Paola Bartolommei

Wild boar rooting behaviour can be shaped by several environmental variables (e.g., food availability and habitat features) and can directly or indirectly influence various habitats, ecological processes and taxa. One of these, ground-dwelling rodents, are known to be affected by wild boar foraging activity due to food competition and direct disturbance. In the current study, the following questions were investigated: do vegetation composition, structural components of forest habitats (at ground, shrub, and tree levels) and acorn availability influence rooting activity of wild boars and consequently, also the abundance of Apodemus flavicollis and A. sylvaticus in the same area. This research was carried out in a Mediterranean deciduous oak forest across 12 sampling sites. The results showed that, among the habitat variables considered, only shrub cover at 1 m height had a significant association with the extent of wild boar rooting. Contrary to expectations, acorn availability did not significantly influence rooting activity, suggesting either a more complex relationship between food availability and rooting behaviour or the influence of other local factors. Likewise, the number of Apodemus spp. individuals captured was not significantly related to rooting activity, indicating no detectable effects of wild boar rooting on rodents in the study area. This study contributes to our understanding of the factors driving this foraging behaviour and its ecological and socioeconomic implications.

Rodent–seed foraging behavior plays a key role in seed fate and plant regeneration. Seed mass is a central trait influencing seed predation, removal and caching by hoarding rodents. In ecosystems with multiple sympatric rodent species, differential seed use can exert varying selective pressures on seeds. In a semi-natural experiment, we observed how Quercus cerris acorn mass affected seed predation, removal, and dispersal by 2 sympatric rodents of different body sizes, Apodemus flavicollis and A. sylvaticus. For both species, seed mass had a consistent effect in predicting seed fate. We detected a species-specific response in seed predation: A. flavicollis more likely predated heavier acorns, while seed mass was not found to affect acorn use in A. sylvaticus. Seed removal probability was affected by seed mass but it did not differ between the 2 species, which both showed similar removal patterns with respect to seed mass. Although the mass of removed acorns did not differ between the 2 species, the acorn mass to rodent body mass ratio of removed seeds was higher in A. sylvaticus compared with A. flavicollis. The likelihood of predation versus that of dispersal after removal was found to be species-specific: seed dispersal did not vary with seed mass for A. flavicollis, while A. sylvaticus dispersed heavier acorns. These results suggest that the 2 species might play distinct roles in determining seed fate. Our findings highlight the importance of considering species-specific foraging strategies when assessing the role of sympatric hoarding rodents in seed dispersal and forest regeneration.

Glucocorticoids regulate many physiological functions and play an important role in coping with challenging stimuli. The non‐invasive assessment of glucocorticoids is increasingly used as a tool to evaluate individual and population health status in wild animals. Given the crucial role of rodents in forest ecosystems, it may be useful to study the glucocorticoid profile of these species to find possible links with the characteristics of the environment in which they live and facilitate the development of biodiversity management plans. We studied two closely related species that are the main representatives of the ground‐dwelling rodent communities in sub‐Mediterranean forested areas: Apodemus sylvaticus and A. flavicollis . The fecal corticosterone metabolite (FCM) levels of animals captured in a Mediterranean agroforestry system were measured, taking into account the evidence of methodological assessments to evaluate hormone metabolite differences between feces excreted at different times under captive conditions and the stability of these metabolites. We found that A. sylvaticus males excreted lower FCM levels than females, while A. flavicollis males showed higher FCM levels than females. Males of the two species excreted similar FCM levels, while higher FCM levels were recorded in A. sylvaticus females than in their A. flavicollis counterparts. The FCM levels in both species were similar between breeding conditions, seasons and habitat types. The results of our exploratory investigation suggest that traditional silviculture may not trigger the activity of the hypothalamus‐pituitary‐adrenal axis. Further studies are required for a more detailed examination of how environmental factors affect FCM levels. Long‐term studies may disclose possible effects of interannual environmental factor variability in ground‐dwelling rodents.

The social system of animals involves a complex interplay between physiology, natural history, and the environment. Long relied upon discrete categorizations of “social” and “solitary” inhibit our capacity to understand species and their interactions with the world around them. Here, we use a globally distributed camera trapping dataset to test the drivers of aggregating into groups in a species complex (martens and relatives, family Mustelidae , Order Carnivora ) assumed to be obligately solitary. We use a simple quantification, the probability of being detected in a group, that was applied across our globally derived camera trap dataset. Using a series of binomial generalized mixed-effects models applied to a dataset of 16,483 independent detections across 17 countries on four continents we test explicit hypotheses about potential drivers of group formation. We observe a wide range of probabilities of being detected in groups within the solitary model system, with the probability of aggregating in groups varying by more than an order of magnitude. We demonstrate that a species’ context-dependent proclivity toward aggregating in groups is underpinned by a range of resource-related factors, primarily the distribution of resources, with increasing patchiness of resources facilitating group formation, as well as interactions between environmental conditions (resource constancy/winter severity) and physiology (energy storage capabilities). The wide variation in propensities to aggregate with conspecifics observed here highlights how continued failure to recognize complexities in the social behaviors of apparently solitary species limits our understanding not only of the individual species but also the causes and consequences of group formation.

The wood mouse Apodemus sylvaticus is common in woodlands and open areas of the Western Palearctic. Despite extensive research, little is known about its population ecology in fields in the Mediterranean area, where the climate involves great seasonal changes in environmental features. Here, we investigated wood mice seasonal fluctuations in the number of captures and population structure by sampling long-fallow fields and woodlands, i.e., oak forest and conifer plantation, in a heterogeneous landscape of central Italy. Mice were live-trapped every two months for three years (23.814 trap-days). The number of captures, mice body weight, and proportion of adult, residents and breeding individuals were analyzed. Mice dynamics changed across seasons and habitats. In fields, we recorded more captures, more reproductive individuals, and fewer non-adults and resident individuals in the warmer months compared to the colder months; mice were heavier in warmer months. During the cold season, the captures and adult proportion in fields were lower than in resource-rich woodlands. Breeding and non-resident mice were more abundant in fields than in woodlands in warmer months. Overall, the seasonal demographic variations we recorded provide evidence that fields can represent a suboptimal habitat in Mediterranean heterogeneous landscapes, acting nonetheless as a source of food resources, cover, and mates for mice in spring–summer.

The wood mouse Apodemus sylvaticus is common in woodlands and open areas of Western Palearctic. Despite extensive research, little is known about its population ecology in fields in the Mediterranean area, where climate involves great seasonal changes in environmental features. Here, we investigated wood mice seasonal fluctuations in abundance and population structure by sampling long-fallow fields and two woodland types, i.e. oak forest and conifer plantation, in a heterogeneous landscape of central Italy. Mice were live-trapped in three sites per habitat type, every other month for three years (23.814 trap-days). Population abundance, age structure, mice body weight and proportion of residents and breeding individuals were analysed. Sampling effort resulted in 350 captures of 245 individuals. Mice dynamics changed across seasons and habitats. In fields, we recorded more captures, more reproductive individuals, and fewer immature and resident individuals in warmer than in colder months; mice were heavier in warmer months. These results suggest that fields may better suit the species ecological requirements (i.e. food and cover resources) in spring-summer, representing a seasonally suboptimal habitat for mice. Population abundance in fields was lower than in woodlands during the cold season, when immatures were more frequent in fields than in resource-rich woodlands. Conversely, breeding and non-resident mice were more abundant in fields than in woodlands in warmer months. Overall, the seasonal demographic variations we recorded evidence that fields can represent a suboptimal habitat in Mediterranean heterogeneous landscapes and can nonetheless act as a source of resources, mates and space for mice in spring-summer.

Evidence of abnormal coloration in wild animals provides useful information to better understand its adaptive function and its impact on survival. For this reason, we need to know the frequency and distribution of these abnormal phenotypes in wild populations. Here, we report two records of hypopigmentation in European pine marten Martes martes, obtained during a camera‐trapping survey on Elba Island, Central Italy. We do not know what has caused anomalous coloration of pine marten on Elba Island, but it is possible that the inbreeding may have played a role in this isolated population. Although the light coloration certainly entails an increased visibility of pine martens, it is possible that the low predator pressure and the absence of other wild carnivore populations in our study could mitigate the mortality risk due to the light phenotype. The increased use of camera traps across the world can potentially facilitate the discovery of cases of anomalous colorations in wild populations, providing an unprecedented insight into the occurrence of this phenomenon in wild mammal species.

The American mink Neovison vison is a widespread alien carnivore in Europe due to escapes from fur farms through this continent. Impacts by naturalized mink include competition with native species and predation of crayfish and small vertebrates. Therefore, an updated monitoring of mink distribution is required to design management plans. The American mink has been reported with an established population in North-Eastern Italy, in Sardinia, and two small nuclei respectively in the Central and in the Northern Apennine ridge. Available information for the latter dates back to early 1990s. In this note, we described the range expansion of the American mink population in the Northern Apennine ridge and we estimate the current distribution range and the extent of occurrence by using data collected from 2006 to 2021 through the Minimum Convex Polygon (MCP). We compared the current distribution range with that of 1990s. The American mink showed a remarkable range increase since its first escape in the Northern Apennines, thus requiring rapid actions to limit impacts on native biodiversity.