Sexual segregation is a common phenomenon among animals, particularly dimorphic ones. Although widely addressed, the reasons and consequences of sexual segregation are still an important topic in need of better understanding. In this study, we mainly evaluate the diet composition and feeding behaviour of animals, which are related to the use of different habitats by the sexes, a special case of sexual segregation also termed habitat segregation. Sexually size dimorphic males and females often have different energetic and nutritional needs and, thus, different diets. We collected fresh faecal samples from wild Iberian red deer (Cervus elaphus L.) in Portugal. Samples were analysed in terms of diet composition and quality. As expected, both sexes differed in their diet composition, with males eating more arboreous species than females, but this difference was affected by sampling periods. Diet composition of both sexes had the biggest differences (and the lowest overlap) in spring, which corresponds to the end of gestation and beginning of birth. These differences might be a consequence of the sexual body size dimorphism characteristic of this species, as well as of different needs due to different reproductive costs. No differences regarding the quality of the excreted diet were observed. Our results may help to understand some patterns of sexual segregation observed in this red deer population. However, besides foraging ecology, other factors may also be contributing to sexual segregation in this Mediterranean population of red deer, and further studies focusing on sexual differences regarding feeding behaviour and digestibility are needed.

The COVID-19 pandemic has drastically affected people’s social habits, especially those related to outdoor activities. We intended to understand the effects of the two national lockdowns in Portugal on the presence and activity of a wild population of red deer (Cervus elaphus) by analysing data from camera traps installed at Lousã mountain, in the central part of Portugal. The cameras were set between 2019 and 2021, and a total of 2434 individual contacts of red deer and 182 contacts of people were recorded. Results showed a higher human presence in the mountain area during the COVID-19 outbreak, especially during the first lockdown in 2020 (0.05 ± 0.17 individuals/day), compared to the same period of the year before the pandemic (0.02 ± 0.05 individuals/day), which resulted in an increase of people by 150%. The increase in human presence did not have a significant direct effect on the presence of red deer. Despite the low overlap of activity patterns between people and red deer, deer showed avoidance behaviour in the 24 h after the detection of human presence on camera traps, as well as an increase in daily activity during the 2020 lockdown, showing red deer’s awareness of human visitation. These results showed that people’s increased search for cultural services in wild environments during COVID-19 lockdowns, such as hiking and biking, seemed to influence the population of red deer, albeit momentarily.

The red deer (Cervus elaphus), a large ungulate, significantly influences ecosystem dynamics, particularly through its foraging behavior, and is a key species in several important ecosystem services. This review aims to consolidate information on the provision of ecosystem services by this ungulate across various climates and different study conditions. Our literature review analyzed 86 published studies, focusing on a set of specific ecosystem services related to the role of red deer at the soil level, plant communities, tourism, and hunting. Of these, 60 studies primarily addressed seed dispersal and the effects of herbivory by red deer. Provisioning services were mentioned in 20 studies. Cultural services, on the other hand, seem highly disregarded in literature (six studies), highlighting a relevant research gap. 69% of the studies reported positive impacts of red deer in terms of delivering ecosystem services, such as seed dispersal. However, negative effects, such as negative effects on plant communities via reductions in plant diversity and abundance due to herbivory, were also documented. Besides providing a foundation for developing conservation strategies, we also highlight literature gaps, providing guidelines for future studies. Given the significant role of red deer in ecosystems, comprehensive studies on their role as ecosystem service providers not only deepen our understanding of ecological dynamics but also offer promising insights for informed conservation strategies and wildlife management approaches. Fostering effective conservation and management practices is essential to avoid biodiversity losses, preserving and promoting sustainable management of natural environments, ecosystem health, and consequently human well-being throughout ecosystem services provisioning.

Invasive alien plants like Acacia species are key drivers of ecosystem change, with considerable effects on forest structure, nutrient cycling, and biodiversity. In the Mediterranean region, which is already vulnerable to challenges such as anthropogenic forest fragmentation, Acacia species have become dominant invasive plants at the landscape scale. In this study, we explored the effects of Acacia dealbata Link, and Acacia melanoxylon R. Br. to a lower extent, in a fragmented forest landscape in Central Portugal. We hypothesised that Acacia invasion would alter vegetation structure, litter, soil, and springtail communities, with cascading effects on ecosystem dynamics. We established 25 sampling points within a 25 km² grid to collect data on Acacia invasion status, vegetation structure (cover of different plant layers and species richness), litter and soil quality (litter C/N ratio and soil organic carbon), and springtail communities (abundances of epigeic, hemiedaphic, and euedaphic springtails). We considered an Acacia invasion gradient as a continuous variable calculated with the sum of the covers of A. dealbata and A. melanoxylon divided by the total tree cover to study the combined effect of the two species. High levels of Acacia invasion were associated with reduced herb cover and plant species richness. Moreover, as Acacia invasion intensified, there was a significant decrease in the litter C/N ratio, and an increase in soil organic carbon. Subsequently, these Acacia-induced impacts triggered cascading effects on the relationships between shrub cover, litter and soil quality, and springtail functional structure. These findings showed that even low levels of Acacia invasion altered above- and belowground dynamics, thereby highlighting the cascading impacts of these invasive alien plant species on ecosystem functioning. Prioritizing early intervention in areas with smaller infestations (i.e., especially in fragmented landscapes like those in Central Portugal) can help prevent further spread and impacts of both A. dealbata and A. melanoxylon.

Aim: Herbivory has pronounced effects on ecosystems, altering plant community composition and structure while shaping functional traits, highlighting the need for a comprehensive analysis of its impacts, alongside the effects of abiotic factors known to affect plant communities. This study aimed to assess whether red deer herbivory pressure (measured by population density and feeding time), tree cover, altitude, and northness influence plant communities and their functional traits and diversity. Location: The study was conducted in the Lousã Mountain, central Portugal. Methods: We evaluated the influence of herbivory and environmental variables on plant communities by analysing ten plant traits: specific leaf area, plant height, leaf length and width, leaf perimeter and roundness, fresh and dry leaf weight, chlorophyll fluorescence, and quantum yield. Results: Contrary to our predictions, herbivory did not significantly affect plant functional diversity, although it influenced some plant traits. In contrast, tree cover, altitude, and north‐facing slopes strongly affected several traits, including plant height, leaf dimensions, SLA , and chlorophyll fluorescence. Conclusions: These findings suggest that environmental factors predominantly shape plant trait patterns, potentially conferring resilience against intermediate levels of herbivory in Mediterranean mountain communities. This functional resistance highlights the importance of environmental filters in maintaining ecosystem stability and suggests that future changes in climate or land use may have stronger impacts on plant trait dynamics than moderate herbivore pressures.