Colin Lawton‌Room 215, Martin Ryan Institute, NUI, Galway
Phone: 353 91 492335

Research Interests

My main research interest is in the field of mammal ecology.  I have worked on a number of squirrel ecology projects, with particular reference to their distribution, red and grey squirrel competition, red squirrel conservation and the management of grey squirrel populations.  My research group, the Animal Ecology and Conservation Unit, has also investigated the use of translocation as a conservation tool for red squirrels, and the interactions between both squirrel species and pine martens.  The ecology of small mammal populations, the control of pest species, the ecology of invasive species, mammal monitoring techniques and their applications and mammal parasitology are other areas of interest.  The Animal Ecology and Conservation Unit also conducts projects investigating the biodiversity of tardigrades (or ‘water bears’) in Ireland, frog ecology in coniferous forests and fish passage at hydroelectric power stations.

Animal Ecology and Conservation Unit

Current Projects

Margaret Flaherty, final year PhD student

The decline of the native red squirrel (Sciurus vulgaris) has been attributed to the spread of the non-native invasive grey squirrel (Sciurus carolinensis) since its introduction at a single site in Co. Longford in 1911. The grey squirrel is also responsible for causing significant economic losses to the forestry industry through its habit of bark stripping. Since its introduction the grey squirrel has spread to the north, east and south but has never established in the west of Ireland, and the river Shannon has delineated the western range of the species distribution. This project aims to investigate the barrier (if any) which is preventing the spread of the grey squirrel into the west of Ireland. It also aims to predict the future distribution of grey squirrels, identifying potential dispersal corridors and woodlands vulnerable to invasion. With this knowledge the red squirrel stronghold in the west of Ireland can also be protected. This work will further supplement existing squirrel research in the Animal Ecology & Conservation Unit and will inform management policies for grey squirrels and conservation strategies for red squirrels in Ireland and other parts of Europe.

Erica De Milio, Third year PhD student

Tardigrades (Phylum Tardigrada) are microscopic animals commonly known as “water bears”. These aquatic animals are found in marine, freshwater and moist terrestrial environments such as moss cushions. Tardigrades have a remarkable ability to survive extreme environmental conditions by entering a state known as cryptobiosis in which normal metabolic functions are suspended. In this state, tardigrades are able to survive and disperse over great distances by wind, rain, or other passive mechanisms and therefore are thought to be cosmopolitan in distribution with no species-specific habitat requirements. This project seeks to thoroughly investigate the biodiversity and ecology of tardigrades in Ireland for the first time. 

Anne Bateman, Second year PhD student

The global decline of fish stocks can be attributed to factors such as climate change, pollution and over-exploitation. Although hydro-electric power is a renewable energy resource, the construction of dams on river systems has a significant negative affect on fish populations. Impacts of hydropower on migrating fish populations include loss of habitat connectivity and habitat degradation and have contributed to the worldwide decline of many fish species such as Atlantic salmon (Salmo salar) and the critically endangered European eel (Anguilla anguilla). The aim of this project is to investigate migration behaviour of salmon and eel at Ardnacrusha dam on the River Shannon with a view to mitigating the effects of hydropower installations.

Laura O’Flynn, Second year PhD student

The Irish stoat (Mustela erminea hibernica) is recognised as a near endemic subspecies, quite distinct from stoats found in Britain and further afield. The stoat is an important element of Irish biodiversity, yet very little is known about this native mammal. This is partly due to the difficulty in studying an elusive species which is challenging to handle. This project includes a distribution survey, genetic analysis, dietary analysis, and investigation into habitat usage. Population densities in given habitats will be determined by genotyping hair and faeces samples. Results will also provide information on genetic diversity, as well as population size and structure, answering questions on home range and habitat use. Besides providing essential information on an important native species, this project will examine the use of various non-invasive techniques in studying mammals.

Previous Projects

Alan Poole (2007). An investigation of translocation as a technique to conserve the red squirrel (Sciurus vulgaris). PhD Thesis.
Cameron Clotworthy (2009). The distribution and ecology of Eurasian Golden Plover (Pluvialis apricaria) in the Owenduff/Nephin Complex Special Protection Area 4098. MSc Thesis.
Niamh Quinn (2010). Population dynamics of small mammals in the west of Ireland: Implication of hill sheep activity and habitat.  PhD Thesis.
Peter Stuart (2010). Investigating the role of wild carnivores in the epidemiology of parasitic disease. PhD Thesis.
Conall Hawkins (2011). The distribution, status and control of American mink (Mustela vison) in Ireland. PhD Thesis.
Reilly Dibner (2011).  Breeding site selection and development success of the European common frog (Rana temporaria) in conifer plantations and blanket bogs in western Ireland.  MSc Thesis.
Catherine Waters (2012). Post release monitoring of two translocated red squirrel (Sciurus vulgaris) populations. PhD Thesis.
Emma Sheehy (2013). The role of the pine marten in Irish squirrel population dynamics. PhD Thesis.
Emily Goldstein (2014). Ecology of frontier populations of the invasive grey squirrel (Sciurus carolinensis) in Ireland. PhD Thesis (joint project with UCC)

Selected publications:

Goldstein, E., Butler, C. & Lawton, C. (2014). Frontier population dynamics of an invasive squirrel species: do introduced populations function differently than those in the native range? Biological Invasions. 10.1007/s10530-014-0787-x

Sheehy, E. & Lawton, C. (2014).  Population crash in an invasive species following the recovery of a native predator: the case of the American grey squirrel and the European pine marten in Ireland. Biodiversity and Conservation. 10.1007/s10531014-0632-7

Goldstein, E. A., Lawton, C., Sheehy, E. & Butler, F. (2014).  Locating species range frontiers: a cost and efficiency comparison of citizen science and hair tube survey methods for use in tracking an invasive squirrel.  Wildlife Research. 10.1071/WR13197

Reilly, R. R., Lawton, C & Marnell F. (2014). Reproduction of Common Frogs, Rana temporaria, in a Managed Conifer Forest and Bog Landscape in Western Ireland. Herpetological Conservation and Biology: Volume 9, Issue 1.

Sheehy, E. & Lawton, C. (2014). Distribution of the non-native hazel dormouse, Muscardinus avellanarius, in Ireland. Irish Naturalist's Journal.

Sheehy, E., O'Meara, D. B., O'Reilly, C., Smart, A. & Lawton, C. (2014).  A non-invasive approach to determining pine marten abundance and predation. European Journal of Wildlife Research. 60: 223-236.

O’Meara D.B., Sheehy E., Turner P.D., O’Mahony D., Harrington A.P., Denman H., Lawton C., MacPherson J. and O’Reilly C. (2013). Non-invasive multispecies monitoring – Real-time PCR detection of squirrel and small mammal prey DNA in pine marten (Martes martes) scats. Acta Theriologica, 10.1007/s13364-013-0155-8.

Stuart, P., de Waal, T., Mulcahy, G., Zintl, A., McCarthy, E., Golden, O. & Lawton, C. (2013).  A Coprological Survey of Parasites of Wild Carnivores in Ireland. Parasitology Research. 112 (10): 3587-3593.

Buckley, K. P., Stuart, P., Lawton, C. & Sleeman, D. P. (2013).  Skrjabingylus nasicola (Leuckart, 1842)as a parasite of Irish stoats (Mustela erminea hibernica (Thomas & Barrett-Hamilton 1895)).  Irish Naturalist's Journal. 33 (1): 14-18.

Marnell, F., Donoher, D., Sheehy, E. & Lawton, C. (2013). First confirmed record of hazel dormouse (Muscardinus avellanarius) in the wild in Ireland.  Irish Naturalist's Journal. 33 (1): 77-78.

White, T. A., Lundy, M. G., Montgomery, W. I., Montgomery, S., Perkins, S. E., Lawton, C., Meehan, J., Hayden, T. J., Reid, N. and Searle, J. B. (2012).  Range expansion in an invasive species: influence of landscape, habitat quality and life-history. Biological Invasions 14, 2203-2215.

Stuart, P., Zintl, A., de Waal, T., Mulcahy, G., Hawkins, C. & Lawton, C. (2012). Investigating the role of wild carnivores in the epidemiology of bovine neosporosis.  Parasitology. 140 (3), 296-302. 

Waters, C. and Lawton, C. (2011) Red Squirrel Translocation in Ireland. Irish Wildlife Manuals, No. 51.  National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland.

Hawkins, C. J., Stuart, P., Heddergott, M. & Lawton, C. (2011).  Sinus worm (Skrjabingylus nasicola) infection in American mink (Mustela vison) in Ireland.  Irish Naturalist's Journal. 31(2): 108-112.

Lawton, C., Cowan, P., Bertolino, S., Lurz, P. W. W. & Peters, A. R. (2010) Consequences of introduction of non-indigenous species: two case studies, the grey squirrel in Europe and the brushtail possum in New Zealand, OIE (World Organisation for Animal Health) Scientific and Technical Review, 29 (2), August 2010: 287-298.

Stuart, P., Hawkins, C. J., Sleeman, D. P. & Lawton, C. (2010).  First record of Skrjabingylus petrowi (Nematode: Mestastrongyloidea) in a pine marten Martes martes from Ireland.  European Journal of Wildlife Research. 56: 679-680.

Hawkins, C. J., Caffrey, J. M., Stuart, P. & Lawton, C. (2010). Biliary parasite Pseudamphistomum truncatum (Opistorchiidae) in American mink (Mustela vison) and Eurasian otter (Lutra lutra) in Ireland.  Parasitology Research. 107(4): 993.

Poole, A. & Lawton, C. (2009).  The translocation and post release settlement of red squirrels Sciurus vulgaris to a previously uninhabited woodland.  Biodiversity and Conservation 18: 3205-3218.

Finnegan, L. A., Poole, A., Lawton, C., Rochford J. (2009).  Morphological diversity of the red squirrel Sciurus vulgaris in Ireland.  European Journal of Wildlife Research 55 (2) 145-151. 

Emily Goldstein, PhD Awarded (at UCC) 2014 

The 2007 survey of Irish squirrel populations noted that the invasive grey squirrels have continued to spread to the north, east and south of their previous recorded range. This project aimed to investigate the population dynamics and demographics of grey squirrels at the edge of their invasion frontier. This information was used to model future range expansion of grey squirrels in Ireland. This project linked in with ongoing red and grey squirrel research in the Animal Ecology and Conservation Group and elsewhere in Europe and provided a deeper understanding of the mechanisms of species invasions at the range frontier.

Emma Sheehy, PhD Awarded 2013

Recent anecdotal reports have linked a revival of red squirrel populations and a reduction in the range of grey squirrels, in certain midland counties of Ireland, with the resurgence of the pine marten, suggesting that the pine marten is preying on the introduced grey squirrel to a greater extent than the more nimble red squirrel.  This project aimed to investigate the relationship between the three species, and identify the impact that the pine marten is having on squirrel dynamics in Ireland. A strong negative correlation in the distribution of grey squirrels and pine martens was apparent, with the loss of grey squirrels in an area linked to high densities of pine martens.  Red squirrels quickly re-established in areas from which they had disappeared following the loss of grey squirrels.

Catherine Waters, PhD Awarded 2012

Red squirrel numbers in Ireland have been in decline since the early part of last century; this can mainly be attributed to the introduction of the grey squirrel in 1911.  The translocation of squirrels to two separate sites in the west of Ireland was attempted to expand the distribution of the red squirrel and to try and conserve their numbers from dropping any further.  This project's main aim was to monitor the post release stage of those translocations at Derryclare woodland, Connemara, Co. Galway and Belleek wood, Ballina Co. Mayo and examine how the squirrels adapt to their new habitats and use the resources available to them.  This information was used to derive best practice techniques for monitoring translocated populations, and detailed the establishment and spread of the new populations.

Niamh Quinn, Phd awarded 2010

Activities, such as grazing by farm animals, can greatly affect grassland habitats, and therefore have an impact upon the wildlife that depends on that habitat.  Pygmy shrews are an important species in Ireland as they are listed as protected under the Bern Convention (Appendix III).  Wood mice are common to most Irish habitats and are not protected, but are vital members of the mammal community.  This project investigated the impact of hill sheep activity on wood mice and pygmy shrew population dynamics and diet on the Teagasc Hill Sheep Farm, Leenane, Co. Mayo. 

Conall Hawkins, PHD Awarded 2010

This research focused on aspects of the ecology of American mink  in Ireland. The American mink is a semi-aquatic Mustelid (member of the weasel family). Mink in Ireland are an invasive alien species introduced for fur-farming purposes in the 1950’s; descendants of escapees are now found feral throughout the country. Mink are considered by many to be a pest, because of damage to fisheries, poultry and native wildlife. The damage caused by mink to economic interests in Ireland was examined, along with the methods used to control mink populations and the effectiveness of those measures.

Peter Stuart, PHD awarded 2010

This project aimed to investigate the role of carnivores in the epidemiology of bovine neosporosis.  Bovine neosporosis is a disease caused by the obligate intracellular protozoan, Neospora caninum, which infects a wide variety of mammals, but primarily dogs and cattle.  Neospora can cause abortions in cattle and has been found in up to 90% of cattle in some herds.  Therefore an improved understanding of its modes of transmission, so that preventative methods of its spread can be put in place, is required.  The prevalence of bovine neosporosis in the Irish population of American mink ( Mustela vison), fox ( Vulpes vulpes) and badger ( Meles meles) was assessed. Otter ( Lutra lutra) and stoat ( Mustela erminea) were also examined, where samples were available.  The presence of Neospora in brain (using PCR techniques), faeces (using microscopic examination and PCR techniques) and blood (using ELISA tests) samples from these animals was examined. 

Reilly Dibner, MSc awarded 2010

Amphibians are excellent indicators of ecosystem health and currently face extinction and decline worldwide.  Ireland’s only frog, the European common frog ( Rana temporaria), is threatened by habitat loss throughout the country.  Alongside pesticide use, water pollution, and urban development, forestry is one pressure that could endanger the frog.  There is, however, a distinct lack of information detailing how frogs respond to forest planting and clear-felling in Ireland, and how the species copes in a fragmented landscape of bogs and conifer forest.  The National Parks and Wildlife service funded this study of frog activity in unplanted peat bogs, clear-felled forests, and standing conifer plantations to assess differences in breeding patterns and development success.

Alan Poole, PhD awarded 2007

Translocation is the deliberate movement of wild individuals or populations in order to establish a viable, free-ranging population in the wild.  This project aimed to expand the current distribution of red squirrels in Ireland, by translocating a number of individuals into a woodland in Connemara, uninhabited by squirrels (red or grey).  Care was taken to follow the IUCN guidelines throughout, and so the source population was fully assessed before any animals were removed, squirrels were moved, under licence, to enclosures within the target site and a post-translocation monitoring was carried out in both the source and target sites.  The resulting translocation was a success with good recovery in the source population, better than expected survival over the first winter in the target site, and evidence of breeding the following spring.  The behaviour of newly translocated individuals in setting up new home ranges was assessed.  Models were developed predicting the success of future translocations and investigating the minimum requirements of a translocated population.