JOBNAME: No Job Name PAGE: 1 SESS: 18 OUTPUT: Mon Mar 12 14:45:29 2012 SUM: 8A81CE40 /v2503/blackwell/journals/mam_v0_i0_new_style_2010/mam_212 Mammal Rev. 2012 1 REVIEW 2 3 The successful introduction of the alpine marmot 4 Marmota marmota in the Pyrenees, Iberian Peninsula, 5 Western Europe 6 7 Isabel C. BARRIO* Pyrenean Institute of Ecology, Avda, Regimiento de Galicia s/n 8 PO Box 64, 22700 Jaca (Huesca), Spain, and Department of Biological Sciences, 9 University of Alberta T6G 2E9 Edmonton, Alberta, Canada. 10 E-mail: [email protected] 11 Juan HERRERO Technical School of Huesca, University of Zaragoza, 22071 Huesca, 12 Spain. E-mail: [email protected] 13 C. Guillermo BUENO Pyrenean Institute of Ecology, Avda. Regimiento de Galicia 14 s/n PO Box 64, 22700 Jaca (Huesca), Spain, and Department of Biological Sciences, 15 University of Alberta T6G 2E9 Edmonton, Alberta, Canada. 16 E-mail: [email protected] 17 Bernat C. LÓPEZ Center for Ecological Research and Forestry Applications, 18 Autonomous University of Barcelona, 08193 Bellaterra, Spain. 19 E-mail: [email protected] 20 Arantza ALDEZABAL Landare-Biologia eta Ekologia Saila, UPV-EHU, PO Box 644, 21 48080 Bilbo, Spain. E-mail: [email protected] 22 Ahimsa CAMPOS-ARCEIZ School of Geography, University of Nottingham 23 Malaysian Campus, Semenyih 43,500, Selangor, Malaysia. 24 E-mail: [email protected] 25 Ricardo GARCÍA-GONZÁLEZ Pyrenean Institute of Ecology, Avda. Regimiento de 26 Galicia s/n PO Box 64, 22700 Jaca (Huesca), Spain. E-mail: [email protected] 27 28 29 ABSTRACT 30 1. The introduction of non-native species can pose environmental and economic 31 risks, but under some conditions, introductions can serve conservation or recre- 32 ational objectives. To minimize risks, introductions should be conducted following 33 the International Union for Conservation of Nature’s guidelines and should include 34 an initial assessment and a follow-up. 35 2. In 1948, to reduce the predation pressure on Pyrenean chamois Rupicapra pyrena- 36 ica pyrenaica by golden eagles Aquila chrysaetos, the alpine marmot Marmota 37 marmota was introduced to the Pyrenees in Western Europe. In successive introduc- 38 tions, about 500 marmots were released, but the fate of the released animals and 39 their impacts on the environment remain largely unstudied. 40 3. The aim of this study was to assess the success of the introduction of the alpine 41 marmot into the Pyrenees, 60 years after the initial release, and the potential 42 impacts of this species on Pyrenean ecosystems. 43 4. We reviewed what is known about the marmot populations introduced to the 44 Pyrenees and other populations within their native range in the Alps, particularly in 45 46 47 *Correspondence author. © 2012 The Authors. Mammal Review © 2012 Mammal Society/Blackwell Publishing JOBNAME: No Job Name PAGE: 2 SESS: 18 OUTPUT: Mon Mar 12 14:45:29 2012 SUM: 6193DD75 /v2503/blackwell/journals/mam_v0_i0_new_style_2010/mam_212 2 I. C. Barrio et al. 1 terms of population structure and dynamics, habitat use and potential environmen- 2 tal impacts. 3 5. The alpine marmot is widely distributed and, apparently, well established in the 4 Pyrenees. Population structure and demographic parameters are similar within and 5 outside the historical distribution range of the species, and habitat suitability is one 6 of the main reasons for the species’ success in the Pyrenees. Few researchers have 7 investigated the impacts of alpine marmots in the Pyrenees; thus, those impacts have 8 to be inferred from those observed in the species’ native range or in other species of 9 marmot. Introduced alpine marmots are likely to impact on Pyrenean grasslands 10 through grazing and burrowing, have the potential to alter Pyrenean food webs and 11 could act as vectors of parasites and disease. 12 6. Although the introduction of the alpine marmot in the Pyrenees appears to have 13 been successful, more needs to be known about the effects of the established 14 populations on the environment before informed management actions can be taken 15 in the Pyrenees. 16 17 Keywords: alien species, biogeographical comparison, herbivore, mountain ecosys- 18 tems, translocation 19 Mammal Review (2012) 20 doi: 10.1111/j.1365-2907.2012.00212.x 21 22 INTRODUCTION 23 The intentional release of living organisms into the wild, the so-called translocation, 24 can be carried out in order to achieve species conservation goals (Griffith et al. 1989). 25 The International Union for Conservation of Nature (IUCN) recognizes three main 26 types of translocation: introduction, reintroduction and restocking (Anonymous 27 1987). Introductions involve the dispersal by human agency of a living organism 28 outside its historical distribution range, while reintroductions involve the release of a 29 species into the native range from which it disappeared in historical times (Anony- 30 mous 1998). Restocking is a means of increasing the size of a population. While 31 reintroductions typically have been viewed as valid means of conserving species (e.g. 32 Halley 2011), introductions of non-native species have often had harmful effects on 33 native species, ecosystems and human well-being. Non-native species, especially if 34 they become invasive, can have negative effects on the dynamics of natural systems, 35 which can lead to the extirpation of native species and significant economic losses 36 (Anonymous 2000). Biological invasions are an increasing threat to biodiversity 37 (Soorae 2010), and generally, the IUCN discourages species introductions (Anonymous 38 1987). 39 Some introductions, however, can be beneficial to humans or natural communi- 40 ties, e.g. by providing sources of food or habitat for rare or declining species, by 41 acting as functional substitutes for extinct species or by providing desirable eco- 42 system functions (Schlaepfer et al. 2011). Thus, in some circumstances, the intro- 43 duction of a species into an area that is outside its historical native range can be 44 a valid conservation tool (Thomas 2011). In any case, to avoid unnecessary risks, 45 introductions should comply with the IUCN guidelines and should include an initial 46 assessment phase and monitoring of released animals after the introduction 47 (Anonymous 1987). Ideally, the potential effects of the introduced species on © 2012 The Authors. Mammal Review © 2012 Mammal Society/Blackwell Publishing JOBNAME: No Job Name PAGE: 3 SESS: 18 OUTPUT: Mon Mar 12 14:45:29 2012 SUM: 5D378DAB /v2503/blackwell/journals/mam_v0_i0_new_style_2010/mam_212 Alpine marmot in the Pyrenees 3 1 ecosystem functioning should be assessed. However, in many instances, introduc- 2 tions have not been followed up. 3 The alpine marmot Marmota marmota was introduced to the Pyrenees, a region 4 that is outside of the historical distribution range of the species, first by individual 5 hunters (Couturier 1955) and then by the staff of the Parc National des Pyrénées, 6 France, with the objectives of reducing the predation pressure on Pyrenean chamois 7 Rupicapra pyrenaica pyrenaica by golden eagles Aquila chrysaetos and providing 8 food for brown bears Ursus arctos (Besson 1971). Unfortunately, the results and 9 effects of the introduction and the achievement of its goals remain largely untested. 10 From the release points in southern France, the species spread rapidly into the 11 southern Pyrenees, probably because the habitats were favourable, and because 12 natural predators and important interspecific competitors were absent (Herrero 13 et al. 1987, 1992). Alpine marmots seem to be well established in the Pyrenees, but 14 the status of the populations is uncertain. 15 A translocation is successful if it produces a self-sustaining population (Griffith 16 et al. 1989, Williamson & Fitter 1996); however, to understand fully the success of an 17 introduction, the ecology of populations within and outside the species’ native range 18 has to be compared (Hierro et al. 2005). Such comparative studies can help in the 19 assessment of the impact of non-native species within their introduced range 20 (Hufbauer & Torchin 2007). Introduced mammals can have an impact on the environ- 21 ment through, e.g. herbivory, the transmission of diseases or other effects on agricul- 22 ture, livestock and forestry. Furthermore, the effects are likely to be greater in the 23 areas occupied by the introduced populations than they are in the areas of the 24 species’ native distribution (Kumschick et al. 2011). 25 In this study, we review what is known about the alpine marmot populations that 26 became established after introductions in the Pyrenees. In addition, we describe the 27 past and present distribution of alpine marmots and compare the populations of 28 alpine marmot in the Pyrenees with those within the species’ native range, compar- 29 ing habitat selection, population parameters and life-history traits reported in the 30 literature. We examine the potential effects of alpine marmots on ecosystems in the 31 Pyrenees. We propose hypotheses for the possible fate of their populations under 32 global change scenarios, based on available information from the native range of 33 the species and from other marmot species. 34 35 METHODS 36 To assess the status of alpine marmot populations within the species’ native range 37 and those that were introduced to the Pyrenees, we searched the published and 38 unpublished literature for information on specific aspects of the species’ ecology, 39 following the guidelines proposed by Pullin and Stewart (2006). Specifically, between 40 January and April 2011, we searched electronic databases (Scholar Google, ISI Web 11 41 of Knowledge, Scopus, ScienceDirect), professional networks (International Marmot 42 Network) and bibliographies, and consulted experts. We focused on key aspects of 43 the population structure and dynamics of alpine marmots and their potential 44 impacts on Pyrenean ecosystems. The searches were based on the following terms: 45 alpine marmot, Marmota, Pyrenees, introduction, habitat, population, dynamics, 46 impact, diet, vegetation, predator, soil and burrow.