Jasja Dekker

Jasja Dekker Dierecologie · -

Wildlife tagging provides critical insights into animal movement ecology, physiology, and behavior amid global ecosystem changes. However, the stress induced by capture, handling, and tagging can impact post-release locomotion and activity and, consequently, the interpretation of study results. Here, we analyze post-tagging effects on 1585 individu...

IntroductionRoads may act as barriers in bat flight paths. Since all bat species are protected in the European Union, negative effects of road construction or expansion on essential flight paths require mitigation. One example of a mitigation measure is bat gantries. Several designs of bat gantries are available, but their effectiveness remains unc...

First results of reintroduction of rabbits ( Oryctolagus cuniculus) in the Amsterdam Dunes are shown.

In dit rapport worden op basis van de wetenschappelijke literatuur een aantal practische aanbevelingen gegeven voor herstelmaatregelen voor de populaties van de vijf soorten van de wildlijst. Het gaat om fazant, wilde eend, houtduif, haas en konijn. This report provides a number of practical recommendations for recovery measures for the population...

De auteurs hebben een analyse uitgevoerd naar wat kan worden verwacht omtrent de verdere ontwikkeling van de in Nederland voorkomende wolvenpopulatie in groei en ook verdere verspreiding. Meer specifiek heeft de analyse zich gericht op het verkrijgen van inzicht in: 1. De huidige en toekomstige ontwikkeling van de wolvenpopulatie in Nederland en de...

The stone marten population in Fryslân has been increasing rapidly since 2000. Monitoring the nest success of over 5,500 meadow bird nests, using camera traps, and gps-tracking of stone martens and meadow bird chicks showed that the stone marten can locally be a significant predator of nests and chicks of meadow birds. In 2018, culling of stone mar...

A neurocysticercosis-like lesion in an 11-year-old boy in the Netherlands was determined to be caused by the zoonotic Taenia martis tapeworm. Subsequent testing revealed that 15% of wild martens tested in that region were infected with T. martis tapeworms with 100% genetic similarity; thus, the infection source was most likely local.

In October 2020, a new lineage of a clade 2.3.4.4b HPAI virus of the H5 subtype emerged in Europe, resulting in the largest global outbreak of HPAI to date, with unprecedented mortality in wild birds and poultry. The virus appears to have become enzootic in birds, continuously yielding novel HPAI virus variants. The recently increased abundance of...

In October 2020, a new lineage of clade 2.3.4.4b HPAI virus of the H5 subtype emerged in Europe, resulting in the largest global outbreak of HPAI to date, with unprecedented mortality in wild birds and poultry. The virus appears to have become enzootic in birds, continuously yielding novel HPAI virus variants. The recently increased abundance of in...

Knowledge of species' functional traits is essential for understanding biodiversity patterns, predicting the impacts of global environmental changes, and assessing the efficiency of conservation measures. Bats are major components of mammalian diversity and occupy a variety of ecological niches and geographic distributions. However, an extensive co...

Animals moving through landscapes need to strike a balance between finding sufficient resources to grow and reproduce while minimizing encounters with predators. Because encounter rates are determined by the average distance over which directed motion persists, this trade-off should be apparent in individuals’ movement. Using GPS data from 1,396 in...

We report how we estimated the number of stone martens Marten foina in the Netherlands and province Fryslan and explored the effects of different culling scenarios on the latter population through modelling.

The paper evaluates a culling experiment of stone martens Martes foina as a management tool for the conservation of ground breeding birds.

Quantifying animal movements is necessary for answering a wide array of research questions in ecology and conservation biology. Consequently, ecologists have made considerable efforts to identify the best way to estimate an animal’s home range, and many methods of estimating home ranges have arisen over the past half century. Most of these methods...

BatLife Europe launched as an international non-governmental organisation, formed from a partnership of national bat conservation NGOs from across Europe and its bordering countries. This poster sets out what the organisation wants to achieve and how it works.

Aim: Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with de...

Different bat species are known to differ in their detectability. Having available presence-absence data from 100 randomly stratified selected 1 km² squares in the north of the Netherlands, collected during autumn 2009 and spring 2010 following Environmental Impact Assessment protocols, we calculated probabilities of occupancy and detection for ten...

A protocol for the translocation of rabbits for population recovery. We cover when to translocate, how to select source populations, how to prepare the site, and how to trap, move and release in the best way, based on research in the Netherlands and abroad.

In the European Union, all bat species are strictly protected and member states must ensure their conservation. However, if populations are genetically structured, conservation units that correspond to whole countries may be too large, putting small populations with specific conservation requirements at risk. Geoffroy's bat (Myotis emarginatus) has...

In 2021 22 pairs of White-tailed Eagles occupied a nest in or near wetlands in the Netherlands. At least 17 pairs commenced egg-laying. Eleven pairs were successful, raising a total of 15 fledglings (7x 1, 4x 2), of which eleven were colour-ringed. Four nestlings on three nests were equipped with a datalogger; one of these birds was killed by colli...

We review how different bat guilds respond to artificial light at night (ALAN) and assess how the impacts can vary according to ecological context. All studied European species respond negatively to ALAN close to roosts and drinking sites, and impacts occur across a wide range of light colours and intensities. Most bat species are sensitive to ALAN...

Humans have transformed most landscapes across the globe, forcing other species to adapt in order to persist in increasingly anthropogenic landscapes. Wide-ranging solitary species, such as wild felids, struggle particularly in such landscapes. Conservation planning and management for their long-term persistence critically depends on understanding...

Basisrapport Rode Lijst Zoogdieren 2020 Nederland Report Red List Mammals 2020 the Netherlands

Accurately quantifying species’ area requirements is a prerequisite for effective area‐based conservation. This typically involves collecting tracking data on species of interest and then conducting home‐range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on the previous w...

Achtzig Prozent der Weltbevölkerung leben derzeit unter einem lichtverschmutzten Himmel, und die Milchstraße ist für mehr als ein Drittel der Menschheit nicht mehr sichtbar. Das Tempo, in dem die Lichtverschmutzung zunimmt, ist schneller als das globale Bevölkerungswachstum und die wirtschaftliche Entwicklung. Während sich die Umweltbedingungen in...

The White-tailed Eagle bred for the first time in the Netherlands in 2006. Until 2008 breeding was restricted to the Oostvaardersplassen. From 2009 onwards other wetlands were occupied (Tab. 2). In 2018 the population had increased to 14 occupied nests (Fig. 1). Observations of colour-ringed individuals showed that the first Dutch breeding birds or...

Until recently, much conservation efforts have fo-cused on protecting bat roosting sites, most vulnerable to disturbance, exclusion or persecution. EUROBATS has already published guidance on the conservation and management of underground roosts (caves, abandoned mines, bunkers, etc.) and overground roosting sites (such as buildings of cultural heri...

Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autoc...

A recent review of the status of the Western or European polecat ( Mustela putorius ) by Croose et al. (Croose, E., J.W. Duckworth, S. Ruette, D.V. Skumatov, V.V. Kolesnikov and A.P. Saveljev. 2018. A review of the status of the Western polecat Mustela putorius : a neglected and declining species? Mammalia. 82: 550–564.) showed that the species is...

These guidelines explain how European bats respond to artifiical light at night and how the negative effects of artificial light at night can be mitigated when new street lamps are installed or when the type of lighting is changed, e.g. from conventional to energy efficient lighting schemes.

Using GPS collars, 4 reintroduced red deer Cervus elaphus were tracked during the first six months in their new habitat. We report activity over the day, habitat use, and the interaction between the individuals.

The Vijlenerbos (Limburg, Netherlands) was first colonized by the European wildcat (Felis silvestris) in late 2013. Between May 2014 and September 2015, five wildcats (3 adult males, 1 adult female, 1 juvenile male) were caught in the Vijlnerbos and tagged using GPS-collars to monitor their movements. In addition, camera traps were extensively used...

The SafeBatPaths project aimed to elucidate on the current extent of implementation of bat mitigation on roads in Europe, review the evidence of the effectiveness of the measures and needs for further knowledge, and experimentally to test one type of measure (hop-overs) in a field study. The findings were to be collated in an updated end-user guide...

Samenvatting Landgebruik en beheer In het Kempen~Broek en in twee gebieden in Zuid-Limburg, te weten de omgeving van Schweiberg/ Dal-Bissen en Cottessen, is er in het open gebied naast intensief landbouwkundig gebruik ook ruimte gecreëerd voor natuur. De landschappen bestaan uit akkers, beweide graslanden, maaigraslanden (silage), extensief begraa...

Bats are a biodiverse mammal order providing key ecosystem services such as pest suppression, pollination, and seed dispersal. Bats are also very sensitive to human actions, and significant declines in many bat populations have been recorded consequently. Many bat species find crucial roosting and foraging opportunities in European forests. Such fo...

The EU NON-NATIVE SPECIES RISK ANALYSIS – RISK ASSESSMENT TEMPLATE for Neovison vison was made as an argument to introduce this species on the EU Invasive Alien Species list. The first Union list of 37 plant and animal species was introduced in August 2016 and another 12 were added in August 2017. However, this accounts for just 3% of all IAS belie...

During autumn in the temperate zone of both the new and old world, bats of many species assemble at underground sites in a behaviour known as swarming. Autumn swarming behaviour is thought to primarily serve as a promiscuous mating system, but may also be related to the localization and assessment of hibernacula. Bats subsequently make use of the s...

Guidelines

In several west European countries, the distribution of hedgehogs Erinaceus europaeus is declining. In the UK, predation by the European badger Meles meles is considered to be the main death cause of hedgehogs. In the Netherlands, badger density is rising, which suggests the same cause for the decline. As landscape and land use largely differ betwe...

Since 2013, the number of observations of Wildcats (Felis sylvestris) in Limburg has increased. To identify potential bottlenecks in landscape or management a radiotracking study was initiated. In this article we present the preliminary results. On the 1 June 2014 a male Wildcat of about 1.5 years old was caught and fitted with a GPS radio collar....

The American mink (Neovison vison) is a north American mustelid that has been farmed for its fur in Europe since the 1920s. It has been feral in the Netherlands since 1958. This paper discusses its distribution, diet, the indications for reproduction, and whether feral animals are born in the wild or are escapees. The American mink mostly occurs in...

Monitoring data on hibernating bats were aggregated for the first time across a number of European countries. These supranational trends revealed that nine out of sixteen bat species examined increased at their hibernation sites in Europe between 1993-2011, while only one is decreasing. This is reflected in the positive trend shown by a prototype m...

Wanneer in Nederland verblijfplaatsen van vleermuizen verdwijnen door bijvoorbeeld sloop van gebouwen of kap van bomen, dan moet vaak in vervangende verblijfplaatsen worden voorzien. Daarvoor worden steeds vaker vleermuistorens en grote vleermuiskasten ingezet. Het met succes aanbieden van vervangende verblijfplaatsen vraagt echter om maatwerk. Dat...

In Dutch: In 2012 waren de aantallen ingekorven vleermuizen in zomerverblijf Lilbosch ongeveer een tiende van de aantallen in voorgaande jaren. Een deel van de dieren leek te zijn verhuisd naar Mariahoop, maar het vermoeden was dat een deel van de dieren een of meerdere andere nog niet bekende verblijven gebruikte. Om te bepalen of dit juist was w...

This project set out to support the Streamlining European Biodiversity Indicators (SEBI) process by developing a prototype indicator of European bat population trends. The methodology for the construction of the indicator was built by adapting and testing a statistical approach previously developed for birds and butterflies. Several tasks were carr...

Europe is faced with the need to tackle climate change and pollution and to find sustainable means to meet demands for energy generation. Thus the promotion of alternative methods for the production of energy such as wind power has been intensified. The low-emission production of wind energy brings benefits for the environment but on the other hand...

European bats are a species-rich group widely distributed through the range of agricultural and non-agricultural landscapes and habitats that form the wider countryside. The landscape of Europe has been and continues to be affected by intensive and varied human influences that have had widespread and sometimes devastating effects on bat populations...

Geoffroy’s bat (Myotis emarginatus) has four known breeding colonies in the Netherlands. Two of these are the known most northerly maternity roosts of the species. Both colonies have received Natura 2000 status. In order to collect ecological data needed to develop a management plan of these two sites, seven female Geoffroy’s bats from these two br...

Bat hibernacula selection depends on various spatial and nonspatial variables that differ widely between sites. However, previous studies have focused mainly on nonspatial variables. This research investigated factors that determined the abundance and species richness of hibernating bats in hibernation objects of the New Dutch Waterline, The Nether...

Het Faunafonds heeft Alterra gevraagd voorstellen te doen om de kwaliteit van de gehanteerde schattingen van populaties van zoogdieren te bestuderen en waar gewenst en waar mogelijk te verbeteren. Bijzondere aandacht wordt gevraagd voor de methode 'Integrated Population Monitoring' (IPM). De aandacht gaat hierbij uit naar ree, edelhert, wild zwijn...

Tellen van wilde hoefdieren wordt steeds belangrijker, onder andere vanwege eventuele beperking van de wildstand. Maar hoe moeten herbivoren geteld worden om een goed beeld te krijgen van de aantallen? Begrippen als precisie (herhaling van tellingen), nauwkeurigheid (geschatte waarneming t.o.v. werkelijkheid) en betrouwbaarheid (systematische foute...

Weather conditions can have a significant influence on short-term fluctuations of animal populations. In our study, which is based on time series of hunting bag records of up to 28 years from 26 counties of The Netherlands and Germany, we investigated the impact of different weather variables on annual counts of European rabbits (Oryctolagus cunicu...

http://www.zoogdiervanhetjaar.nl/sites/default/files/imce/nieuwesite/Zoogdiersoorten/Bever/downloads/VNBL_dec2012_bevers.pdf

De laatste jaren zie je het weer: afgegraasd duingrasland met veel konijnenkeutels. De terreinbeheerders zijn blij met de terugkeer van het konijn, want deze dieren zijn belangrijke hulpkrachten bij het duinbeheer. Door ziekten waren er niet veel meer van over. Het herstel is nog wankel en de mogelijkheden van terreinbeheerders om wat aan de lage s...

Sneeuw en ijs: de winter is voor veel dieren een moeilijke tijd. Zo ook voor hazen en konijnen. De weersomstandigheden kunnen een behoorlijke invloed hebben op overleving van deze dieren, maar bijvoorbeeld ook op het succes van de voortplanting. Om te achterhalen hoe dat precies werkt op populatieniveau analyseerden Heiko Rödel en Jasja Dekker bijn...

Het is alweer bijna 25 jaar geleden dat de bevers werden teruggebracht in Nederland. Het is hun goed gegaan, maar hoe zonnig ziet de toekomst er voor de bever uit? En waar moeten we als mensen rekening mee gaan houden?

Context: Wild rabbits are considered a key species in the coastal dunes of the Netherlands, but populations have collapsed as a result of viral diseases. Aim: We studied to what extent population collapse led to local extinction and whether recolonisation of empty patches in the dunes happened. Methods: We investigated occupancy dynamics using data...

Decision making by animals is likely to be influenced strongly by the behaviour of conspecifics. In this study we tested whether public information affected the foraging behaviour of common pipistrelles (Pipistrellus pipistrellus) by manipulating public information about the quality of foraging patches. Capture attempts during foraging are revealed...