The successful introduction of the alpine marmot Marmota marmota in the Pyrenees, Iberian Peninsula, Western Europe

Abstract

The introduction of non‐native species can pose environmental and economic risks, but under some conditions, introductions can serve conservation or recreational objectives. To minimize risks, introductions should be conducted following the International Union for Conservation of Nature's guidelines and should include an initial assessment and a follow‐up. In 1948, to reduce the predation pressure on Pyrenean chamois Rupicapra pyrenaica pyrenaica by golden eagles Aquila chrysaetos, the alpine marmot Marmota marmota was introduced to the Pyrenees in Western Europe. In successive introductions, about 500 marmots were released, but the fate of the released animals and their impacts on the environment remain largely unstudied. The aim of this study was to assess the success of the introduction of the alpine marmot into the Pyrenees, 60 years after the initial release, and the potential impacts of this species on Pyrenean ecosystems. We reviewed what is known about the marmot populations introduced to the Pyrenees and other populations within their native range in the Alps, particularly in terms of population structure and dynamics, habitat use and potential environmental impacts. The alpine marmot is widely distributed and, apparently, well established in the Pyrenees. Population structure and demographic parameters are similar within and outside the historical distribution range of the species, and habitat suitability is one of the main reasons for the species' success in the Pyrenees. Few researchers have investigated the impacts of alpine marmots in the Pyrenees; thus, those impacts have to be inferred from those observed in the species' native range or in other species of marmot. Introduced alpine marmots are likely to impact on Pyrenean grasslands through grazing and burrowing, have the potential to alter Pyrenean food webs and could act as vectors of parasites and disease. Although the introduction of the alpine marmot in the Pyrenees appears to have been successful, more needs to be known about the effects of the established populations on the environment before informed management actions can be taken in the Pyrenees.

Factors affecting the spread of parasites in populations of wild European terrestrial mammals

“…Reduced exposure to natural antigens and loss of immunogenetic variation during captive breeding may impair the survival probability of released animals (Cunningham 1996;Mathews et al 2006;Viggers et al 1993). Another issue is the potential transfer of pathogens into previously unexposed wild populations in often sensitive, protected areas (Barrio et al 2012;Daszak et al 2000;Kołodziej-Sobocińska et al 2018b;Vadlejch et al 2016). For example, the successful introduction of wild alpine marmot (Marmota marmota) in the Pyrenees, Iberian Peninsula, Spain, is associated with various threats from this introduced species (Barrio et al 2012).…”

“…Another issue is the potential transfer of pathogens into previously unexposed wild populations in often sensitive, protected areas (Barrio et al 2012;Daszak et al 2000;Kołodziej-Sobocińska et al 2018b;Vadlejch et al 2016). For example, the successful introduction of wild alpine marmot (Marmota marmota) in the Pyrenees, Iberian Peninsula, Spain, is associated with various threats from this introduced species (Barrio et al 2012). Alpine marmots are likely to impact Pyrenean grasslands (grazing, burrowing), alter Pyrenean food webs, and act as vectors of parasites and diseases (Barrio et al 2012).…”

“…For example, the successful introduction of wild alpine marmot (Marmota marmota) in the Pyrenees, Iberian Peninsula, Spain, is associated with various threats from this introduced species (Barrio et al 2012). Alpine marmots are likely to impact Pyrenean grasslands (grazing, burrowing), alter Pyrenean food webs, and act as vectors of parasites and diseases (Barrio et al 2012). Preliminary studies revealed that the introduced alpine marmots have fewer parasites in the Pyrenees than they have in their native range; however, some of the alpine marmot parasite species were new to the Pyrenees, e.g., Calodium hepaticum, Ctaenotenia marmotae, Eimeria marmotae, and E. arctomysi (Gortázar et al 1996;Riba and Tena 1999).…”