Ganzenoverlast, perceptie en oplossingen

Overwinterende ganzen trekken in het beleid veel aandacht. Met name in denoordelijke provincies houdt de toename van de brandgans (Branta leucopsis) degemoederen bezig. De provincies streven een beleid na dat overlast voor boerenen voldoen aan internationale verplichtingen in balans houdt. Zij hechten sterkaan draagvlak en overleggen intensief met alle betrokkenen (agrariërs, jagers,terreinbeheerders, natuurbeschermers). Over het algemeen blijken de ideeën over effectieve reductie van schade sterk uiteen te lopen bij verschillende belangengroepen. Agrariërs hebben weinig fiducie in de werking van opvanggebieden. Ecologen stellen dat populatiereductie door afschot niet tot evenredige schadereductie leidt. Hoe hier verder te komen

Raptor research during the COVID-19 pandemic provides invaluable opportunities for conservation biology

Authors acknowledge financial support from: the Dean Amadon Grant of the Raptor Research Foundation (to PS); the Raptor Research and Conservation Foundation, Mumbai, and the University of Oxford's Global Challenges Research Fund through the Ind-Ox initiative (KCD00141-AT13.01) (both to NK), and the Gordon and Betty Moore Foundation (GBMF9881) and the National Geographic Society (NGS-82515R-20) (both to CR).Research is underway around the world to examine how a wide range of animal species have responded to reduced levels of human activity during the COVID-19 pandemic. In this perspective article, we argue that raptors are particularly well-suited for investigating potential ‘anthropause’ effects, and that the resulting insights will provide much-needed impetus for global conservation efforts. Lockdowns likely alter many of the extrinsic factors that normally limit raptor populations. These environmental changes are in turn expected to influence – mediated by behavioral and physiological responses – the intrinsic (demographic) factors that ultimately determine raptor population levels and distributions. Using this framework, we identify a range of research opportunities and conservation challenges that have arisen during the pandemic. The COVID-19 anthropause allows raptor researchers to address fundamental and applied research objectives in a large-scale, quasi-experimental, well-replicated manner. Importantly, it will be possible to separate the effects of human disturbance and anthropogenic landscape modifications. We explain how high-quality datasets, accumulated for a diverse range of raptor species before, during, and after COVID-19 lockdowns, can be leveraged for powerful comparative analyses that attempt to identify drivers of particular response types. To facilitate and coordinate global collaboration, we are hereby launching the ‘Global Anthropause Raptor Research Network’ (GARRN). We invite the international raptor research community to join this inclusive and diverse group, to tackle ambitious analyses across geographic regions, ecosystems, species, and gradients of lockdown perturbation. Under the most tragic of circumstances, the COVID-19 anthropause has afforded an invaluable opportunity to significantly boost global raptor conservation.Publisher PDFPeer reviewe

The status of cheetah and African wild dog in the Benoue Ecosystem, North Cameroon

Conservation Biology - ol

Using Simulation Models to Evaluate Ape Nest Survey Techniques

BACKGROUND: Conservationists frequently use nest count surveys to estimate great ape population densities, yet the accuracy and precision of the resulting estimates are difficult to assess. METHODOLOGY/PRINCIPAL FINDINGS: We used mathematical simulations to model nest building behavior in an orangutan population to compare the quality of the population size estimates produced by two of the commonly used nest count methods, the 'marked recount method' and the 'matrix method.' We found that when observers missed even small proportions of nests in the first survey, the marked recount method produced large overestimates of the population size. Regardless of observer reliability, the matrix method produced substantial overestimates of the population size when surveying effort was low. With high observer reliability, both methods required surveying approximately 0.26% of the study area (0.26 km(2) out of 100 km(2) in this simulation) to achieve an accurate estimate of population size; at or above this sampling effort both methods produced estimates within 33% of the true population size 50% of the time. Both methods showed diminishing returns at survey efforts above 0.26% of the study area. The use of published nest decay estimates derived from other sites resulted in widely varying population size estimates that spanned nearly an entire order of magnitude. The marked recount method proved much better at detecting population declines, detecting 5% declines nearly 80% of the time even in the first year of decline. CONCLUSIONS/SIGNIFICANCE: These results highlight the fact that neither nest surveying method produces highly reliable population size estimates with any reasonable surveying effort, though either method could be used to obtain a gross population size estimate in an area. Conservation managers should determine if the quality of these estimates are worth the money and effort required to produce them, and should generally limit surveying effort to 0.26% of the study area, unless specific management goals require more intensive sampling. Using site- and time- specific nest decay rates (or the marked recount method) are essential for accurate population size estimation. Marked recount survey methods with sufficient sampling effort hold promise for detecting population declines

Nieuw stelsel agrarisch natuurbeheer : criteria voor leefgebieden en beheertypen

In het nieuwe stelsel Agrarisch Natuur en Landschapsbeheer (ANLb-2016) worden vier agrarisch leefgebieden onderscheiden en daarbinnen 10 beheertypen. Deze eenheden vormen de basiseenheden van het stelsel waarvan het beheer in zogenaamde gebiedsplannen zal worden uitgewerkt. Voor deze eenheden zijn op basis van ecologische kennis kwalitatieve en kwantitatieve criteria uitgewerkt. De criteria zijn bedoeld als hulpmiddel voor het opstellen en beoordelen van gebiedsplannen. De soortenfiches, soortenmaatregelen en de eerder genoemde leefgebiedenbeschrijving, opgesteld door Wouter van Heusden, zijn gebruikt als uitgangspunt

Priority areas for vulture conservation in the Horn of Africa largely fall outside the protected area network

Vulture populations are in severe decline across Africa and prioritization of geographic areas for their conservation is urgently needed. To do so, we compiled three independent datasets on vulture occurrence from road-surveys, GPS-tracking, and citizen science (eBird), and used maximum entropy to build ensemble species distribution models (SDMs). We then identified spatial vulture conservation priorities in Ethiopia, a stronghold for vultures in Africa, while accounting for uncertainty in our predictions. We were able to build robust distribution models for five vulture species across the entirety of Ethiopia, including three Critically Endangered, one Endangered, and one Near Threatened species. We show that priorities occur in the highlands of Ethiopia, which provide particularly important habitat for Bearded Gypaetus barbatus, Hooded Necrosyrtes monachus, Ruppell's Gyps ruppelli and White-backed Gyps africanus Vultures, as well as the lowlands of north-eastern Ethiopia, which are particularly valuable for the Egyptian Vulture Neophron percnopterus. One-third of the core distribution of the Egyptian Vulture was protected, followed by the White-backed Vulture at one-sixth, and all other species at one-tenth. Overall, only about one-fifth of vulture priority areas were protected. Given that there is limited protection of priority areas and that vultures range widely, we argue that measures of broad spatial and legislative scope will be necessary to address drivers of vulture declines, including poisoning, energy infrastructure, and climate change, while considering the local social context and aiding sustainable development.Peer reviewe