Luc Lens

Ghent University | UGhent · Department of Biology

The sixth mass extinction is a consequence of complex interplay between multiple stressors with negative impact on biodiversity. We here examine the interaction between two globally widespread anthropogenic drivers of amphibian declines: the fungal disease chytridiomycosis and antifungal use in agriculture. Field monitoring of 26 amphibian ponds in...

Shade coffee farms in southwest Ethiopia are known to host high levels of avian biodiversity. However, these farms vary in terms of forest management, which affects their understory, mid-story, crown cover, and canopy closure, and hence their structural complexity. Such differences in vegetation structure can potentially affect the survival of spec...

In colonial breeding species, the number of adverse social interactions during early life typically varies with breeding density. Phenotypic plasticity can help deal with this social context, by allowing offspring to adjust their behaviour. Furthermore, offspring may not be unprepared since mothers can allocate resources to their embryos that may p...

Hedgehog diphtheric disease (HDD), an ulcerative skin disease with a high fatality rate is an emerging threat to European hedgehogs (Erinaceus europaeus). We explored the potential role of a panel of zoonotic pathogens in the presumed multifactorial nature of HDD in 188 hedgehogs from three wildlife rescue centers in Belgium. As expected, and with...

In cooperatively breeding species, group members may derive multiple benefits from helping to raise other individuals’ offspring, yet not all individuals do so. In this study, we tested predictions from the “kin selection”, “pay-to-stay”, “group augmentation” and “skills” hypotheses, to explain why group members feed nestlings of breeding placid gr...

Colonial breeding provides benefits such as reduced predation risk, but also entails costs due to the enhanced levels of competition. In particular, it may require a significant amount of time and energy to establish a territory at the onset of reproduction, which in turn can impose carry-over effects on subsequent reproductive investments. Here we...

Introgressive hybridisation is a process that enables gene flow across species barriers through the backcrossing of hybrids into a parent population. This may make genetic material, potentially including relevant environmental adaptations, rapidly available in a gene pool. Consequently, it has been postulated to be an important mechanism for enabli...

Despite the microbiome’s key role in health and fitness, little is known about the environmental factors shaping the gut microbiome of wild birds. With habitat fragmentation being recognised as a major threat to biological diversity, we here determined how forest structure influences the bacterial species richness and diversity of wild great tit ne...

Despite devastating effects on global biodiversity, efficient mitigation strategies against amphibian chytridiomycosis are lacking. Since the free-living pathogenic zoospores of Batrachochytrium dendrobatidis (Bd), the infective stage of this disease, can serve as a nutritious food source for components of zooplankton communities, these groups may...

Human activities benefit a range of animal species, the resulting presence of which in cities can have negative societal consequences. One example are food subsidies, which buffer natural variation in food availability and allow these species to maintain larger populations. These buffers will likely gain importance under future environmental change...

Human activities benefit a range of animal species, the resulting presence of which in cities can have negative societal consequences. One example are food subsidies, which buffer natural variation in food availability and allow these species to maintain larger populations. These buffers will likely gain importance under future environmental change...

There is a growing awareness that experience may play a major role in migratory decisions, especially in long-lived species. However, empirical support remains to date scarce. Here, we use multiyear GPS-tracking data on 28 adult Lesser Black-backed Gulls (Larus fuscus), a long-lived species for which migratory strategies typically consist of a seri...

Diverse communities of symbiotic microbes inhabit the digestive systems of vertebrates and play a crucial role in animal health, and host diet plays a major role in shaping the composition and diversity of these communities. Here, we characterized diet and gut microbiome of fire salamander populations from three Belgian forests. We carried out DNA...

While the amphibian disease chytridiomycosis is causing ongoing population declines and biodiversity losses around the globe, efficient mitigation strategies are lacking. The free‐living zoospores of the causative agents of this disease, the chytrid pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), are a po...

Contemporary forest management strives to satisfy contrasting demands on forest ecosystems by promoting multiple ecosystem services. These services are affected in varied manners by alternative management actions operating at local or landscape scales, potentially leading to trade‐offs and synergies that may impede or encourage forest managers to c...

Anthropogenic pressure such as agricultural pollution globally affects amphibian populations. In this study, a total of 178 different compounds from five agrochemical groups (i.e. antimicrobial drugs residues (ADRs), coccidiostats and anthelmintics, heavy metals, mycotoxins and pesticides) were determined monthly, from March until June 2019 in 26 a...

Background Parental care benefits the offspring, but comes at a cost for each parent, which in biparental species gives rise to a conflict between partners regarding the within-pair distribution of care. Pair members could avoid exploitation by efficiently keeping track of each other’s efforts and coordinating their efforts. Parents may, therefore,...

Abstract Ethiopian shade coffee plantations are well documented to be bird-friendly and act as refuges for disappearing tree species. The extent to which these plantations support mammal conservation, as well as mammal sensitivity to coffee intensification, remain little studied. We studied the distribution and diversity of mammals under three coff...

Gastrointestinal microbiota fulfill pivotal roles in providing a host with nutrition and protection from pathogenic microorganisms. Up to date, most microbiota research has focused on humans and other mammals, whereas birds and especially wild birds lag behind. Within the field of the avian gut microbiome, research is heavily biased towards poultry...

Ethiopian shade coffee plantations are well documented to be bird-friendly and act as refuges for disappearing tree species. The extent to which these plantations support mammal conservation, as well as mammal sensitivity to coffee intensification, remain little studied. We studied the distribution and diversity of mammals under three coffee manage...

Trophic interactions may strongly depend on body size and environmental variation, but this prediction has been seldom tested in nature. Many spiders are generalist predators that use webs to intercept flying prey. The size and mesh of orb webs increases with spider size, allowing a more efficient predation on larger prey. We studied to this extent...

Individual niche variation is common within animal populations, and has significant implications for a wide range of ecological and evolutionary processes. However, individual niche differences may also temporally vary as a result of behavioural plasticity. While it is well understood how niche variation is affected by changes in resource availabil...

Aim Recent breakthroughs in environmental niche models (ENMs) have substantially improved our insights in niche evolution. Assuming that closely related taxa have similar niches (i.e. niche conservatism), the combination of ENMs with phylogenetic information allows the reconstruction of ancestral niches. This reconstruction helps to identify the un...

While epizootics increasingly affect wildlife, it remains poorly understood how the environment shapes most host-pathogen systems. Here, we employ a three-step framework to study microclimate influence on ectotherm host thermal behaviour, focusing on amphibian chytridiomycosis in fire salamanders (Salamandra salamandra) infected with the fungal pat...

Grading the fecal consistency of carnivores is a frequently used tool for monitoring gut health and overall digestion. Several fecal consistency grading systems are available for mainly felids and canids. No such system exists for the brown bear (Ursus arctos Linnaeus, 1758). We aim at extending current fecal consistency grading systems with a scor...

1. Non‐frugivorous waterbirds disperse a wide variety of plants by endozoochory, providing longer dispersal distances than other mechanisms. Many waterbirds visit both agricultural and natural landscapes during their daily movements, but potential bird‐mediated dispersal of weed plants within and from agricultural landscapes to other habitats is co...

Biodiversity loss affects ecosystem functioning. Top down effects of amphibian declines on the trophic food web of the forest floor are poorly understood. Here we quantify and explain the effects of disease-driven loss of salamanders on the dynamics of forest leaf litter. Using paired mesocosms, within a Belgian forest, we tested the effect of fire...

As environmental conditions fluctuate across years, seasonal migrants must determine where and when to move without comprehensive knowledge of conditions beyond their current location. Animals can address this challenge by following cues in their local environment to vary behaviour in response to current conditions, or by moving based on learned or...

While epizootics increasingly affect wildlife, it remains poorly understood how the environment shapes most host-pathogen systems. Here, we employ a three-step framework to study microclimate influence on ectotherm host thermal behaviour, focusing on amphibian chytridiomycosis in fire salamanders (Salamandra salamandra) infected with the fungal pat...

Communities across trophic levels, and the functional roles they play, are vital for the sustained provision of ecosystem services. In forest systems, diversification of overstorey composition has been shown to be a key driver of biodiversity, but its influence on across‐trophic level relationships remains scarcely known. Species across trophic lev...

It remains poorly understood how effects of anthropogenic activity, such as large-scale habitat fragmentation, impact sociality in animals. In cooperatively breeding species, groups are mostly formed through delayed offspring dispersal, and habitat fragmentation can affect this process in two opposite directions. Increased habitat isolation may inc...

It remains poorly understood how effects of anthropogenic activity, such as large-scale habitat fragmentation, impact sociality in animals. In cooperatively breeding species, groups are mostly formed through delayed offspring dispersal, and habitat fragmentation can affect this process in two opposite directions. Increased habitat isolation may inc...

While the emerging amphibian disease chytridiomycosis is causing dramatic and ongoing biodiversity losses worldwide, sustainable strategies to mitigate this global threat to amphibians are currently missing. We here propose a conceptual framework for a novel biological mitigation strategy based on the increasing evidence that naturally occurring mi...

Forest fragmentation is globally pervasive but especially severe in tropical forests, as exemplified by the state of Afrotropical montane forests in Ethiopia, where remnant forests almost exclusively exists as small, isolated fragments centered around churches, forming networks of partially intact ‘habitat islands.’ Church forests deliver ecosystem...

Background Habitat loss can force animals to relocate to new areas, where they would need to adjust to an unfamiliar resource landscape and find new breeding sites. Relocation may be costly and could compromise reproduction. Methods Here, we explored how the Lesser black-backed gull (Larus fuscus), a colonial breeding seabird species with a wide e...

Wildlife diseases are contributing to the current Earth's sixth mass extinction; one disease, chytridiomycosis, has caused mass amphibian die-offs. While global spread of a hypervirulent lineage of the fungus Batrachochytrium dendrobatidis (BdGPL) causes unprecedented loss of vertebrate diversity by decimating amphibian populations, its impact on a...

Widespread endemism of host-adapted pathogens poses a heavy burden on animal and human health. Mechanisms underpinning long-term host pathogen co-existence and concurrent costs are poorly understood. We use infections in pigeons with pathogenic, pigeon adapted Salmonella Typhimurium to explain how host and pathogen trade-offs and benefits sustain l...

jats:p>The microbiome of wild birds has been associated with health status and risk of disease development, but underlying metabolomic mechanisms are still unknown. Metabolites produced by microbial organisms may affect host metabolic processes and by doing so influence host health. Here we provide for the first time data on the faecal metabolome o...

Mycotoxins are known for their negative impact on human and animal health as they frequently contaminate food and feed products from crop origin that are consumed by humans and animals. Furthermore, mycotoxins can leach out of plant tissue, to be transported through runoff water into nearby ponds where they can exert negative effects on aquatic org...

Current emission and mobilization rates of mercury (Hg) in the environment pose extensive threats to both wildlife and human health. Assessing the exposure risk and effects of Hg contamination in model species such as seabirds is essential to understand Hg risks at the population and ecosystem levels. The Lesser Black‐backed Gull (Larus fuscus), a...

Species breeding in urban environments are highly prone to a wide variety of non-natural, human activities, which range from short-term disturbances to the degradation or loss of suitable habitat. The latter in turn may force individuals to relocate to new sites for foraging or breeding, both of which presumably entails fitness costs due the trade-...

Trophic interactions may strongly depend on body size and environmental variation, but this prediction has been seldom tested in nature. Many spiders are generalist predators that use webs to intercept flying prey. The size and mesh of orb webs increases with spider size, allowing a more efficient predation on larger prey. We studied to this extent...

The standard Dynamic Energy Budget (DEB) model is widely used to describe the physiology of individual animals. Here we parametrized the DEB model for the lesser black-backed gull Larus fuscus mainly on the basis of literature data. Next we performed an inverse modeling approach to predict the food intake rate of gull chicks (model input) on the ba...

Decades of research suggest that species richness depends on spatial characteristics of habitat patches, especially their size and isolation. In contrast, the habitat amount hypothesis predicts that: 1) species richness in plots of fixed size (species density) is more strongly and positively related to the amount of habitat around the plot than to...

Human activities can lead to a shift in wildlife species' spatial distribution. Understanding the specific effects of human activities on ranging behavior can improve conservation management of wildlife populations in human-dominated landscapes. This study evaluated the effects of forest use by humans on the spatial distribution of mammal species w...

The Taita White-eye (Zosterops silvanus) is an endangered songbird endemic to the Taita Hills of Southern Kenya, where it is confined to small areas of fragmented forest. With diversification rates exceeding those reported in most other vertebrates, White-eyes are a prime example of a Great Speciator. Nevertheless, we still know surprisingly little...

Habitat destruction and deterioration are amongst the main drivers of biodiversity loss. Increasing demand for agricultural products, timber and charcoal has caused the rapid destruction of natural forests, especially in the tropics. The Taita Hills in southern Kenya are part of the Eastern Afromontane Biodiversity Hotspot and represent a highly di...

Urban sprawl increasingly affects the ecology of natural populations, including host–microbiota interactions, with observed differences in the gut microbiota between urban and rural hosts. While different mechanisms could explain this pattern, dietary uptake constitutes a likely candidate. To assess the contribution of diet in explaining urban–rura...

Socially monogamous females regularly mate with males outside the pair bond. The prevailing explanation for this behavior is that females gain genetic benefits resulting from increased fitness of extra-pair offspring. Furthermore, because of the risk of reduced paternal care in response to cuckoldry, females are expected to seek extra-pair copulati...

Background: Animals can obtain a higher foraging yield by optimizing energy expenditure or minimizing time costs. In this study, we assessed how individual variation in the relative use of marine and terrestrial foraging habitats relates to differences in the energy and time investments of an avian generalistic feeder (the Lesser Black- backed Gull...

Biodiversiteit en het functioneren van ecosystemen Steeds meer plant-en diersoorten gaan achteruit en verdwijnen uit ons landschap. De gevolgen hiervan voor het functioneren van ecosystemen-zoals weerspiegeld in biomassaproductie, bestuiving of koolstofopslag-zijn een 'hot topic' in het ecologisch onderzoek. De voorbije dertig jaar voerden ecologen...

Vulnerability to habitat fragmentation Habitat fragmentation caused by human activities has consequences for the distribution and movement of organisms. Betts et al. present a global analysis of how exposure to habitat fragmentation affects the composition of ecological communities (see the Perspective by Hargreaves). In a dataset consisting of 448...

Among seabirds, lesser black-backed gulls (Larus fuscus) are considered to be at high risk of colliding with offshore wind turbines. In this respect, we used GPS tracking data of lesser black-backed gulls caught and tagged in two colonies along the Belgian North Sea coast (Ostend and Zeebrugge) to study spatial patterns in the species’ presence and...

The increasing urbanization process is hypothesized to drastically alter (semi‐)natural environments with a concomitant major decline in species abundance and diversity. Yet, studies on this effect of urbanization, and the spatial scale at which it acts, are at present inconclusive due to the large heterogeneity in taxonomic groups and spatial scal...

Most of Earth's biodiversity is found in 36 biodiversity hotspots, yet less than 10% natural intact vegetation remains. We calculated models projecting the future state of most of these hotspots for the year 2050, based on future climatic and agroeconomic pressure. Our models project an increasing demand for agricultural land resulting in the conve...

Human-mediated food sources offer possibilities for novel foraging strategies by op-portunistic species. Yet, relative costs and benefits of alternative foraging strategies vary with the abundance, accessibility, predictability and nutritional value of anthropogenic food sources. The extent to which such strategies may ultimately alter fitness, can...

Heterogeneity in soil characteristics promotes and maintains coexistence between a diverse set of species. In forests, trees have species-specific impacts on soil abiotic characteristics and mixing of tree species is being promoted as a tool to ensure high levels of diversity and functioning. Yet, limited knowledge is available on the effect of tre...

• In forests, besides tree diversity, tree identity can determine herbivore species diversity. Herbivore species diversity can also depend on spatial factors, such as edge effects; however, empirical evidence for this remains scarce. Furthermore, patterns in herbivore diversity may differ between forest stand level and responses at individual tree...

In species with biparental care, individuals only have to pay the costs for their own parental investment, whereas the contribution of their partner comes for free. Each parent hence benefits if its partner works harder, creating an evolutionary conflict of interest. How parents resolve this conflict and how they achieve the optimal division of par...

Habitat fragmentation and forestry practices affect forest structure and composition, and hence, their intrinsic value for biodiversity conservation. While higher tree species diversity is commonly proposed to result in habitat of higher quality for forest species, how these tree diversity and tree composition effects interact with forest fragmenta...

To better understand natural regeneration of trees and forest dynamics it is important to gain insight into the drivers of invertebrate herbivory. In mature forests, associational resistance of trees resulting from a high diversity of neighbouring trees is common, and can have cascading effects on tree growth through resource concentration effects...

Understanding the mechanisms governing the coexistence of organisms is an important question in ecology, and providing potential solutions contributes to conservation science. In this study, we evaluated the contribution of several mechanisms to the coexistence of two sympatric frugivores, using western lowland gorillas (Gorilla gorilla gorilla) an...

Forest fragments in highly disturbed landscapes provide important ecosystem services ranging from acting as biodiversity reservoir to providing timber or regulating hydrology. Managing the tree species richness and composition of these fragments to optimize their functioning and the deliverance of multiple ecosystem services is of great practical r...