What is the kangaroo rat's life cycle?

Answer 1

Koalas breed between August and February. 35 days after conception, the tiny, blind, hairless embryo emerges and moves into its mother's pouch, purely by instinct. At this stage it weighs about half a gram. Once in the mother's pouch, it then latches onto a teat, which swells in its mouth, securing it firmly so it does not fall out of the pouch. The koala baby, called a joey, feeds only on mothers' milk for 6-7 months.

To make the transition from mothers' milk to eucalyptus leaves, at about 6-7 months the joey begins to feed on "pap", which is actually a special form of the mother's droppings through which she can pass onto her joey the micro organisms which allow for digestion of eucalyptus leaves. No other animal lives solely on gum leaves, and special proteins are needed to digest them. One of the reasons the koala has a backward-opening pouch is so that the joey can stick its head out and feed on this pap which comes from the mother's own digestive system.

When the joey grows too large to fit in its mother's pouch, it still feeds a bit on mother's milk, lying on her stomach to feed, and spending the rest of its time firmly attached to her back. It only leaves "home" when the next breeding season starts.

For a diagram of the koala's life cycle, see the related link below.

Answer 2

Baby Joeys are born about 2cm long. The baby kangaroo, or joey, emerges from the birth canal, much as any mammal young does, but it is completely blind and hairless. Moving by instinct only, it crawls up the mother's fur to the pouch, where it attaches to a teat. The teat then swells in the joey's mouth, securing it through all the mother's movement so it cannot be dislodged, until it has grown for several weeks.

Depending upon the species, kangaroo joeys spend about 10 - 12 months in the mother's pouch being nursed followed by another 6 - 9 months 'at foot', only placing just their heads in the mother's pouch to suckle until weaned.

In the initial stages, the joey stays attached to the teat until it is ready to begin being independent. A mother kangaroo is capable of supporting one joey in the pouch and another joey at foot living permanently outside the pouch but still suckling. When nursing both a joey at foot and a joey in the pouch, the mother produces a different milk concentration for each joey, as each joey has its own teat. Kangaroos and other macropods produce colostrum throughout the entire joey stage, unlike placental mammals that only provide colostrum for a few days after birth.

Kangaroos have "embryonic diapause". This means that the mother kangaroo can suspend the development of the joey when it is still an embryo within her body, awaiting a time when conditions may be better suited for the birth of the young joey (for example, if she is already nursing a joey in the pouch or during drought times). This is why female kangaroos of reproductive age spend all of the adult lives pregnant.

Kangaroos can live anywhere between 8-12 years, sometimes longer.

Details on a kangaroo's life cycle can be found at the related links below.

Answer 3

The tree kangaroo has a gestation period of about 39 - 45 days, depending on the species.

A joey is born very undeveloped, tiny, blind and hairless, then it crawls into its mother's pouch. It attaches to a nipple for about 90-100 days, and stays in the pouch for a total of 8-9 months.

The tree kangaroo reaches reproductive age at about two years old.

Answer 4

Baby Red kangaroo joeys are born about 2cm long. The red kangaroo joey, emerges from the birth canal, much as any mammal young does, but it is completely blind and hairless. Moving by instinct only, it crawls up the mother's fur to the pouch, where it attaches to a teat. The teat then swells in the joey's mouth, securing it through all the mother's movement so it cannot be dislodged, until it has grown for several weeks.

Joeys spend about 6-8 months in the mother's pouch being nursed. In the initial stages, the joey stays attached to the teat until it is ready to begin being independent. A mother kangaroo is capable of having more than one joey of different ages in the pouch at the same time, feeding on different types of milk.

Kangaroos have "embryonic diapause". This means that the mother kangaroo can suspend the development of the joey when it is still an embryo within her body, awaiting a time when conditions may be better suited for the birth of the young joey (for example, during drought times). This is why female kangaroos of reproductive age spend all of the adult lives pregnant.

Kangaroos can live anywhere between 8-12 years, sometimes longer.

Details on a kangaroo's life cycle can be found at the related links below.

Answer 5

When first born, a joey is completely blind and hairless, and about 2cm long, or the size of a bean. It must move by instinct to crawl up the mother's fur to the pouch, where it attaches to a teat. The teat then swells in the joey's mouth, securing it through all the mother's movement so it cannot be dislodged, until it has grown for several weeks. Almost all of the joey's development takes place in the mother's pouch

A mother kangaroo is capable of having more than one joey of different ages in the pouch at the same time, feeding on different types of milk.

Kangaroos have "embryonic diapause". This means that the mother kangaroo can become pregnant soon after the birth of one joey, but suspend the development of the joey when it is still an embryo within her body, awaiting a time when conditions may be better suited for the birth of the young joey. This means that female kangaroos of reproductive age spend virtually all of their adult life pregnant.

Answer 6

Baby Joeys are born about 2cm long. They have to climb from the birth canal to the mother's pouch. They spend about 6-8 months in the mother's pouch being nursed. In the initial stages, the joey stays attached to the teat until it is ready to begin being independent. A mother kangaroo is capable of having more than one joey of different ages in the pouch at the same time, feeding on different types of milk.

There are over sixty known species of kangaroo, ranging from the largest, the Red kangaroo, to the smallest, the Musky rat kangaroo. Therefore, gestation periods vary. The musky rat kangaroo has a gestation period of 19 days, whilst the red kangaroo has a gestation period of about 33 days. Most other kangaroo species have a gestation period of 31-36 days. Most of the development of the joey occurs in the pouch rather than in the womb. Young musky rat kangaroo joeys spend about 21 weeks in the pouch, while red kangaroo joeys spend an average of 9 months in the pouch.

However, in reality, pregnancy length may differ. The mother kangaroo spends most of her adult life pregnant, but in drought times, she has the ability to indefinitely "freeze" the development of the young embryo until food sources are replenished. This is called embryonic diapause.

The young Joey continues to suckle until it is about 12 months old.

Answer 7

2 to 5 years