Luca Corlatti

Males and females of sexually dimorphic ungulates exhibit distinct competitive abilities due to differences in body size, digestive function and role in reproduction. In the attempt to enhance the hunting experience or manipulate population dynamics, management may favour increasing the proportion of either sex. Depending on the relationship between the sexes, management practices may have different consequences for individuals and populations. Females are often considered the primary drivers of population dynamics of polygynous ungulates. The role of males is often overlooked, but mounting evidence suggests that the proportion of males within a population may have important effects on population dynamics, either because of impacts on mating systems or intersexual competition. The effect of males within ungulate populations may thus have important implications for management, particularly when intersexual interactions influence females. We used long‐term data on productivity (2007–2022) and body reserve dynamics (2015–2022) to quantify the influence of an increase in male proportion on population dynamics of free‐ranging mule deer Odocoileus hemionus . We examined if an increasing male proportion, in relation to population density, influenced: (i) individual females through a change in body reserve accumulation; (ii) female population growth rate. Higher male:female ratios were associated with reduced seasonal body fat accumulation in females. Similarly, higher male:female ratios were associated with lower female population growth rates in the following year, consistent with a potential carry‐over effect mediated through female body condition. Changes in male proportion affected body fat reserve accumulation and female population growth rate after accounting for climatic variation and density, at least with the levels observed in the study populations. Practical implication: A common shift in management of mule deer over the late 20th century has been an increase in the proportion of mature males in the population (i.e., higher male:female ratio). Our results suggest that such a management strategy may involve demographic trade‐offs, being associated with reduced female body condition and lower population productivity. These findings are increasingly pertinent as mule deer populations appear to be declining in many areas.

In carnivore guilds, apex predators and mesocarnivores may interact through mechanisms ranging from antagonism to facilitation. The recent recolonization of the gray wolf Canis lupus in the Alps offers a valuable opportunity to investigate how wolf kill sites influence mesocarnivore behavior. We analyzed interactions between wolves and red foxes Vulpes vulpes at red deer Cervus elaphus carcasses in the Stelvio National Park (Italian Alps). Using camera traps deployed at 26 wolf‐killed carcasses between November 2022 and December 2024, we assessed whether foxes exploited wolf kills and exhibited temporal avoidance of wolves, controlling for carcass characteristics and environmental factors. Fox presence–absence was modeled at an hourly resolution using generalized linear mixed models. Four variables were derived from camera‐trap data to assess wolf influence on fox presence: wolf presence in the same hour, wolf presence in the preceding hour, time elapsed since the last wolf visit, and total wolf visit duration per hour. Foxes were detected at all monitored carcasses, whereas wolves were recorded at 20 of the 26 sites, with most activity occurring at night. Fox presence was most strongly associated with initial carcass consumption and, to a lesser extent, by human activity and habitat features. Our results provide limited evidence that fine‐scale wolf activity influenced fox scavenging at wolf‐killed carcasses, with no detectable temporal avoidance or attraction. Carcass profitability explained fox occurrence more strongly than any of the measured wolf variables, suggesting that foxes may respond primarily to carcass profitability rather than to fine‐scale predation risk. Carcass sites represent high‐value food resources, highlighting the ecological role of wolf kill provisioning in Alpine ecosystems.

Environmental conditions interact with genetic factors to shape sexually selected traits. In temperate bovids, horns grow in discrete annual increments, providing the opportunity to link year-specific environmental conditions to developmental trajectories. We combined segment-level horn data from 252 Alpine chamois ( Rupicapra r. rupicapra ) with climate and remotely sensed vegetation productivity (EVI) data and applied a path-modelling framework to quantify how sex, environmental variation, and compensatory growth jointly determine total horn length. As expected, horn growth occurred primarily early in life. The first measurable growth segment (L2) accounted for most between-individual variance and was strongly influenced by sex and current-year vegetation productivity. Subsequent segments contributed progressively less to total variance but were not independent. In particular, we detected condition-dependent compensatory growth between L2 and L3: individuals with reduced early growth tended to show stronger recovery under high vegetation productivity, whereas under poorer environmental conditions compensatory growth was weaker. This indicates that the ability to compensate for poor early growth depends on environmental conditions. Consequently, horn size reflects both developmental constraints established early in life and the opportunity for environmentally mediated compensation in later years. Because horn segments represent annual, time-stamped growth increments, they provide a framework for reconstructing how environmental variability shapes phenotypic development. Interpreting total horn length requires understanding which life stages dominate its variance, with direct implications for understanding the evolution of sexually selected traits and for wildlife management.

Understanding how species coexist is essential for explaining how biodiversity is maintained and how ecological communities respond to environmental change. In Alpine ecosystems, where strong environmental gradients intersect with increasing anthropogenic pressure, mechanisms of coexistence among sympatric large herbivores remain poorly resolved. Here, we investigated niche segregation among three mountain herbivores — Alpine chamois (Rupicapra rupicapra), red deer (Cervus elaphus), and roe deer (Capreolus capreolus) — in the south-eastern Alps. Using five stable isotope ratios (δ13C, δ15N, δ34S, δ18O, δ2H) in summer-grown hair, we quantified multidimensional niche hypervolume structure within a Bayesian framework and evaluated patterns of niche overlap and differentiation. Despite substantial spatial overlap, and broad dietary overlap typically observed among these ungulates, the three species exhibited clear isotopic niche segregation, with mean pairwise overlap below 40%. Niche differentiation was primarily structured along gradients of water sourcing (δ18O), diet quality (δ15N), and habitat openness (δ13C). Specifically, Alpine chamois appeared to derive more water from plants in their diet rather than from drinking, and to consume a higher-quality diet compared to Cervids, whereas red deer relied more heavily on forested habitats for foraging compared to roe deer and chamois. Additional isotopic differences between red deer and roe deer may reflect abiotic variation such as microclimate and topography. Together, these patterns indicate functional differentiation across multiple ecological axes, allowing coexistence despite potential for resource overlap. Our results highlight how multidimensional niche differentiation can structure large herbivore communities in mountain ecosystems and provide a mechanistic framework for anticipating how such assemblages may reorganise under accelerating environmental change.

Dynamic occupancy models are fundamental for understanding complex species recolonisation processes, as they allow the assessment of both colonisation and persistence probabilities over time. Using a dynamic occupancy model and a large‐scale multi‐year dataset on wolf presence collected in the Italian alpine region between 2014 and 2020, we analysed temporal trends in wolf colonisation and persistence probabilities in relation to environmental factors, prey availability and human‐related characteristics. Our results demonstrate that wolf recolonisation is an ongoing and dynamic process in the Italian Alps, with colonisation probabilities increasing throughout the study period, particularly in the northeast of the study area. Although we detected a slight positive temporal trend in the effect of human density, wolves continue to preferentially colonise natural areas, despite a decreasing availability, as evidenced by the continued positive effects of forest cover, low natural vegetation and presence of wild ungulates. Persistence probabilities remained relatively high and constant on average, but we noticed an increasingly negative effect of the presence of livestock pastures and densely populated areas. On the other hand, we noticed an increasingly positive effect of covariates associated with natural areas, such as forest cover, low natural vegetation and wild ungulate richness. This resulted in an increasingly contrasted spatial pattern in persistence probability throughout the region, likely reflecting conflict zones where wolves attempt to establish but struggle to survive. Overall, our study aligns with trends observed in other wolf populations across Europe, showing an expansion into new areas with different characteristics, highlighting potential areas of emerging conflict that warrant continued targeted monitoring. These patterns offer valuable insights for wolf conservation and management in human‐dominated landscapes.

Global environmental change is reshaping biodiversity by altering species connectivity, genetic diversity, and long-term viability. A key challenge is to disentangle how historical, environmental, and anthropogenic factors jointly shape contemporary genetic patterns. Here, we combine population genomics with landscape ecology tools to investigate the drivers of levels of genetic diversity and patterns of population genetic structure using more than 20k Single Nucleotide Polymorphisms (SNPs) in the Northern chamois (Rupicapra rupicapra), a wide-ranging Alpine ungulate. Based on 465 individuals sampled across the European and Dinaric Alps as well as the Tatra Mountains, we revealed a pronounced hierarchical genetic structure, with clusters showing marked geographic variation in genetic diversity across the species range. Our results show that current genetic diversity largely reflects the genetic legacy of past climatic conditions, with areas of long-term stability acting as reservoirs of genetic variation. At the same time, large Alpine rivers emerge as strong barriers to gene flow, emphasizing the powerful role of natural landscape features in shaping genetic structure. In contrast, recent anthropogenic infrastructures exerted limited detectable influence, suggesting that contemporary patterns are still predominantly driven by natural processes of population differentiation. By explicitly quantifying the relative contributions of long-term climatic stability and contemporary landscape features to genetic diversity and connectivity, this study demonstrates that historical processes outweigh recent anthropogenic fragmentation in shaping current genetic patterns in this mountain ungulate.

As wolves recolonise their historical range across Europe, ungulates face predation once more – but in landscapes profoundly altered by human activity. This shift raises crucial questions about their capacity to express adaptive antipredator behaviours. Using a quasi‐experimental camera‐trap design, we examined diel activity responses of ungulates along the ongoing wolf recolonisation in the south‐eastern Alps. Red deer showed higher summer diurnality in sites with a longer history of wolf presence (7% increase over five years, on average) and progressively reduced nocturnality within sites as local wolf establishment advanced (5% decrease per year, on average), also heightening activity overlap with humans. This ‘diel shield effect' disappeared when human hunting occurred. Roe deer and Alpine chamois did not exhibit significant diel activity shifts in relation to wolves, though both species responded to human disturbance, with roe deer adjusting activity to hunting (18% less diurnal, on average) and chamois reducing diurnality in areas of intense outdoor use (up to 38% difference in diurnality between undisturbed and highly disturbed areas). Red deer, too, were less diurnal (up to 27% difference) and more nocturnal (up to 37% difference) in such highly disturbed areas, as well as near human settlements (up to 42% difference in diurnality between remote areas and villages). Our findings show that wolf recovery can induce detectable diel activity shifts in large herbivores over relatively short timescales, yet responses depend on species biology and behavioural plasticity. Importantly, human risk and disturbance can offset or override these behavioural adjustments, potentially altering the ecosystemic effects of returning large carnivores.

Snow cover plays a critical role for many alpine animals, but our understanding of how snow effects vary with elevation is limited. The white‐winged snowfinch is restricted to high‐elevation habitats, relying on snowfields, edges of melting snow patches, and short‐sward alpine grasslands to collect invertebrates for nestlings. To explore potential elevation‐dependent snow effects on breeding occurrence, we monitored 37 nest‐boxes in central Italian Alps from 2017 to 2025 (210 nest‐box–year combinations in total). Nest‐boxes were deployed from 2300 to 3010 m a.s.l., thus encompassing continuous alpine grassland, mosaics of scattered alpine grassland and rocky habitats, and landscapes dominated by rocks and snowfields. Average percentage snow cover was estimated (using remote sensing data) within a 300 m radius around each nest‐box during June (peak of breeding activity), and was used to model nest‐box use at different elevations. June snow cover varied greatly between years (average 5–64%) and influenced nest‐box use in a complex manner. At low elevation (< 2487 m a.s.l.), usage increased with snow cover, whereas it decreased with snow cover at higher elevation (> 2753 m a.s.l.), and was apparently unrelated to snow cover at intermediate ones. At low elevation, increased snow cover means more suitable foraging habitats, including snow patches and the melting margins, as well as short‐sward grassland (the most exploited foraging habitat by breeding snowfinches). At higher elevations, nest‐boxes tended to be occupied more frequently with relatively limited snow cover. Reduced snow cover here implies more suitable short‐sward grassland available to foraging snowfinches, and therefore more profitable conditions. However, above 2900 m a.s.l., nest‐boxes were used only thrice and with high snow cover. There, snowfinches probably rely on wind‐blown arthropods deposited on snowfields, requiring substantial snow cover. The elevation‐dependent patterns we found provide examples of the possible reasons for complex distribution shifts in response to climate change and deserve more investigation.

Humans are thought to have a disproportionately negative impact on wildlife and are viewed by some as the ultimate ‘super predator'. This view implies that wild animals perceive humans primarily as predators. However, a growing body of evidence shows that wildlife can have remarkable tolerance for, or even attraction to, humans. Here, we present wildlife responses to humans along the avoidance–attraction continuum, to highlight that avoidance, tolerance, and attraction are all within the normal range of wildlife behavioural responses to humans. We embed the avoidance–attraction continuum in a mechanistic framework to understand behavioural responses to humans as the result of a species' evolutionary history and accumulated experiences during their lives. We find that historical and current human behaviour towards wildlife – whether it is aversive, neutral or beneficial to animals – plays an important role in shaping selective pressures and learning outcomes in the focal population. By shifting from a restrictive view of wildlife as inherently fearful of humans to a broader understanding of wildlife responses, we are better able to refine public perception of wildlife behaviour, wildlife management and ecological research, and ultimately promote human–wildlife coexistence.