Emiliano Manzo

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.

Global biodiversity is declining as human impacts increase and mammals, especially carnivores, are declining particularly quickly. Small carnivores (such as in the Guloninae subfamily) are less frequently considered than large carnivores, despite also being affected by biodiversity declines, because their status and population ecology are exceedingly difficult to assess. Although all but one Guloninae species are globally listed as Least Concern by the International Union for Conservation of Nature (IUCN), this designation obscures conservation challenges and does not include local population declines. Proactive efforts to improve population persistence in regions of most concern may prevent species from becoming globally threatened in the future. We briefly introduce the 11 Guloninae species, highlight collective challenges, and synthesize possible options focused on recovery and conservation. To inform our paper, we conducted a 3-phase process to gather expert opinions: an online survey, an in-person prioritization exercise of online results, and directed in-person group discussions. We focused efforts within the international Martes Working Group consisting of species experts. We followed the IUCN and Conservation Measures Partnership (CMP) threats and actions classifications nomenclature to enable cross-project learning and data aggregation. From our results, the largest described global threat to Guloninae was ‘Climate Change’ (e.g., ecosystem encroachment; changes in temperature regimes) as most Guloninae species appear to have a narrow thermal range where persistence is possible. The largest threat at the jurisdictional level was ‘Biological Resource Use’ (e.g., hunting and collecting terrestrial animals; logging and wood harvesting). The identified action needed to further Guloninae conservation and recovery was ‘Land/Water Management’ (e.g., ecosystem and natural process re-creation; site/area stewardship). We identified unifying themes threatening and benefitting Guloninae; but given the wide geographic range of Guloninae species, the many countries involved, and the diversity of ecosystems with different levels of human impacts, conservation actions need to be locally appropriate. Our paper synthesizes natural history and guidance from experts to provide a foundation for future research efforts and conservation actions for Guloninae conservation.

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.

Anthropogenic activities often lead to changes in the distribution and behavior of wild species. The mere presence of humans and free‐roaming domestic cats (Felis catus) can affect wildlife communities; however, responses to these disturbances might not be ubiquitous and may vary with local conditions. We investigated European pine marten's (Martes martes) distribution on Elba Island, Italy, where the species is the only wild carnivore. In this system, pine martens act as the top predator, and human presence is mostly driven by seasonal tourism. We evaluated (1) pine marten's occurrence in relation to vegetation type and elevation and the potential effects of proximity to settlements, (2) whether pine marten's distribution was associated with the co‐occurrence of humans and domestic cats, and, if so, (3) whether these co‐occurrence patterns were associated with proximity to anthropogenic infrastructures. Additionally, we explored similarities in activity patterns between pine marten and the other two species. We collected camera‐trap data at 77 locations throughout Elba Island in February–July 2020. Using single‐season multistate occupancy models, we found evidence that pine martens' occupancy was generally high across all vegetation types and elevation, and proximity to settlements was only weakly associated with the species occurrence. Contrary to expectations, we found no evidence of an association between pine martens' distribution and the presence of either humans or free‐roaming domestic cats on Elba Island. Opposing activity patterns might have facilitated pine martens' co‐existence with humans, with pine martens being active at ground level almost exclusively during nighttime. On the contrary, cats and pine martens showed similar activity patterns, and further studies are needed to define the co‐existence mechanisms. These findings have important management implications and suggest that response to direct and indirect anthropogenic pressures can be highly context‐dependent and mediated by the availability of resources and competition mechanisms.

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.

Evidence for divergent selection and adaptive variation across the landscape can provide insight into a species' ability to adapt to different environments. However, despite recent advances in genomics, it remains difficult to detect the footprints of climate‐mediated selection in natural populations. Here, we analysed ddRAD sequencing data (21,892 SNPs) in conjunction with geographic climate variation to search for signatures of adaptive differentiation in twelve populations of the bank vole (Clethrionomys glareolus) distributed across Europe. To identify the loci subject to selection associated with climate variation, we applied multiple genotype‐environment association methods, two univariate and one multivariate, and controlled for the effect of population structure. In total, we identified 213 candidate loci for adaptation, 74 of which were located within genes. In particular, we identified signatures of selection in candidate genes with functions related to lipid metabolism and the immune system. Using the results of redundancy analysis, we demonstrated that population history and climate have joint effects on the genetic variation in the pan‐European metapopulation. Furthermore, by examining only candidate loci, we found that annual mean temperature is an important factor shaping adaptive genetic variation in the bank vole. By combining landscape genomic approaches, our study sheds light on genome‐wide adaptive differentiation and the spatial distribution of variants underlying adaptive variation influenced by local climate in bank voles.

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.

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.