The hazel dormouse (Muscardinus avellanarius ) has recently been discovered in County Kildare, Ireland and is being treated as non-native and, hence, potentially invasive. The mode of arrival and origins are unknown; however, initial theories included transfer via hay from Great Britain. The population in Kildare appears to be thriving, and as native populations throughout England are in decline the success is of broad conservation relevance. To gain insight into the recent demography of the County Kildare population, the cytochrome b gene was profiled for individuals from Kildare, England and Wales and compared to known haplotypes throughout its European range. The individuals from County Kildare shared the same previously unrecorded haplotype, which was placed in a separate clade from the GB haplotype, along with more southern European populations. The French haplotype was the most recent closest relative, albeit with a 3 base pair difference, inferring that either the dormouse has been present in Ireland for longer than expected, or it is recently derived from a source population yet to be sampled. The latter is considered the most likely scenario. Future work and concerns about the hazel dormouse in Ireland are discussed.

To quantify levels of gene flow among and genetic variation within different age cohorts of pedunculate oak ( Quercus robur L.) in a semi-natural oak woodland, diversity and parentage studies were undertaken on a stand in Ballytobin, Co. Kilkenny, Ireland. Trees were categorised into four size classes seedlings, saplings, mature trees and veterans, and genetic differentiation was estimated for three microsatellite markers using AMOVA. Parentage was assessed using a likelihood assignment approach. Between nine and fourteen alleles were detected per locus (mean gene diversity, h, 0.8312). All samples from Ballytobin were heterozygous. AMOVA between age cohorts (veterans, mature, saplings and seedlings) estimated that only 2% of the variation was partitioned among age cohort and the mean FSt was low (0.015) but significant (P = 0.034). Parent-pair analysis revealed that out of 24 candidate trees, fifteen were assigned as parents to at least one offspring and, out of these, five were veteran. The average pollination distance was estimated at 47.8m with seven out of the twelve parent-pairs being within 50m of each other. The measured range of distances between trees indicated in the analysis as parents was between 22m and 150m. The highest values for number of parent/ offspring assignments were between 40m and 49m. Overall, veteran oak at the site were found to be reproductively successful and a low level of differentiation was found between age cohorts indicating that population genetic diversity has been maintained over time.

Turloughs are a type of karst wetland found extensively in western Ireland. Turloughs have a dynamic flooding regime, are groundwater dependent and lack a surface outflow. The EU Habitats and Water Framework Directives provide the impetus for evaluating the impacts of nutrient pressures on this internationally protected habitat. Differences in hydrogeological settings are thought to be a key driver of nutrient variation among turloughs. An holistic assessment of turlough trophic conditions should include the terrestrial phase, and an improved understanding of turlough soil property spatial variation is necessary for informing attempts to link nutrient pressures and impacts on the terrestrial phase of the habitat. This study compared nutrient-related soil properties among two groups of turloughs situated in East Burren, Co. Clare, and Coole Garryland, Co. Galway. Each group is representative of a contrasting hydrogeological setting indicative of a trophic gradient. Soils within Coole Garryland turloughs are potentially more nutrient rich than East Burren turloughs owing to the larger zones of groundwater contribution with faster throughflow, greater levels of disturbance and more intense grazing pressures. Turloughs in East Burren had distinctly more alkaline and peaty soils than Coole Garryland, reflecting the relatively longer flood durations of the former. There was no clear distinction in soil total phosphorus, total nitrogen or desorbable phosphorus between East Burren and Coole Garryland. The soils of dry, more intensively grazed turloughs are apparently not more nutrient rich than wet, less intensively grazed turloughs. Variation in nutrient availability and inter-relationships of soil properties were examined along the flooding gradients of two turloughs representative of each hydrogeological setting, namely Garryland turlough and Cooloorta turlough. Elevated concentrations of available forms of N and P in the saturated lower zones of each turlough may be the result of anaerobic conditions or nutrient accumulation. High coefficients of variation reveal that available forms of N and P exhibit a high degree of spatial variation in turloughs. Consequently, the occurrence and distribution of vegetation communities and plant species indicative of different trophic conditions are likely to be more useful than soil nutrient assessments for assessing the impacts of nutrient pressures on turloughs. pH was identified as an important driver of P availability in turloughs. The negative association between available P and pH highlights the potentially significant influence of marl accumulation on turlough ecological functioning. Future turlough soil research should be cognisant of spatial variation along flooding gradients and should focus on N and P mineralisation studies of mineral, organic and calcareous soils to develop understanding of turlough nutrient cycling processes and retention capacities.

Throughout the European Union (EU), agricultural soils with high phosphorus (P) status due to surplus fertiliser input have been identifi ed as a landscape pressure impacting on water quality. In Republic of Ireland, approximately 80% of agricultural land is devoted to grass, 11% to rough grazing, and 9% to arable cereal and crop production. Consequently, the majority of erosion research has focused on quantifying nutrient and sediment losses from grassland. Tillage soils are, however, more susceptible to erosion than grassland soils and, in general, have higher levels of soil P. This paper reviews the current state of research and the regulatory regime relating to diffuse P and sediment loss for tillage soils. It identifi es the key threats to soil quality associated with cultivated soils, and proposes the targeting and remediation of critical source areas for effective mitigation of P losses from tillage soils. A multiscaled approach is recommended, in which catchment and fi eld-scale monitoring is complemented with controlled laboratory and small plot-scale rainfall simulation experiments to identify areas where P loss and soil erosion are at critical levels and may pose a threat to water quality. Catchment scale research will help to link critical source areas of sediment and P loss with hydrological pathways to surface waters in the catchment area. These areas can then be targeted for remediation in the river basin management plans.

Biomass allocation and leaf attributes are traits that discriminate between plants that exploit different light resource environments. Disturbed and high light environments provide easy access for resource-demanding, fast-growing invasive species. Comparing growth, ecophysiological and reproductive characteristics between invasives and non-invasives could help to predict a species' invasiveness and identify which habitat would be most susceptible to its invasion. In a common garden experiment we compared traits in Impatiens species that vary in their invasive status. They were the aggressive invader Impatiens glandulifera, which is invasive in mainland Europe and Ireland, I. parviflora, invasive in Central and Northern Europe but only established and not invasive in Ireland, and I. balfourii, naturalised in central and southern Europe but not reported in Ireland. We aimed to investigate their ecological requirements and to identify which traits promote invasion in this genus in a high-resource environment. Photosynthetic and allometric traits characterised the contrasting investment in light harvesting and carbon fixation of I. parviflora and I. glandulifera. The comparison of reproductive, photosynthetic and growth characteristics explained I. glandulifera's superior invasiveness when compared to I. parviflora. However, there was no evidence that the invasive performed better than the non invasive when it was compared to I. balfourii. Other traits that were not considered in this study, such as germination characteristics and adaptability, might also be responsible for invasiveness. We conclude that I. balfourii may possess an intrinsic invasiveness that, due to differences in invasion history, may not have reached its full potential yet.

C. McGee, C. Brougham, J. Roche and A. Fogarty (corresponding author; email: afogarty@ait.ie), School of Science, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath.

A programme of afforestation has increased forest cover in Ireland from around 1% to more than 10% in less than a century. This study describes planting trends up to 2005 according to habitat and characterises the bird assemblages of the most commonly afforested habitat types. Most afforestation has taken place on peats, gleys [typical of wet grassland (WG) habitats] and well-drained mineral soils [typical of improved grassland (IG) habitats]. Since 1986, afforestation of gley sites increased dramatically, and afforestation rates on both peats and gleys were more than two times greater than on well-drained mineral soils. Bird diversity was assessed at 27 peatland, WG and IG sites. Bird density and species richness were positively related to shrub and tree cover, which was highest in WG and lowest in peatland sites. Indicator analysis identified several characteristic bird species of WG and peatland, but no characteristic species were identified for IG sites. The ways in which choice of afforestation habitat and subsequent management of plantations could affect bird diversity in Ireland are discussed. Afforestation is likely to benefit the birds most in areas of high-productivity grassland managed at high intensity for grazing and/or cutting, with relatively low levels of shrub cover.

As a consequence of the sustained interest in exotic plants we now face the challenge of dealing with the economic and ecological impacts of many environmental weeds. Exotic ornamental plants can often flourish as they have been imported without their natural enemies that suppress the plant’s growth and reproduction in the native range. The aim of classical biological control is to re-establish the natural regulation provided by host-specific primary consumers from the native range of the weed. In contrast to the long history of arthropod biological control in Europe, environmental weed biological control is only now gaining some momentum. Ireland stands to benefit from developments made in other EU member states and other parts of the world as it shares many of the same environmental weed problems. Both terrestrial and aquatic weeds are good targets for biological control, and developments relevant to Ireland are described in this paper to illustrate the potential benefits of this management option.

Received 19 October 2009. Accepted 28 February 2011. Published 29 March 2012. Since its inception in 1994, there has been strong demand for evidence of the environmental effectiveness of the Rural Environment Protection Scheme (REPS), which has paid farmers in the Republic of Ireland over €3 billion up to 2010. A variety of research projects have been undertaken that investigate the environmental effects of REPS through an examination of either specific environmental measures or specific geographical areas. A review of available publications has confirmed the absence of a comprehensive, national-scale study of the environmental impacts of REPS. For this reason, there is insufficient evidence with which to judge the environmental effectiveness of the national-scale implementation of the whole scheme. For some specific meas ures, however, sufficient evidence is available to inform an objective assessment in some cases, and to help learn how to improve environmental effectiveness in most cases. The majority of the REPS payments are now dedicated to biodiversity objectives. Thus, biodiversity measures and options should be a priority for any national-scale environmental assessment of the scheme. Such a study would help identify the environmental benefits of REPS, the specific elements of REPS that are performing adequately, and those elements that are in need of improvement. Given the considerable overlap between REPS measures and options and those included in the 2010 Agri Environment Options Scheme (AEOS), the assessment of REPS measures could also be used to inform the likely environmental performance of the AEOS.

This article addresses the lack of knowledge with regards to the macroinvertebrate communities of Irish headwater streams. The main objective of this study was to describe the macroinvertebrate communities of 74 headwater sites representing a range of geological and geographical settings with the focus on reference systems and to propose a typological classification of these sites. Four main groups of headwaters were identified using multivariate clustering and ordination techniques to develop groups and to determine the environmental factors associated with macroinvertebrate assemblages. The groups identified are largely grouped according to environmental variables. Group 1 sites drained softer geology with non-peaty soils, with a higher conductivity and total hardness than any other group. Group 2 had a similar geology and again drained mainly non-peaty soils but had lower conductivity levels than Group 1 and had the greatest representation of cobble/pebble substrate among the groupings. Group 3 sites drained mainly siliceous geology with peaty soils and were characterized by predominately bedrock and boulder substrates. Finally, Group 4 sites drained siliceous geology with peaty soils and were located at the highest elevations and had the lowest pH. A Canonical correspondence analysis (CCA) was conducted to determine the relationships between the macroinvertebrate communities and the physico-chemical variables. It was clear that geology and its co-variables, including conductivity and pH, played a considerable role in defining the groups. A one-way ANOVA also highlighted the significance of some of these variables in the grouping of these sites. This study highlights the importance of defining headwater typologies so that reference conditions for each type can be established and thus form a baseline against which future changes in biodiversity or water quality can be measured.

Although now we have had many years of research completed on assessing the potential environmental impact of GM crops, concern remains over their potential impact on biodiversity in the rural landscape. In particular, issues have arisen in regards to the modification of crops with traits that could introgress into sexually compatible wild relatives. In contrast to wheat, barley, potato and maize, Brassica napus (oilseed rape) is the only commercial crop grown in Ireland at present with the potential to successfully transfer its DNA, via pollen-mediated gene flow, into inter-related weed species. This review details the species in question and by examining the relevant literature that relates to Irish agronomic conditions, demonstrates that gene flow is likely to occur, especially to an earlier used cultivar, Brassica rapa. However, the critical factor remains not that GM traits will flow from the commercial source but what might the consequences of said gene flow events be. This review indicates that the conferred trait in question (in this case, herbicide tolerance) can only impact on weed diversity in the presence of selecting herbicide action. In the absence of the herbicide, the GM traits will be lost from the wild species over time and will not confer any selective advantage that could facilitate population growth.

Genetic diversity can play a key role in the survival of endangered species. Both the number and size of populations of a species can affect genetic diversity and may be reduced by fragmentation of natural habitats. Here we examine the effects of a low number of populations and small population sizes on the population genetics of the nationally endangered and red-listed orchid Pseudorchis albida. To determine genetic variability within and among populations of P. albida, we employed AFLP and four plastid microsatellite (SSR) markers. In addition, we compared the SSR data from Irish P. albida to the closely related P. straminea. AFLP markers showed that P. albida has a high level of polymorphism and that significant differentiation occurred both within and among populations, with increasing population genetic isolation through distance. However, SSR mark ers revealed no variation, but did show that all Irish individuals had the same alleles as P. straminea rather than P. albida. Further work is required to assess the taxonomic status of P. albida/straminea in Western Europe. Irish populations of P. albida s.l. require immediate conservation attention due to their decreasing number and low numbers of individuals within populations.

COFORD (The National Council for Forest Research and Development in Ireland) & coordinated by Coillte Teoranta and Marine Institute

Separate subhabitats are distinguishable in tufts of Corallina offi cinalis, including the surface of the algae itself and the interspace (areas of water) within the algal tufts. The oxygen microenvironment of each of these was investigated in laboratory investigations using oxygen microelectrodes to test the hypothesis that oxygen gradients form adjacent to the seaweed surface and that the oxygen concentration of the seawater between the branches of individual plants differs from that of the surrounding water body due the tuft forming nature of this seaweed. Regions of hyperoxia (up to 250% of saturation) were detected at the surface of Corallina branches in static conditions, with steep declining gradients of oxygen concentration through the diffusive boundary layer in the vertical plane to 100% of saturation a distance almost 2mm from the surface. Oxygen concentration at the surface did not vary with position along individual branches, or with position on any one branch segment. Concentrations were signifi cantly higher on main branches than on peripheral branches of individual plants. Water fl ow was the dominant factor controlling the depth and oxygen supply of diffusive boundary layers and in moving water oxygen levels did not achieve such high saturation levels and the boundary layer was thinner. On a larger scale, oxygen concentrations in the interspace of C. offi cinalis tufts were highly variable and commonly in excess of air saturation. The oxygen environment was both temporally and spatially dynamic, and very rapid changes in oxygen concentration were observed in response to changing fl ow conditions. Despite the ranges of oxygen concentrations, and often hyperoxic conditions described, a thriving epiphytic community of animals smaller than 2mm, dominated by harpacticoid copepods and marine mites is associated with this extreme and dynamic environment.

Zooplankton communities are an important component of the pelagic food web, but they are absent from the list of biotic elements to be considered for the assessment of ecological status in Annex V of the Water Framework Directive (2000/60/EC). We report here on an assessment of zooplankton populations across 32 lakes that represent a gradient of alkalinity and anthropo genic impact, primarily owing to nutrients and/or acidity. Acidic and oligotrophic lakes were typified by a high relative abundance of cladocerans, but with some key taxa groups absent from the most acidified lakes. Zooplankton total abundance increased across the trophic gradient. This interplay between acidity and productivity provides the potential to assess effects of anthropo genic pressure on zooplankton communities. Incorporation of ecological function, as opposed to structure, can additionally be evaluated through community attributes, particularly fecundity and size distribution. The assessment of the zooplankton can be cost-effective and related to refer ence conditions. Reasons for this omission from the requirements of monitoring under the Water Framework Directive are unclear, but this should not preclude the use of zooplankton communi ties if they can provide a valuable component for ecological assessment.

This study investigates methods to rejuvenate the fl ora of previously degraded fi eld margins on a pastoral farm in County Longford. We also assess the effects of individual treatments on the abundance of various orders of invertebrates recorded within the experimental plots. Field margin treatments were 1.5m-wide unfenced control margins, 1.5m-wide fenced margins or 3.5m-wide fenced margins. Nutrient inputs were excluded from all of the experimental plots. The botanical composition of the plots was examined on four occasions between 2002 and 2004 using permanent, nested quadrats. Emergence traps were used to measure invertebrate abundance within treatment plots and the main sward. Results indicated that 1) exclusion of nutrient inputs had a positive effect on plant species richness within the fi eld margins; 2) plant species richness decreased with increased distance from the hedgerow; 3) herb species richness was greatest in the 1.5m closest to the hedgerow; 4) greater abundance of invertebrates occurred within the 3.5m-wide margins; 5) successful control of Pteridium aquilinum was achieved through spot treatment with the selective herbicide ‘Asulox’; and 6) a combination of management techniques such as cutting and grazing is likely to enhance plant species richness and facilitate the structural diversity of vegetation that is necessary for many invertebrate taxa.

On 31 July 2004 a tornado that was unusual in several ways occurred in the west of Ireland. It had an anticyclonic, rather than the more normal cyclonic, rotation, and it occurred under relatively unpromising synoptic conditions, where there was a slack surface-pressure gradient close to the centre of a ridge of high pressure over north-west Europe. However, regional low-level wind shear and strong convergence are shown to have created a favourable environment over Co. Mayo, aided by a limited amount of convective available potential energy (CAPE) that accumulated beneath an inversion at 816hPa and by a strong vertical moisture profile. The role of the contrasting thermal properties between Lough Carra and the adjacent land surface in producing an anticyclonically rotating tornado from a horizontal vortex that developed within the sheared environment is considered. All of these features are found to be strongly localised. Comparisons are made with the non-mesocyclonic tornado environments documented in US research, and a number of contrasts are noted. The tornado track was only partially traceable due to the terrain, and it reached its widest point of 18m where it entered bogland after 0.75km. John Tyrrell (email: j.tyrrell@ucc.ie), Department of Geography, UCC, Cork.

The Water Framework Directive (WFD) has been the catalyst for a considerable amount of data collection, analysis and research, covering a wide range of physical and biological characteristics and involving a wide range of scientific, social and management-related disciplines. This paper starts with a short description of the discipline of hydrology and then identifies the main hydro logical aspects of work for the WFD, noting their ecological significance. It also provides some idea of the range of organisations and disciplines involved in the work and of the links between them. Of particular significance is the degree of cooperation between river basin districts in setting up working groups for special studies, helping to avoid overlaps in research.

Phenology, the study of the timing of recurring life cycle events, has gained global scientifi c recognition in recent years as it demonstrates how ecosystems are responding to climate change. However, in Ireland the systematic recording of phenological events has not been traditionally undertaken. Here we present some recently rediscovered historic phenological records, abstracted from the Irish Naturalists’ Journal for the period 1927‐1947 (with a gap from 1940 to 1945) and analyse them with respect to temperature data, sourced from Dr Tim Mitchell’s Tyndall Centre webpage. We fithat in many cases in Ireland spring phenological events, such as fifl owering, fi rst leafi ng and fi rst observations of insects, show an earlier trend in response to increasing spring temperatures over the study period. In addition, we compare spring migrant bird arrival dates from the Irish Naturalists’ Journal records with those abstracted from various published and unpublished bird records from the eastern region of Ireland for the period 1969‐1999. We demonstrate that fi ve out of the seven species analysed were recorded earlier in the more recent time period, and three of these were signifi cantly earlier. These results illustrate the value of historic phenological data records for investigating and comparing past and present climate infl uences on species developmental behaviour.

The Water Framework Directive (WFD) requires understanding of both technical issues and, under Article 14, dialogue among stakeholders. To date, consultation with stakeholders, including the general public, has occurred mainly through the establishment of river basin district advisory councils, and following the dissemination of documents, entitled Water matters, outlining sig nificant issues for meeting the WFD's environmental objectives. Here, we review progress in the Republic of Ireland for meeting the goals of Article 14 and examine how that progress compares with a set of principles of best practice for stakeholder participation. Overall, information is gen erally available, but there are some problems in accessing background information, unprocessed (raw) data and land-use data. While the main issues were outlined in Water matters, the clarity with which these issues were presented, the extensiveness of coverage and the quality of feedback were of concern to some stakeholders. A series of associated public meetings were generally poorly attended. Active involvement, through the advisory councils, appears limited, with no formal process for information dissemination or dialogue with stakeholders. Adoption and promotion of guiding principles of best practice that promote inclusiveness; transparency; commitment, includ ing provision of adequate resources; accountability; a general openness for mutual learning; and improved structures to address stakeholder concerns are likely to provide a more effective process. A complementary approach to meet overall WFD objectives would be to view the WFD as an environmental management system; this provides a continuous process that circumvents pitfalls of imprecise or inappropriate targets, but it is likely to provide more realistic decision support, facilitating stakeholder understanding. Kenneth Irvine, School of Natural Sciences, Trinity College Dublin (corresponding author; email: kirvine@tcd.ie); Sinead O'Brien, Sustainable Water Network, 9 Upper Mount Street, Dublin 2.

Studies over two decades have shown a marked trend towards a decrease in blood lead levels in the mute swan (Cygnus olor) in parts of Ireland. However, this study shows that a small percentage of some populations of mute swans in Co. Cork still have significandy elevated lead levels, causing some potentially sublethal effects to the health status of the swans. Overall, at both urban and rural sites the median blood lead levels in adults and cygnets of both sexes were below a threshold level of 1.21 11~ which is indicative of elevated lead. However, 27% of the population at Cork Lough had elevated lead levels, with the highest blood lead level being 27.66 11~~1, indicating that acute poisoning is still a problem in some individuals. Mute swans from rural sites generally showed no variation, and median blood lead levels were generally low. Lead levels reached a peak in October 2004 and again during the spring months of 2005. Swans may be more susceptible to lead poisoning during spring, as it follows the winter months when natural food is scarce and lead is easily absorbed across the gut after ingestion. Autumn peaks may be explained by an increase in fishing activity over the summer months. A positive association was found between elevated lead levels and packed cell volume?an indicator of health status. Overall, a decline in acute lead poisoning at urban and rural sites is apparent from this study. However, due to its continued and persistent use in the environment, lead still poses a threat at a sublethal level. Merita M. O'Connell (corresponding author; email: m.oconnell@ucc.ie), John O'Halloran, Department of Zoology, Ecology and Plant Science, Environmental

An understanding of the chemical nature of in soil is essential to the sustainability of agriculture in Ireland. This study used 31P nuclear magnetic resonance (NMR) spectroscopy and wet-chemical analysis to characterise NaOH-EDTA-extractable in a grassland soil in south-east Ireland. Soil samples of 10cm depth were collected over five sampling days between September and December 2003. Total soil (Pt) ranged between 723 and 819mg kg-1 soil, while Morgan's (Pm) ranged between 3.4 and 12.5mg PI-1 soil. Recovery rates of extracted in the NaOH-EDTA solution were high, ranging from 75 to 88% of soil Pt. Four distinct classes of compound were detected in the 31P NMR spectra: inorganic orthophosphate ( =6.72 to 6.85ppm, with a mean of 6.79ppm), orthophosphate monoesters ( = 3.83 to 6.11ppm), orthophosphate diesters ( = ?0.32 to 0.54ppm) and pyrophosphates ( = ?3.44 to ? 3.13ppm, with a mean of ? 3.26ppm). Distinct signals at 5.64, 5.39, 5.02 and 4.55ppm in the spectra showed the dominance of myo-inositol hexakisphosphate in the orthophosphate monoester region. Orthophosphate diesters were subclassified as phospholipids ( =0 and 1.88ppm) and DNA ( =0.09 to ? O.lOppm). Over the three-month sampling period the mean percentages of the four main functional classes?inorganic orthophosphate, orthophosphate monoesters, orthophosphate diesters and pyrophosphates?in the soil samples were approximately 52, 42, 3 and 3%, respectively. The ratio of orthophosphate monoesters to orthophosphate diesters ranged from 10 to 19. Further research is required to assess the potential bioavailability of organic (Po) in Irish grassland soils in order to understand its role in the transfer of from agricultural soil to our water bodies. David Bourke (corresponding author; email: bourkedo@tcd.ie)

In Ireland agricultural activities have been identified as major sources of nutrient input to receiving waters, and it has been estimated that these activities contribute 75.3% of the N and 33.4% of the P found in these waters. The strategy at European level focuses on the prevention of nutrient loss by improved farm management. However, it does not focus on nutrient remediation or incidental nutrient loss from farmyard manures to surface water and groundwater. This review describes the impact of agriculture on the environment in Ireland and examines emerging technologies for agricultural waste-water treatment. An integrated approach at pretreatment and field stages for nitrate (NO 3 ) remediation and P control is recommended.

Hair tubes were investigated as an indirect means of monitoring red and grey squirrel populations and estimating squirrel densities. Hair tube surveys and live trapping was carried out in six sites, three conifer and three mixed conifer/broadleaf, four of which had both red and grey squirrels resident. Hair tubes detected both red and grey squirrels in these four sites, but no grey squirrels were detected with trapping. Reasons for this are discussed. These results suggest that hair tubes are an effective method for monitoring red and grey squirrel populations and the spread of grey squirrels in different site types. Calibration between hair tube surveys and live trapping was only carried out with red squirrel data. The proportion of tubes visited by red squirrels and densities estimated from live trapping were correlated (r = 0.846, d.f. =6, = 0.034). The generalised linear model, assessing the relationship between the two monitoring methods, revealed a significant relationship (P < 0.001); however, the proportion of used tubes explained very little of the variation within the model (42%). The use of hair tubes as means of estimating squirrel densities is unclear, and further calibration of red squirrel data and initial calibration of grey squirrel data is needed. Laura Finnegan (corresponding author e-mail: lfinnega@tcd.ie), Geoff Hamilton, Julie Perol and