The Red-necked wallaby
Written by Kendall Jackson (Lincoln University)
Edited by Michael Hudson, Lincoln University, September 2006
- Scientific name: Macropus rufogriseus (Desmarest)
- Synonyms: Wallabia rufogrisea, Macropus rufogriseus subspecies fruticus
- Popular Common names: Red-necked wallaby
- Other common names: red neck wallaby, scrub wallaby, Bennett’s wallaby, bush wallaby
- New Zealand Status: naturalised
- Taxonomy sources: King (1990), Long (2003), Macdonald (2001), The Chambers Dictionary (1993).
The long coat of the red-necked wallaby (Macropus rufogriseus) varies from grey to red on the head and body, from grey to white on its underside, and reddish-brown on the shoulders and neck. The muzzle, paws and the largest toes of the wallaby are black. The wallabies have long ears and grey-brown tails with black tips (Long, 2003). This wallaby has an acute sense of hearing and sight (King, 1990).
The red-necked wallaby is the largest wallaby in all of New Zealand, and the female is generally smaller than the male (Table 1) (King, 1990).
|Body Weight (kg)||Total Body length (mm)||Head and body length (mm)||Tail length (mm)||Hind foot length (mm)|
|Male||12–21||435 ± 23||650||620||200–230|
|Female||10–12||275 ± 17||610||620||200|
The red-necked wallaby is just one of six wallaby species in New Zealand. The main differences between each of the species are the markings of their tail and fur, as well as the geographical location where each of the species is predominantly found (Table 2) (King, 1990).
|Bushtailed rock |
|Tail||Tapering, dark towards tip||Tapering, uniform colour, well furred||Tapering, often white tipped, relatively hairless||Tapering, uniform colour, relatively short hair||Bushy, rufous colour, black tip||Tapering, almost black|
|Fur||Grey above, pale grey below, rufous-brown on neck and shoulders||Grey-brown, above, pale grey below, rufous shoulders||Brown-grey above , pale grey below, white cheek stripe||Brown above with distinct dark dorsal stripe, belly fur white, horizontal white stripe on thigh||Bluish-grey above, rufous on rump and belly, dark face with light white-grey cheeks||Dark black-grey above, yellow-rufous below, light yellow cheek stripe, distince orange band around base of ears.|
|Rank order of size||1=||4||5||1=||3||2|
|Distribution||South Canterbury||Rotorua district, Kawau Island||Kawau Island||Possibly liberated on Kawau Island, now believed extinct||Kawau Island, Maotutapu Island, Rangitoto Island||Kawau Island|
Full natural and naturalised range
The main regions that red-neck wallabies can be found are New Zealand, Australia, Tasmania, and King Island and Flinders Island in Bass Straight (Long 2003). Because the wallaby was originally from Australia, the natural distribution is much greater there than in New Zealand (King, 1993).
New Zealand range
The wallaby has stayed on the South Island since its introduction sometime between 1867 and1870. It was first introduced in the Hunter Hills near Waimate (Long, 2003) where the main population remains today (King, 1993). A second introduction in 1948 at the head of Quartz Creek on the west coast explains how the Wallaby has settled such a large part of the island (Long, 2003).
The red-neck wallaby populations remain in the Hunter Hills, the Kakahua Forest, Pioneer Park, and the Peel Forest of Southern Canterbury (Long, 2003). The main population is found predominantly in the one million acre range of the Hunter Hills; although most of the wallabies are found in just a quarter of this area (Poole, 1970). There have been several illegal attempts to introduce the red-neck wallaby outside of their existing range. So far none of these attempts have been successful (Long, 2003).
Natural History in Canterbury
Tussock grassland (Poole, 1970)
In order to satisfy the needs of both protection and food, the wallaby is considered an “edge” species. This means that the preferred habitat of the wallaby is on the edge of forests (or forest remnants) for protection, and tussock grasslands that provide food. These grasslands are covered with various types of grass with Chionochloa rigida (King, 1993) being most common. Wallabies have been found at altitudes up to 1000 metres above sea level (King, 1993).
Red-neck wallabies become reproductively mature after roughly two years. On average, the male wallabies become sexually mature before the female wallabies, around 21–22 months compared to 23–24 months for females (King, 1993).
Female wallabies are fertile throughout the year in New Zealand. This gives them the choice of when to breed. In other parts of the world the female is only fertile for a few months of the year (Long, 2003). Although the female wallaby is fertile all year round, the male wallabies’ reproductive ability fluctuates drastically with changes in size of the prostrate gland. From February to March, when the prostate reaches maximum size, the male is at his peak reproductive capacity. Beyond this period there is a steady decline. However, if the female wallaby wants to mate in late December; tough for the male (King 1993).
The female wallaby goes through an estrous cycle of 33 days (Long, 2003). If, at the time of mating, there is a young joey already in the pouch, a quiescent blastocyst will form and remain at that stage until the joey in the pouch leaves. Upon leaving, the quiescent blastocyst will remain in the birth canal until the following February–March. Only then will the blastocyst undergo gestation (King, 1993). On average, gestation is 30–31 days (Long, 2003). Most young are born between February and March (King, 2003).
The joey will open its eyes as early as the 135 days or as late as 150 days after birth. Between days 165 to 175, the joey will begin to develop fur while still inside the pouch. Remaining in the mother’s pouch for 274-280 days, the joey will continue suckling for 12–17 months (Long, 2003).
Nine years (Long, 2003).
Red neck wallabies have been observed to move an average of 1–3 km every night; but always staying close to the edge of the forest in their home range (King, 1993). During the day the wallabies tend to stay on the lower slopes of the grassland for cover and protection, moving up to the middle slopes in order to feed on the grasses at night (King, 1993).
A grazer by nature, the red neck wallaby eats the grasses that it surrounds itself in, but has also been known to eat various tree species (King, 1993). The wallaby enjoys feeding on a rich diet of foods; especially grasses, herbs, leaves, clover, roots, and a variety of weeds (Long, 2003). The food source the wallaby eventually decides to eat is not based on what it wants to eat, but instead the most available food source. Preferring to eat certain grasses, if these are unavailable, the wallaby will eat broad-leafed forbs (Sprent & MacArthur, 2002).
Wallabies are nocturnal animals that prefer a solitary life. During the day the wallabies find shelter using rest and den sites. Male wallabies prefer to use rest sites found on grass-clearings or among tussock grasses. Female wallabies prefer to use dens which are “in more secluded places, often under thick undergrowth or logs, with a depression often covered with leaves and moss” (King, 1993, page 47). Both dens and rest sites are used by only one wallaby. The sites are not marked or defended with a wallaby taking any site that is available (King, 1993).
Being reclusive creatures, the main time of contact between red neck wallabies is during mating season. During this mating period they use their acute sense of smell to differentiate one wallaby from another (King, 1993). To warn others of danger the wallabies will thump their hind feet on the ground (King, 1993).
In aggressive situations the male wallaby displays his dominance by standing erect “with ears pricked, chest expanded and forepaws crossed” (King, 1993, page 47). If the situation escalates into a fight, both wallabies attack, punching and kicking at one another until one turns his head and torso away in submission. After which the dominant wallaby will usually chase the defeated wallaby for up to 30 yards (King, 1993).
The breeding season of the red neck wallaby is throughout February and March (though mating can happen at any time during the year). Males will fight each other to mate with the estrous females. Once dominance is established, the male goes up to the female of choice to “sniff her pouch and cloaca” (King, 1993, page 49). The female then chooses whether she will allow the male to mate with her or not. If the male is successful, after mating the wallabies defy their social natures by either grooming one another or by grazing in the tussock land together. About 10 minutes later the male will try to mount the female again. If the female decides this is not what she wants, as the male is coming towards her, she will leave the area, sometimes coughing and hissing at him as she leaves (King, 1993).
There are no predators that hunt the wallaby specifically. Dogs have posed some threat by getting hold of the weak or young wallabies (King, 1993).
In a study done by S. McLeod, it was discovered that 75% of all red-necked wallabies have eaten, and carry within their stomach, up to six species of endoparasites (King, 1993).
How to find the Red-necked wallaby
There are two ways to know if you are near wallabies: firstly by finding their fecal matter on the ground (which is in the shape of a flattened square) and secondly by finding the distinctive footprints (with a prominent long toe). Once found, tracks will usually lead into wallaby tunnels that lead to resting places or dens (King, 1993).
Abundance and Conservation Status
- New Zealand: abundant (within range) (King, 1993)
- Canterbury: abundant
The wallaby was deemed to be a pasture pest in the 1940s (Long, 2003). Farmers called for this after finding that the wallaby was running their sheep off of pasturelands, destroying property, crops and exotic pines (King, 1993). As for plant life, there is some questioning as to whether the fault should be placed solely on the wallaby, or whether some lies with the sheep as well (King, 1993).
Significance for people
The wallabies were originally introduced out of curiosity. What started as an experiment, three wallabies were set free in the Hunter Hills region, two females and one male. The population increased rapidly to a point where the wallabies posed a hazard to the environment by destroying shrubs, crops and exotic trees (Poole, 1970). As interesting as they may be to look at or study, now the main focus for people is exterminating the wallaby (Poole, 1970). Shooting and poisoning have been the main method to control the population. Roughly 20% of the population is killed every year. However, this has proved to be inadequate to curb the rapidly expanding population (Long, 2003).
Although considered to be a pest, the red-necked wallaby is a creature whose behaviour is fascinating. Unique in its mating and breeding habits, the wallaby is sure not to disappoint those who study it. The future could be grim for the red-necked wallaby if man is ever able to fulfill his need to exterminate these naturalized animals. For now, it looks like the red neck wallaby shall remain a thriving member of the New Zealand faunal community.
Anonymous (1993) The Chambers Dictionary. Great Britain: Chambers Harrap Publishers Ltd.
King, C. M. (1990). The Handbook of New Zealand Mammals. Auckland, NZ: Oxford University Press.
Macdonald, D. (2001). The new encyclopedia of mammals. UK: Oxford University Press.
Long, J. (2003). Introduced mammals of the world-Their history, distribution and influence. VIC, Australia: CSIRO Publishing.
McArthur, C. & Sprent, J. (2002). Diet and diet selection of two species in the macropodid browser-grazer continuum: do they eat what they ‘should’? Australian Journal of Zoology, 50: 183-192.
Poole, A. (1970). Wild Animals in New Zealand. Wellington, NZ: A. H. & A. W. Reed Ltd.