13 research outputs found

    Does predation risk affect spatial use in an introduced ungulate species? The case of a Mediterranean mouflon alpine colony

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    Predation risk is known to affect the spatial use of prey species, imposing a trade-off between feeding requirements and predation avoidance. As a result, prey species can leave high-quality forage areas to use sub-optimal, but safer, habitat patches, defined as “refuge areas.” In this study, we describe changes in the spatial use of an introduced ungulate species, the Mediterranean mouflon Ovis aries musimon, following the recolonization (in 1996) of wolves Canis lupus into the Albergian Hunting Estate (Italian Western Alps). Since 1988, we monitored the mouflon population by spring counts from vantage points. We georeferenced all observations and recorded the size and structure of the spotted groups. Finally, we identified available refuges by selecting patches characterized by (i) the presence of rocks and (ii) high values of steepness and ruggedness. We found that mouflons significantly reduced the average distance from refuge areas over the years, with the yearly average distance from refuges being 56% lower after wolves recolonized the area (i.e., 93.8 ± 32.1 vs. 213.1 ± 40.9 m). The analysis of orographic parameters showed that mouflons used patches with higher values in elevation, slope, ruggedness, and a significant difference in all three parameters when comparing years pre and post wolf return. Both sexes were significantly affected, but ewes were particularly sensitive and selected patches closer to refuge areas (75.8 ± 30.3 m) than males (131.0 ± 53.6 m). Our results suggest that the presence of new predators can alter the distribution of an introduced species such as the Mediterranean mouflon, triggering the resurgence of anti-predation behavior

    Recent distribution of Red-legged Partridge Alectoris rufa in Piedmont (North Western Italy): signs of recent spreading.

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    The red-legged partridge Alectoris rufa in Piedmont (NW Italy) is historically limited to the hilly and low-mountain areas of the southern half of the region, in particular lying in the Langhe and the Apennines on the Ligurian border, in the districts of Cuneo, Asti and Alessandria. In the Cuneo district, on the Maritime Alps, hybrid populations with Alectoris graeca were also known. The distribution of the species has been mapped in some occasions with the \u201cAtlases\u201d projects of the GPSO (Gruppo Piemontese Studi Ornitologici) and special enquiries. On this occasion we tried to update the geographical distribution of the species using data conferred by bird-watchers on www.regione.piemonte.it/aves/, managed by the GPSO, enquiries among hunters\u2019 organizations and specific field researches. The resulting distribution is shown on a 10 km square grid. The species shows signs of distribution dynamism, with the occupation of some lowland areas, where it was totally absent until the \u201890s. A little range expansion is noticeable also in the Western Monferrato. The situation seems to be more stable (or even declining) in the Langhe area and the species is now disappeared from the alpine border. In general we are seeing an areal contraction or density reduction on hills and mountains and an extension on lowlands. The observed changes seem to be attributable mainly to environmental and climate changes

    Comparative evaluation of effort, capture and handling effects of drive nets to capture roe deer (Capreolus capreolus), Southern chamois (Rupicapra pyrenaica) and Spanish ibex (Capra pyrenaica)

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    The objective of this study is to assess the usefulness of drive nets to capture roe deer (Capreolus capreolus), Southern chamois (Rupicapra pyrenaica) and Spanish ibex (Capra pyrenaica), comparing the results obtained with other capture methods and amongst the three species. Sixty-five drive net capture operations using beaters were conducted from January 1998 to September 2004. A total of 161 wild ungulates (31 roe deer, 95 Southern chamois and 35 Spanish ibexes) were captured. The average number of animals captured per operation was 1.07 for roe deer, 3.96 for Southern chamois and 2.92 for Spanish ibex. The average number of person–days per captured animal was 21.5, 7.1 and 10.6 for roe deer, Southern chamois and Spanish ibex, respectively. Specificity was 100% for Southern chamois and Spanish ibex (only the target species captured) and 77.5% for roe deer. Risk for the animals (mortality plus injuries) was 3.23% for roe deer, 5.27% for Southern chamois and 0% for Spanish ibex, whereas injuries to the operators occurred with 3.1% of the handled animals. Sex ratio was skewed towards females in roe deer, towards males in Southern chamois and balanced in Southern chamois. Drive nets showed good performance, although many operators were required. Safety for the animals and specificity were higher than traditionally attributed to this capture method. It is concluded that drive nets are an efficient and safe method to capture many ungulate species.This work is part of the research projects ‘Capture and handling stress in roe deer’ (AGF97-0493), ‘Assessment of capture and handling stress in Southern chamois (Rupicapra pyrenaica)’ (AGF99-0763-C02), and ‘Assessment of capture and post-capture handling stress in Spanish ibex (Capra pyrenaica)’ (REN 2001-1989/GLO), all of them financed by the Spanish ‘Comisión Interministerial de Ciencia y Tecnología’ (CICYT). One of the authors had a grant from the ‘Direcció General de Recerca’ (DGR) of the Catalan government, and another one had a FPI grant of the Universidad Autónoma de Barcelona.Peer reviewe
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