Dissecting phenotypic variance in life history traits into its genetic and environmental components is at the focus of evolutionary studies and of pivotal importance to identify the mechanisms and predict the consequences of human-driven environmental change. The timing of recurrent life history events (phenology) is under strong selection, but the study of the genes that control potential environmental canalization in phenological traits is at its infancy. Candidate genes for circadian behaviour entrained by photoperiod have been screened as potential controllers of phenological variation of breeding and moult in birds, with inconsistent results. Despite photoperiodic control of migration is well established, no study has reported on migration phenology in relation to polymorphism at candidate genes in birds. We analysed variation in spring migration dates within four trans-Saharan migratory species (Luscinia megarhynchos; Ficedula hypoleuca; Anthus trivialis; Saxicola rubetra) at a Mediterranean island in relation to Clock and Adcyap1 polymorphism. Individuals with larger number of glutamine residues in the poly-Q region of Clock gene migrated significantly later in one or, respectively, two species depending on sex and whether the within-individual mean length or the length of the longer Clock allele was considered. The results hinted at dominance of the longer Clock allele. No significant evidence for migration date to covary with Adcyap1 polymorphism emerged. This is the first evidence that migration phenology is associated with Clock in birds. This finding is important for evolutionary studies of migration and sheds light on the mechanisms that drive bird phenological changes and population trends in response to climate change.

A knowledge of population trends is essential in order to assess the conservation status of a species and to develop practices to manage ecologically sustainable land use. However, monitoring programmes designed to assess trends are often not carried out due to their high operating costs. Therefore, in order to obtain population trend estimates without a specific monitoring programme, it is necessary to use heterogeneous historical information. The aim of this research was to assess population indices and trends between 1992 and 2007 for common bird species breeding in Lombardy (Italy), applying a previously developed method, which permits data derived from different survey projects to be utilised. Among the 51 species considered, there were seven negative and 10 positive trends, whereas the remaining species did not show a significant population change. Major declines regarded farmland species, namely the Red-backed Shrike Lanius collurio and the Sky Lark Alauda arvensis which, over a 15 year period, decreased by more than 70%. Among forest species, the Common Chiffchaff Phylloscopus collybita declined, whereas the others either increased or did not demonstrate a significant trend. The population index also highlighted recurring patterns of inter-annual changes in the populations of different species, suggesting that certain ecological processes may have an effect on the whole community. The general decline of farmland species, which is known to occur in many other European regions, suggests the need for specific monitoring schemes for birds and their habitats, in order to understand the effects of changes in agricultural practices and to be able to plan effective measures for bird conservation in productive areas.

The multistep method here applied in studying the genetic structure of a low dispersal and philopatric species, such as the Fire Salamander Salamandra salamandra, was proved to be effective in identifying the hierarchical structure of populations living in broad-leaved forest ecosystems in Northern Italy. In this study, 477 salamander larvae, collected in 28 sampling populations (SPs) in the Prealpine and in the foothill areas of Northern Italy, were genotyped at 16 specie-specific microsatellites. SPs showed a significant overall genetic variation (Global FST = 0.032, P < 0.001). The genetic population structure was assessed by using STRUCTURE 2.3.4. We found two main genetic groups, one represented by SPs inhabiting the Prealpine belt, which maintain connections with those of the Eastern foothill lowland (PEF), and a second group with the SPs of the Western foothill lowland (WF). The two groups were significantly distinct with a Global FST of 0.010 (P < 0.001). While the first group showed a moderate structure, with only one divergent SP (Global FST = 0.006, P < 0.001), the second group proved more structured being divided in four clusters (Global FST = 0.017, P = 0.058). This genetic population structure should be due to the large conurbations and main roads that separate the WF group from the Prealpine belt and the Eastern foothill lowland. The adopted methods allowed the analysis of the genetic population structure of Fire Salamander from wide to local scale, identifying different degrees of genetic divergence of their populations derived from forest fragmentation induced by urban and infrastructure sprawl.

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Aim Overall species richness in habitat remnants is seldom explained by the island biogeography theory (IBT). In this study, we tested the effectiveness of the IBT in explaining species richness of forest birds with or without considering the effect of the different forest specialization of species (generalist, edge and interior; community analysis). We also identified single species and groups of species that could serve as indicators of different fragmentation degrees (indicator species analysis). Location Broadleaved forests in western Lombardy (northern Italy). Methods We evaluated bird species richness in 344 forest fragments. Fragment area (FA), distance from the nearest source area (> 1000 ha) (DSA) and number of neighbouring fragments (NF) were calculated for each fragment. Using Poisson generalized linear models, we compared a model that evaluated the relationships between fragment covariates and species richness to a model that also considered the effect of forest species specialization on each relationship. Moreover, we investigated the association between each species and particular fragmentation conditions by calculating the IndVal index. Results The application of the IBT to species richness performed significantly better if we took into account forest species specialization when evaluating the effect of fragment covariates. In particular, the positive effects of FA and NF and the negative effect of DSA were significantly stronger on interior species rather than on generalist and edge species. Using the IndVal index we identified six species in three groups strongly associated with specific fragmentation degrees. Main conclusions The results showed the strong influence of the specialization of species on their distribution in fragmented landscapes. Interior species were the best candidates as a proxy of fragmentation effects. However, the indicator species analyses revealed that not all interior species showed the same sensitivity to fragment covariates.

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Climate warming and habitat transformation are widely recognized as worrying threatening factors. Understanding the individual contribution of these two factors to the change of species distribution could be very important in order to effectively counteract the species range contraction, especially in mountains, where alpine species are strongly limited in finding new areas to be colonized at higher elevations. We proposed a method to disentangle the effects of the two drivers of range change for breeding birds in Italian Alps, in the case of co‐occurring climate warming and shrub and forest encroachment. For each species, from 1982 to 2017, we related the estimated yearly elevational distribution of birds to the correspondent overall average of the daily minimum temperatures during the breeding season and the estimated amount of shrubs and forest cover. Using a hierarchical partitioning approach, we assessed the net contribution (i.e., without the shared effect) of each driver. Both temperature and shrub and forest cover showed a positive trend along the time series and resulted the most likely causes of the significant elevational displacement for 21 of the 29 investigated birds. While shrub and forest cover was found to be an important driver of the expansion of forest bird range toward higher elevations, the effect of temperature on favouring the colonization of previously climatically unsuitable forests at higher elevations was not negligible. Shrub and forest expansion resulted the main driver of the range contraction for edge and open habitat species, which suffered a distribution shrinkage at their lower elevational boundary. In light of climate warming, these results highlighted how the net range loss for edge and open habitat species, caused by shrub and forest encroachment consequent to land abandonment, should be counteracted by implementing proper conservation management strategies and promoting sustainable economic activities in rangeland areas.

ABSTRACT. To identify the causes of population decline in migratory birds, researchers must determine the relative influence of environmental changes on population dynamics while the birds are on breeding grounds, wintering grounds, and en route between the two. This is problematic when the wintering areas of specific populations are unknown. Here, we first identified the putative wintering areas of Common House-Martin (Delichon urbicum) and Common Swift (Apus apus) populations breeding in northern Italy as those areas, within the wintering ranges of these species, where the winter Normalized Difference Vegetation Index (NDVI), which may affect winter survival, best predicted annual variation in population indices observed in the breeding grounds in 1992-2009. In these analyses, we controlled for the potentially confounding effects of rainfall in the breeding grounds during the previous year, which may affect reproductive success; the North Atlantic Oscillation Index (NAO), which may account for climatic conditions faced by birds during migration; and the linear and squared term of year, which account for nonlinear population trends. The areas thus identified ranged from Guinea to Nigeria for the Common House-Martin, and were located in southern Ghana for the Common Swift. We then regressed annual population indices on mean NDVI values in the putative wintering areas and on the other variables, and used Bayesian model averaging (BMA) and hierarchical partitioning (HP) of variance to assess their relative contribution to population dynamics. We re-ran all the analyses using NDVI values at different spatial scales, and consistently found that our population of Common House-Martin was primarily affected by spring rainfall (43%-47.7% explained variance) and NDVI (24%-26.9%), while the Common Swift population was primarily affected by the NDVI (22.7%-34.8%). Although these results must be further validated, currently they are the only hypotheses about the wintering grounds of the Italian populations of these species, as no Common House-Martin and Common Swift ringed in Italy have been recovered in their wintering ranges. RÉSUMÉ. Afin de cerner les causes de déclin des oiseaux migrateurs, les scientifiques doivent déterminer l'influence relative des changements environnementaux sur la dynamique des populations, tant sur les aires de reproduction et d'hivernage que sur les haltes migratoires. Cette démarche est particulièrement problématique lorsque les aires d'hivernage de populations spécifiques sont inconnues. Dans la présente étude, nous avons d'abord déterminé les aires d'hivernage présumées des populations d'Hirondelle de fenêtre (Delichon urbicum) et de Martinet noir (Apus apus) qui se reproduisent dans le nord de l'Italie; ces aires présumées correspondent aux endroits, dans l'ensemble de l'aire d'hivernage de ces espèces, où l'indice de végétation par différence normalisée (IVDN) -qui affecte peut-être la survie hivernaleexpliquait le mieux la variation annuelle des indices de population observés sur les aires...