Evidence for the effectiveness of controlling muskrat (Ondatra zibethicus L.) populations by trapping

Unambiguous evidence for the effectiveness of muskrat (Ondatra zibethicus L.) control in well-established populations in mainland Europe is lacking. Yet, this evidence is important given ongoing public challenges to the need for muskrat control and the expressed political aim of the European Union to eradicate invasive alien species, including the muskrat. In this study, indices of muskrat abundance based on livetrapping were compared among (i) sites at which muskrat control had been suspended for 3 years (suspended trapping), (ii) sites with ongoing control by kill trapping (ongoing trapping) and (iii) a site at which control efforts had ceased more than 8 years previously (no trapping). In the no trapping site, the muskrat abundance index was variable but consistently high, while in the ongoing trapping sites, the muskrat abundance index was consistently low. In the suspended trapping sites, the index of muskrat abundance increased from a level near that of the ongoing trapping sites to that of the no trapping sites. The findings are corroborated by population estimates based on data from robust design mark-recapture models and data from kill trapping. The results are interpreted as compelling proof for an effect of control on muskrat numbers, a basic premise of the control programme.</p

Op weg naar gestandaardiseerd onderzoek met wildcamera’s : Lokstoffen spelen belangrijke rol

Het gebruik van wildcamera’s als onderzoeksmethode heeft in de ecologischewereld de laatste tien jaar een vlucht genomen. Vaak worden daarbij geurstoffengebruikt om doelsoorten voor de camerate krijgen. Over het gebruik en effectiviteit van deze geurstoffen is nog veelonbekend. Toch zien veel onderzoekersvisolie als een van de meest effectievelokmiddelen. In de praktijk is het gebruikvan een blikje sardines gemakkelijk endaardoor uitgegroeid tot het gestandaardiseerde geurstation voor landelijkewildcamera-projecten. Maar hoe is diemethode tot stand gekomen en levert hetwel de gewenste resultaten op

Replication Data for: Evidence for the effectiveness of controlling muskrat (Ondatra zibethicus L.) populations by trapping

Data files with capture data (Excel files) and R-scripts used to process the data

Ontwikkeling van de hamsterpopulatie in Limburg : stand van zaken 2019-2020

Each year about 100 European hamsters are released in the southern part of the province of Limburg. They are part of a breeding programme with genetic material from the last five remaining populations in northwest Europe. To investigate their survival and distribution, the movements of the hamsters are tracked with transmitters and their burrows recorded. In 2019 144 burrows were found in 19 kilometre quadrants. After two months almost 45% of the hamsters were still alive. Hamsters can only live in arable fields under an adapted management regime, and are unable to survive in conventional arable fields. To conserve the European hamster, at least 25% of arable land must provide suitable conditions for their survival. At the moment this percentage has not been achieved, with the exception of several very small areas

European badger habitat requirements in the Netherlands – combining ecological niche models with neighbourhood analysis

European badger populations in the Netherlands suffered strong declines in the 1900s, becoming endangered in the 1980s. Despite mitigation actions, recovery of the population has been slow. Here, we use ecological niche modelling, relating 1515 badger sett (burrow) localities to data on topographic, groundwater table, soil type and land-cover variables, to investigate the factors defining badger habitat suitability. Niche modelling of mobile animals such as badgers is challenging, as relevant features that determine habitat suitability surrounding animal sightings or burrow locations are often unaccounted for. In this study, habitat properties of the entire home range of individuals were incorporated via neighbourhood analysis on land-cover variables. The neighbourhood analysis was applied at different spatial scales, to assess maximum model fit at the scale most representative of badger home-range area in the Netherlands, which was approximately 3.6 km2. Our results showed that marine and river clay render highly unsuitable habitat for badgers. Grassland and maize crops presence, typically reported as driving factors, had little effect on badger distribution in the Netherlands. Instead, moderate vegetation cover, remoteness from urban infrastructures and low groundwater tables resulted in optimal conditions. We conclude that food availability is not a limiting factor for badgers in the Netherlands, but rather appropriate soil conditions for sett digging and non-urban landscapes with sufficient cover for hideout determine their distribution. Our predictions indicate suitable areas that are not currently colonized. The results presented have important implications for management and conservation strategies in the Netherlands. Furthermore, we provide a useful general approach for niche modelling of mobile animals

Ecologie en beheer van droge dooradering

In deze brochure is kennis bijeengebracht over de ecologie en het beheer van planten en dieren in de droge dooradering van het cultuurlandschap

The effectiveness of bovine tuberculosis surveillance in Dutch badgers

Countries survey wildlife for bovine tuberculosis (bTB) to ensure case detection or to ascertain a high probability of freedom from bTB in wildlife. The Eurasian badger (Meles meles) is a potential bTB reservoir host. Between 2008 and 2019, 282 badgers were examined post-mortem in the context of general wildlife disease and targeted bTB surveillance programmes in the Netherlands, and no bTB cases were detected. However, it was unclear how effective this surveillance effort was to demonstrate freedom from Mycobacterium bovis infection in the badger population of ±6000 or to detect cases if present. Therefore, surveillance effectiveness was assessed using scenario tree modelling. For lack of standards for wildlife, the models were run against three assumed levels of disease in the population called design prevalence P*: 0.1%, 0.5%, and 3%. A small risk of introduction (0.015/year) was applied, because the Netherlands are officially free from bTB in cattle, with rare import of bTB-infected cattle and no bTB-infected wildlife reported along the Belgian and German borders with the Netherlands. Surveillance more readily picks up bTB presence in badgers when case detection sensitivity tends towards 100% and demonstrates freedom best when the probability of freedom tends towards 100%. For P* 0.1%, 0.5% and 3%, respectively, maximum case detection sensitivity during 2008–2019 was 8%, 35% and 94% and the probability of freedom in 2019 was 46%, 67%, and 95%. At P* = 3%, performing targeted surveillance on 300 badgers in a year would make it extremely unlikely to miss a case (case detection sensitivity > 99.9%); and if no cases are detected, the adjusted probability of freedom would then reach nearly 98.5%. Stakeholders should be made aware that at P* = 3%, one case detected implies around 3% infected badgers. Additional surveillance system components to assess bTB in wildlife and its economics are to be explored further

Daphnis et Chloé : suites de ballet nos 1 et 2 / Maurice Ravel, comp. ; orchestre de la Résidence de la Haye ; Choeur de chambre néerlandais ; Willem van Otterloo, dir.

Titre uniforme : Ravel, Maurice (1875-1937). Compositeur. [Daphnis et Chloé. O 57a (Suites. No 1)]BnF-Partenariats, Collection sonore - BelieveContient une table des matière