Taxonomy
Macropus rufogriseus | Red-necked Wallaby
Distribution
Status
Conservation status
Least Concern
First reported in the wild
2002
Invasiveness
Invasive species - risk of Medium Impact
Irish status
Established
Introduction pathways - 1
Release in Nature
Introduction pathways subclass - 1
Landscape/flora/fauna improvement
Invasive score
15
NAPRA Ireland risk assessed
No
Species Biology
Identification
Appear similar to other Macropus spp (Kangaroos) but smaller, 0.82-1.5m in length tip to tail, exhibiting sexual dimorphism (males larger than females) weighing 3.4kg at 1 year up to 20.8kg at year 7 in males and 3.9-12.4kg in females (Catt,1977). Greyish brown fur with a white stomach and a 'rusty patch' on the shoulders, long tail and moving with a distinctive 'hopping' gait (Baker, 2008).
Ecology
Lambay Island population are predominately grassland grazers thought they supplement their diet with hay and silage in the winter (Matthew Jebb, personal communication). Diet in Scotland consists of heather, bilberry and grasses (Wier et al., 1995) and in New Zealand the diet comprises mainly grasses and herbs, however they will browse shrubs and trees, including commercially important species (Baker, 2008). If a population was allowed to establish in Ireland they would be expected to impact on commercial forestry, browse native plant species and alter communities and contribute to road traffic accidents through collisions (Baker, 2008; Lever, 2009). While risks are cited in relation to wallabies acting as a reservoir for toxoplasmosis, most cases appear to be animals in captivity where transfer rates would be higher and stress of transport and captivity may be a contributing factor (Bermúdez et al., 2009).
Habitat
Coastal; Woodland, forest and other wooded land
Reproduction
Seasonal breeding, with breeding season June-December (January - July in the southern Hemisphere) with births peaking in August & September (Baker, 2008), though birth may be a month later in first time breeders (Catt, 1977). Males mature at 21-22 months, females at 14-17 (Catt, 1977), one young per litter with an even sex biased ratio reported for New Zealand and Britain (Baker, 2008; Catt, 1977). More detailed descriptions of the complicated reproduction in wallabies in Johnson (1986).
Pathway and vector description
It's extremely unlikely this population could expand to the mainland, though the potential exists for deliberate introductions of animals to other parts of Ireland. The New Zealand population, that has established and expanded to the extent it is a pest species (estimated 15,000 individuals), is thought to have descended from as few as 3 individuals (Le Page, 2000) and the Loch Lomond population in Scotland is from an initial population of 4 individuals (Wier et al., 1995). There is a captive population of Bennet's wallabies at Fota wildlife park Co Cork.
Mechanism of impact
Competition, Grazing/Herbivory/Browsing
Broad environment
Terrestrial
Habitat description
Irish population on Lambay Island shelter in the gorse thickets on the hill and predominately graze grassland (Matthew Jebb, personal communication). However in Britain, where wild populations of wallabies are present they live in scrub, moorland and woodland (Baker, 2008) and might occupy similar habitat if released in Ireland.
Species group
Vertebrate
Native region
Australasia
Distribution
World distribution(GBIF)
Irish distribution
Established - Rare & Localised. Restricted to the population on Lambay Island. Originally two individuals kept on the island in the 1950s though they only survived for 5-8 years before a population of 6 individuals from Dublin Zoo were released in the 1980s (Matthew Jebb, personal communication). The population is thought to have begun breeding in the late 1990s and by the early 2000s the mob was thought to consist of ~30 individuals with a current population of ~60 (Matthew Jebb, personal communication).
Native distribution
Native to Australia, there are two sub-species of red necked wallabies Macropus rufogriseus rufogriseus found in Tasmania and thought to be source of the British and Irish populations and M. r. banksianus native to Queensland and New South Wales (Lever, 2009).
Temporal change
Date of first record category
Unknown
Fifty year date category
1951-2000
Records submitted to Data Centre in 2024
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How can you help
Report any sightings to the National Biodiversity Data Centre.
References
Publications
Baker, S.J., Hills, D. & Yalden D.W. (2008). Red-necked wallaby Macropus rufogriseus. In: Mammals of the British Isles : Handbook, 4th edition Harris, S. & Yalden, D.W. (eds) The Mammal Society, UK.
Bermúdez, R., Faílde, L. D., Losada, A. P., Nieto, J. M., & Quiroga, M. I. (2009). Toxoplasmosis in Bennett’s wallabies (Macropus rufogriseus) in Spain. Veterinary parasitology, 160(1), 155-158.Johnson, C. N. (1986). Philopatry, reproductive success of females, and maternal investment in the red-necked wallaby. Behavioral Ecology and Sociobiology, 19(2), 143-150.
Catt, D. C. (1977). The breeding biology of Bennett's wallaby (Macropus rufogriseus jruticus) in South Canterbury, New Zealand. New Zealand journal of zoology, 4(4), 401-411.
Le Page, S. L., Livermore, R. A., Cooper, D. W., & Taylor, A. C. (2000). Genetic analysis of a documented population bottleneck: introduced Bennett’s wallabies (Macropus rufogriseus rufogriseus) in New Zealand. Molecular Ecology, 9(6), 753-763.
WEIR, A., McLeod, J., & Adams, C. E. (1995). The winter diet and parasitic fauna of a population of Rednecked Wallabies Macropus rufogriseus recently introduced to Scotland. Mammal Review, 25(3), 111-116.