Pine Martens

The pine marten (Martes martes) is considered one of the rarest and most elusive wildlife species in Ireland.

What is a pine marten?

Pine martens are native to Ireland and are members of the weasel family and are related to otters, badgers, stoats, weasels and mink. The Irish name for the species, Cat Crainn or tree cat is a good description as it is around the size of a domestic cat and is often seen close to forests or woodlands. It is an omnivore (i.e. carnivore and vegetarian) but in Ireland, the few diet studies undertaken, show it has more vegetarian tastes than its Scottish cousins (see Lynch and McCann, 2007; Caryl et al., 2012).

Until the millennium, the pine marten was restricted to the west of Ireland with a few isolated populations elsewhere. It found itself in this situation, like many predators in Britain and Ireland, due to persecution during the 19th and early 20th centuries. However, the distribution of this enigmatic species has increased since 2000 (O’Mahony et al., 2012) and it now appears to be making a comeback in Northern Ireland including south Armagh (Tosh, 2015).

They have a rich fur coat, typically dark brown in colour and a distinguishing creamy-yellow throat patch. Life expectancy can be up to ten years, although the majority of individuals are unlikely to survive past five years in the wild.

Similar species

At a glance, pine martens can be confused with American mink. It is, however, easy to distinguish the two species. Pine martens have longer legs than mink and are more cat-like in shape. Mink have a long, slinky body, thin tail and blunt face with small rounded ears and often a small white patch on the chin. Pine martens have bushy tails, sharp pointed faces, upright, triangular ears and a large, creamy-yellow chest.

Habitat

Pine marten are habitat specialists, requiring forest or scrub habitat to exist in an area. They are adept at climbing trees as they have powerful non-retractable claws. The species is primarily active at night and individuals live in territories that can vary in size from 60 hectares to 430 hectares. Males typically have bigger territories than females and there can be partial overlap between adjacent territories.

Food

In terms of diet, pine marten are omnivorous taking both plant and animal material. In Ireland, pine marten exploit a variety of resources including berries, fruits, small mammals, invertebrates, birds and amphibians. In some areas where pine marten occur close to towns and villages the species will exploit rubbish bins for food. In other countries, pine martens rely heavily on microtine rodents such as voles and also in colder countries on carrion, especially in winter. When foraging, pine marten will usually stay within their own territory, which will have a variety of food resources available within it.

Den & refuge sites

Pine marten can utilise a variety of den sites, which are used for breeding. Den sites can include rock crevices, tree cavities, subterranean burrows, buildings (abandoned or occupied), old bird nests, squirrel dreys and log piles. These sites provide cover from weather extremes and safety from potential predators. Den sites are normally only occupied during the breeding season. Outside of this period, pine marten use what are termed refuge sites. Refuge sites can be very varied although normally they are located several metres off the ground in forest canopy. Upturned or blown over tress are often used as refuge sites but the species can exploit any habitat feature that provides cover and safety. Pine marten will tend to have refuge and den sites that are used repeatedly in a forest and they can have a high fidelity to these sites.

In 2015, the Ring of Gullion and Cooley Red Squirrel Group and Queen’s University Belfast worked together to help survey Northern Ireland (NI) for pine marten and squirrels. This revealed that pine marten occur across much of South Armagh and that grey squirrels were less likely to occur in areas where pine martens were found. Consequently we want to encourage pine marten numbers in the area whilst also reducing the potential for conflict with humans.

Breeding season

Pine marten are solitary and adults avoid contact with each other throughout most of the year. The species only breeds once with mating typically occurring in early summer between adults that are at least two years old.

Pine marten have what is termed ‘delayed implantation’, which means that fertilised eggs are not implanted in the uterus until the following January. This is a strategy to ensure that young (known as kits) are born during the most favourable time of year, which for pine marten is during March and April. Typically, two to three kits will be born in spring, each weighing less than 30g. The kits will stay in the den for about six weeks and are totally dependent on the female. Kits will then start exploring the area around the den and will stay with the female for at least six months, up to a maximum of 12–16 months. After this period, juveniles will disperse and attempt to establish their own territory. Only a small number of juveniles will survive to become adults and breed. Pine marten are considered to be slow breeders both in the terms of the number of young that are produced and the age at which reproductive maturity is reached.

Conservation status

• Listed on Schedule 5 of the Wildlife (Northern Ireland) Order 1985
• Listed in Schedule 3 of the Conservation of Habitats and Species Regulations 2010
• Listed in Annex III of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention)
• Listed in Annex V (Animal and Plant Species of Community Interest in Need of Strict Protection) of the EC Habitats Directive
• Listed in Schedule 3 of The Conservation (Natural Habitats, etc.) Regulations (Northern Ireland) 1995

Why is this species a priority in Northern Ireland?

• Listed as a UK Priority species
• It is an Irish Red Data Book species and classed as internationally important

In the last 30 years, the distribution of pine marten in Ireland may have increased which could have been influenced by increased afforestation, less persecution and some deliberate re-introductions of pine marten into areas where the species had become extinct. Despite this recent increase, pine marten currently only occur in approximately half of their historical distribution range.

Recent abundance estimates suggest that the total population of pine marten in Ireland is approximately 2,700 individuals, making it Ireland’s rarest native mammal species. There are number of factors that can impact on pine marten populations including land use planning, forest management practices such as harvesting, habitat fragmentation, inbreeding, illegal persecution either through generic poisoning or deliberate killing and destruction of forest/scrub habitat for development. Pine marten are susceptible to habitat loss and human persecution in Ireland, and due to their low population size and slow breeding performance should be seen as vulnerable for the foreseeable future.

What you can do

To report pine marten sightings to CEDaR.

Research carried out in the Ring of Gullion

Ulster Wildlife (2020) Squirrel and pine marten presence/absence survey 2020 report.

Twining, J.P., Montgomery, W.I., Price L, Kunc H.P. & Tosh D.G. (2020a) Native and invasive squirrels show different behavioural responses to scent of a shared native predator. R. Soc. open sci. 7: 191841. 26 http://dx.doi.org/10.1098/rsos.191841

Twining, J.P., Montgomery, W. I., & Tosh, D.G. (2020b). The dynamics of pine marten predation on red and grey squirrels. Mammalian Biology. https://doi.org/10.1007/s42991-020-00031-z

Twining, J.P., Montgomery, W.I., & Tosh, D.G. (2020c). Declining invasive grey squirrel populations may persist in refugia as native predator recovery reverses squirrel species replacement. Journal of Applied Ecology. 58.10.1111/1365-2664.13660. https://doi.org/10.1111/1365-2664.13660

Twining, J.P., Sutherland, C., Reid, N. & Tosh, G.G. (2021) Habitat mediates coevolved but not novel species interactions. Proc. R. Soc. B 20212338. https://doi.org/10.1098/rspb.2021.2338

Further information

Links

Northern Ireland’s Mammals, Amphibians & Reptiles

Pine Martens – The Vincent Wildlife Trust

Pine Marten Gallery

Pine Martens in the Ring of Gullion

View gallery slideshow