Pierluigi Bombi

Mitochondrial phylogeography of the Bedriaga's rock lizard, Archaeolacerta bedriagae (Reptilia: Lacertidae) endemic to Corsica and Sardinia

Archaeolacerta bedriagae is a rock-dwelling lizard endemic to the Corso-Sardinian insular system. We investigated the phylogeography of the species by using the mitochondrial ND4 and flanking tRNAs genes from 94 specimens belonging to 19 populations. Phylogenetic, Barrier, and SAMOVA analyses revealed a highly structured pattern characterized by two levels of discontinuities in the geographical distribution of mtDNA diversity: (i) a deep phylogeographic break in Northern Corsica between Lineage A, restricted to northernmost Corsica, and Lineage B widespread all over the remaining range of the species, and (ii) some minor phylogeographic discontinuities within lineage B, which is sub-structured into six closely related haplotype clades with remarkable concordance with geography. The first evolutionary event concerning the split between the two main lineages from an ancestral population occurred in the Upper Pliocene (5.87-3.68 mya), while the divergence within lineage B would have started from the Upper Pleistocene (2.5-1.6 mya), between Corsican and Sardinian populations. Somewhat later (1.7-1.1 mya), the Sardinian ancestral population underwent fragmentation into population groups inhabiting North, Central, and South Sardinia. As inferred from previous allozyme surveys, the divergence among population groups would be driven by allopatric fragmentation, while the discrepancy concerning the major partition into two lineages inferred from mtDNA but not apparent in analysis of allozymes needs further investigation.

Interdisciplinary research for the proposal of the Urban Biosphere Reserve of Rome Municipality

Abstract The issue of urban sustainability is considered within the context of the metropolis of Rome, the capital of Italy. The aim is pursued through an Urban Biosphere Reserve proposal, drawn up by an interdisciplinary group of experts comprising landscape ecologists, geologists, plant ecologists, zoologists, geographers, city planners and environmental psychologists. The potential applicability of this project on an international level is discussed, with particular focus on its importance as (i) one of the first proposals of an Urban Biosphere Reserve encompassing the whole municipality of a large city, (ii) an original approach to urban ecosystem investigations within the framework of landscape ecology principles, and (iii) a good example of cooperation between scientists and local decision-makers to preserve the cultural and landscape identity in an urban and periurban context.

Modelling Bedriaga's rock lizard distribution in Sardinia: An ensemble approach

Many techniques for predicting species potential distribution were recently developed. Despite the international interest for these procedures, applications of predictive approaches to the study of Italian fauna distribution are exceptionally rare. This paper aimed at: (a) detecting climatic exigencies of A. bedriagae in Sardinia; (b) predicting the Archaeolacerta bedriagae Sardinian potential distribution; (c) identifying the most vulnerable Italian populations of the species. Literature and field data were utilized as presence records. Six modelling procedures (BIOCLIM, DOMAIN, ENFA, GAM, GLM, and MAXENT) were adopted. The species climatic requirements were defined using the WorldClim databank for deriving the environmental predictors. AUC and Kappa values were calculated for models validation. AUC values were compared by using Anova Monte Carlo. The best four models were combined through the weighted average consensus method for producing a univocal output. GAM and MAXENT had the best performances (respectively: AUC = 0.93 ± 0.03, Kappa = 0.77 ± 0.08; AUC = 0.93 ± 0.03, Kappa = 0.78 ± 0.07). Good results were also obtained by GLM and DOMAIN (respectively: AUC = 0.89 ± 0.04, Kappa = 0.72 ± 0.05; AUC = 0.88 ± 0.04, Kappa = 0.69 ± 0.07). BIOCLIM and ENFA gained relatively low performances (respectively: AUC = 0.78 ± 0.07, Kappa = 0.57 ± 0.14; AUC = 0.75 ± 0.06; Kappa = 0.49 ± 0.10). In Sardinia A. bedriagae is mainly influenced by seasonality, which causes the evidenced range fragmentation. Moreover, the general importance of multi-methods approaches and consensus techniques in predicting species distribution was highlighted.

Distribution, ecology and conservation of Archaeolacerta bedriagae in Sardinia (Reptilia, Lacertidae)

Arcbaeolacerta bedriagae is a polytypic species endemie to Corsica and Sardinia II represents one of the most peculiar elements of the Italian herpetofauna. This species has a fragmented range in Sardinia. The aim of this paper is to summarise the knowledge on the distribution of this lizard in Sardinia, based both on literature and original records, and to define the conservation status of its populations This research was carried out throughout the entire Sardinian territory, from June 2000 to September 2002. Most of the known sites of occurrence of A. bedriagae were checked, characterised from geomorphologic and florofaunistic points of view and gco-referenced. The surveys carried out explored only the potentially suitable habitats in different hours of the day. Three new localities were discovered, 10 checked sites were confirmed, 12 localities were not confirmed and 43 previously quoted sites were not explored. Two sampling sites were selected for a population study. In the latter two localities, several population parameters, such as density and sex ratio were studied. In the mountain site, a population density twenty limes higher than that found at the sea level site was estimated. Only five species were found to be syntopic with A. bedriagae, Podarcis tiliguerta, Algyroides fitzingeri, Tarentola mauritanica, Chalcides ocellatus and Coluber viridiflavus. The Sardinian subrange includes seven main areas of certain presence, but an underestimation due to their elusivity and the low density of some populations is possible The species generally inhabits areas of scarce interest and difficult for man to reach, though at least in some localities it seems to be disturbed by an increase in tourism. Some conservation actions were proposed.

Phylogenetic position of the southern rock lizard Australolacerta australis within the Lacertidae radiation : short communication

Abstract The southern rock lizard Australolacerta australis is a rock-dwelling lizard endemic to South Africa. The phylogenetic relationships of this species with other lacertid lizards are still not clear and have never been assessed in any phylogeny of Lacertidae using DNA sequence data. In this study we employed 3 044 base pairs from mitochondrial cytochrome b, 12S and 16S rRNA genes to investigate the phylogenetic position and the evolutionary history of A. australis. We performed phylogenetic analyses under the assumptions of Maximum Likelihood and Bayesian inference and estimated the timing of the cladogenic events related to A. australis by using a relaxed molecular clock method. Our phylogenetic reconstruction clearly placed A. australis within the southern African branch of the tribe Eremiadini including genera Tropidosaura, Meroles, and Pedioplanis. The former genus constitutes with A. australis a clade endemic to southernmost mountains of Africa. The radiation of this southern African clade is estimated to have occurred during the Mid Miocene (14.7–11.5 Mya), and it was likely due to the climate changes that occurred in the South African region at that time.

Food habits of Podarcis filfolensis (Reptilia, Lacertidae) on a small Mediterranean island during the dry season

Small islands are typically characterised by simplified ecosystems with low levels of complexity and reduced biodiversity. This condition may determine a scarcity of food resources which in turn can affect several aspects of the ecological features of the species, particularly their trophic niche (e.g., Gorman, 1979; Stephen and Krebs, 1986; Pérez-Mellado and Corti, 1993). Predators are extremely sensitive to the complexity and structure of their ecosystems, and lacertids, which are characterised by small size and generalist habits, usually get over the poverty of resources by in some cases adding vegetal material in their diet (Ouboter, 1981; Sorci, 1990; Pérez-Mellado and Corti, 1993; Van Damme, 1999). The Podarcis species inhabiting the Mediterranean islands are a quite well studied group concerning adaptation to island conditions (e.g., Ouboter, 1981; Valakos, 1987; Pérez-Mellado and Corti, 1993). The rich background on phylogeny (e.g., Lanza and Cei, 1977; Capula, 1990, 1994; Oliverio et al., 1998, 2000; Harris and Arnold, 1999) and autoecology (e.g., Valakos, 1987; Rugiero, 1994; Sorci, 1990; Pérez-Mellado and Corti, 1993; Bombi and Bologna, 2002) of these lizards has stimulated the use of this genus as a model for ecoethological studies. Moreover, this group includes a high number of very common species

Climate change threatens the survival of highly endangered Sardinian populations of the snake Hemorrhois hippocrepis

Sardinian populations of the snake Hemorrhois (= Coluber) hippocrepis are likely the most endangered populations of snakes in Italy. Major threats to survivorship are the anthropogenic habitat alteration and the extremely low population density, while nothing is known about the potential effects that climate change could exert on this species. The main goal of this paper is to provide helpful instruments for the short- and long-term conservation of H. hippocrepis in Sardinia. By means of an ecological modeling approach, we derived the Sardinian whip snake habitat suitability map, and we compared the potential range extent under present condition and future climatic scenarios. Results clearly show an alarming trend for H. hippocrepis conservation: changing climate conditions will cause a dramatic reduction on suitable surface since 2020, with a further collapse by 2050 (down to 11 km2). We also identified areas of species potential persistence up till 2050, where prospective management initiatives could have the greatest probability of success in this region. In particular, only one existing protected area will likely still keep suitable habitats for H. hippocrepis. Therefore, we suggest that very careful management of this relictual area should be implemented by now if we really want to save these exceedingly threatened snake populations.

How many Archaeolacerta inhabit the Corso-Sardinian Plate? Allozyme variation and differentiation in Archaeolacerta bedriagae (Camerano, 1885)

Archaeolacerta bedriagae is a rock lizard endemic to Corsica and Sardinia. Four subspecies have been recozied to date on the basis of morphological traits. Previous allozyme investigations revealed high genetic differentiation among populations of the species. Based on these results some authors hypothesized that more than one species of Archaeolacerta may occur on Corsica and Sardinia. In this paper we investigated allozyme variation at 19 gene loci in 5 populations belonging to all subspecies of A. bedriagae in order to study genetic differentiation among populations from Corsica and Sardinia, and to compare our results with those obtained in previous studies carried out on allozyme variation and taxonomy of the species. Low levels of genetic differentiation (average Neis D = 0.026) and heterogeneity (mean FST = 0.147) were found comparing the A. bedriagae populations, and there was no evidence of interruption or restriction of gene flow. This is in agreement with the available molecular and morphometric data, while it is not in accordance with allozyme data reported in the previous studies. Our data do not support the hypothesis of an unrecognized criptic species of Archaeolacerta in Corsica and Sardinia, and indicate that the definitive assessment of the taxonomic status of the A. bedriagae populations requires further investigation.

From Continental Priorities to Local Conservation: A Multi-Level Analysis for African Tortoises

Terrestrial tortoises are the most endangered group of vertebrates but they are still largely ignored for defining global conservation priorities. In this paper, we explored within a hierarchical framework the potential contribution of prioritization studies at the continental scale to the planning of local initiatives for the conservation of African tortoises at the regional level. First, we modeled the distribution of all the African tortoise species, we calculated three indicators of conservation priority (i.e. species richness, conservation value, and complementarity), and we carried out a gap analysis at continental scale. Second, we focused on the most important region for tortoise conservation and performed the same analyses at higher resolution. Finally, we compared the results from the two scales for understanding the degree to which they are complementary. Southern Africa emerged from the continental analysis as the most important region for tortoises. Within this area, the high-resolution analysis pointed out specific core sites for conservation. The relative degree of species protection was assessed similarly at the two different resolutions. Two species appeared particularly vulnerable at both scales. Priority indices calculated at high resolution were correlated to the values calculated for the corresponding cells at low resolution but the congruence was stronger for species richness. Our results suggest to integrate the calculation of conservation value and complementarity into a hierarchical framework driven by species richness. The advantages of large scale planning include its broad perspective on complementarity and the capability to identify regions with greatest conservation potential. In this light, continental analyses allow targeting fine scale studies toward regions with maximum priority. The regional analyses at fine scale allow planning conservation measure at a resolution similar to that required for the practical implementation, reducing the uncertainty associated with low resolution studies.

Do demographic aspects of neighbouring lizard populations differ? A case study with the common wall lizard, Podarcis muralis

Demographic and morphological aspects of two nearby subpopulations of the common wall lizard (Podarcis muralis) were studied, by a capture-mark-recapture procedure, at an archaeological site in the surroundings of Rome, central Italy. In both sites, the births peak was observed in September. Adult sex-ratio was skewed towards males in one subpopulation, but was close to equality in the other. Morphological characteristics were consistent in the two sites, with males always exhibiting larger snout-vent-length and head size. Population size and density, computed by a Jolly-Seber index applied by using POPAN model revealed differences between subpopulations, with lizard density being much higher in the site with higher habitat heterogeneity and shelter availability. Tail condition was similar between sites. The general implications of these data are discussed.