Habitat fragmentation and (re-)connection - a conservation concept for the wildcat in Germany

Inhalt Zusammenfassung 4 Abstract 7 Einleitung 9 Struktur der Arbeit 13 Kapitel 1: Habitat selection models for European wildcat conservation 16 Kapitel 2: Between ecological theory and planning practice: (Re-) Connection of forest patches for the wildcat in Lower Saxony, Germany 38 Kapitel 3: Effects and mitigation of the impact of roads on individual movement behaviour of wildcats 56 Kapitel 4: Effects of roads on a founder population of lynx in the biosphere reserve „Pfälzerwald-Vosges du Nord“ 74 Kapitel 5: Aktionsplan zum Schutz der Europäischen Wildkatze in Deutschland 95 Diskussion und Synthese 121 Methodische Überlegungen 121 Ergebnisse und Diskussion 126 Relevanz für den Wildkatzenschutz und Ausblick 129 Literatur (Einleitung und Diskussion) 131 Danksagung 135 Verzeichnis der eingebundenen Publikationen 137 Weitere Publikationen 138 Abbildungsverzeichnis 139 Tabellenverzeichnis 140Die derzeit schon starke und weiter zunehmende Fragmentierung und Zerschneidung der Landschaft in Mitteleuropa stellt ein Problem für die sich langsam erholenden Bestände der größeren Wildtiere dar. Ein Beispiel ist die Europäische Wildkatze (Felis silvestris, Schreber 1777). In dieser Arbeit wurde untersucht, wo noch geeigneter Lebensraum für die Wildkatze in Deutschland vorhanden ist, wie dieser vernetzt werden kann, wo und welche Konflikte mit Straßen entstehen und wie diese gelöst werden können. Außerdem sollten die vordringlichsten Ziele im Wildkatzenschutz identifiziert werden. Es wurden 13 000 Lokalisationen von 12 telemetrierten Wildkatzen und fein aufgelöste Landschaftsdaten aus Rheinland-Pfalz verwendet, um ein Habitatmodell auf der Basis von Habitatnutzung und –verfügbarkeit zu konzipieren. Mit Telemetriedaten von weiteren 19 Wildkatzen aus unterschiedlichen Gebieten wurde das Modell überprüft. Das ausgewählte Modell zeigte positive Korrelationen von Wildkatzenhabitatnutzung mit der Nähe zu Wald, Wiesen und linearen Gewässern und negative Korrelationen mit der Nähe zu Straßen, Dörfern und Einzelhäusern. Mit dem Modell können geeignete Wildkatzengebiete z.B. für Rheinland-Pfalz und Niedersachsen erfolgreich vorhergesagt werden. Mit der Least-Cost-Path-Methode wurden Korridore auf der Grundlage des Habitatmodells zwischen geeigneten Lebensräumen in Niedersachsen berechnet. Das fertige Korridormodell zeigt die günstigsten Verbindungen zwischen Lebensräumen, in denen Vernetzungsmaßnahmen gebündelt werden könnten. Um die Auswirkung von Konflikten von Wildkatzen und anderen Wildtieren mit Straßenverkehr zu beurteilen, wurden die Telemetriedaten von 12 Wildkatzen und Schneespuren während und nach dem Bau einer neuen Autobahn in Bezug auf Barriereeffekte ausgewertet. Wildkatzen passten ihr räumliches wie zeitliches Verhalten an den Straßenverkehr an. Ein wildkatzensicherer Wildschutzzaun reduzierte die Mortalität im Vergleich zu einem herkömmlichen Wildschutzzaun erheblich. Talbrücken stellten die am häufigsten genutzte Querungsmöglichkeit dar. Zusätzlich wurde ein bereits verfügbares Simulationsmodell für den Luchs (Lynx lynx L.) angewendet, um Auswirkungen von Straßen auf Populationsebene zu erkunden. Während eines Wildkatzensymposiums in Wiesenfelden wurden die wichtigsten Ziele für den Wildkatzenschutz und dazu geeignete Maßnahmen entwickelt. Die Ergebnisse wurden in einem Aktionsplan mit der Struktur eines „Logischen Rahmenplanes“ zusammengefasst. Diese Arbeit hat praktische Relevanz für den Wildkatzenschutz. Das Habitatmodell kann als Entscheidungsgrundlage für Artenschutzmaßnahmen in der Planungspraxis dienen. Mit den Korridoren können z.B. prioritäre Standorte für Grünbrücken identifiziert werden. Der wildkatzensichere Wildschutzzaun sollte für eine Reduktion der Straßenmortalität an entsprechend stark befahrenen Straßen regelhaft installiert werden. Mit Hilfe des Aktionsplanes können die zu erreichenden Ziele fortlaufend überprüft und die erforderlichen Maßnahmen entsprechend angepasst werden.The ongoing fragmentation of the Central European landscape is a key problem for the recovery of larger wildlife populations. One example is the European wildcat (Felis silvestris, Schreber 1777). In this thesis I examined where in Germany suitable habitat for wildcats is still present, how it could be (re-)connected, where and which conflicts arise between wildcat habitat use and road traffic and what measures might reduce them. I also identify the most urgent aims for wildcat conservation. I used 13,000 locations of 12 radio- tracked wildcats from the Eifel region in Germany and fine-scale landscape data to construct a habitat model on habitat use versus availability. The model was evaluated with data of 19 additional wildcats from two different study areas in Rhineland-Palatinate, Germany. The selected model showed a positive correlation of wildcat habitat use with proximity to forests, meadows and riverrine habitat and a negative correlation with proximity to human settlements, single houses and roads. The evaluation showed that the model is appropriate for different landscapes and could also be successfully applied to the state of Lower Saxony, Germany, as demonstrated with data on wildcat sightings and road kills. Using the least-cost-paths principle, a corridor model was developed to propose the most suitable matrix of reconnections between isolated habitat patches in Lower Saxony, Germany, on the basis of the habitat model. In order to identify conflicts with road traffic and to propose appropriate mitigation measures, I analysed snow tracks and radio-tracking data of 12 wildcats before and after a new motorway was built. Wildcats adjusted their spatial and temporal behaviour in relation to road traffic. Open span viaducts were preferred crossing structures. A wildcat-proof fence remarkably reduced wildcat mortality. Additionally, I used an existing simulation model for the lynx (Lynx lynx L.) to explore the population consequences of effects of road mortality and barrier effects in long-lived species. During an expert symposium in Wiesenfelden, Germany, the most important targets and measures for a wildcat conservation action plan were identified. The results were summarised in an action plan for the wildcat in Germany, using the method of the “logical framework” structure. This work has practical relevance for the conservation of wildcats. The habitat model can be used as a basis for decision-making for species conservation measures within the planning process. The corridor model can help to identify priority locations for wildlife overpasses. The wildcat-proof fence can be regularly installed at highly frequented roads to reduce road mortality. With the help of the action plan the goals can be evaluated and the required measures can be adjusted accordingly

Arrays of Ag split-ring resonators coupled to InGaAs single-quantum-well gain

We study arrays of silver split-ring resonators operating at around 1.5-{\mu}m wavelength coupled to an MBE-grown single 12.7-nm thin InGaAs quantum well separated only 4.8 nm from the wafer surface. The samples are held at liquid-helium temperature and are pumped by intense femtosecond optical pulses at 0.81-{\mu}m center wavelength in a pump-probe geometry. We observe much larger relative transmittance changes (up to about 8%) on the split-ring-resonator arrays as compared to the bare quantum well (not more than 1-2%). We also observe a much more rapid temporal decay component of the differential transmittance signal of 15 ps for the case of split-ring resonators coupled to the quantum well compared to the case of the bare quantum well, where we find about 0.7 ns. The latter observation is ascribed to the Purcell effect that arises from the evanescent coupling of the split-ring resonators to the quantum-well gain. All experimental results are compared with a recently introduced analytical toy model that accounts for this evanescent coupling, leading to excellent overall qualitative agreement

Evaluating the effectiveness of road mitigation measures.

The last 20 years have seen a dramatic increase in efforts to mitigate the negative effects of roads and traffic on wildlife, including fencing to prevent wildlife- vehicle collisions and wildlife crossing structures to facilitate landscape connectivity. While not necessarily explicitly articulated, the fundamental drivers behind road mitigation are human safety, animal welfare, and/or wildlife conservation. Concomitant with the increased effort to mitigate has been a focus on evaluating road mitigation. So far, research has mainly focussed on assessing the use of wildlife crossing structures, demonstrating that a broad range of species use them. However, this research has done little to address the question of the effectiveness of crossing structures, because use of a wildlife crossing structure does not necessarily equate to its effectiveness. The paucity of studies directly examining the effectiveness of crossing structures is exacerbated by the fact that such studies are often poorly designed, which limits the level of inference that can be made. Without well performed evaluations of the effectiveness of road mitigation measures, we may endanger the viability of wildlife populations and inefficiently use financial resources by installing structures that are not as effective as we think they are. In this paper we outline the essential elements of a good experimental design for such assessments and prioritize the parameters to be measured. The framework we propose will facilitate col- laboration between road agencies and scientists to undertake research programs that fully evaluate effectiveness of road mitigation measures. We discuss the added value of road mitigation evaluations for policy makers and transportation agencies and provide recom- mendations on how to incorporate such evaluations in road planning practices

Carnivores: Struggling For Survival In Roaded Landscapes

Carnivores are a diverse group of wildlife that occur in most environments around the world. Large, wide-ranging carnivores play key ecological roles in natural systems. They regulate population sizes of herbivores and other small- and medium-sized carnivores that in turn affect the growth, structure and composition of plant communities and habitats and the health of the small-animal populations that live in these habitats. Carnivores are particularly susceptible to the impacts of roads because many species require large areas to sustain their populations, have low reproductive output and occur in low densities. 1 Carnivores with large home ranges, long dispersal distances or inability to tolerate human disturbance are particularly vulnerable to the effects of roads and traffic. 2 Threats from roads and traffic such as wildlife-vehicle collisions barriers to movement, habitat disturbance and road avoidance jeopardise the persistence of certain carnivore populations. 3 Road and landscape-related features influence behavioural responses of carnivores to roads, mortality risk and barrier effects. 4 Different types of crossing structures are needed to increase habitat connectivity for the wide diversity of carnivore species. 5 Fencing, when paired with crossing structures, is critical to reducing the negative effects of roads on carnivores. The effects of roads and traffic on carnivores are well understood and vary significantly because of the diversity in their body size, movement ecology, prey selection and habitat preferences. Consequently, carnivores require a diverse suite of mitigation options, many of which have been well studied. Further research is needed to evaluate effects of roads and mitigation success in maintaining genetic integrity that supports long-term viable populations of carnivores