Impala

Sabtu, 19 April 2008 03.10

Impala

scientific name

aepyceros melampus

size/weight/height

Length: male 56" ; female 50 " • Tail: 12" • Height: male 36"; female 34" • Weight: males 176 lbs.; female 100 lbs.

adaptations/coloration

Color: light mahogany w/fawn flanks; hind legs have black glandular tufts; tail/thighs vertical stripes; white underside • Horns: males only

behavior

Defense: great leaps when alarmed; usually seek shelter in shrubbery/forests • Forage: graze on grass; browse on leaves • Group: large during dry season; often includes males & females; males generally leave before breeding age; during wet season herd breaks up into groups 15-25 females ; territorial males attempt to control female groups by entering their territory - males fight & frequently utter loud, hoarse grunts (serious injuries rare) • Movement: active morning/afternoon; alternately feed/rest

reproduction/lifespan

Birth: all yr.; concentrated in rainy season • Cycle: closely related to rainfall pattern; may be synchronized w/moon phase • Gestation: ~171 days

diet

Wild: flowers, grass, leaves, seeds • Zoo: alfalfa hay, oats

habitat/range

open woodland • sandy bush country • acacia savanna • C & S Africa

status

not listed • 2 species; 1 endangered

Hippopotamus

03.10

Hippopotamus

scientific name

Hippopotamus amphibius

size/weight/height

Height: 4.5'
Weight: 3000 - 7000 lbs.
Length: 11'
second largest land mammal

adaptations/coloration

Color: skin gray-brown • upperparts blue-black • underparts pink
Glands: in skin • exude thick red oil ("sweats blood") • shields sunburn & protects skin
Hearing/Sight/Smell: excellent
Hair: fine; hair covers body
Physical: eyes/ears/nostrils on top head
Swim: submerge 3 - 5 min • prevents skin dehydration

behavior

Movement: can move very fast; active on land 5 - 6 hours nightly when grazing; daytime in water for predator avoidance and temperature regulation
Group: females with young • adult males compete for territories containing groups of females & young via ritualized confrontations (last 1.5 hrs. • sometimes lethal)

reproduction/lifespan

Lifespan: 35 - 45 yrs
Mating: dry season
Birth: in shallow water • sometimes underwater
Young: reported to swim before walking
Parenting: nurse underwater • mother very protective • baby lies across mother’s back in deep water

diet

Wild: grass
Zoo: apples, carrots, grain, timothy hay & lettuce

habitat/range

waterways (day) • short grasslands (night) • Africa

status

CITES App II • due to poaching (meat, fat, hide & ivory) & human encroachment • common in captivity • breed readily - many captive females are on birth control

note

exhibit has 2 inside stalls, each with its own 6000-gal pool • 50,000-gal exhibit pool outside

Hedgehog

02.56

Erinaceus Sp.

size/weight/height

Weight: 8 - 24 oz.
Head & Body: 6.5 - 9"
Tail: 0.52"

adaptations/coloration

Color: body brown or gray with yellow ticking • underparts soft light gray hair • body covered with dense spines on upper surfaces
Snout: snout "prehensile" • used to search for food in forest litter

behavior

nocturnal
Defense: escapes enemies by running and hiding in rock crevices & under logs • rolls into ball to use spines as protection
Personality: gregarious • solitary
Vocalization: squeal & grunt when hungry, excited or afraid

reproduction/lifespan

Lifespan: known to live as long as 7 yrs in wild & captivity
Litters: usually 4 - 5
Young: born with soft, short spines which lengthen & harden shortly after birth

diet

Wild: carrion, eggs, frogs, fruit, fungi, lizards, mice, snakes and vegetables
Zoo: Hedgehog Maintenance Chow by Pretty Pets, supplemented by various insects and occasionally fruit.

habitat/range

forest, grassland, scrub areas with adequate food & cover • several species in Europe, Africa & Asia

other

Hedgehogs are not related to hogs. They are an insectivore.

Red-Tailed Hawk

02.56

Buteo jamaicensis

CLASSIFICATION

Class: Aves
Order: Falconiformes
Family: Accipitridae
Genus: Buteo
Species: jamaicensis

SIZE

Length: Male: 48-60 cm.
Female: 55-63 cm.

Weight: Male: 794-1200 gm.
Female: 900-1590 gm.

Wingspan: Male: 3 1/2-4 feet
Female: 4 feet

APPEARANCE:

The Red-Tail Hawk is one of the most common large broad-winged hawks in North America. The hawks also have a broad fan shaped tail. Adults are readily identified by the upper surface of their red tails. Typically, their backs and upper wing surfaces are dark gray or reddish brown, streaked and barred with lighter colors. Their plumage is highly variable though. In a lighter color phase, adult breasts are cream colored and streaked with brown. There is a darker blackish band across the belly. Dark phase birds may have red or black bellies, breasts, or wing linings. There will also be a difference in the Eastern vs. the Western species.

Immature birds begin to obtain adult plumage in their second year. Their colors also vary, but usually brown above, white below with heavy spots and streaks; tail gray-brown, indistinctly banded. As they change to the adult plumage, their tail feathers will drop out and be replaced by the red ones, and their other feathers will also turn more reddish in color. They will usually have their full adult plumage by the time they are two years old.

RANGE/DISTRIBUTION:

Red-Tails range from northern Canada and Alaska to Panama and Central America. They are one of North America’s most common raptors. The smallest of the Red-Tails are found in Alaska with the largest ones found in Northern Mexico.

HABITAT/TERRITORY SIZE:

Typical habitats of Red-Tails include open country, scrub, woodlands, or wide rocky canyons. They inhabit forests of the east as well as prairies and desserts of the west. They usually nest in tall trees near the edge of woodlands. In prairie and deserts, however, they may dwell on a ledge or in a low tree or cactus.

Red-Tails are very adaptable and wide ranging so they may be found almost anywhere. They are often seen perched within a few yards of busy highways, looking for live prey or road kills.

MIGRATION:

Red-Tails will winter from southern Canada south to Central America.

DIET:

Red-Tails prey on a wide variety of animals from grasshoppers to rats and mice, squirrels, rabbits, and other birds. They are successful because their prey species varies. About 75% of their diet consists of rodents and other small mammals. They will also consume rattlesnakes and reptiles as well as carrion.

HUNTING METHOD:

Red-Tailed Hawks, like other buteos, expend less energy in their hunting than accipiters. They soar above or will scan fields from a perch in a tree or from a fence post, and then move in for the kill. For unwary prey like mice, they will fly openly from perch to perch. Mice don’t pay any attention until it’s too late. For larger, more alert prey, Red tails sneak! They may approach indirectly, behind a cover of trees and bushes, or they may perch and look unconcerned and disinterested until the prey’s head is hidden or its attention is distracted. Then they’ll attack quickly and fiercely, and may even pursue their prey over short distances.

Red-Tails have unusual techniques for hunting shelter-oriented animals, such as snakes. They don’t attack the animal directly, but instead land on the ground between the animal and its shelter. In these cases, the shelter-oriented animal (one whose first defense is to hide) won’t generally run away. Instead, it will move slowly toward or even RUSH toward the bird, hoping to bluff its way to safety. It takes a special kind of courage to face down a frightened and enraged gopher snake or rattler intent upon reaching shelter.

BREEDING INFORMATION:

Especially during mating season, Red-Tails are acrobatic technicians, often touching their mates in mid-air or dropping 2,000 feet in a single dive. Their courtship displays are exhibitions of strength and flying ability. The male flies high in the sky, then cartwheels to the earth. Sometimes the female joins him in the air, and they’ll interlock their talons and tumble through space until they lose so much altitude they must break apart. It is believed the Red Tails mate for life, but if one bird dies, it is quickly replaced. In fact, if an accident should befall the female during the nesting period, she may be replaced so quickly that the eggs aren’t even chilled! Paired Red-Tails display courtship behavior throughout the spring even after the young are hatched. Breeding season lasts from March-May. Red-Tailed Hawks breed in the early spring—the exact month depends on the latitude.

These birds nest on the forest edge, on the horizontal limb of a tall tree, close to the trunk. If no tree is available, they will use a cliff edge or holes in rocks. As with most buteos, Red-Tails may have more than one nest, and will alternate from year to year. If the breeding in one nest is unsuccessful, the pair may abandon it altogether. After the nest is built by both mates, the female lays 2 to 4 eggs in March and early April, which are incubated by the female for a month. The male feeds the female while she is sitting. Eggs are grayish white with red or grayish brown spots, and measure 57 x 46 mm. Red-Tails bring fresh green foliage to the nest throughout this period. There are four possible reasons for this: shade for the young, prevention or reduction of insect problems, improvement of sanitation, or aesthetics. During the incubation period and while the chicks are small, the male supplies all the food for the family. (Squirrels are preferred during this period.) Young birds remain in the nest for at least four weeks, the last two spent practicing wing movements prior to fledging.

BEHAVIOR:

When threatened by an intruder, few Red-Tails will stay to defend its nest. They are generally shy and non-aggressive toward people, but are commonly attacked (but usually not injured) by crows, magpies, owls, other hawks, and even songbirds over territorial disputes. Calls are actually long, drawn-out raspy screams. In flight, they will make a high pitched “skeeeer”, at close range a croaking “guh-runk”. Birds frequently call while soaring.

STATUS:

Very common, probably the most often seen western bird of prey. They do, however, suffer high losses from ranchers and farmers who, not realizing their great benefit in controlling rodents, shoot them off telephone poles.

FOLKLORE AND MYTHS:

Red-Tailed Hawks were once called “Chickenhawks” because it was believed they routinely killed chickens. This, however, is a rare occurrence; and it is now generally accepted that Red-tails are very beneficial to the environment.

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