40 Facts About Lumholtz's Tree Kangaroos That You May Not Know
A Kangaroo That Lives in Trees
The idea of kangaroos climbing and living in trees may sound very strange to some people and perhaps even fictional. Tree kangaroos are real animals, however. They belong to the same biological family as “normal” kangaroos, wallaroos, wallabies, and pademelons. They live in northern Australia, Papua New Guinea, and Indonesia. The Lumholtz’s tree kangaroo lives only in a small area of northern Queensland in Australia.
Tree kangaroos (or tree-kangaroos) belong to the family Macropodidae and the genus Dendrolagus. Fourteen species exist, though scientists disagree about how a few of them should be classified. The scientific name of the Lumholtz's tree kangaroo is Dendrolagus lumholtzi. Like the other members of its family, it's a marsupial. In this article I list forty facts about the animal that you may not know.
Kangaroos, wallaroos, wallabies, and pademelons have a typical kangaroo appearance but different sizes. The kangaroo is the biggest animal in the group and the pademelon is the smallest.
Introduction to the Lumholtz's Tree Kangaroo
1. The Lumholtz's tree kangaroo is named after a Norwegian explorer and ethnographer named Carl Sofus Lumholtz (1851-1922).
2. Lumholtz spend four years in Queensland. He got to know the indigenous people in the area and also studied the local wildlife. In 1883, he discovered the tree kangaroo that is today named in his honour. (As always, when someone from another country or area "discovers" a species, it may already be known by the local people.)
3. Though it has a bulky body, the Lumholtz's tree kangaroo is actually the smallest species in the genus Dendrolagus.
4. The genus name of tree kangaroos is derived from two Greek words: dendron, which means tree, and lagos, which means hare.
5. According to various reports, the Lumholtz's tree kangaroo is active during the day (diurnal), the night (nocturnal), or dusk and dawn (crepuscular). The actual situation may depend on the local environment.
6. As one of the references listed below says, the most accurate term for describing the animal's activity is probably cathemeral, which means that the animal is intermittently active throughout a twenty-four hour period.
The only other species of tree kangaroo living in Australia is the Bennett's tree kangaroo (Dendrolagus bennettianus). It lives in a small area in Queensland to the north of the Lumholtz's tree kangaroo's habitat.
Physical Features of the Animal
7. The Lumholtz's tree kangaroo is grey, brown, or red-brown in colour. The coat may have patches of different colours. The animal has a dark and often black face.
8. The head is small in proportion to the rest of the body and the ears are small.
9. The paws are black and have long and curved claws.
10. The animal has strong, muscular forelimbs and long and wide hind feet.
11. Like the other species in its genus, the animal has a very long, pendulous tail that helps it to maintain its balance in the trees. The tail isn't prehensile and therefore can't be coiled around branches.
12. Males weigh an average of seventeen pounds and females an average of fourteen pounds.
13. Though the animal travels through the trees with ease and spends most of its time there, it comes to the ground at times. It has no difficulty in moving over the ground, as shown in the video above, and often hops from one tree to another.
In the video below, a rescued youngster demonstrates its ability to move in the trees. A wild adult would probably be even more skillful.
Life in the Trees
14. The Lumholtz's tree kangaroo is usually found at higher elevations in montane rainforest, though it's also seen in drier areas and at lower elevations.
15. The animal is a folivore, which means it primarily eats leaves. These are thought to come from a wide variety of plants.
16. The marsupial also eats some fruits and vines.
17. The animals climb trunks quickly as long as the bark is rough enough for them to grasp.
18. Tree kangaroos in general are agile and adept in the trees. They balance well in the tree canopy and can leap from one branch to another.
19. The animals have flexible ankles and use both bipedal and quadrupedal locomotion in the canopy. They can move their hind legs independently of one another.
20. A tree kangaroo can splay and curl its front toes to enable it to grasp objects. It doesn't have opposable thumbs, however.
21. The Lumholtz's tree kangaroo is mostly solitary, except during the mating season or when a mother is caring for a joey (youngster).
As one scientist has said, many people are impressed by the ability of arboreal monkeys to move through the tree canopy, but tree kangaroos deserve respect for their ability, too.
22. A male's territory overlaps that of several females. It's thought that the male is polygamous and mates with multiple females in his territory.
23. Females are reproductively mature at around two years of age. Males don't mature until they are four-and-a-half years old (on average).
24. The species doesn't have a specific breeding season. Further research may change this assumption.
25. The gestation period is forty-two to forty-six days.
26. Only one joey is produced per mating.
27. Since the tree kangaroo is a marsupial, its youngsters are born in a very immature state and then crawl up to the pouch opening. Here a youngster attaches to a teat and continues its development.
28. The joey doesn't completely leave the pouch until it's around eight months old.
29. Before it lives independently, the joey is gradually weaned and spends some time outside of the pouch and some time in it.
30. Even when the youngster is completely weaned, it stays with its mother for a while. This period may last for up to a year—or perhaps even longer— until the mother mates again.
31. The average lifespan of the species in the wild is unknown. It may be much less than the number given in the quote below.
There is little information regarding the lifespan of the Lumholtz tree-kangaroo, but the Matchies tree-kangaroo, a closely related tree kangaroo, has been reported to live for up to 20 years in captivity— The Zoo Aquarium Association
The IUCN abbreviations shown above represent the following categories describing animal populations.
LC: Least Concern
NT: Near Threatened
CR: Critically Endangered
EW: Extinct in the Wild
Population Status and Threats
32. The IUCN, or International Union for Conservation of Nature, maintains a Red List for animals. The list classifies populations according to their nearness to extinction. The Lumholtz's tree kangaroo is classified in the "Near Threatened" category of the Red List.
33. It's thought that the population size is somewhere around 20,000 animals, including juveniles. The last population assessment done by the IUCN was in 2014.
34. In the past, the species was threatened by habitat loss. Now that conservation laws are in place, this is no longer a problem.
35. The animal's current habitat is quite fragmented, causing animals to exist in isolated groups. This is normally harmful for a species. Genetic diversity in a population is reduced when genetically similar animals breed. This may make the population more susceptible to new stresses. So far, the fragmentation doesn't seem to be affecting the tree kangaroo population in terms of diversity.
36. Habitat fragmentation is causing some problems for the species, however. Some animals are leaving their habitat, presumably to find new areas to browse. In certain locations, they are being attacked by dogs or being hit by motor vehicles as they do this.
37. In some areas, safe corridors between different patches of habitat exist. The corridors are important because they help to protect the animals as they travel.
38. Climate change might pose a problem for the species, since it is so dependent on eating nutritious and safe leaves from specific trees.
Another Threat and a Worrying Mystery
39. The Lumholtz's tree kangaroo is facing another threat. Some animals have recently become blind. This is a worrying observation, especially since the cause in unknown.
40. The blindness may be caused by a bacterial or viral infection or by a toxin. The scientist in the video above says that some animals are arriving at the tree kangaroo rescue centre with brain damage as well as blindness.
Dendrolagus lumholtzi is not a common animal, which is a concern. It may be more common than some people realize, however, because it's often hidden by the tree canopy. The animal's population doesn't appear to be in major trouble at the moment, though the vision loss is a concern.
Another area of concern is the fact that the IUCN says that the population trend for the animal is unknown. A new assessment is needed to determine whether the population is increasing, stable, or decreasing.
It would be helpful if scientists performed further studies relating to the animal's behaviour and biology. Unanswered questions about its life still exist. The creation of additional habitat corridors could also be an important strategy to help the species.
Like its relatives, the Lumholtz's tree kangaroo is an interesting animal. Hopefully its population numbers won't decrease any more and will increase instead. The diversity in nature is fascinating. Tree kangaroos are an important part of that diversity.
© 2018 Linda Crampton