Eastern Grey Kangaroo, Macropus giganteus
The eastern grey kangaroo (Macropus giganteus), also known as the Forester kangaroo or the great grey kangaroo, is a marsupial that can be found in eastern and southern areas of Australia. It prefers a habitat within woodlands, coastlines, inland scrublands, and mountainous forests. It is more common to see this species than the red kangaroo, although the red kangaroo is more well-known.
The eastern grey kangaroo varies in size depending on the sex, with males typically growing larger than females. Males can reach an average weight between 110 and 150 pounds, while females reach an average weight between 37 and 88 pounds. Bigger males have been recorded, with the largest weighing 200 pounds. This species has grey to light brown fur throughout its body, with a whitish underbelly, and lacks the face markings of the red kangaroo. It is similar in appearance to the western grey kangaroo, and in areas where the two species overlap, it can be difficult to distinguish between them. The western grey kangaroo has darker fur, while the eastern grey kangaroo has lighter fur.
As is common to kangaroo species, the eastern grey kangaroo is typically active during the nighttime and during the early morning and late evening hours. Its rests and eats in the shade of trees during the day, preferring to be most active when the heat is not so bad. It consumes a large variety of grasses, including those found on agricultural lands. This species is sociable and will gather in large groups. These groups contain two or three females, two or three males, and the young produced between them. One male is dominant, and he will have better access to desirable food, females, and shady areas. Despite this dominance hierarchy, males do not hold a territory and will only fight over a female that is ready to breed. Groups rely heavily on large numbers for protection and will allow most kangaroos to join the group, even if females have entered estrous.
Female eastern grey kangaroos form close bonds, and it is thought that this behavior allows the females a greater chance to breed. Females are pregnant for the majority of their lives, with the exception of days that they are giving birth. If food is scarce or weather conditions are poor, males will fail to produce sperm and females will delay the fertilization of any egg. This is known as embryonic diapause, and this will occur if a joey, or baby kangaroo, is already occupying its mother’s pouch or in times of drought. It is common to see females raising two young, one of which is still within her pouch, and she is able to alter the nutritional content of her milk to suit the older and younger joeys. Joeys are raised by their mothers alone and are weaned at around 550 days of age. Females will reach sexual maturity at up to 28 months of age, while males are able to breed at 25 months of age.
The population number of the eastern grey kangaroo is in the millions. It is thought that an increase in numbers occurred after European settlers moved into its range, creating a less forested and more suitable open habitat for the species, as well as reducing the numbers of its natural predator, the dingo, and creating artificial watering holes. In some areas, the eastern grey kangaroo has overgrazed the natural and introduced vegetation, and culls have been conducted to control the population. This species is also hunted for commercial purposes, but it still occurs in large numbers across its range. The eastern grey kangaroo appears on the IUCN Red List with a conservation status of “Least Concern.”
Image Caption: An Eastern grey kangaroo female grazing, Macropus giganteus. Credit: Benjamint444/Wikipedia (CC BY-SA 3.0)