Monday, June 4, 2012

Animal Baby Costumes 7 Pics








Baby Platypus

Platypuses <Ornithorhynchus anatinus> are semi-marine mammals endemic to eastern Australia, including Tasmania

The female platypus has a pair of ovaries, but only the left one is functional. It lays one to three (usually two) small, leathery eggs (similar to those of reptiles), about 11 mm (0.43 in) in diameter and slightly rounder than bird eggs. The eggs develop in utero for about 28 days, with only about 10 days of external incubation (in contrast to a chicken egg, which spends about one day in tract and 21 days externally). After laying her eggs, the female curls around them. The incubation period is divided into three phases. In the first phase, the embryo has no functional organs and relies on the yolk sac for sustenance. The yolk is absorbed by the developing young. During the second phase, the digits develop and, in the last phase, the egg tooth appears.

The newly hatched young are vulnerable, blind, and hairless, and are fed by the mother's milk. Although possessing mammary glands, the platypus lacks teats. Instead, milk is released through pores in the skin. There are grooves on her abdomen in which the milk pools, allowing the young to lap it up. After they hatch, the offspring are suckled for three to four months. During incubation and weaning, the mother initially leaves the burrow only for short periods, to forage. When doing so, she creates a number of thin soil plugs along the length of the burrow, possibly to protect the young from predators; pushing past these on her return forces water from her fur and allows the burrow to remain dry. After about five weeks, the mother begins to spend more time away from her young and, at around four months, the young emerge from the burrow. A platypus is born with teeth, but these drop out at a very early age, leaving the h0rny plates with which it grinds its food.











Baby Hippotamus

Hippos are semi Marine Aquatic Mammals.

A study of hippopotamus reproductive behavior in Uganda showed that peak conceptions occurred during the end of the wet season in the summer, and peak births occurred toward the beginning of the wet season in late winter. This is because of the female's estrous cycle; as with most large mammals, male hippopotamus spermatozoa is active year round. Studies of hippos in Zambia and South Africa also showed evidence of births occurring at the start of the wet season. After becoming pregnant, a female hippopotamus will typically not begin ovulation again for 17 months.

Mating occurs in the water with the female submerged for most of the encounter,:63 her head emerging periodically to draw breath. Hippos are one of the few mammals that give birth under water, along with Cetaceans and Sirenians (manatees and dugongs). Baby hippos are born underwater at a weight between 25 and 45 kg (60–110 lb) and an average length of around 127 cm (50 in) and must swim to the surface to take their first breath. A mother typically gives birth to only one hippo, although twins also occur. The young often rest on their mothers' backs when in water that is too deep for them, and they swim underwater to suckle. They also will suckle on land when the mother leaves the water. Weaning starts between six and eight months after birth and most calves are fully weaned after a year. Like many other large mammals, hippos are described as K-strategists, in this case typically producing just one large, well-developed infant every couple of years (rather than large numbers of small, poorly developed young several times per year as is common among small mammals such as rodents)











Baby Walrus

$EXUAL MATURITY
1. Most male walruses are $exually mature at about eight to ten years. Successful reproduction, however, probably doesn't occur until 15 years when a male attains full physical size and is able to compete for females.
     
2. Most females are $exually mature at about five to six years. Successful reproduction probably begins at about ten years.

MATING ACTIVITY

1. Only a portion of the female population mates each year, as some are pregnant from the year before. Non-pregnant females may go into estrus some time between December and June and most ovulate in February.
     
2. In the Pacific, female herds meet male herds as they move south into the central and south Bering Sea in January. Estrous females gather in herds separate from pregnant females and are attended by males displaying nearby in the water.
     
3. Most mating probably occurs from December through March, when most $exually mature males produce viable sperm. Mating takes place off the pack ice, underwater and remote from shore; breeding locations are thus largely inaccessible for observation.
     
4. Each herd of estrous females is attended by one or more large adult males. According to one study, the ratio of males to females averaged 1 to 23.
• Males display visually and vocally from the water while the females rest. A display occurs both at and below the surface and lasts about two to three minutes. The males' displays include clanging bell-like sounds, pulses, and clicks under water, and teeth clacking and whistles at the surface.








Baby Seals

Seal pups are born on land in the spring and summer. To take advantage of warmer seasonal environments and plentiful food, some seal species are migratory, feeding in one spot in the summer and early autumn, and then traveling to a warmer spot in the autumn and winter to give birth and mate shortly afterwards. Seals can give birth in large groups, in which a crowd of seals have returned to a particular spot to breed, or they can give birth alone. Migratory seals usually give birth in groups, after which they mate with males and conceive another pup.

Another way to ensure that a pup is born at an optimal time is to delay implantation of the embryo inside the uterus. In seals, fertilization (the meeting of egg and sperm) may take place in April, but the embryo might not implant in the mother's uterus until October. This phenomenon of delayed implantation also occurs in roe deer, armadillos, and badgers. The total gestation period (the time it takes for the pup to develop inside its mother) is 9-15 months, depending on the species. The average active gestation period (the time from implantation to birth) is probably about 3-5 months.










Baby Polar Bears

$EXUAL MATURITY
1. Female polar bears reach $exual maturity at about four to five years.
     
2. Male polar bears reach $exual maturity at about six years.
     
3. Most male polar bears don't successfully mate until 8 to 10 years and older.

MATING ACTIVITY

1. Breeding takes place from March to June on the sea ice, but most occurs during April and May.
     
2. During the breeding season, males and females find each other by congregating in the best seal-hunting habitats.
     
3. Male polar bears have been seen following the tracks of breeding female polar bears for more than 100 km (62 mi.). Scientists are uncertain what signals males use to track breeding females.
     
4. Competition for females is intense. Females breed about once every three years; therefore, there are about three adult males to every breeding female.
     
5. Before mating, a female polar bear may be accompanied by several males. The males fight fiercely among themselves until the strongest or largest male succeeds in chasing the others away.
• A polar bear threatening to attack another polar bear usually lowers its head, flattens its ears back, and gives an open mouth threat with a hiss-like roar.
• Fights are rarely fatal, but do result in broken canines and scars on the head, neck, and shoulders.
     
6. Dominant males may succeed in mating with several females in a season.
     
7. Once paired, the male and female stay together for a week or more.
• Females are induced ovulators - the act of mating causes a female to release an egg for fertilization.
• Several days of mating interactions may be required to stimulate ovulation and guarantee fertilization of the egg.
       
8. Polar bears may have many different mates over their lifetime.