TY - JOUR A1 - Heim, Olga A1 - Lenski, Johannes A1 - Schulze, Jelena A1 - Jung, Kirsten A1 - Kramer-Schadt, Stephanie A1 - Eccard, Jana A1 - Voigt, Christian C. T1 - The relevance of vegetation structures and small water bodies for bats foraging above farmland JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Bats are known to forage and commute close to vegetation structures when moving across the agricultural matrix, but the role of isolated landscape elements in arable fields for bat activity is unknown. Therefore, we investigated the influence of small isolated ponds which lie within arable fields close to vegetation structures on the flight and foraging activity of bats. Additionally, we compared species-specific activity measures between forest edges and linear structures such as hedgerows. We repeatedly recorded bat activity using passive acoustic monitoring along 20 transects extending from the vegetation edge up to 200 m into the arable field (hereafter: edge-field interface) with a small pond present at five transects per edge type (linear vs. forest). Using generalized linear mixed effect models, we analyzed the effects of edge type, pond presence and the season on species-specific flight and foraging activity within the edge-field interface. We found a higher flight activity of Nyctalus noctula and Pipistrellus pygmaeus above the arable field when a pond was present. Furthermore, Pipistrellus nathusii and Pipistrellus pipistrellus foraged more frequently at forest edges than at linear structures (e.g. hedgerows). Additionally, we found three major patterns of seasonal variation in the activity of bats along the edge-field interface. This study highlights the species-specific and dynamic use of forest and hedgerow or tree line edges by bats and their importance for different bat species in the agricultural landscape. Further, additional landscape elements such as small isolated ponds within arable fields might support the activity of bats above the open agricultural landscape, thereby facilitating agroecosystem functioning. Therefore, additional landscape elements within managed areas should be restored and protected against the conversion into arable land and better linked to surrounding landscape elements in order to efficiently support bats within the agroecosystem. KW - Hedgerow KW - Forest edge KW - Pond KW - European bats KW - Agricultural landscape KW - Wind turbines Y1 - 2017 U6 - https://doi.org/10.1016/j.baae.2017.12.001 SN - 1439-1791 SN - 1618-0089 VL - 27 SP - 9 EP - 19 PB - Elsevier GMBH CY - München ER - TY - JOUR A1 - Heim, D. M. A1 - Heim, Olga A1 - Zeng, P. A. A1 - Zheng, Jeffrey T1 - Successful Creation of Regular Patterns in Variant Maps from Bat Echolocation Calls JF - Variant Construction from Theoretical Foundation to Applications N2 - We created variant maps based on bat echolocation call recordings and outline here the transformation process and describe the resulting visual features. The maps show regular patterns while characteristic features change when bat call recording properties change. By focusing on specific visual features, we found a set of projection parameters which allowed us to classify the variant maps into two distinct groups. These results are promising indicators that variant maps can be used as basis for new echolocation call classification algorithms. KW - Echolocation KW - Algorithms KW - Morphometry KW - Fourier KW - Analysis KW - Quaternions Y1 - 2019 SN - 978-981-13-2282-2 SN - 978-981-13-2281-5 U6 - https://doi.org/10.1007/978-981-13-2282-2_25 SP - 391 EP - 400 PB - Springer CY - Singapore ER - TY - JOUR A1 - Heim, Olga A1 - Puisto, Anna I. E. A1 - Fukui, Dai A1 - Vesterinen, Eero J. T1 - Molecular evidence of bird-eating behavior in Nyctalus aviator JF - Acta ethologica N2 - Insectivorous bats consume a large variety of food items. Previous observations of feathers found in feces led to the hypothesis that the birdlike noctule (Nyctalus aviator, Vespertilionidae) could prey on birds. To test the hypothesis, we analyzed fecal samples from six species (Barbastella pacifica, Murina hilgendorfi, Myotis frater, N. aviator, Plecotus sacrimontis, and Vespertilio sinensis) collected from central Hokkaido, Japan, via DNA barcoding. We identified the presence of the Middendorff’s grasshopper warbler (Locustella ochotensis) in the diet of a pregnant individual of N. aviator. All the other samples proved negative regarding bird prey DNA. This is the first time that the consumption of a bird by N. aviator is confirmed with molecular evidence. Our findings add invaluable insight into the diet of this bat and its potentially opportunistic foraging behavior. KW - Nyctalus aviator KW - Locustella ochotensis KW - Bird prey KW - DNA barcoding KW - Sanger sequencing Y1 - 2019 U6 - https://doi.org/10.1007/s10211-019-00319-5 SN - 0873-9749 SN - 1437-9546 VL - 22 IS - 3 SP - 223 EP - 226 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Heim, Olga A1 - Schröder, Assja A1 - Eccard, Jana A1 - Jung, Kirsten A1 - Voigt, Christian C. T1 - Seasonal activity patterns of European bats above intensively used farmland JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters N2 - Bats are top insect predators on farmland, yet they suffer from intensive farmland management. Here, we evaluated the seasonal activity patterns of European bats above large, arable fields and compared these patterns between ecologically distinct bat species. Using repeated passive acoustic monitoring on a total of 93 arable fields in 2 years in Brandenburg, Germany, we surveyed the activity of different bat species between early spring and autumn. We then used generalized additive mixed models to describe and compare the seasonal bat activity patterns between bat categories, which were build based on the affiliation to a functional group and migratory class, while controlling for local weather conditions. In general, the affiliation to a bat category in interaction with the season in addition to cloud cover and ambient air temperature explained a major part of bat activity. The season was also an important factor for the foraging activity of open-space specialists such as Nyctalus noctula but showed only a weak effect on species such as Pipistreilus nathusii which are adapted to edge-space habitats. Across the seasons, habitat use intensity was high during the period of swarming and migration and low during the energy demanding period of lactation. Seasonal patterns in foraging activity showed that open-space specialists foraged more intensively above agricultural fields during the migration period, while edge-space specialists foraged also during the energy demanding period of lactation. We conclude that the significant seasonal fluctuations in bat activity and significant differences between bat categories in open agricultural landscapes should be taken into consideration when designing monitoring schemes and management plans for bat species in regions dominated by agriculture. Also, management plans should be directed to improve the conditions on arable land especially for bat species which would be classified as narrow-space foragers such as Myotis species. (C) 2016 Elsevier B.V. All rights reserved. KW - Agricultural intensification KW - Seasonality KW - European bat species KW - Functional bat group KW - Migration KW - AgroScapeLabs Y1 - 2016 U6 - https://doi.org/10.1016/j.agee.2016.09.002 SN - 0167-8809 SN - 1873-2305 VL - 233 SP - 130 EP - 139 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Heim, Olga A1 - Lorenz, Lukas A1 - Kramer-Schadt, Stephanie A1 - Jung, Kirsten A1 - Voigt, Christian C. A1 - Eccard, Jana T1 - Landscape and scale-dependent spatial niches of bats foraging above intensively used arable fields T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Introduction Bats are threatened by agricultural intensification, and although bat ecology in agricultural landscapes is in the focus of current research, the effects of interacting spatiotemporal factors on species-specific bat activity above farmland remain understudied. Our aim was to identify spatiotemporal factors and their interactions relevant for the activity of bat species above conventionally managed arable fields. Methods We repeatedly monitored relative bat activity above open arable fields in Germany using acoustic monitoring. We used site-related biotic and abiotic factors and landscape characteristics across five spatial scales, their combinations, and interactions to identify those factors which best explain variation in bat activity. Results Numerous interactions between landscape characteristics and the insect abundance affected bat activity above fields. For instance, Pipistrellus pipistrellus became more active with increasing insect abundance, but only above fields with a low proportion of woody vegetation cover in the surroundings. Additionally, the level of bat activity in summer depended on landscape characteristics. For example, the activity of Pipistrellus nathusii was relatively low in summer above fields that were surrounded by vegetation patches with a high degree of edge complexity (e.g., hedgerow). However, the activity remained at a relatively high level and did not differ between seasons above fields that were surrounded by vegetation patches with a low degree of edge complexity (e.g., roundly shaped forest patch). Conclusions Our results revealed that landscape characteristics and their interactions with insect abundance affected bat activity above conventionally managed fields and highlighted the opportunistic foraging behavior of bats. To improve the conditions for bats in agricultural landscapes, we recommend re-establishing landscape heterogeneity to protect aquatic habitats and to increase arthropod availability. KW - AgroScapeLabs KW - european bat species KW - agriculture KW - landscape KW - multi-scale habitat modeling KW - ecosystem service KW - conservation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428166 IS - 826 ER - TY - THES A1 - Heim, Olga T1 - Spatiotemporal effects on bat activity above intensively managed farmland N2 - Intakte und widerstandsfähige Ökosysteme sind essenziell für die Aufrechterhaltung optimaler Lebensbedingungen für das Leben auf der Erde. Die Basis für solche Ökosysteme bilden intakte ökologische Wechselwirkungen zwischen einer Vielzahl von Arten. Durch den beispiellosen Verlust der Biodiversität, welcher durch die in der zweiten Hälfte des 20. Jahrhunderts zunehmende Intensivierung der Agrarwirtschaft und die Zerstörung und Fragmentierung von Habitaten hervorgerufen wurde, können ökologische Wechselwirkungen und damit die Funktionsfähigkeit von Agrarökosystemen stark eingeschränkt werden. Um den Rückgang der Biodiversität in Agrarökosystemen abschwächen zu können, müssen wir die ökologischen Wechselwirkungen in Agrarökosystemen besser verstehen. Hierbei spielen Fledermäuse eine besondere Rolle, weil sie verschiedenste ökologische Nischen besetzen und eine Reihe von Ökosystemleistungen erfüllen so wie z.B. die Kontrolle von Schädlingspopulationen in Agrarlandschaften. Überdies trägt die Ordnung der Fledermäuse (Chiroptera) beträchtlich zur globalen Diversität der Säugetiere bei. Obwohl viele Fledermauspopulationen durch die Intensivierung der Agrarwirtschaft dezimiert wurden, ist noch relativ wenig darüber bekannt wie unterschiedliche Fledermausarten die offene Agrarlandschaft nutzen. Dieses Wissen ist jedoch essenziell für den Schutz von Fledermausarten in intensiv bewirtschafteten Agrarlandschaften und dringend notwendig besonders vor dem Hintergrund der vorhergesagten erweiterten Ausweitung der intensiven Agrarwirtschaft. Zusätzlich werden Fledermäuse durch den zuletzt massiven Ausbau von Windkraftanlagen, welche für viele Vogel- und Fledermausarten ein erhöhtes Tötungsrisiko darstellen, bedroht. Das Ziel dieser Dissertation war es deshalb, die Einflüsse ausgewählter raum-zeitlicher Faktoren auf die artspezifische Fledermausaktivität über intensiv genutzten Agrarflächen in einer von Agrarwirtschaft dominierten Landschaft zu untersuchen. Dazu habe ich die Fledermausaktivität mittels passiver akustischer Echoortungsaufnahme in den Jahren 2012 bis 2014 auf insgesamt 113 Untersuchungsflächen in offenen Ackerflächen im Nordosten Brandenburgs erfasst. Die Echoortungsrufe in etwa 27.779 Aufnahmen habe ich manuell bis auf die Art bestimmt und die berechneten artspezifischen Aktivitätsparameter mit Hilfe von komplexen statistischen Verfahren untersucht. Im ersten Kapitel dieser Arbeit, habe ich die berechneten Aktivitätsparameter von ökologisch unterschiedlichen Fledermausgruppen auf saisonale Muster hin untersucht. Dabei war ich besonders an Unterschieden zu den bekannten saisonalen Aktivitätsmustern in naturnahen Habitaten interessiert. Im zweiten Kapitel dieser Arbeit, habe ich den Einfluss von linearen Gehölzstrukturen am Feldrand und von kleinen Wasserflächen (Söllen) innerhalb von Ackerflächen auf die Flug- und Jagdaktivität verschiedener Fledermausarten über diesen Flächen untersucht. Zusätzlich war ich daran interessiert, ob sich etwaige Effekte dieser Landschaftselemente auf die Fledermausaktivität im Laufe des Jahres verändern. Im dritten Kapitel dieser Arbeit war es mein Ziel den Zusammenhang zwischen unterschiedlichen räumlichen und zeitlichen Einflüssen auf die artspezifische Fledermausaktivität über offenen Agrarflächen zu untersuchen. Dabei habe ich meine Untersuchungen auf Faktoren fokussiert, die dafür bekannt sind Fledermausaktivität zu beeinflussen, wie z.B. Faktoren auf kleinräumiger Skala, die mit der Beuteverfügbarkeit zusammenhängen, und verschiedene Landschaftscharakteristika auf großräumiger Skala. Auf der zeitlichen Skala, habe ich mich auf den Einfluss der Saison konzentriert. Zusammenfassend heben die Ergebnisse dieser Arbeit die Wichtigkeit naturnaher Landschaftselemente für die Fledermausaktivität über Agrarflächen hervor. Allerdings war nicht nur die Landschaftsstruktur für die Fledermausaktivität über Ackerflächen ausschlaggebend, sondern auch der Einfluss von interaktiven Effekten zwischen z.B. Landschaftscharakteristika und der lokalen Beuteverfügbarkeit. Ein weiteres Kernergebnis ist die saisonale Variabilität des Einflusses der Landschaftsstruktur auf die Fledermausaktivität. Hierbei hatten bestimmte Landschaftselemente vor allem im Sommer einen großen Einfluss auf die Fledermausaktivität. Das Potenzial der Ökosystemleistung durch spezifische Fledermausarten, welches wiederholt in den unterschiedlichen Kapiteln hervorgehoben wurde, ist ein weiteres Kernergebnis. Da die Fledermausaktivität jedoch stark von der Landschaftsstruktur in der Umgebung abhängt, ist es wichtig diese fledermausfreundlich zu gestalten, um die Ökosystemleistung der Schädlingskontrolle über Agrarflächen nutzen zu können. Schlussendlich trägt diese Arbeit in ihrer Gesamtheit zum bestehenden Wissen über die Fledermausbiologie und -ökologie bei und verdeutlicht die komplexen Wechselwirkungen unterschiedlicher Einflüsse auf mehreren raum-zeitlichen Ebenen. Die Ergebnisse dieser Arbeit können als Basis zur Verbesserung und Entwicklung von Schutzmaßnahmen für Fledermäuse in intensiv genutzten Agrarlandschaften dienen. Da Fledermäuse als gute Bioindikatoren gelten, können effektive Schutzmaßnahmen für Fledermäuse auch zum Schutz anderer Arten beitragen und damit potenziell den weiteren Verlust der Biodiversität in Agrarlandschaften abschwächen. N2 - Biodiversity and intact ecological interactions form the basis for functional and resilient ecosystems that maintain optimal conditions for life on earth. During the second half of the 20th century, especially land-use changes and an intensification of agricultural management caused an unprecedented loss of biodiversity in agroecosystems worldwide. Concerns have been raised that the ongoing loss of biodiversity would ultimately lead to impaired ecological interactions and ecosystem functioning in agricultural landscapes. In order to stop biodiversity loss while producing enough food for a growing world population, we need to gain detailed knowledge on ecological interactions and the functioning of agroecosystems as a whole. Bats (Chiroptera) represent an important component of global biodiversity, occupy a variety of ecological niches and fulfill numerous ecosystem services. Especially in temperate zone agroecosystems, bats were repeatedly reported to contribute to the reduction of pest insects above intensively managed arable fields. However, bat populations have been decimated by the consequence of land-use intensification which led to their legal protection status in the European Union (Council of Europe, 1979). The increasing number of wind turbines on arable fields poses an additional threat to bats as they might get injured or killed when flying too close to wind turbine blades. Although a large amount of land area is covered by arable fields, not much is known about how bats use the intensively managed agricultural landscape. In the present thesis, my general aim was to identify the relevance of factors at different spatiotemporal scales for shaping species-specific bat activity above intensively managed arable fields. Therefore, I repeatedly monitored bat activity above open arable fields in a landscape dominated by agriculture which is located in Northeast Brandenburg, Germany. From 2012 to 2014, I recorded echolocation calls of bats on a total of 113 sites using a passive acoustic approach. I obtained a total of 27,779 recordings, identified the recorded echolocation calls manually to species level and calculated species-specific bat activity measures. Depending on the focus of research, I modeled the obtained species-specific activity measures using generalized linear and additive mixed effect models. In Chapter I, I focused on identifying seasonal patterns in several species-specific activity measures of different functional bat groups. In Chapter II, I investigated small-scale effects of landscape elements, such as hedgerows and forest edges, on the flight and foraging activity of different bat species along the edge-field interface. Additionally, I aimed at identifying whether these effects are influenced by small ponds located within arable field and whether these effects change across seasons. In Chapter III, my aim was to investigate the interaction between factors from different spatiotemporal levels on the flight and foraging activity of bats above arable fields. At the small spatial scale, I focused on prey availability, at a large spatial scale on selected parameters which describe landscape characteristics and at the temporal scale on seasonal effects. The major findings obtained in each chapter can be summarized in the following three points. The first major finding is that not only landscape elements on a small spatial scale, e.g. a hedgerow at the edge of an arable field, but also landscape characteristics on a large spatial scale, e.g. landscape composition, shaped species-specific bat activity above open arable fields. This activity was also strongly influenced by interactions between landscape characteristics and local prey availability. Second, the influence of landscape elements and characteristics on bat activity above arable fields was not constant over time but changed across seasons with the strongest impact during summer as compared to spring and autumn. Third, I found indications of ecosystem service provided by N. noctula and P. nathusii in all three chapters, as especially these bat species were repeatedly found to forage above arable fields. This foraging activity was positively influenced by the proximity to landscape elements at the edge of the arable field but also by the presence of small ponds within the arable field. In light of the obtained findings, I strongly recommend protecting and most importantly recreating semi-natural landscape elements in the agricultural landscape. Furthermore, I strongly recommend against the construction of wind turbines close to these linear woody vegetation edges as bats were found to be active close to these landscape elements. Additionally, the operation times for wind turbines should be down-regulated during the mating and migration period in autumn due to high bat activity above arable fields. Since bats are considered being good bioindicators, effective conservation measures for bats might contribute to the protection of species from other taxa leading to an overall support of biodiversity in agricultural landscapes. In their entirety, the findings in this thesis contribute to the knowledge of different aspects of bat ecology and shed light on the complex interplay between factors from different spatiotemporal levels that shape bat activity above arable fields. Additionally, they can serve as a basis for the improvement and development of conservation measures for bats in agricultural landscapes. KW - European bats KW - Europäische Fledermausarten KW - conventional agriculture KW - konventionelle Landwirtschaft KW - landscape analysis KW - Landschaftsanalyse KW - conservation KW - Naturschutz Y1 - 2017 ER -