From the Apennines to the Alps: Colonization genetics of the naturally expanding Italian wolf (Canis lupus) population

University of Lausanne, Lausanne, Vaud, Switzerland
Molecular Ecology (Impact Factor: 6.49). 04/2007; 16(8):1661-71. DOI: 10.1111/j.1365-294X.2007.03262.x
Source: PubMed


Wolves in Italy strongly declined in the past and were confined south of the Alps since the turn of the last century, reduced in the 1970s to approximately 100 individuals surviving in two fragmented subpopulations in the central-southern Apennines. The Italian wolves are presently expanding in the Apennines, and started to recolonize the western Alps in Italy, France and Switzerland about 16 years ago. In this study, we used a population genetic approach to elucidate some aspects of the wolf recolonization process. DNA extracted from 3068 tissue and scat samples collected in the Apennines (the source populations) and in the Alps (the colony), were genotyped at 12 microsatellite loci aiming to assess (i) the strength of the bottleneck and founder effects during the onset of colonization; (ii) the rates of gene flow between source and colony; and (iii) the minimum number of colonizers that are needed to explain the genetic variability observed in the colony. We identified a total of 435 distinct wolf genotypes, which showed that wolves in the Alps: (i) have significantly lower genetic diversity (heterozygosity, allelic richness, number of private alleles) than wolves in the Apennines; (ii) are genetically distinct using pairwise F(ST) values, population assignment test and Bayesian clustering; (iii) are not in genetic equilibrium (significant bottleneck test). Spatial autocorrelations are significant among samples separated up to c. 230 km, roughly correspondent to the apparent gap in permanent wolf presence between the Alps and north Apennines. The estimated number of first-generation migrants indicates that migration has been unidirectional and male-biased, from the Apennines to the Alps, and that wolves in southern Italy did not contribute to the Alpine population. These results suggest that: (i) the Alps were colonized by a few long-range migrating wolves originating in the north Apennine subpopulation; (ii) during the colonization process there has been a moderate bottleneck; and (iii) gene flow between sources and colonies was moderate (corresponding to 1.25-2.50 wolves per generation), despite high potential for dispersal. Bottleneck simulations showed that a total of c. 8-16 effective founders are needed to explain the genetic diversity observed in the Alps. Levels of genetic diversity in the expanding Alpine wolf population, and the permanence of genetic structuring, will depend on the future rates of gene flow among distinct wolf subpopulation fragments.

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    • "c o m / l o c a t e / b i o c Alps will predictably increase chances to originate mixed packs and increase the local genetic diversity as has been already described (Fabbri et al., 2014;Randi, 2011). The sub-population of wolves inhabiting the Liguria region thus plays a crucial role in assuring the linkage between the wolves of central Italy and those of the Western Alps (Fabbri et al., 2007). If this link should break, the wolf population of the Western Alps would be isolated, perhaps failing to recolonize the remaining part of the Alps. "
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    ABSTRACT: Thanks to protection by law and increasing habitat restoration, wolves (Canis lupus) are currently re-colonizing Europe from the surviving populations of Russia, the Balkan countries, Spain and Italy, raising the need to update conservation strategies. A major conservation issue is to restore connections and gene flow among fragmented populations, thus contrasting the deleterious consequences of isolation. Wolves in Italy are expanding from the Apennines towards the Alps, crossing the Ligurian Mountains (northern Italy) and establishing connections with the Dinaric populations. Wolf expansion is threatened by poaching and incidental killings, mainly due to livestock depredations and conflicts with shepherds, which could limit the establishment of stable populations. Aiming to find out the factors affecting the use of livestock by wolves, in this study we determined the composition of wolf diet in Liguria. We examined 1457 scats collected from 2008 to 2013. Individual scats were genotyped using a non-invasive genetic procedure, and their content was determined using microscopical analyses. Wolves in Liguria consumed mainly wild ungulates (64.4%; in particular wild boar Sus scrofa and roe deer Capreolus capreolus) and, to a lesser extent, livestock (26.3%; in particular goats Capra hircus). We modeled the consumption of livestock using environmental features, wild ungulate community diversity, husbandry characteristics and wolf social organization (stable packs or dispersing individuals). Wolf diet varied according to years and seasons with an overall decrease of livestock and an increase of wild ungulate consumption, but also between packs and dispersing individuals with greater livestock consumption for the latter. The presence of stable packs, instead of dispersing wolves, the adoption of prevention measures on pastures, roe deer abundance, and the percentage of deciduous woods, reduced predation on livestock. Thus, we suggest promoting wild ungulate expansion, the use of prevention tools in pastures, and supporting wolf pack establishment, avoiding lethal control and poaching, to mitigate conflicts between wolf conservation and husbandry.
    Full-text · Article · Mar 2016 · Biological Conservation
    • "The current distribution of the Italian wolf population is the result of a natural expansion. From a wreck population divided into small groups located in Southern and Central Italy, where in 1973 it was estimated at about 100 individuals (Zimen and Boitani 1975), the species has recolonized the Northern Apennines and reached the Alps through the ecological corridor in Liguria (Fabbri et al. 2007). Palomares and Caro (1999) reported several examples of lethal encounters involving wolves, as killer species, and smaller carnivores (e.g. "
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    ABSTRACT: We investigated the seasonal spatial and temporal co-occurrence of three carnivore species in Liguria region (NW Italy)—the red fox (Vulpes vulpes), the European badger (Meles meles) and the wolf (Canis lupus)—using the information provided by camera-trapping monitoring. Data were collected from January 2013 to January 2015 by positioning camera traps in 200 sample stations. During 3479 trap days, we collected 1048 independent videos of target carnivore species, which revealed a general spatial coexistence among carnivores with some differences in seasonal occurrence of species. The red fox and the European badger showed temporal segregation, as their activity patterns suggested a differential use of night-time in all seasons. Activity patterns of the red fox and the wolf revealed moderate-high overlap and similar density distributions in all seasons except during winter. Coexistence between these species may be allowed by temporal segregation during winter and spatial segregation during spring. Finally, results regarding the European badger and the wolf suggest a moderate temporal segregation with a marked avoidance effect for the European badger induced by the presence of tracks left by wolves. Programmes aimed at carnivore conservation, and management should treat the entire guild, as it has been demonstrated that populations of different carnivores interact with each other in complex ways and that fine-scale mechanisms regulating carnivore assemblage influence different aspects of natural communities.
    No preview · Article · Dec 2015 · acta ethologica
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    • "During the past decades, the use of microsatellite markers (single tandem repeats—STRs) permitted to identify the fine-scale structuring in natural populations (Perez et al. 2013; De Barba et al. 2010; Mucci et al. 2010; Fabbri et al. 2007) and supported the discovery of illegal traffics and wildlife crime in forensic genetics (Alacs et al. 2010; Mucci et al. 2014; Barbanera et al. 2012; Caniglia et al. 2010). Availability of new molecular markers such as the use of animal traces and non-invasive samplings as a source of DNA, allowed researchers to accomplish conservation projects with minimal stress on animals. "
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    ABSTRACT: Testudo graeca, Testudo hermanni and Testudo marginata are endangered species listed in the IUCN Red List and Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Correct identification of species and distinct population units can support sound conservation projects and forensic applications. However, the collection of biological samples is not always easy or harmless. Blood sampling is usually invasive and risky. Salivary swab sampling is commonly used in other reptiles but can be unsafe for tortoises by the reason of their head retraction escape response. Cloacal swab sampling should be easier and less risky. In this study, we genotyped 37 tortoises at eight microsatellite loci and compared the reliability of individual genotypes obtained from blood, cloacal and buccal swabs. Results showed that performances of cloacal samples are comparable with those of buccal and blood samples, and proved that cloacal sampling is an alternative and reliable source of DNA for tortoise genotyping.
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