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Citizen science initiatives have been increasingly used by researchers as a source of occurrence data to model the distribution of alien species. Since citizen science presence‐only data suffer from some fundamental issues, efforts have been made to combine these data with those provided by scientifically structured surveys. Surprisingly, only a few studies proposing data integration evaluated the contribution of this process to the effective sampling of species' environmental niches and, consequently, its effect on model predictions on new time intervals. We relied on niche overlap analyses, machine learning classification algorithms and ecological niche models to compare the ability of data from citizen science and scientific surveys, along with their integration, in capturing the realized niche of 13 invasive alien species in Italy. Moreover, we assessed differences in current and future invasion risk predicted by each data set under multiple global change scenarios. We showed that data from citizen science and scientific surveys captured similar species niches though highlighting exclusive portions associated with clearly identifiable environmental conditions. In terrestrial species, citizen science data granted the highest gain in environmental space to the pooled niches, determining an increased future biological invasion risk. A few aquatic species modelled at the regional scale reported a net loss in the pooled niches compared to their scientific survey niches, suggesting that citizen science data may also lead to contraction in pooled niches. For these species, models predicted a lower future biological invasion risk. These findings indicate that citizen science data may represent a valuable contribution to predicting future spread of invasive alien species, especially within national‐scale programmes. At the same time, citizen science data collected on species poorly known to citizen scientists, or in strictly local contexts, may strongly affect the niche quantification of these taxa and the prediction of their future biological invasion risk. [ABSTRACT FROM AUTHOR]

Ardeidae tend to exhibit low sexual dimorphism, both in size and plumage coloration, making sex attribution in the field challenging for both birdwatchers and ringers. Here, we assessed whether biometrics and plumage patterns are a good proxy for sex assignment in the Purple Heron (Ardea purpurea). We based our work on 27 molecularly-sexed free-living adults captured in Italy and Romania during the breeding season from 2018 to 2021. We found significant sexual size dimorphism in the beak, which resulted longer in males, but not in weight, wing, tarsus or sternum length. Birds with darker plumages, stronger contrast between reddish ornamental feathers and blackish mantle were classified as males, allowing for correct sex attribution in 70% of the males and 73 % of the females. On the one hand, we concluded that molecular sexing is the most reliable approach for sex attribution in this species. On the other hand, we also found that trained ringers or expert observers may achieve satisfactory sex attribution rates either based on biometrics or accurate plumage observation, possibly even from a distance. [ABSTRACT FROM AUTHOR]

The spreading of invasive species in new continents can vary from slow and limited diffusion to fast colonisations over vast new areas. We studied the sacred ibis Threskiornis aethiopicus along a 31-year period, from 1989 to 2019, with particular attention to the first area of release in NW Italy. We collected data on species distribution through observations by citizen science projects, population density by transects with distance method, breeding censuses at colonies, and post breeding censuses at roosts. The birds counted at winter roosts in NW Italy increased from a few tens up to 10,880 individuals in 2019. Sacred ibises started breeding in 1989, with a single nest in north-western Italy. The number of breeders remained very low until 2006, when both overwintering and breeding sacred ibises started to increase exponentially and expand their range throughout northern Italy with isolated breeding cases in central Italy. In 2019, the number of nests had increased to 1249 nests in 31 colonies. In NW Italy, the density of foraging birds averaged 3.9 ind./km2 in winter and 1.5 ind./km2 in the breeding period, with a mean size of the foraging groups of 8.9 and 2.1 birds respectively. Direct field observations and species distribution models (SDM) showed that foraging habitats were mainly rice fields and wetlands. A SDM applied to the whole Italian peninsula plus Sardinia and Sicily showed that the variables best related to the SDM were land class (rice fields and wetlands), altitude, and the temperature seasonality. The areas favourable for species expansion encompass all the plains of Northern Italy, and several areas of Tuscany, Latium, Sardinia, and Apulia. [ABSTRACT FROM AUTHOR]

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The article discusses a study which revealed the effects of rice agriculture on waterbird population size and dynamics. The study observed the breeding habits of herons and egrets living within the three sectors of northwestern Italy such as rice fields, planitial rivers, and small upland rivers. The population rose during the time of the study, between 1982 to 2002. Results revealed that rice fields held the bulk of the population with the rest of the breed expanding to the other sectors when population exceeded a certain level.

Factors affecting bird population dynamics include climate, harvesting by humans, and habitat changes. Here, we describe the long-term (1972–2006) population trends of seven heron species in NW Italy, an area holding important European breeding populations of these species. Grey ( Ardea cinerea), purple ( Ardea purpurea), and squacco ( Ardeola ralloides) herons, and little egrets ( Egretta garzetta) exhibited a strong logistic increase, leveling off around year 2000 at 3–23 times their initial level. Black-crowned night herons ( Nycticorax nycticorax) began by increasing like the former species but then dropped to initial levels. Such trends were found to be influenced by several candidate ecological factors, as assessed by ARIMA models. Specifically, grey herons increased following a decrease in human-induced mortality, as quantified by an index of hunting pressure, and an increase in winter temperatures. Little egrets increased mainly with the increase of the extent of ricefields, whereas squacco herons increased with increasing rainfall in the African wintering range. Black-crowned night herons were also positively affected by increasing African rainfall, but only during 1972–1988, whereas in later years competition with other herons could have affected the species’ decline. The improved protection of colony sites by special reserves was unlikely to be the primary trigger of the observed increase, although obviously important for the long-term population persistence. In conclusion, our study shows that heron populations of southern Europe are sensitive to environmental and climatic changes, as well as to temporal variation in human disturbance and changes in foraging habitats, though the importance of the different factors differs among species. [ABSTRACT FROM AUTHOR]

The occurrence of variation in body size and reproductive traits of Vipera aspis was assessed by analysing 74 reproductive females of different populations, collected throughout a large part of the distribution range of the taxon, from central-western France to central Italy. Six populations were analysed, two of plain habitats, in France and Italy, characterized by a Continental climate, whereas the other four derived from two coastal and two inland, hilly Italian habitats, respectively, showing a Mediterranean climate. Females of the French area showed the smallest mean body size, whereas the pre- and post-partum body masses of females from the coolest, central Italic area were significantly higher. Litter size varied among habitats and was significantly correlated with maternal body size. If the snout–vent length feature varied largely among offspring of different habitats (with the longest size occurring in representatives of the coastal, central Italian area), the average of both body mass and total mass of offsprings did not exhibit any clear pattern among populations colonizing different habitats. Nevertheless, relative litter mass was higher in the French continental populations, and lower in the coolest, Mediterranean, Italian ones. It is worth emphasizing the positive correlation between the snout–vent length feature of females and the total litter mass to environmental factors, such as hottest month temperature and total rainfall. The available literature records that female body size affects offspring size and fecundity. If the present study bolsters this correlation, it also rules out any other effect of female body size on the offspring characteristics analysed. Finally, evidence is provided for the role of climatic factors on life-history traits (e.g. pre-partum body mass) of asp vipers, although confounding effects pursued, for example, by food availability may occur. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 383–391. [ABSTRACT FROM AUTHOR]

We used geometric morphometric analysis to investigate latitudinal variation in size and shape of carapace and plastron of 111 Testudo hermanni hermanni (60 males and 51 females) collected in 6 different Italian regions. Basing on a sample of 14 landmarks for carapace and 18 landmarks for plastron, we showed that the size and shape of both sexes changed according to a North-South cline following the Bergmann's rule, tortoises of Northern Italy being 1.1-1.2 larger than that of Southern Italy. Shape variation was higher in carapace probably because sexual selection in this species acts stronger on plastron than on carapace shape. [ABSTRACT FROM AUTHOR]

We describe the behavioral adaptations of a population of Hermann's tortoise to the climate of a northern sector of its range, and to a wooded biotope that is uncommon for the species. The activity, the home range, and the thermal relations along the daily and the yearly cycle are described. In contrast to other populations that have bimodal activity peaking in spring and in autumn, the tortoises in our study area had unimodal seasonal activity that can be related to lower summer temperatures. Home range size, 7.4 ha for females and 4.6 ha for males in our study area, was from three to seven times larger than that of all other populations. The large home range, and the low population density of the tortoises in our study area, may be due to food scarcity in the wooded habitat. [ABSTRACT FROM AUTHOR]

The article focuses on the ecological effects of global climate changes, in particular the colour polymorphism of Italian scops owls from museum collections from 1870-2007. The researchers found a significant increase in plumage redness in relation to an increase in temperature and rainfall during the period. Also noted is the compatibility of the detected temporal change in plumage coloration with a shift in balance of selective pressures favouring dark-reddish morphs.

Colonial waterbirds, a major biodiversity element occurring in the core of ultra-anthropized Europe, are ideal indicators of the wellness of inland wetlands. Nonetheless, there is a critical knowledge gap in their trend and population status. We present an uninterrupted 47 years-long dataset of the breeding populations of 12 species of colonial waterbirds (Ardeidae, Phalacrocoracidae, Plataleidae, Threskiornitidae) throughout a 58,000 km 2 agricultural region in the higher Po basin (NW Italy). A trained team of collaborators censused with standardized field techniques the number of nests of each species at 419 colonies in the 1972-2018 period, summing up a total of 236,316 records. Data cleaning and standardization were performed for each census year, ensuring robust and consistent data. This dataset is among the largest ever collected for a guild of European vertebrates. It has already been used to describe the factors influencing population trends, and still offers opportunities to explore a wide range of key ecological processes such as biological invasions, global change consequences and biodiversity impact of agricultural practices., (© 2023. The Author(s).)