Annika M. Zuleger

West African savannahs provide habitats to diverse species assemblages, yet remain understudied compared to their East and Southern African counterparts. The Niokolo‐Koba National Park in southeastern Senegal constitutes one of the largest remaining protected areas in West Africa and supports a mosaic of savannah and forest habitats with a diverse assemblage of medium‐ and large‐sized mammals. Here, we analysed camera‐trap data originally collected to monitor predator presence in the northwestern sector of the National Park. We deployed 37 cameras across 37 km ² from February 2022 to March 2023, resulting in 13,080 camera‐trap days. We assessed diversity indices and spatiotemporal activity patterns of large and medium‐sized mammals across habitat types. Evenness values—the degree to which species abundances are distributed uniformly within a community—were higher in the savannah than in forest habitats, although overall species richness was comparable. Estimated diel activity mostly corresponded with established species‐specific behavioural patterns. Our analyses revealed differential use of certain habitat types throughout the day, likely driven by spatially segregated sleeping and foraging sites. Our results provide a reference for future studies and monitoring efforts and highlight the value of the forest‐savannah mosaic for the local species assemblage within the larger ecosystem of Niokolo‐Koba National Park.

Traditional pastoralism has long shaped Southern European ecosystems, but widespread agricultural abandonment is transforming these landscapes. Yet, extensive livestock grazing remains a persistent driver of ecological dynamics. Simultaneously, the concept of agricultural rewilding has gained attention as a means of using domestic livestock to restore functions once filled by wild ungulates. However, the ecological interactions between livestock and native wild ungulates, especially across seasons, remain poorly understood. Using long‐term camera trap data from Peneda‐Gerês National Park, Portugal, we examined how free‐ranging cattle and horses influence the spatiotemporal activity of roe deer and wild boar across summer and winter. We assessed diel activity levels and patterns and applied generalized linear mixed models to evaluate the effects of livestock abundance and activity, as well as the presence of herding dogs, using encounter rates as a proxy for livestock abundance. Cattle and horses were predominantly diurnal, whereas roe deer and wild boar were mainly crepuscular and nocturnal, showing increased nocturnality in summer. Both wild ungulate species showed seasonal differences in response to cattle: activity was higher at high cattle abundance sites in summer but declined in winter. This pattern suggests that grazing may facilitate resource access when plant productivity is high but drive temporal avoidance and competition when resources are limited. Herding dog presence further modified these responses, reinforcing positive associations in summer, particularly outside of core cattle activity periods. In contrast, horse presence was associated with higher wild ungulate activity across seasons and times of day, indicating facilitative interactions. This highlights the seasonal variability in wildlife‐livestock relationships and demonstrates that conclusions based solely on summer data risk underestimating livestock impacts. It further underscores the need for year‐round monitoring and adaptive, species‐specific grazing strategies that account for livestock‐associated disturbance factors such as herding dogs to balance biodiversity restoration with sustainable pastoral management.

West African savannahs provide habitats to diverse species assemblages, yet remain understudied compared to their East and Southern African counterparts. The Niokolo-Koba National Park in southeastern Senegal constitutes one of the largest remaining protected areas in West Africa and supports a mosaic of savannah and forest habitats with a diverse assemblage of medium- and large-sized mammals. Here, we analysed camera-trap data originally collected to monitor predator presence in the northwestern sector of the National Park. We deployed 37 cameras across 37 km² from February 2022 to March 2023, resulting in 13,161 camera-trap-days. We assessed alpha diversity indices and spatiotemporal activity patterns of large and medium-sized mammals across habitat types. Evenness values — the degree to which species abundances are distributed uniformly within a community — were higher in the savannah than in forest habitats, although overall species richness was comparable. In contrast, animal sighting rates were higher in forests than in savannahs. Estimated diel activity mostly corresponded with established species-specific behavioural patterns. Our analyses revealed differential use of certain habitat types across the day, likely driven by spatially segregated sleeping sites and foraging locations. Our results provide a reference for future studies and monitoring efforts and highlight the value of the forest-savannah mosaic for the local species assemblage within the larger ecosystem of Niokolo-Koba National Park.

The recruitment life stage, including germination and early seedling establishment, is the most vulnerable life stage of plants and has cascading effects on plant performance at later life stages. However, surprisingly little is known on the eco-evolutionary processes that determine the success of biological invasions at this life stage. We performed germination experiments with and without simulated drought stress and monitored early seedling growth in diploid and tetraploid Centaurea stoebe. While diploids are the major cytotype in the native European range, only tetraploids became invasive in North America. Thus, C. stoebe is an excellent model species to simultaneously study both, pre-adaptive differences in the native range (diploids vs. tetraploids) and post-introduction evolution in the non-native range (native tetraploids vs. non-native tetraploids). To account for broad spatial-environmental variation within cytotypes and ranges, we germinated 23,928 seeds from 208 widely distributed populations. Tetraploids germinated better than diploids. Within tetraploids, invasive populations outperformed native populations in germination. However, these differences were not evident under simulated drought stress. Seedlings of invasive tetraploids had a higher biomass and developed the first true leaf earlier than those from the native range, while the native cytotypes did not differ in these early seedling traits. Our results suggest that a combination of pre-adaptation related to superior performance of polyploids (greater and faster germination) and post-introduction evolution towards higher performance in the invasive range (greater and faster germination, greater and faster accumulation of seedling biomass) may have contributed to the invasion success of tetraploid C. stoebe in North America.

The issue of agricultural land abandonment in southern Europe has raised concerns about its impact on biodiversity. While abandoned areas can lead to positive developments like creating new habitats and restoring native vegetation, they can also result in human–wildlife conflicts, particularly in areas with extensive farming and free‐ranging livestock. To understand habitat selection and use of livestock and wild ungulates, it is essential to study their spatial and temporal distribution patterns. In this context, we conducted a long‐term large mammal monitoring project using camera traps in the Peneda‐Gerês National Park in northern Portugal. Our primary focus was on exploring habitat preferences, occupancy dynamics, and potential spatial use correlations between domestic and wild species, utilizing dynamic occupancy models. Most wild species exhibited stable area use patterns, while domestic species experienced marginal declines, and the Iberian ibex displayed signs of repopulation. We observed distinct effects of habitat variables on occupancy, colonization, and extinction, revealing species‐specific patterns of habitat utilization. Human disturbance had a notable impact on domestic species but did not affect wild ones. Camera sensitivity emerged as a critical factor, enhancing detection probability for all species. Additionally, habitat and weather variables exerted varying effects on detection probabilities, underscoring the necessity of accounting for these factors in modeling the detection process. We found shared habitat preferences between cattle and horses, both positively correlated with wolves, suggesting potential human–wildlife conflicts. Despite extensive spatial overlap, domestic and wild species seem to exhibit ecological independence possibly due to distinct strategies and low predation pressure. Overall, the study emphasizes the multifaceted factors influencing habitat use. The observed species associations contribute to understanding ecological relationships and potential resource competition, emphasizing the importance of considering environmental variables for effective wildlife conservation and management.

In the past decades, agricultural land abandonment and declining land-use intensity became common, especially in the Mediterranean countries of southern Europe. In some areas, this development opened up possibilities for rewilding and the recolonisation or expansion of large mammal populations. Yet, in some instances, co-occurrence of wild mammals and free-ranging domestic herbivores might lead to potential conflicts. It is, therefore, necessary to study the ecological interactions between wild and domestic mammal species to understand the effects of land abandonment and rewilding on biodiversity and ecosystem services. Camera traps are an effective tool for studying species interactions and occupancy dynamics as they allow for long-term monitoring with minimal interference. We conducted a long-term monitoring programme with camera traps in the Peneda-Gerês National Park in northern Portugal. The area has undergone substantial land-use changes following the abandonment of agricultural areas in the past 60 years. While agro-pastoral activities, especially the breeding of free-ranging horses and cattle, are still common in the area, the intensity of these activities has decreased significantly, promoting natural succession and an increase or return of several large mammal species in recent years. Overall, our project aims at: (1) assessing the population trends of the medium and large sized mammals in the area over time; (2) analysing the effects of passive rewilding on occurrence, abundance and behaviour; and (3) understanding potential interactions or conflicts between wild and domestic herbivores. In this publication, we present results of a primary occupancy analysis between 2015 and 2020, as well as a comparison between occupancy and density estimates for 2019.Our publication provides a dataset from long-term camera-trap monitoring in the Peneda-Gerês National Park between 2015 and 2021. We established a 16 km² grid of 64 cameras deployed yearly during the summer months. Together with this publication, we publish the data and images collected between 2015 and 2021, using both the Camtrap DP standard and the GBIF Darwin Event Core. We obtained a total of 934,810 pictures on 41,234 trap nights. The pictures were automatically grouped into sequences with each sequence representing a distinct occurrence event, resulting in 80,191 occurrences. Out of those, 14,442 contained observations of a species, while the remaining were either blank or the species was not identifiable. We only obtained the information whether a species was present or absent on a picture, disregarding the number of individuals. Most observations were of domestic cattle (Bos taurus) and horses (Equus caballus), followed by European roe deer (Capreolus capreolus) and wild boar(Sus scrofa). Further observations include red fox (Vulpes vulpes), gray wolf (Canis lupus), Eurasian badger (Meles meles), stone marten (Martes foina), common genet (Genetta genetta), Iberian ibex (Capra pyrenaica) and red deer (Cervus elaphus). We estimated occupancy and densities for the most common species. The project is on-going and additional data will be included in the future. The dataset is freely available for ecological analysis, but also for training machine-learning systems in automated image classification as all pictures have been manually classified.

In the past decades, agricultural land abandonment and declining land-use intensity became common, especially in the Mediterranean countries of Southern Europe. In some areas this development opened up possibilities for rewilding and the recolonization or expansion of large mammal populations. Yet, in some instances, co-occurrence of wild mammals and free-ranging domestic herbivores might lead to potential conflicts. It is therefore necessary to study the ecological interactions between wild and domestic mammal species to understand the effects of land abandonment and rewilding on biodiversity and ecosystem services. Camera traps are an effective tool for studying species interactions and occupancy dynamics as they allow for long-term monitoring with minimal interference. We conducted a long-term monitoring program with camera traps in the Peneda-Gerês National Park in Northern Portugal. The area has undergone large land-use changes following the abandonment of agricultural areas in the past 60 years. While agro-pastoral activities, especially the breeding of free-ranging horses and cattle, are still common in the area, the intensity of these activities has decreased significantly, promoting natural succession and an increase or return of several large mammal species in recent years. Our project aims at (1) assessing the population trends of the medium and large sized mammals in the area over time; (2) analyzing the effects of passive rewilding on occurrence, abundance and behavior; and (3) understanding potential interactions or conflicts between wild and domestic herbivores. Our publication provides a dataset from long-term camera trap monitoring in the Peneda-Gerês National Park between 2015 and 2021. We established a 16 km² grid of 64 cameras deployed yearly during the summer months. In this paper we publish the data and images collected between 2015 and 2021, using both the Camtrap DP standard and the GBIF Darwin Event Core. We obtained a total of 934,810 pictures on 41,234 trap nights. The pictures were automatically grouped into sequences with each sequence representing a distinct occurrence event, resulting in 80,191 occurrences. Out of those, 14,442 contained observations of a species, while the remaining were either blank or the species was not identifiable. We only obtained the information concerning whether a species was present or absent on a picture, disregarding the number of individuals. Most observations were of domestic cattle (Bos taurus) and horses (Equus caballus) followed by European roe deer (Capreolus capreolus) and wild boar (Sus scrofa). Further observations include red fox (Vulpes vulpes), gray wolf (Canis lupus), Eurasian badger (Meles meles), stone marten (Martes foina), common genet (Genetta genetta), Iberian ibex (Capra pyrenaica) and red deer (Cervus elaphus). We estimated occupancy and densities for the most common species. The project is on-going and additional data will be included in the future. The dataset is freely available for ecological analysis but also for training machine learning systems in automated image classification as all pictures have been manually classified.

Camera trap distance sampling (CTDS)o is a recently developed survey method to estimate animal abundance from camera trap data for unmarked populations. It requires the estimation of camera‐animal observation distances, which previously was done by comparing animal positions to reference labels at predefined intervals. Here, we test a photogrammetry approach to derive camera‐animal observation distances. We applied both, the reference label and photogrammetry approaches to five ungulate species varying widely in body size (Giraffa camelopardalis,Equus grevyi,Oryx dammah,Kobus megacerosandEudorcas thomsonii) and one ground‐dwelling bird species (Numida meleagris) inhabiting a large enclosure and estimated their density with CTDS. Both procedures provided highly correlated observation distances (ρ = 0.99,p < 0.001). A paired t test revealed a minor but significantly higher mean of the photogrammetry approach (MD = 0.28 m,p < 0.001). This, however, seems negligible as for analyses, distances were grouped in intervals of 2 to 5 metres. In general, estimated animal abundance was close to the true number of individuals in the enclosure for both approaches, with the exception of zebra, whose density was underestimated. The photogrammetry approach offers an alternative approach for deriving camera‐animal observation distances and is particularly useful for application in open habitats, with little occlusion of animals.