Is Lepus europaeus native to Pianosa Island? F Riga 1 , V Trocchi 2 , F Giannini 3 , C Gotti 1 , N Baccetti

1

ISPRA, Italian National Institute for Environmental Protection and Research, via V. Brancati 48, 00144 Rome, Italy. e-mail: francesco.riga@isprambiente.it

2_{Federazione Italiana della Caccia, Study Center, Via Salaria n. 298/A, 00199 Rome, Italy} 3_{Arcipelago Toscano National Park, Loc. Enfola, 57037 Portoferraio (LI), Italy}

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Introduction Genetic results indicate that the European brown

hare population inhabiting Pianosa island carry the most com- mon historical Italian haplotype. Considering autosomal mark- ers, Pianosa brown hare and current Italian peninsular population are genetically distinct. The discovery of this ancient and pos- sibly native population, isolated at least since the mid-nineteenth century, and not affected by modern translocation/restocking events, has a great relevance in conservation. In a previous study we found morphological differences in the skull between the Italian historical European brown hares than recent ones. With this work we intend to propose a first craniometric characteriza- tion of Pianosa’s hares and their comparison with samples of four other populations.

Methods Craniometric characterization was assessed analyz-

ing 128 skulls belonging to 6 different groups (21 Pianosa, 21 historical Italian Peninsula – before 1930, 53 modern Italian Peninsula, 20 South America, 13 East Europe). To avoid age variation, only adult hares (age class IV) were used. We recorded 21 cranial and mandibular linear measurements, from each skull using a digital caliper with an accuracy of 0.01 mm. The original data set was log transformed. The differences between groups was analyzed using Kruskal-Wallis test. Each group was tested against the null hypothesis that the median was the same across the categories, using the independent samples median test. The null hypothesis was rejected when an exact significance <0.05 was reached. When rejected, the test was considered statistically

significant. Furthermore we performed a principal component analysis to select the most explicative variables and used the first 5 component scores to implement a discriminant analysis between hare groups.

Results Nonparametric median test reject the null hypothesis

that there are significant differences among groups of hares re- spect to centroid size of the measures (p<0.05), the analysis of variance conducted on the 5 groups shows significant differences in 17 linear measures on 21. The discriminant analysis correctly classified 100% of hares inhabiting Pianosa, however, the other groups had a correct classified percentage ranging from 69.8% to 84.6%.

Discussion The Pianosa’s L. europaeus population is well dif-

ferentiated in the skull morphology compared to all the groups tested. Most of the cranial measures are significantly smaller, even compared to the historical samples of the Italian Penin- sula. These morphological differences, together with those of autosomal markers, denote a long isolation period. However the historical information’s report the hare presence in Pianosa already in 1835. The morphological condition of this hare pop- ulation seems to correspond to the Island Rule, which leaves the island mammal populations free to evolve towards the body size most advantageous for exploiting local resources of energy in the diet, in the absence of effective predators and interspecific competition. Further studies are needed to reconstruct the history of this L. europaeus population, and ensure its conservation.

Hystrix, It. J. Mamm. (2018) 29 (Supplement) – XI Congresso Italiano di Teriologia

XI Congresso Italiano di Teriologia

Healthy invaders do it better: loss of parasites in mammals introduced to Italy

1_{Department of Veterinary Medicine, Università degli Studi di Milano, Milano, Italy. e-mail: claudia.romeo@unimi.it} 2_{Department of Theoretical and Applied Sciences, Università degli Studi dell’Insubria, Varese, Italy}

3_{Centro di Ricerca Coordinata Epidemiologia e Sorveglianza Molecolare delle Infezioni, Università degli Studi di Milano, Milano, Italy}

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Parasitic infections are ubiquitous in wild animals, with most in- dividuals having to cope with several parasite species. However, alien species often lose part of their parasite community during invasion due to stochastic processes, treatments during captiv- ity or suboptimal environmental conditions. At the individual level, hosts will benefit from a reduced parasite pressure, as they may shift resources away from costly immune functions towards other activities, such as reproduction and growth. Consequently, the loss of parasites observed in many alien species is among the mechanisms that may explain why successful invaders often show improved performances in introduction ranges compared to native ranges (enemy-release hypothesis). We surveyed gastro- intestinal helminths infecting three invasive mammals introduced to Northern Italy (grey squirrels, Sciurus carolinensis; Pallas’ squirrels, Callosciurus erythraeus; raccoons, Procyon lotor), to verify whether any loss of parasites that may have facilitated their invasion had occurred. We examined 504 grey squirrels, 74 Pal- las’ squirrels and 44 raccoons culled within alien species control programmes. Gastro-intestines were removed from carcasses, dissected and rinsed through a 0.03 mm sieve. The obtained material was examined under a microscope and the recovered helminths were identified through a combination of morphology and molecular tools.

In grey squirrels we found 7 gastro-intestinal helminth taxa, most of which were detected only rarely (i.e. prevalence <5%) and had low intensity of infection. Parasite richness ranged from 0 to 3 species/host (mean: 0.77), with 62% of squirrels infected by at least one species. The most represented parasites were

Strongyloides robustus(prevalence: 57%; mean intensity±SE:

23.1±0.8 worms/infected host). Trichostrongylus spp. (8%; 2.9±0.7) and Rodentoxyuris sciuri (6%; 18.2±13.5). In Pallas’ squirrels we detected 6 parasitic taxa, but only 15% of the ex- amined individuals were infected by gastro-intestinal helminths and we did not detect any coinfection (mean richness: 0.15 species/host). The most abundant parasites were Rodentoxyuris

sciuri(5%; 2.25±1.5) and Trichuris muris (4%; 1±0). Finally, in

raccoons we found a total of 11 parasitic taxa, 6 of which had pre- valence >5%. Richness ranged from 0 to 6 species/host (mean: 1.25) and 70% of raccoons were infected by at least one spe- cies. The most represented parasites were Strongyloides procy-

onis(25%; 17.4±8.1 parasites/infected host), Capillaria putorii

(23%; 7.9±2.4) and Porrocaecum spp. (14%; 24.8±9.7). Our findings show that grey squirrels, Pallas’ squirrels and raccoons introduced to Italy harbour impoverished parasite communities compared to their native ranges. Grey squirrels and raccoons both retained two North American helminths, whereas Pallas’ squirrels carried along from SE Asia a single nematode. Local parasites were detected only sporadically and in all the three hosts, especially Pallas’ squirrels, we found many individuals that were completely free of gastro- intestinal helminth infections. Raccoons were the most parasitised host species, but considering their omnivorous diet and opportunistic behaviour, their helminth community still appears poor in terms of richness and intensity of infection. The present survey supports the premises for an enemy-release, suggesting that the establishment and spread of these three alien mammals may have been facilitated by a reduced parasite pressure.

Poster

XI Congresso Italiano di Teriologia

Are Chiroptera influenced in the use of underground cavities by geomorphology and