Are pine martens the answer to grey squirrel control?

Are pine martens the answer to grey squirrel control?

Journalists seem to think so..

The Vincent Wildlife Trust Founded in 1975 by Hon. Vincent Weir A charity engaged in mammal research, surveys, monitoring & conservation History of national distribution surveys otter, water vole, polecat & pine marten Current focus on rare bats and the smaller mustelids- polecat, stoat, weasel and pine marten.

The pine marten One of six native British mustelids Cat-sized, cream bib, bushy tail, prominent pale ears 3-D habitat specialist Typically associated with extensive woodland & old growth features Prefer to den above ground (tree cavities) Home range size 1-32km 2 Omnivorous & opportunistic diet small mammals, fruit, small birds & invertebrates. Research Education Conservation

The grey squirrel Non-native. Introduced to Britain & Ireland. Threatens survival of native red squirrels through competition & disease (squirrel pox virus). Cost of grey squirrel damage to commercial forestry in UK = > 10 million per year. One of the world s most invasive alien species (Lowe et al. 2004). Natural range of grey squirrel in North America overlaps with American marten and fisher (natural predators) only in very small area (Sheehy & Lawton, 2014).

Pine martens and squirrels in Ireland Grey squirrels introduced to Ireland in 1911. Grey squirrels present in 26 of 32 counties (Carey et al. 2007). In late 1990s, red & grey squirrel populations in some northern counties reported as unsettled for first time (O Teangana et al. 2000). Anecdotal reports that grey squirrel had declined locally since the 1980s, allowing for a resurgence of the red squirrel population. This coincided with recovery of the pine marten. Suggestion that the distribution of the 3 species may be linked (Carey et al. 2007).

Pine martens and squirrels in Ireland Study carried out in 2011-2012 by Emma Sheehy & Colin Lawton at National University of Ireland. Investigated the role of the pine marten in grey and red squirrel population dynamics. The majority of respondents (84.7%) wish to see the Pine marten restored in Wales

Pine martens and squirrels in Ireland Methods: Study area: Laois & Offaly (in the midlands) including a buffer zone, & Wicklow (in east). Sightings and hair tube surveys used to collect distribution data on pine martens & squirrels. Squirrels live trapped to determine abundance and density. Squirrel body size, condition & breeding activity recorded. Research Education Conservation Sheehy & Lawton, 2014

Pine martens and squirrels in Ireland Results: Strong negative correlation between detection of grey squirrel & pine marten. Only 1 site where both species were found. Grey squirrel population has crashed in 9,000 km 2 of its former range. Red squirrel has recolonised 6,500 km 2 of its historic range. Red squirrel & pine marten populations overlap extensively but grey squirrel & pine marten overlap is limited. In woodland where pine martens occurred at high density, grey squirrel density was very low & grey squirrel body mass was low & overall health was poor. High density predator population may be influencing foraging behaviour, body condition, reproductive activity or density in grey squirrel population. Research Education Conservation Sheehy & Lawton, 2014

Pine martens and squirrels in Ireland Grey squirrel & pine marten distribution & densities from sightings between 2010-2012. Sighting locations (left) & 10km radius kernel density (right). Sheehy & Lawton, 2014 Research Education Conservation

Pine martens and squirrels in Ireland Pine marten diet Grey squirrel % frequency of occurrence in diet = 15.6%. Similar to contribution of grey squirrel to American marten & fisher diet in North America. Red squirrel % frequency of occurrence in diet = 2.4%. Consistent with other studies in Ireland & Scotland. Sheehy et al. 2013

Pine martens and squirrels in Scotland Anecdotal evidence that where pine martens have recovered & expanded their range in parts of Scotland, grey squirrels have declined. Research underway by Emma Sheehy & Xavier Lambin at Aberdeen University to investigate relationship between pine martens, grey & red squirrels in Scotland.

Pine Marten Recovery Project Aims to restore viable, self-sustaining pine marten populations across England and Wales where habitat & other conditions are suitable. First translocations taking place now: 20 animals being translocated from Scotland to mid Wales, to reinforce small existing population.

Feasibility Study Feasibility study completed in 2014 Evaluated proposal against IUCN guidelines Used habitat suitability model to identify suitable release sites Community/stakeholder engagement in potential release areas Identify potential conflicts Detailed field surveys & risk assessments Disease Risk Analysis completed by wildlife vet & reviewed by veterinary experts

Identifying reinforcement areas Habitat suitability model (MAXENT) identified areas of suitable habitat for pine marten reinforcement (most suitable areas in green on map). Optimal areas will have: - Minimum habitat area and connectivity for viable numbers of pine marten home ranges. - Minimum potential conflict & full support of local communities.

Identifying reinforcement areas Initial release sites in mid- Wales.

Preparing release sites Gathered baseline data on: Prey availability (small mammal surveys) grey squirrel abundance bat species woodland structure & composition Prepared release sites Release pens Den boxes

Engaging people Liaising with landowners/users. Meetings with NFU/FUW. 3 public community meetings. Attendance of local shows (e.g. Welsh Game Fair). Highlighting local history & heritage Bele r coed. Public opinion survey showed >90% respondents supportive of pine marten recovery.

Sourcing animals Surveys at donor sites in Scotland. Licence granted by Scottish Natural Heritage to remove pine martens. Catching 2-4 adults from each site (equal ratio of males & female). Full health check & fitted with radiocollars before translocation. NRW licences granted to release, and Home Office licences to catch, process & tag animals

Pine Marten Recovery Project Why help pine martens recover? Native species - it should be here! No evidence of natural recovery in Wales & England Intrinsic value, biodiversity, iconic woodland species Potential for eco-tourism Biological control for grey squirrels? (Interest in ecosystem services ) Feasibility study cost 100k Reinforcement program total > 1m

Pine martens and squirrels in Wales As part of pine marten release, a PhD student is researching direct & indirect influences of pine martens on grey squirrels before, during & after translocation. Research includes: Pine marten foraging & the extent of predation of squirrels Squirrel population studies Radio-tracking of squirrels to investigate behavioural change. Assessing any reduction in tree damage by grey squirrels over time.

So, are pine martens the answer to grey squirrel control?? Maybe.but that s not why we re conserving them! www.vwt.org.uk www.pine-marten-recovery-project.org.uk