Luc De Bruyn

• PhD in Zoology, MS in Biostatistics
• Research Institute for Nature and Forest

Best practice guidelines for successful brown hare monitoring on farmland - Line-transect spotlight method The brown hare is a crucial part of a healthy farmed environment and holds significant value as a game species across Europe. To evaluate conservation efforts and promote sustainable hunting of local hare populations, clear monitoring guideli...

Best practice guidelines to survey wintering farmland birds - Point counts Farmland birds are in decline in Europe and hence urgent action is needed to halt and reverse this decline. To evaluate conservation efforts, reliable, reproducible monitoring is vital. The point count method, detailed in this factsheet, provides a user-friendly and efficie...

Best practice guidelines to survey breeding farmland birds - Territory mapping Farmland birds are among the fastest declining group of birds in Europe and hence practical solutions that halt and reverse this decline are urgently needed to help meet national farmland Biodiversity targets. To evaluate the effectiveness of proposed or implemented con...

Intensivering van de landbouw is in Europa een belangrijke oorzaak van verlies aan biodiversiteit en de eraan gerelateerde ecosysteemdiensten. Biolandbouw wordt vaak naar voor geschoven als een manier om dit probleem te verminderen. In dit artikel vergelijken we de biodiversiteit en de gewas-bestuiving tussen bioappelteelt en conventionele appeltee...

Major advances in the understanding of infectious diseases have been achieved in the last decades. However, the persistence and re-emergence of pathogens continue to raise public and veterinary health concerns, of which the recent COVID-19 pandemic may be one of the most dramatic examples. Understanding the impact of habitat alterations and concomi...

Considerable advances and breakthroughs in wildlife tracking technology have occurred in recent years, allowing researchers to gain insights into the movements and behaviours of a broad range of animals. Considering the accessibility and increase in use of tracking devices in wildlife studies, it is important to better understand the effects on the...

Emerging and re-emerging infectious diseases have posed significant global health threats, with many attributed to zoonotic RNA viruses. These pathogens can, under some conditions, cross species barriers, facilitating transmission from animal hosts to humans. Bats, characterised by unique physiological and ecological features, and remarkable specie...

Executive summary Farmland birds are in decline in Europe and hence urgent action is needed to halt and reverse this decline. From mid-2016 to mid-2023, the Interreg PARTRIDGE project, improved the area of ten 500-hectare farmland demonstration sites - two each in Belgium-Flanders, The Netherlands, Germany, Scotland, and England - by enhancing exi...

International and regional legislations require authorities to report regularly on the state of species of conservation concern in their region or country (e.g., the EU Birds and Habitats Directives). Monitoring schemes for species across a variety of taxonomic groups are being set up to estimate abundance trends. In Flanders (northern Belgium), un...

Assessing how bats respond to habitat attributes requires an integrative approach to reliably predict direct community‐level effects. We focused on hipposiderid and pteropodid bats because of their diverse resource use patterns, body size ranges, and dispersal abilities. We combined an array of bat species‐level characteristics with key forest stan...

Bats exhibit a variety of life-history traits that can serve as valuable surrogate metrics of terrestrial ecosystem health. Here, we investigate how sonotype activity of hipposiderid bats covaries with habitat structure at finer spatial scales. We recorded passive echolocation calls and measured key habitat attributes in six rainforests in the Loma...

During the PARTRIDGE project, we increased the amount of good- to high-quality (ie. wildlife-friendly) habitats by 4.1% on average across 10 demonstration sites (see Review of 2021, p.22-25). The project’s key high-quality measure is the PARTRIDGE wild-flower plot, because it provides suitable habitat year-round for the grey partridge and a wide ra...

The balance between costs and benefits is expected to drive associations between species. While these balances are well understood for strict associations, we have no insights to which extent they determine facultative associations between species. Here, we quantified the costs of living in a facultative association, by studying the effects of red...

The bat fauna of the Adriatic islands is relatively poorly known. Seven species were documented so far on the remote Adriatic islands of Vis and Biševo (Croatia). This study aims to increase knowledge on the bat communities on these islands. Bat echolocations were recorded between 30 April and 11 May 2018 at seven sites showing bat presence. Calls...

Urbanization has been shown to strongly affect community composition of various taxa with potentially strong shifts in ecological interactions, including those between hosts and parasites. We investigated the effect of urbanization on the composition of arthropods in nests of great tits in Flanders, Belgium. These nests contain taxonomically and fu...

In temperate regions, winter is characterized by cold temperatures and low food availability. Heterothermic animals can bridge this period by entering a state of torpor characterized by decreased body temperature and reduced metabolic rate. Hibernation site choice is crucial since temperature conditions in the hibernaculum will impact torpor. We an...

It has been a long time since the world has experienced a pandemic with such a rapid devastating impact as the current COVID-19 pandemic. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is unusual in that it appears capable of infecting many different mammal species. As a significant proportion of people worldwide...

In this data paper three datasets are described containing GPS tracking and acceleration data of Western marsh harriers ( Circus aeruginosus ) breeding in Belgium and the Netherlands. The Western marsh harrier is included as a threatened bird species in Annex I of the European Bird Directive due to the steep decline in population densities. In orde...

It has been a long time since the world has experienced a pandemic with such a rapid devastating impact as the current COVID-19 pandemic. The causative agent, the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is further unusual in that it appears capable of infecting many different mammal species. As a significant proportion of peopl...

The 100 km long Międzyrzecz Fortified Front, Ostwall or Festungsfront im Oder-Warthe Bogen, is located between the rivers Odra in the south and Warta in the north and was built by Germany in 1934 – 1944. The Central Sector “Wysoka” (Zentralabschnitt or Abschnitt Hochwalde), starting south of Staropole, and ending on the lake Kursko, only ca. 15 km...

The ability to accurately identify individuals is essential for both management and research of wild or captive animals. Marks need to be clear enough to be recovered, long-lived enough to provide useful information and not have health implications for the tagged animal which may affect survival. Substantial evidence suggests that more invasive, pe...

BACKGROUND Aphids (Hemiptera: Aphididae) are a problematic pest in global sweet pepper cultivation. Control of aphids often relies on insecticides, leading to widespread resistance. Biological control of aphids is mainly based on releasing specialist natural enemies, but they often fail to control outbreaks. Macrolophus pygmaeus Rambur (Hemiptera:...

Each Member State needs to report every 6 years (2013-2019, 2025…) to the European Commission (EC) about the conservation status of habitats and species present in each biogeographical region. This document presents the reporting files for the different bat sepcies for the period 2013-2018 of the species present in Flanders (northern Belgium). The...

Each Member State needs to report every 6 years (2013-2019, 2025…) to the European Commission (EC) about the conservation status of habitats and species present in each biogeographical region. This document presents the applied method and results for the period 2013-2018 of the species present in Flanders (northern Belgium). Flanders is nearly comp...

The Chequered Skipper Carterocephalus palaemon inhabits a variety of habitats in NW Europe: heathlands, wet grasslands and chalk grasslands, usually at woodland edges and wide rides and glades in different types of woodlands. It mainly uses broadleaved grasses such as Molinia, Calamagrostis and Brachypodium as host plants. The species became extinc...

Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a generalist natural enemy that is used to control multiple pest species in a variety of horticultural crops. The bugs are released at the start of the crop cycle to allow them to establish and build up a population in the crop that can control pest infestations later in the season. To facilitate...

This report describes the monitoring networks for the mammals European hamster (Cricetus cricetus), Common dormouse (Muscardinus avellanarius), European badger (Meles meles) and European otter (Lutra lutra). The aim of the monitoring is to obtain a population trend estimate on a Flemish scale. Common dormouse is counted annually along transects and...

Biological control is widespread in management of greenhouse sweet pepper crops. Several species of predatory mites, bugs, and parasitoids are used against a wide range of pest species. However, biological control of particular pests like aphids, caterpillars, and the tobacco whitefly, Bemisia tabaci Gennadius, remains problematic. Macrolophus pygm...

Morimus funereus Mulsant, 1862, a longhorn beetle listed in the Habitats directive, is reported for the first time in Belgium. A specimen was intercepted in Nijlen (near Antwerp) which is very likely explained by transport although the exact origin and route is unclear.

De Stad Antwerpen wil de indicator‐ en doelsoorten opvolgen van alle gebieden in kader van het groenplan, om de evolutie in deze gebieden op te volgen en een gepast beheer toe te passen. Dit rapport geeft de resultaten van de uitgevoerde monitoring van planten, vogels, ongewervelden, amfibieën en reptielen en vleermuizen in Klaverblad/Hollebeek te...

This report describes the monitoring networks for the mammals European hamster (Cricetus cricetus), Common dormouse (Muscardinus avellanarius), European badger (Meles meles) and European otter (Lutra lutra). The aim of the monitoring is to obtain a population trend estimate on a Flemish scale. Common dormouse is counted annually along transects. Eu...

Background: In order to optimize net transmission success, parasites are hypothesized to evolve towards causing minimal damage to their reservoir host while obtaining high shedding rates. For many parasite species however this paradigm has not been tested, and conflicting results have been found regarding the effect of arenaviruses on their rodent...

SUMMARY Westra T, De Knijf G, Ledegen H, De Bruyn L, Maes D, Onkelinx T, Piesschaert F, Vanreusel W, Van Elegem B, Pollet M & Quataert P. 2016. Monitoring priority species in Flanders. Implementation of new monitoring schemes. Natuur.focus 15(4): 156-165 [in Dutch] Reliable information on the status and trends of species is needed to support natur...

This report describes the protocol for the monitoring of grasshoppers in Flanders. We present the species that have to be monitored and the field protocol. The Saddle‐backed Bushcricket Ephippiger ephippiger must be monitored by counting the number of singing males. The Lesser‐mottled Grasshopper Stenobothrus stigmaticus is monitored by capturing a...

This report describes the protocol for the dragonfly monitoring network in Flanders (Belgium). We list the species that need to be monitored and the methods to do so. Three easily observed species of dragonfly (Calopteryx virgo, Coenagrion pulchellum and Aeshna isoceles) are counted using dragonfly-transects. We explain how the sampling frame was c...

Metal oxide nanoparticles are increasingly being produced and will inevitably end up in the aquatic environment. Up till now, most papers have studied individual nanoparticle effects. However, the implementation of these data into a risk assessment tool, needed to characterise their risk to the aquatic environment, is still largely lacking. Therefo...

Fish assemblages in reservoirs and lakes are mainly assessed by multiple sampling gear. The challenge exists in how to combine all the data from the different types of gear to develop a fish-based index. In this paper, we describe a novel approach to this challenge in reservoirs in Flanders. The developed approach can also be used for natural lakes...

Background Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid...

Why this study? In the polder region of SW Netherlands, Belgium and NW France, Marsh Harriers breed in a variety of rather small and often fragmented marshland habitats. Locally the species started to shift to intensive farmland as a nesting habitat. • During the last decade breeding numbers or/and breeding succes have declined in some areas. Yearl...

Red Lists are used to assess the extinction risk of species. Regional IUCN criteria were applied to categorise 42 indigenous freshwater fish species in Flanders into Red List categories. As such, three species are assessed as Regionally Extinct, eight as Critically Endangered, two as Endangered and eight as Vulnerable. A further five species are co...

SUMMARY Bird-specific ticks do not infest humans and livestock, but these ticks often share their avian hosts with generalist ticks that do. Therefore, their feeding activity may have an impact on the transmission of pathogens outside bird-tick transmission cycles. Here we examined the seasonal feeding activity of the tree-hole tick (Ixodes arboric...

Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical plant in the immediate vicinity of the study area....

Gene flow and adaptive divergence are key aspects in metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis lo...

Population-ecological research on the hazel dormouse population in Voeren in 2013. [in Dutch]

The Marsh harrier (Circus aeruginosus) is listed on Annex I of the EU Bird Directive and thus requires appropriate conservation, in particular of its most suitable breeding areas. Moreover, this species is an interesting study object as it seems to have found a way to cope with agricultural intensification. In some regions, a varying part of the po...

Four years (2009-2012) of population research on the hazel dormouse population in Voeren: experiences with research methods and first results. [in Dutch]

We investigated the accumulation of persistent organic pollutants in damselfly larvae (Ischnura elegans) in sixteen ponds in Flanders (Belgium), widely differing in the surrounding land use. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenz...

1. Disturbance is one of the most important factors structuring the taxonomic and functional composition of vegetation. Vegetation resistance or resilience to disturbance depends on local environmental conditions, further modifying the pool of species and traits. This paper aims to understand how disturbance and local environment combine to affect...

The relative importance of body size as a factor in life-history variation is poorly understood in hermaphrodites, especially in reciprocally mating species. Succinea putris is a reciprocally mating land snail with different courtship roles, i.e. an 'active' individual mounts the shell of a 'passive' partner after which penes are intromitted simult...

Differences in reproductive success (RS) between different groups of individuals are of interest to researchers studying natural and sexual selection. Since it is often not feasible to quantify RS in the wild, researchers make use of proxies instead. One such proxy is clutch size. However, research on species providing parental care (mainly birds a...

This paper is a reply to the criticisms formulated by Halme et al. against a meta-analysis dealing with the effects of forest management on biodiversity. We mainly contradicted the problems of pseudo-replication, distribution of covariable effects, taxonomic generalizations and inclusion criteria. We conclude on the necessity of compromises during...

Studies on the effects of perfuorooctane sulfonic acid (PFOS) exposure on terrestrial invertebrates are very scarce. Here, we quantifed the effects of PFOS on the number of offspring for two generations of Drosophila hydei Sturtevant 1921 (Diptera:Drosophilidae) reared in the laboratory. The frst generation was exposed to a range of PFOS concentrat...

Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. However, the possible biodiversity gains and losses due to forest management (i.e. anthrop...

An undescribed species of Oncopodura was found by Leruth (1939) while making his inventory of the fauna of Belgian caves. The 'lost' collection of Collembola specimens of 1932-1934 of Leruth was backtracked by Michel Dethier and eventually recovered from the Museo Nacional de Ciencias Naturales of Madrid in Spain. In the Delhez collection of Belgia...

Dit hoofdstuk focust op de effecten van klimaatveranderingen op de natuur in Vlaanderen. Het is opgebouwd rond volgende hoofdlijnen: • De ontwikkelde Vlaamse klimaatscenario’s wijzen eenduidig op een stijging van de gemiddelde omgevingstemperatuur tegen 2100 met 1,5°C tot 4,4°C in de winter en met 2,4°C tot 7,2°C in de zomer en op meer neerslag tij...

We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10000 microg/L. Our results show reduced egg hatching success, slower larval development, grea...

National or regional conservation strategies are usually based on available species distribution maps. However, very few taxonomic groups achieve a full coverage of the focal region. Distribution data of well-mapped taxonomic groups could help predict the distribution of less well-mapped groups and thus fill gaps in distribution maps. Here, we pred...

Female polymorphism is considered to be maintained through negative frequency-dependent selection imposed by costly male harassment. However, few studies have questioned whether male harassment negatively affects female morph success and does so differently for female morphs, especially in the wild. In the present study, we quantified female morph...

Perfluorooctane sulfonic acid (PFOS) is a persistent and ubiquitous environmental contaminant that has been detected in organisms worldwide. Here, we evaluate whether long-term (1 and 4 months) exposure to PFOS contamination affects the behavioural performance of freshwater larvae of the damselfly Enallagma cyathigerum (Insecta: Odonata). Our resul...

When habitats become fragmented, variation in patch size and quality are expected to impose changes on the spacing pattern and social organization of animal populations. General theory predicts different possible responses including shrinking home ranges (fission response), increasing range overlap (fusion) and incorporation of multiple patches in...

In aerial animals, flight morphology needs to be designed to allow daily behavioural activities. Within species differences in behaviour can therefore be expected to relate to differences in flight morphology, not only between males and females but also between same-sex members when they use different behavioural strategies. In female polymorphic d...

Abstract According to biophysical principles, colour and size are important phenotypic factors that may influence body temperature and activity in ectothermic insects. In taxa showing female-limited polymorphism, males and female morphs differ in body colour, size and activity pattern. However, no previous study has evaluated whether such phenotypi...

We studied the effects of population size, plant density, and interpopulation distance on the process of sexual reproduction in experimental populations of the perennial self-incompatible Primula vulgaris (Primulaceae). Decreasing population size significantly reduced the proportion of flowers setting fruit, the seed:ovule ratio, and the overall se...

In many damselfly species a female-limited colour polymorphism is encountered which is assumed to be the result of sexual conflict. Typically, one morph resembles the male's body colouration (andromorph), while the other is dissimilar (heteromorph). Little is known about the extent of temporal variation in female morph proportions at the water wher...

Plague surveillance programmes established in Kazakhstan, Central Asia, during the previous century, have generated large plague archives that have been used to parameterize an abundance threshold model for sylvatic plague in great gerbil (Rhombomys opimus) populations. Here, we assess the model using additional data from the same archives. Through...

We studied the effects of heavy metal exposure on host plant choice and performance of the grass miner Chromatomyia milii (Diptera, Agromyzidae). Cadmium decreased plant growth in a dose-dependent way. C. milii preferred the control to the cadmium-exposed plants for feeding and oviposition. Moreover, preference for the control plants increased with...

This study investigates the commonly-held belief in the SLA community that second language acquisition is somehow influenced by the learner’s personality. It builds on previous research on the relation between one personality variable, extraversion, and second language acquisition but is innovative in three ways. First, it examines L2 learners’ spe...

We investigate the effects of different levels of predation pressure and rodent dispersal on the population dynamics of the African pest rodent Mastomys natalensis in maize fields in Tanzania. Three levels of predation risk were used in an experimental set‐up: natural level (control), excluding predators by nets and attracting avian predators by ne...

In many Zygoptera spp. ♀ ♀ occur in different colour morphs, with one morph coloured like the ♂ (andromorph), while the others are not (gynomorph). Two hypotheses have been proposed to explain frequency-dependent harassment of ♀ morphs. According to the first, ♂ ♂ should prefer the more frequent of the 2 ♀ morphs (learned-mate recognition hypothesi...

In many damselfly species mature females exhibit colour polymorphism: one female morph resembles the conspecific male (androchrome) while the others do not (gynochromes). Hypotheses for the maintenance of such polymorphisms differ mainly as to whether they are based on density- and/or frequency-dependent selection and on the nature of the frequency...

A popular hypothesis to explain the high degree of host specialisation observed among mites and insects is the existence of host-associated fitness trade-offs. According to this theory, adaptation to a host results in a relatively poorer performance on alternative hosts due to the antagonistic pleiotropic action of one or more genes. Evidence in fa...

The present-day geographic distribution of individual species of five taxonomic groups (plants, dragonflies, butterflies, herpetofauna and breeding birds) is relatively well-known on a small scale (5 5 km squares) in Flanders (north Belgium). These data allow identification of areas with a high diversity within each of the species groups. However,...

Although opposing selection forces cause drastic differences in community structure between temporary and permanent ponds, some species are able to persist in both pond types. Little is known about the underlying life history strategies that enable species to do so. This is especially true for embryonic development times. Here, we describe within a...

For many animal groups, both sexes have been reported to attempt to mate with members of their own sex. Such behaviour challenges theories of sexual selection, which predict optimization of reproductive success. We tested male mate choice between opposite- and same-sex members in the damselfly Ischnura elegans. Binary choice experiments were conduc...

The family Chloropidae comprises 23 known gall-inducing species, belonging to five genera (Lipara, Pseudeurina, Eurina, Chlorops, Homaluroides). Gall inducers are confined to the temperate regions of the northern hemisphere, but many chloropid flies are still unknown and many still have to be described, especially in the tropics. Almost all species...

The plant stress hypothesis predicts that environmental stress increases the suitability of plants as food for herbivores, especially for senescence feeders. Yet, performance is enhanced only at moderate stress intensities in several herbivores. Even more paradoxically, a large number of insect species prefer and perform better on vigorously growin...

Between 1994 and 1999, 219 red foxes (Vulpes vulpes) were collected in northern Belgium and examined for intestinal helminths. The effects of host-related (age, sex, body mass/size ratio) and temporal factors on the prevalence and on the num- ber of parasite species per individual host were investigated. The following parasites were found: cestodes...

We studied the relationship between plant stress intensity and herbivore response in the grass miner Chromatomyia milii (Kaltenbach) (Diptera: Agromyzidae) on nutrient stressed plants. We subjected the host grass Holcus lanatus (Poaceae) to a range of nutrient treatments (0%, 25%, 50%, 100%, and 200% Hoagland nutrient solution) and recorded plant s...

The coexistence of multiple female colour morphs in damselflies remains poorly understood. Typically, one of the female morphs is coloured like the male (andromorph), while the other morphs are not (gynomorphs). Andromorphs, by resembling males, are thought to benefit from avoiding male harassment. Some authors have proposed that this benefit is of...