First assessment of habitat suitability and connectivity for the golden jackal in north-eastern Italy

AbstractCompared with the rapid expansion across Europe, the golden jackal colonization of Italy is still limited and slow. No study focused on the habitat selection or landscape connectivity for this species was performed in Italy; thus, the potential distribution and dispersal patterns in the country remain unknown. Our objectives were to evaluate the suitability of the Friuli-Venezia Giulia region (north-eastern Italy) for the golden jackal, as well as to identify the ecological corridors connecting the areas currently occupied by the species. Corridors modelling allowed us both to hypothesize the dispersal dynamics occurring in the study region and to identify possible obstacles to future range expansion. We surveyed golden jackal presence in two study areas, covering an area of 500 km2, from March 2017 to February 2018. Using collected data, we modelled the species home-range scale habitat suitability based on an ensemble modelling approach. Subsequently, a habitat suitability prediction at a finer scale was used to estimate landscape resistance, starting from which, we modelled dispersal corridors among areas currently occupied by the species using a factorial least cost path and a cumulative resistant kernel approach. Our results indicated a moderate potential for large parts of the study region to support the occurrence of golden jackal family groups, whose presence seems to be mainly driven by the presence of wide areas covered by broadleaved forests and shrublands and by the absence of wide intensive agricultural areas. The predicted connectivity networks showed that three main permeable corridors are likely to connect golden jackal occurrence areas within the study region, while all the other corridors are characterized by a very low path density. Both the habitat selection and connectivity analyses showed a strong negative impact of the intensive cultivated plain on species stable presence and movement providing critical information for the conservation of the golden jackal in Italy

New Evidence on the Linkage of Population Trends and Species Traits to Long-Term Niche Changes

Despite the assessment of long-term niche dynamics could provide crucial information for investigating species responses to environmental changes, it is a poorly investigated topic in ecology. Here, we present a case study of multi-species niche analysis for 71 common breeding birds in Northern Italy, exploring long-term niche changes from 1992 to 2017 and their relationship with both population trends and species traits. We (i) quantified the realized Grinnellian niche in the environmental space, (ii) compared variations in niche breadth and centroid, (iii) tested niche divergence and conservatism through equivalency and similarity tests, (iv) calculated niche temporal overlap, expansion and unfilling indices, and (v) investigated their association with both population changes and species traits. Results supported niche divergence (equivalency test) for 32% of species, although two-thirds were not supported by the similarity test. We detected a general tendency to adjust the niche centroids towards warmer thermal conditions. Increasing populations were positively correlated with niche expansion, while negatively correlated with niche overlap, albeit at the limit of the significance threshold. We found moderate evidence for a non-random association between niche changes and species traits, especially for body size, clutch size, number of broods per year, inhabited landscape type, and migration strategy. We encourage studies correlating long-term population trends and niche changes with species traits’ information and a specific focus on cause-effect relationship at both the single and multiple-species level

Long-term viability of a reintroduced population of roe deer Capreolus capreolus, in a lowland area of northern Italy

In the last decades European roe deer (Capreolus capreolus) expanded its range, recolonizing also highly anthropized areas. In northern Italy this species recently reached the Po Plain, suggesting the possibility for the future settlement of a metapopulation in the whole plain. In this process, a key role may be played by internal source areas, such as Ticino Natural Park, where roe deer was reintroduced in 1990s. We carried out drive counts and surveys in a sample area of Ticino NP, in order to investigate about the current status of this population. Population Viability Analysis (PVA) was applied to infer about the population viability and its potentiality as source for dispersals. Our results showed a high-density population (30.7 +/- 4.1 individuals per km(2)), with quite low proportion of juveniles (10.7 %), litter size (1.35 fawns/mother) and proportion of successful breeding females (24.6 %). Considering the high density of this population, its low productivity is most likely due to the onset of density-dependent factors and the approach to the carrying capacity. Neverthless, the PVA showed that in the next 30 years this population is likely to remain viable, representing an important potential source for a roe deer expansion in the fragmented lowland area of northern Italy

Species Traits Drive Long-Term Population Trends of Common Breeding Birds in Northern Italy

Long-term population trends are considerable sources of information to set wildlife conservation priorities and to evaluate the performance of management actions. In addition, trends observed in functional groups (e.g., trophic guilds) can provide the foundation to test specific hypotheses about the drivers of the observed population dynamics. The aims of this study were to assess population trends of breeding birds in Lombardy (N Italy) from 1992 to 2019 and to explore the relationships between trends and species sharing similar ecological and life history traits. Trends were quantified and tested for significance by weighted linear regression models and using yearly population indices (median and 95% confidence interval) predicted through generalized additive models. Results showed that 45% of the species increased, 24% decreased, and 31% showed non-significant trends. Life history traits analyses revealed a general decrease of migrants, of species with short incubation period and of species with high annual fecundity. Ecological traits analyses showed that plant-eaters and species feeding on invertebrates, farmland birds, and ground-nesters declined, while woodland birds increased. Further studies should focus on investigation of the relationship between long-term trends and species traits at large spatial scales, and on quantifying the effects of specific drivers across multiple functional groups

Habitat selection of European badger Meles meles in a highly fragmented forest landscape in Northern Italy: The importance of hedgerows and agro-forestry systems

The European badger is a common and widespread species considered as a least-concern species by the IUCN. However, there are still many threats for its conservation, especially in areas where the original landscape has been highly modified by humans. The aim of this study was to define the habitat selection criteria of the European badger in a highly modified lowland area in northern Italy, with particular attention to the role that hedgerows and agro-forestry systems could have for this species. The study area is a typical lowland cultivated landscape, where small forest remnants are scattered within an agricultural matrix mainly characterized by intensive cereal crops and areas devoted to agro-forestry. Data collection followed a stratified random sampling design and consisted of detecting the presence of the species within 62 2-km cells. Presence signs were spotted along linear transect from April to September 2014. We investigated the association between species presence/abundance and the environmental variables measured within each cell by means of resource selection probability functions using GLMs. In our study area the European badger significantly depended on broadleaved forests, but the species also selected traditional poplar plantations, short rotation forestry, reforestations, and hedgerows. Conversely, the species avoided meadows with shrubs and trees and areas with scarce or absent vegetation. In conclusion, the European badger seemed to benefit from agricultural landscape elements, such as agro-forestry systems and hedgerows, which probably serve as forest surrogates for this species, both in providing food resources and suitable sett locations

Species specialization limits movement ability and shapes ecological networks: the case study of 2 forest mammals

To counteract the negative effects of forest fragmentation on wildlife, it is crucial to maintain functional ecological networks. We identified the ecological networks for 2 mammals with very different degrees of forest specialization, the European badger Meles meles and the Roe deer Capreolus capreolus, by differentiating 4 agroforestry elements as either nodes or connectivity elements, and by defining the distance that provides the functional connectivity between fragments. Species occurrence data were collected in a wide agroecosystem in northern Italy. To test the role of hedgerows, traditional poplar cultivations, short rotation coppices, and reforestations as ecological network elements for the 2 species we applied the method of simulated species perceptions of the landscape (SSPL), comparing the ability of different SSPLs to explain the observed species distribution. All analyses were repeated considering different scenarios of species movement ability through the matrix. Model outputs seem to show that the specialist and highly mobile Roe deer has the same movement ability throughout the matrix (2 km) as the European badger, a smaller, but generalist species. The ecological network identified for the European badger was widespread throughout the area and was composed of woodlands, poplar cultivations and hedgerows as nodes and short rotation coppices as connectivity elements. Conversely, the ecological network of the Roe deer was mostly limited to the main forest areas and was composed of woodlands, poplar cultivations and reforestations as nodes and short rotation coppices and hedgerows as connectivity elements. The degree of forest specialization strongly affects both species perception of habitat and movement ability throughout the matrix, regardless of species size. This has important implications for species conservation

Wolf habitat suitability in an area of Northern Apennines : a multimodel approach

The Italian wolf population was near to the extinction at the beginning of the seventies of the past century, owing to indiscriminate hunting and poisoning. In 1972 the wolf was named protected species and since this moment the recolonization of the Italian Peninsula has begun, starting from the remaining part of the range in Southern and Central Italy and reaching the Northern Apennines (N-Italy) during the eighties. This study was aimed to individuate suitable areas for wolves in the provinces of Pavia and Piacenza, that include a trait of the Apennines chain that links the more extended wolf areas in Emilia-Romagna and Tuscany to those of Liguria and Western Alps and where wolves suffer a high mortality due to illegal killings and accidents. From August 2011 to August 2012 we searched for wolf and wild ungulate signs of presence on 25 transect (total length 168 km) covered once a season and randomly located in an 860 km2 study area. We split the study area in 4-km2 cells by a grid spaced of 2 km and in each cell we measured the variables concerning altimetry, exposure, slope, and land use. We classified the cells crossed by transects as presence cells if wolf signs were found at least in a season and absence ones if no signs were found. We formulated habitat suitability models following an approach use vs. availability by Binary Logistic Regression Analysis (BLRA), Ecological Niche Factor Analysis (ENFA) and Maximum Entropy algorithm (MaxEnt) and by comparing presence cells with an equal number of randomly selected ones. Moreover we formulated a habitat suitability model following an approach presence vs. absence by BLRA, using only the cells crossed by transects and comparing presence cells with absence ones. For the first approach only the environmental variables were used, while for the second we used also the abundance of wild ungulates. We validated all the models by the K-Fold cross validation and ROC curves. The best model was that resulting from BLRA with presence vs. availability approach, and it was used to create a suitability map for the whole hill and mountainous area of the two provinces (2408 km2). Potential wolf range was 736 km2, i.e. 30.5% of available area. The suitability map can be used to the accomplishment of the actions to awaken public opinion towards the cohabitation with wolves and to plan the methods and interventions of damage prevention to the animal husbandry, so reducing the conflicts between human activities and wolf presence. Moreover on the basis of the habitat suitability map a network of protected areas can be designed to improve wolf protection and conservation policy

Temporal Variation of Ecological Factors Affecting Bird Species Richness in Urban and Peri-Urban Forests in a Changing Environment: A Case Study from Milan (Northern Italy)

Urban and peri-urban forests determine different habitat services for biodiversity according to their characteristics. In this study, we relate ecological characteristics of urban and peri-urban forests to forest bird species richness and we assess whether their effect changed over time due to the urban sprawl within the urban region of Milan, Italy. We analyse two periods (1998–2002 and 2010–2014) using weighted generalized linear models that considered urban and peri-urban forests collectively and urban and peri-urban forests separately. Patch area, proximity to source areas and number of surrounding urban and peri-urban forests were the main factors predicting species richness within urban and peri-urban forests in both periods. While there were no differences in factors affecting bird richness in peri-urban forests between the two periods, the negative effect of urban matrix density was statistically significant for birds inhabiting urban forests in the second period. Moreover, protected areas within urban and peri-urban forests and urban forests in the second period were important determinants in providing suitable habitat for birds at the regional scale. This study offered important insights regarding urban and peri-urban forests characteristics that should be maintained to ensure biodiversity conservation across changing urban landscapes