Taxonomy

Capra hircus | Feral Goat | Gabhar fia

Distribution

Status

Conservation status

No conservation status is assigned.

The extinction risk of feral goat (Capra hircus) was not assessed under the national Red List assessment process for terrestrial mammals as it is known to be descended from domestic animals (Marnell et.al., 2019)

However,  the Domestic Animal Diversity Information System (DAD-IS) database of breed-related information on livestock diversity notes that the breed Irish Goat is at Critical population levels. 
Categorization of Risk Status as Critical according to the FAO Secondary Guidelines for the Development of National Farm Animal Genetic Resources Management Plans (FAO, 1998). P32, 33 states:
A breed is categorized as critical if the total number of breeding females is less than 100 or the total number of breeding males is less than or equal to 5; or the overall population size is close to, but slightly above 100 and decreasing and the percentage of females being bred pure is below 80%.

The most recent figures (up-dated 6th March 2018) on Irish Goat as published in  DAD-IS are:


YearPopulation
Breeding male
Breeding female
Females registered in herd books
2017min 25, max 3081212

First reported in the wild

Pre-historic introduction

Invasiveness

Invasive species - risk of Medium Impact

Irish status

Established

Introduction pathways - 1

Escape from Confinement

Introduction pathways subclass - 1

Agriculture

Invasive score

14

NAPRA Ireland risk assessed

No

Species Biology

Identification

Feral goats are long-haired ungulates (hooved mammals) and extremely variable in colour ranging from white, grey, brown, black or mixtures of various colours  (Bullock, 2008; Rooney & Hayden, 2002). Distinguished from sheep by the presence of a beard in both sexes (Bullock, 2008). Horns grow continously, not shed as in deer, which grow backwards and then outwards in a curve (Bullock, 2008). 

Show strong sexual dimorphism (males larger than females) with males weighing from 40 to 75kg and 60-75cm tall (shoulder height) with females weighing from 30 to 60kg, and 50-75cm tall (Bullock, 2008; Rooney & Hayden, 2002).

Diet

Adapted to season and local conditions , goats graze less than cattle or sheep with browse material from trees comprising an important part of the diet in winter and grasses, sedges and rushes dominating in summer (Bullock, 2008).    

Ecology

Goats have a selective but versatile diet and impact on forestry plantations, semi-natural woodlands and may overgraze sensitive or ecologically important areas, similar to domestic animals (Bullock, 2008; Rooney & Hayden, 2002). Main impacts of feral goats as invasive species has been their introduction to  islands lacking large herbivores where they have  community level impacts on biodiversity, as well as affecting endemic plants (see Campbell & Donlan, 2005 for a more thorough review). In Ireland their impact has not been assessed though they are used to control invasive plant species in areas such as the Burren, as they are more effective than domestic stock (Rooney & Hayden, 2002).

Reproduction

Polygynous mating system, rutting begins in autumn with single kids generally (twinning may be under estimated due to high infant mortality) born in spring after a gestation period of  approximately 150 days (Bullock, 2008). 

Pathway and vector description

Feral goats are descend from domestic goats which in turn are descended from the bezoar of western Asia (C. aegagrus), which was domesticated at some point approximately 9000 years ago (Bullock, 2008; Rooney & Hayden, 2002). The first records of goats in the British Isles are 4,500 years old from Wiltshire in England but an exact date of arrival in Ireland is unknown (Rooney & Hayden, 2002). 

Mechanism of impact

Grazing/Herbivory/Browsing, Rooting/Digging, Trampling

Broad environment

Terrestrial

Habitat description

In Ireland feral goats are traditionally associated with well drained or rocky upland areas, with iconic populations associated with particular areas such as the Burren in Co Clare and Glendalough in Co Wicklow.

Species group

Vertebrate

Native region

Temperate Asia

Distribution

World distribution(GBIF)

Irish distribution

Established - Widespread & Locally abundant. No population estimate for the species is available, though population densities of 14 animals per km2 have been recorded in the Burren, Co Clare (Rooney & Hayden, 2002). In the 1997 breeding season there were 207 (128 females and 79 males) in the Glendalough population (Saunders et al., 2008), which is at odds with other estimates of less than 300 nationally other than a population of 2000+ individuals in the Burren for the period 1990-1999 (Bullock, 2008).

Temporal change

Date of first record category

Pre-1900

Fifty year date category

Pre-1500

Records submitted to Data Centre in 2024

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How can you help

Report any sightings of feral goats (longer haired, smaller and lighter than domestic goats) to the National Biodiversity Data Centre. 

Further information

Invasive Species Specialist Group (ISSG) of the SSC- Species Survival Commission of the IUCN -International Union for Conservation Nature consider the goat one of the 100 Worst Invaders globally.

References

Publications

Bullock, D.J. (2008) Genus Capra Feral goat Capra hircus In: Mammals of the British Isles: Handbook, 4th edition (eds) Harris, S. & Yalden, D.W., The Mammal Society, Southampton.

Campbell, K. and Donlan, C., (2005). Feral goat eradications on islands. Conservation Biology, 19(5), pp.1362-1374.  

Marnell, F., Looney, D. & Lawton, C. (2019) Ireland Red List No. 12: Terrestrial Mammals. National Parks and Wildlife Service, Department of the Culture, Heritage and the Gaeltacht, Dublin, Ireland. 

Rooney, S. & Hayden, T. (2002) Forest Mammals – Management and Control.  A report for COFORD, National Council for Forest Research and Development, Dublin. 

CABI Datasheet

Global Invasive Species Database

Images