A BIT ON KANGAROOS by Brenda
Around the world kangaroos are one of Australia’s best known and loved animals. In Australia they are also one of the most persecuted and sometimes suffer horrific cruel deaths at the hands of humans.
Kangaroos are incredibly beautiful creatures. In certain areas along the length of the Murray river you may see the Red Kangaroo [northern-most areas], Western Grey Kangaroo [northern-most areas but further east than the reds] and Eastern Grey Kangaroos along most of the Murray but few, even none, in the areas the other two species may be found.
The eastern grey kangaroo is the most common macropod in Victoria. At present, in places, you may see quite a number together. The comment is sometimes made that kangaroos breed like flies [or rabbits] when weather conditions are good, this is incorrect, they have a very structured life. They are able to delay birth of young if weather conditions are not suitable. They may dispose of pouch young when weather conditions mean survival is unlikely.
We are seeing bigger mobs now because food and water have become almost impossible to find in most areas and animals are congregating where there is something to eat and drink. This is partly due to the extremely dry weather over the past few years but also of great concern in many areas is the destruction and loss of habitat for all our wildlife species, including the very visible kangaroos, who are being pushed together into smaller and smaller areas as their home ranges are being built on or altered in other ways.
Eastern grey kangaroos give birth to ONE baby each year. Each baby spends between 10 and 11 months in the pouch. When an Eastern Grey joey is born it will be 4 – 6 months before the female mates again. When successful mating has taken place the fertilised egg will develop to the blastocyst stage then become dormant until the current joey vacates the pouch. Just before permanent pouch emergence, the blastocyst that has been dormant since a short time after the successful mating will begin to develop and will be born about one month after joey number one has permanently vacated the pouch.
Red Kangaroos mate within a few days of giving birth to a joey with the egg developing to the blastocyst stage before becoming dormant until the joey in the pouch is permanently out. Pouch life for the Red Kangaroo is a little shorter than for the grey at around 9 months. Western Grey Kangaroos do not mate again until the pouch joey has permanently vacated the pouch; their breeding time is spring and early summer.
During severe weather conditions females may stop breeding, mortality rate for joeys may exceed 40%, males are usually lost first then oldest and youngest. Females may also dispose of pouch young, there is some evidence that male pouch young – up to about a fortnight old – will be disposed of first.
Eastern greys’ are in season for 46 days although there is only a very short time when actual mating takes place, the tiny joey is born about 35 days after mating, the baby looks like a pink baked bean with front legs which it uses to climb up to and into the pouch where it attaches itself to a nipple, the nipple swells permanently attaching the baby. It takes about 3 minutes from the time the baby is born to the time it finds its way into the pouch. If it falls nothing can be done and it will quickly die. Weight is around three quarters of a gram. At around five to five and a half months the eyes will be open, it may be up to a month after this before you will see the joeys head beginning to pop out of the pouch for brief periods but it is not rare for the non-furred joey to be seen with its head out of the pouch earlier than this. First time out of the pouch is usually – but not always – around 7months and lasts a very short time.
An eastern grey joey once it has permanently left the pouch will continue to suckle from mum until it is up to 18 months old, at the same time the new pouch baby will have attached itself to one of the remaining 3 teats and will suckle a different type of milk to its older sibling. Amazing!
Kangaroos are truly amazing creatures! We all need to remember that we have moved into the kangaroos’ habitat, they haven’t moved into ours. It is up to us to care for all our unique wildlife species. Humans are only one of the many species on earth, surely we should be using our intelligence to protect and preserve ALL living things not only ourselves