Ana Piñeiro

Lack of scientific evidence and precautionary principle in massive release of rodenticides threatens biodiversity: old lessons need new reflections

Pesticides are widely used throughout the world to control agricultural pests. Owing to their well identified side-effects on wildlife, the release of high quantities of pesticides to the environment should always require responsible use of both science-based information and the precautionary principle, however decision making in wildlife management and conservation is not systematically supported by scientific evidence. This is particularly worrying when decision making involves release of toxic substances to the environment, as often occurs in rodent plague control. Poorly-informed management decisions to control a rodent plague can adversely affect wildlife, especially when chemical-based treatments are generically designed and applied on a broad scale, with high economic cost. Evidence-based and environmentally sustainable management should be used to control rodent plagues in Spain.

Stress physiological responses to tourist pressure in a wild population of European pine marten

The tourist pressure in natural parks is a potential source of stress and may cause an increase in the adrenal activity of wild populations of European pine marten (Martes martes). Seventy-six faecal samples were collected during 15 months in a natural park of Northwest Spain. Analysis of faecal DNA was used for the specific identification using the PCR-RFLPs technique. Faecal steroid determinations were performed by EIA. Natural park was divided in three areas: free entry, restricted area, and integral reservation, and number of daily human visitors recorded. Faecal glucocorticoid metabolite levels (ng/g dry faeces) were significantly higher in spring (56.36+/-19.62) and summer (31.27+/-11.98) compared to autumn (15.33+/-6.89) and winter (11.13+/-3.30). These data are closely related to daily number of visitors (spring: 3204, summer: 1672, winter: 646, autumn: 551). Androgen, progestin and oestrogen levels were also significantly higher in spring (reproductive season) showing values of 43.62+/-18.6, 154.31+/-53.50 and 829.62+/-456.1, respectively. Glucocorticoid levels were significantly lower in integral reservation (15.95+/-3.56) compared to restricted (31.4+/-16.30) and free entry areas (41.59+/-12.73), respectively. Wild populations of European pine marten showed stress physiological response induced by the tourist pressure and this response is higher during reproductive season.

Monitoring the small-scale distribution of sympatric European pine martens (Martes martes) and stone martens (Martes foina): a multievidence approach using faecal DNA analysis and camera-traps

The European pine marten (Martes martes) and stone marten (Martes foina) are two closely related mustelids that live sympatrically over a large area of Europe. In the northern Iberian Peninsula, the distribution ranges of both species overlap extensively. The objectives of this study were (1) to verify whether, on a small scale, both species also live sympatrically and (2) to compare camera traps and scat DNA as methods for detecting marten species. The study was conducted in a protected area (province of Ourense, north-west Spain), which covers 6700 ha. To test the sympatry hypothesis, 90 fresh faecal samples, identified as faeces of genus Martes on the basis of their morphology, were collected from June 2004 to August 2006. The specific identification of faecal samples was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques. In addition, 20 camera-traps (916 camera-trap-nights) were in operation during the study period. Of the faecal samples collected, 88.8% were attributed to the European pine marten, while the remaining 11.2% were not amplified by PCR and thus could not be assigned. The European pine marten was identified in 57.9% of the photos of carnivores and the stone marten was not detected in any. The faecal DNA analysis and camera-trap results supported previous conclusions about habitat preferences and the distribution of the two species obtained using other methods. The two non-invasive methods that were used in this study were shown to be reliable techniques that can be employed simultaneously, because each method has advantages and disadvantages that are influenced by the size of the area inventoried, sampling effort, and cost and efficiency of the method. The data gathered using these methods provided important information on the understanding of trophic and competitive interactions between the species.

Effects of tourist pressure and reproduction on physiological stress response in wildcats: Management implications for species conservation

Abstract Context. Ecotourism and human recreational activities are increasing and can have a significant impact on fauna. The analysis of faecal glucocorticoid concentrations is a non-invasive method of measuring physiological stress responses of wildlife to various factors (i.e. human disturbances). Aims. The aim of the present study was to determine whether increased physiological stress levels in wildcats (Felis silvestris) were a response to the level of tourism allowed within different zones in a natural park and/or a response to the seasonal reproductive state of wildcats. Methods. The study was conducted from May 2005 to June 2009 at the Natural Park Montes do Invernadeiro (north-western Spain). The Natural Park is divided into the following three zones according to the level of tourism allowed: restricted public-use, restricted zone and integral reserve. An enzyme immunoassay technique was used to quantify cortisol metabolites and sex hormones from each of 110 fresh wildcat faecal samples collected from walked transects on forest roads within each zone. The number of visitors was recorded as a measure of tourist pressure. Key results. The general linear model indicated that park zone and faecal progesterone levels were the factors that explained the variation in the faecal glucocorticoid metabolite levels. Cortisol metabolite concentrations were higher in some park zones where tourism intensity was higher (restricted public-use zone). Faecal cortisol metabolite concentrations were more elevated during gestation (spring) and during the young dispersal period (autumn). Key conclusions. Therefore, we recommend that some zones of park (integral reserve) continue being maintained free of visitor impact and that visitor numbers be specially controlled during the animals’ sensitive periods (gestation) in the zone of restricted public use and in the restricted zone.

The plant physical features selected by wildcats as signal posts: an economic approach to fecal marking

The chemical signals of solitary and territorial felid species are essential for their intraspecific communication. We studied the selection of plant substrates during the fecal marking behavior of the European wildcat Felis silvestris from September 2008 to June 2009 in a protected area in Northwest Spain. The aim of the study was to examine the selection of plants as signal posts with respect to their physical characteristics. We hypothesized that wildcats deposit their fecal marks on plants with physical characteristics (e.g., size, species, and visual conspicuousness) that enhance the olfactory and visual effectiveness of the signal. Our results indicate that diameter, plant group, visual conspicuousness, and interaction between the diameter and plant group influence the decision of wildcats to deposit their fecal marks on plants. The wildcats chose plants with greater diameters and greater visual conspicuousness as scent-marking posts. Moreover, the wildcats chose woody and herbaceous plants, and certain plant species were marked more frequently than expected at random. Indeed, our results indicate that the fecal marks were not randomly distributed on the plants: the wildcats chose to place their marks on plants with certain physical characteristics that maximized the detectability of the signal by intruders and potential mates, thus facilitating the spatial distribution of the species.

Quantification of sexual steroid hormones in faeces of Iberian wolf (Canis lupus signatus): A non-invasive sex typing method

The determination of gender in wild animals is essential for behavioural and ecological studies, and also for conservation. The objectives of this study were (i) the determination of gender in faecal samples of Iberian wolf based on the differential concentrations of sexual steroid hormones (SSH) and (ii) to analyse the profiles of SSH in males and females (considering the gender determination carried out previously) during the non-reproductive and reproductive periods. The quantification of androgens (testosterone, T), progestin (progesterone, P) and oestrogen (oestradiol, E) was conducted by means of enzyme immunoassay. The k-means conglomerate analysis showed that the 59 faecal samples grouped into three different conglomerates, considering SSH levels. Groups 1 and 2 showed higher levels of T than group 3. Therefore, the faecal samples included in groups 1 and 2 (17 samples) corresponded to males and those of group 3 (42 samples) to females. The levels of T + P + E and T/P were higher in the group of males than in the group of females. The results of this study also showed that levels of T in males were higher during the reproductive period than in the non-reproductive period. However, the concentrations of P and E turned out to be higher during the non-reproductive season. In females, the levels of the three hormones (T, P and E) were higher during the reproductive period.

Evaluating the function of wildcat faecal marks in relation to the defence of favourable hunting areas

To date, there have been no studies of carnivores that have been specifically designed to examine the function of scent marks in trophic resource defence, although several chemical communication studies have discussed other functions of these marks. The aim of this study was to test the hypothesis that faecal marks deposited by wildcats (Felis silvestris) serve to defend their primary trophic resource, small mammals. Field data were collected over a 2-year period in a protected area in northwestern Spain. To determine the small mammal abundance in different habitat types, a seasonal live trapping campaign was undertaken in deciduous forests, mature pine forests and scrublands. In each habitat, we trapped in three widely separated Universal Transverse Mercator (UTM) cells. At the same time that the trapping was being performed, transects were conducted on foot along forest roads in each trapping cell and in one adjacent cell to detect fresh wildcat scats that did or did not have a scent-marking function. A scat was considered to have a presumed marking function when it was located on a conspicuous substrate, above ground level, at a crossroad or in a latrine. The number of faecal marks and the small mammal abundance varied by habitat type but not by seasons. The results of the analysis of covariance (ANCOVA) indicated that small mammal abundance and habitat type were the factors that explained the largest degrees of variation in the faecal marking index (number of faecal marks in each cell/number of kilometres surveyed in each cell). This result suggests that wildcats defended favourable hunting areas. They mark most often where their main prey lives and so where they spend the most time hunting (in areas where their main prey is more abundant). This practice would allow wildcats to protect their main trophic resource and would reduce intraspecific trophic competition.

Support vector machines for explaining physiological stress response in Wood mice (Apodemus sylvaticus)

Physiological stress response is a crucial adaptive mechanism for prey species survival. This paper aims to identify the main environmental and/or individual factors better explaining the stress response in Wood mice, Apodemus sylvaticus. We analyzed alterations in fecal glucocorticoid metabolite (FCM) concentration – extensively used as an accurate measure of the physiological stress response – of wild mice fecal samples seasonally collected during three years. Then, support vector machines were built to predict said concentration according to different stressors. These statistical tools appear to be particularly suitable for small datasets with substantial number of dimensions, corroborating that the stress response is an extremely complex process in which multiple factors can simultaneously partake in a context-dependent manner, i.e., the role of each potential stressor varies in time depending on other stressors. However, air-humidity, temperature and body-weight allowed us to explain the FCM fluctuation in 98% of our samples. The relevance of air-humidity and temperature altering FCM level could be linked to the presence of an abundant vegetation cover and, therefore, to food availability and predation risk perception. Body-weight might be related to the stress produced by reproduction and other intraspecific relationships such as social dominance or territorial behavior.