Supporting Information:
Red-Necked Wallabies (Notamacropus rufogriseus) escaped into the Ballaugh Curragh in the north of the Isle of Man (IOM) in the 1960s from the Curraghs Wildlife Park (Ref: Isle of Man: The mystery of the wild wallabies | ITV News Granada October 2021). They are a large non-native animal, which originate from southeast Australia and Tasmania, but have adapted well to the Isle of Man's climate and environment. Wallabies do have a legal status on the Isle of Man, as Tynwald has listed the Red-necked Wallaby on Schedule 8 of the Wildlife Act 1990 meaning that it is an offence to release or allow a wallaby to escape into the wild.
There are different, and polarised views, in the Isle of Man on the relative benefits or negative impacts of wallabies, and consequently about what we should do as an Island with these animals. Views range greatly from “cull them all” or “fence them in”, to “sterilise them” or “make them a headline visitor attraction” and “recognise them as a useful conservation grazing animal”. On the plus side, as the largest land animal with a widespread Manx distribution, they attract much interest from local people and tourists, they are arguably now a part of modern Manx culture and could be a stronger part of our Island’s visitor offer, if their population is healthy. On the downside they are non-natives, eat native vegetation, impact our internationally important habitats, and unrestricted growth in their numbers and distribution might cause long-term, widespread and irreversible harm to the Island’s ecology, agriculture, public health, carbon sequestration efforts and rural economy. They also create a potential risk to road users, including motor sport.
As with any invasive, non-native species, MWT believe there are three options going forward: a) Eradication; b) Management; c) No Action. To determine which of the options should be pursued we need to gather more evidence from an ecological, social, public health, road safety and economic perspective, and to do this will require expertise from a wider base. There are strong and differing views in the IOM, and therefore we advocate the need for scientifically-gathered empirical evidence, to add to anecdotal information. The table below sets out the known facts, the key issues, and what we would like to know to move the discussion forward. MWT have commenced small scale research, however wider support would help assess the situation more quickly and identify appropriate options.
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What We Know |
The Key Issues |
What We Want to Know |
How the IOM Will Find Out |
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Red-Necked Wallabies have been living free in the IOM since 1960s: BBC - Wallabies have run free on the Island for 50 years |
The wallabies have become a part of the modern IOM landscape and culture, but their impact is unknown and we currently have no IOM policy or management plan for them. |
What does the Manx population think about wallabies? Could they be an asset? Are they part of modern Manx culture now? Do we need an agreed management plan? What should that look like? |
Following the publication of scientific data listed below, hold a survey of key stakeholders to hear wider views. |
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The population has expanded since the 1960s and in recent years sightings have spread across the entire IOM with a proven population of at least 870 individuals, and an estimated population of 1000-1300 individuals. Management of the population might be required in the future, as is regularly for other large mammals elsewhere (e.g. deer in Scotland, and Macaque monkeys in Gibraltar). |
The population is potentially increasing to an unsustainable level. If the numbers get too high, then their grazing and browsing could have significant adverse effects and they could out compete other species. We do not know the ecological, logistical, financial, public health, animal welfare, social and technological implications. |
How is their population and distribution changing? What is their ecological impact? Is there an impact on public health? Is there any impact on agricultural biosecurity? Do we need to control numbers? How much do management options cost? Will they work? What have other countries done? |
Drone surveys were carried out in 2023 and 2024 to assess the population in the Ballaugh Curragh and then other woodlands in the north of the IOM. Commence ongoing monitoring of the existing population and its distribution. Conduct feasibility studies in key areas need, with benchmarking against other countries. |
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The gene pool within the population is likely very narrow (i.e. only a few wallabies initially escaped). |
Inbreeding has potentially resulted in an unhealthy population (e.g., blindness and neurological issues) and poor animal welfare. |
What is the genetic variability and health of the Manx wallaby population? |
Potential research project linked to BIAZA, EAZA and/or an off-Island university.. |
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Wallabies eat native flora; disrupt nesting and roosting protected bird species, including Hen Harrier, they invariably change the natural habitats they live in and have an impact on wider Manx ecology |
Wallabies could be having a significant negative impact on the IOM’s flora and fauna and if this isn’t checked Manx nature could be damaged in the long term. |
What precisely are wallabies eating? What impact are they having on Manx habitats and ecology? Can they spread parasites and disease? Are they safe to eat? |
DNA analysis of wallaby dung to determine plant species consumed. Genetic and pathology study a large number of individuals. A full ecological impact assessment (ECIA) must be made by Government to determine future management. |
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Road Traffic Risks Ref: Wallabies have caused a string of police incidents on the Isle of Man (inews.co.uk)
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The risk of road accidents might increase. Potential negative impact on motor sport, as the bulk of the feral wallaby population is adjacent to the northern TT circuit. Potential legal claim against the Government if a wallaby is deemed to have caused an accident |
How many incidents have there been? What is the likely risk to IOM motor users? What is the potential liability claim if a serious accident happens? |
Analysis of IOM road accident data; survey of key stakeholders. |