck either from head to head or head to tail posinon, damping impact by leaning away. Skillful rocking with blows avoids damage. The rare hard blow that lands solidly can down an opponent. Standing broadside in erect posture. Angle horn threat from broadside stance. Aiming horns at adversary is intentional movement or threat to strike a blow. OTHER ACTIONS ASSOCIATED WITH THREAT DISPLAYS Sideswiping, mounting, displacement activities. Submission Giving way turning away from approaching individual; jumping aside. Yielding to displacing superior. Head and ears lowered, chin in. Appeasement display. Displacement Activities Pretended feeding; scraping with incisors or licking. Courtship MALE BEHAVIOR Following female, closely and keeping other males away. Tending bond indicates female approaching or in estrus. Urine testing with pronounced lip curl. Contact rubbing head on female's rump, licking her tail, nudging, gentle bumng, resting neck on her back. Foreleg lifting. Standing immobile in erect posture behind c, Prelude to mounnng. FEMALE BEHAVIOR Bolting and rapid tail swishing. Female urinating in response to male approach and contact/sniffing. Courtship circling. Holding tail out and deflected while standing in copulatory attitude (head up or down, ears back). Mating. Male looks in danger of overbalancing Mother and Offspring Young calves standing seemingly alone, just looking around. Young calves in creches. Play Racing around mother after nursing; calves gamboling; nose to nose greeting; older calves sparring. Especially early and late in day. Response to Predators Alert posture, head raised to maximum. Mothers of small calves especially vigilant. Snorting. Rarely heard. Kicking with front or hind feet. Response to close approach, especially females with calf. Reprinted from "The Safari Companion"