TY - JOUR A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the dark side BT - partial nighttime illumination affects night-and daytime foraging behavior of a small mammal JF - Frontiers in ecology and evolution N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2021.779825 SN - 2296-701X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - GEN A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the Dark Side BT - Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1231 KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544702 SN - 1866-8372 ER - TY - JOUR A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the Dark Side BT - Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal JF - Frontiers in Ecology and Evolution N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2021 U6 - https://doi.org/10.3389/fevo.2021.779825 SN - 2296-701X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - THES A1 - Hoffmann, Julia T1 - Influence of artificial light at night on the behavior of small mammals T1 - Der Einfluss von künstlicher nächtlicher Beleuchtung auf das Verhalten von Kleinsäugern N2 - Artificial light at night (ALAN), one form of human-induced rapid environmental change, is continuously spreading in space and time and increasing in intensity as part of the ongoing urbanization. A vast range of animals is known to be affected by ALAN as, among other things, it can mask natural light cues and change both the perceived as well as the actual predation risk. Since ALAN per se is restricted to the night, the majority of studies so far have focused on nocturnal species or behavioral changes during the night. How polyphasic species respond to ALAN has been largely overlooked, although they can possibly carry over effects of nighttime illumination into the day. Additionally, individuals within a species are known to consistently differ in their personality which includes risk-taking behavior. While this implies that ALAN can lead to varying anti-predatory responses in animals within a population, knowledge on this topic is still very limited. This thesis aims at investigating what initial behavioral reaction is caused by ALAN in polyphasic small mammals while also incorporating an animal’s personality. Nighttime and daytime activity, movement and foraging behavior of the bank vole (Myodes glareolus) were investigated in regards to effects of different light intensities and partial illumination in the laboratory. Additionally, changes in intra- and interspecific interactions of bank voles and striped field mice (Apodemus agrarius) subjected to ALAN were studied in experimental populations in semi-natural outdoor enclosures. Chapter I explores whether behavioral responses to ALAN of varying intensity are related to animal personality. Results showed that bank voles reduced movement and foraging already under dim light and that bold animals generally moved and foraged more than shy animals. Exclusively under bright illumination did bold animals exploit the food patches more than shy animals. The results demonstrate that bank voles are affected by light intensities prevalent in urban habitats. Additionally, certain light scenarios might lead to an advantage of and a shift towards certain personality types. Chapter II focusses on the effects of partial ALAN on foraging behavior of animals with varying animal personalities while extending the view towards possible carry-over effects of ALAN into the daytime. While bank voles reduced foraging behavior in illuminated areas at night, they increased foraging behavior in those areas at the subsequent day. Bold individuals generally had lower giving-up densities than shy individuals but this difference was especially pronounced during daytime at formerly illuminated food patches. Thus, ALAN can have carry-over effects into the daytime in polyphasic animals and thus has the potential to affect daytime intra- and interspecific interactions. Chapter III broadens the view from the individual to the population level. Experimental populations consisting of bank voles and striped field mice were established in large outdoor enclosures successively experienced natural and artificial light conditions at night. VHF telemetry data revealed that animals were predominantly active during the day under natural conditions. This difference between day and night vanished under ALAN. Additionally, conspecifics reduced home range overlap, proximity and activity synchrony while boldness was not associated with behavioral changed due to ALAN. The results suggest that ALAN has the potential to alter intraspecific interactions and thus can have fitness consequences on the population level. Overall, the present thesis shows that ALAN can affect nighttime and daytime behavior as well as intraspecific interactions of polyphasic small mammals. Differences in risk- taking behavior of individuals may vary in importance depending on other environmental variables. Thus, this thesis hopefully triggers broadening the view regarding the role of an animal’s personality in coping with ALAN and the effects on daytime behavior and diurnal species. N2 - Künstliche Beleuchtung bei Nacht ist eine Form schnell eintretender Umweltveränderung, die durch den Menschen verursacht wird. Sie breitet sich in Raum und Zeit kontinuierlich aus und nimmt, als Teil der fortschreitenden Urbanisierung, stetig an Intensität zu. Ein breites Spektrum an Tieren wird von künstlicher Beleuchtung beeinflusst, da sie unter anderem natürliche Lichtsignale maskieren und sowohl das wahrgenommene als auch das reale Prädationsrisiko verändern kann. Da künstliche Beleuchtung an sich auf die Nacht beschränkt ist, hat sich ein Großteil der bisher durchgeführten Studien auf ihre Effekte auf nachtaktive Tierarten bzw. nächtliche Verhaltensweisen beschränkt. Jedoch wurde bisher kaum untersucht, auf welche Weise Tiere mit einem polyphasischen Aktivitätsrhythmus auf künstliche Beleuchtung reagieren, obwohl sie möglicherweise Effekte von künstlicher Beleuchtung bei Nacht auf den Tag übertragen können. Zusätzlich ist bekannt, dass sich Individuen einer Art konsistent in ihrer Tierpersönlichkeit unterscheiden, welche ihr Risikoverhalten einschließt. Während dies darauf hindeutet, dass künstliche Beleuchtung bei Nacht unterschiedliche antiprädatorische Verhaltensanpassungen bei Tieren innerhalb einer Population hervorrufen kann, sind die Kenntnisse über diesen Themenkomplex bisher sehr gering. Diese Doktorarbeit hat zum Ziel, die anfänglichen Verhaltensänderungen von polyphasischen Kleinsäugern, welche durch künstliche Beleuchtung bei Nacht hervorgerufen werden, zu untersuchen. Zusätzlich wird die Persönlichkeit der Tiere berücksichtigt. Es wurden Aktivität, Bewegungsmuster und Nahrungssuchverhalten in der Nacht und am Tag von Rötelmäusen (Myodes glareolus) in Bezug auf die Effekte verschiedener Lichtintensitäten und partieller Beleuchtung bei Nacht untersucht. Während diese Versuche im Labor stattfanden, wurde zusätzlich ein Versuch in semi- natürlichen Außengehegen durchgeführt. In diesem lag der Fokus auf Veränderungen in intra- und interspezifischen Interaktionen innerhalb künstlicher Populationen bestehend aus Rötelmäusen und Brandmäusen (Apodemus agrarius), welche bei Nacht künstlicher Beleuchtung ausgesetzt waren. Kapitel I untersucht inwiefern Verhaltensänderungen aufgrund künstlicher Beleuchtung bei Nacht mit der Persönlichkeit der Tiere in Verbindung stehen. Die Ergebnisse zeigen, dass Rötelmäuse ihre Bewegung und die Nahrungssuche bereits unter schwacher nächtlicher Beleuchtung reduzierten. Risikofreudigere Tiere bewegten sich mehr und suchten häufiger nach Nahrung als weniger risikofreudige Tiere. Diese Resultate verdeutlichen, dass Rötelmäuse durch solche Lichtintensitäten beeinträchtigt werden, wie sie für urbane Habitate typisch sind. Bestimmte Lichtszenarien könnten zudem zu einem Vorteil für und eine Selektion auf bestimmte Persönlichkeitstypen führen. Kapitel II konzentriert sich auf die Effekte, welche eine partielle Beleuchtung auf das Nahrungssuchverhalten von Tieren haben kann, welche sich hinsichtlich ihrer Persönlichkeit unterscheiden. Zusätzlich wird untersucht, inwiefern künstliche Beleuchtung bei Nacht auch am Tag zu Verhaltensveränderungen führen kann. Während die Rötelmäuse bei Nacht ihre Nahrungssuche in beleuchteten Bereichen einschränkten, zeigten sie dort eine gesteigerte Nahrungssuche am folgenden Tag. Risikofreudigere Tiere beuteten die Futterstellen stärker aus als weniger risikofreudige Tiere, wobei dieser Unterschied am Tag in den ehemals beleuchteten Futterstellen besonders stark war. Somit kann künstliche Beleuchtung in der Nacht auch Effekte auf das Verhalten von polyphasischen Tieren am Tag haben. Sie hat somit das Potential am Tag vorkommende intra- und interspezifische Interaktionen zu beeinflussen. Kapitel III weitet schließlich den Blickwinkel von der Individuen- hin zur Populationsebene. Es wurden experimentelle Populationen bestehend aus Rötelmäusen und Brandmäusen in großen Außengehegen etabliert, welche zuerst natürliche Lichtbedingungen und anschließend künstliche Beleuchtung bei Nacht erfuhren. Durch die Nutzung von UKW-Telemetriedaten konnte gezeigt werden, dass die Tiere unter natürlichen Lichtbedingungen vorwiegend tagaktiv waren. Dieser Unterschied in der Aktivität zwischen Tag und Nacht verschwand bei künstlicher Beleuchtung bei Nacht. Zusätzlich reduzierten Artgenossen die Überlappung ihrer Aktionsräume, ihre Nähe zueinander und die Synchronität ihrer Aktivitätszeiten. Risikobereitschaft beeinflusste die gezeigten Verhaltensveränderungen unter künstlicher Beleuchtung bei Nacht nicht. Die Resultate deuten darauf hin, dass künstliche Beleuchtung bei Nacht intraspezifische Interaktionen beeinflussen kann und somit potentiell Konsequenzen für die Fitness auf der Populationsebene haben kann. Zusammenfassend kann diese Doktorarbeit zeigen, dass künstliche Beleuchtung bei Nacht sowohl das Verhalten bei Nacht und bei Tag als auch intraspezifische Interaktionen von polyphasischen Kleinsäugern beeinflussen kann. Wie stark Unterschiede im Risikoverhalten von Individuen eine Rolle spielen, könnte von anderen Umweltfaktoren abhängen, welche mit der künstlichen Beleuchtung interagieren. Diese Arbeit bewirkt so hoffentlich eine Erweiterung des Blickwinkels, indem zukünftig die Rolle von Tierpersönlichkeiten im Umgang mit künstlicher Beleuchtung bei Nacht und die Effekte dieser Beleuchtung auf das Verhalten am Tag sowie tagaktive Arten berücksichtigt werden. KW - light pollution KW - human-induced rapid environmental change KW - urbanization KW - movement KW - activity KW - Lichtverschmutzung KW - anthropogene Umweltveränderungen KW - Urbanisation KW - Fortbewegung KW - Aktivität Y1 - 2021 ER - TY - JOUR A1 - Schirmer, Annika A1 - Hoffmann, Julia A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - My niche BT - individual spatial niche specialization affects within- and between-species interactions JF - Proceedings of the Royal Society of London : B, Biological sciences N2 - Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species (Myodes glareolus, Apodemus agrarius). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture-mark- recapture (n = 126) and automated VHF telemetry (n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity. KW - animal personality KW - competition KW - individual niche specialization KW - movement ecology KW - coexistence KW - small mammals Y1 - 2020 U6 - https://doi.org/10.1098/rspb.2019.2211 SN - 0962-8452 SN - 1471-2954 VL - 287 IS - 1918 PB - Royal Society CY - London ER - TY - JOUR A1 - Hoffmann, Julia A1 - Schirmer, Annika A1 - Eccard, Jana T1 - Light pollution affects space use and interaction of two small mammal species irrespective of personality JF - BMC Ecology N2 - Background: Artificial light at night (ALAN) is one form of human-induced rapid environmental changes (HIREC) and is strongly interfering with natural dark–light cycles. Some personality types within a species might be better suited to cope with environmental change and therefore might be selected upon under ongoing urbanization. Results: We used LED street lamps in a large outdoor enclosure to experimentally investigate the effects of ALAN on activity patterns, movement and interaction of individuals of two species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius). We analyzed effects combined with individual boldness score. Both species reduced their activity budget during daylight hours. While under natural light conditions home ranges were larger during daylight than during nighttime, this difference vanished under ALAN. Conspecifics showed reduced home range overlap, proximity and activity synchrony when subjected to nighttime illumination. Changes in movement patterns in reaction to ALAN were not associated with differences in boldness score of individuals. Conclusions: Our results suggest that light pollution can lead to changes in movement patterns and individual interactions in small mammals. This could lead to fitness consequences on the population level. KW - Nighttime illumination KW - Rodents KW - Outdoor enclosure KW - Animal personality KW - Interspecific interactions KW - HIREC Y1 - 2019 U6 - https://doi.org/10.1186/s12898-019-0241-0 SN - 1472-6785 VL - 19 PB - BioMed Central CY - London ER - TY - GEN A1 - Hoffmann, Julia A1 - Schirmer, Annika A1 - Eccard, Jana T1 - Light pollution affects space use and interaction of two small mammal species irrespective of personality T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Background: Artificial light at night (ALAN) is one form of human-induced rapid environmental changes (HIREC) and is strongly interfering with natural dark–light cycles. Some personality types within a species might be better suited to cope with environmental change and therefore might be selected upon under ongoing urbanization. Results: We used LED street lamps in a large outdoor enclosure to experimentally investigate the effects of ALAN on activity patterns, movement and interaction of individuals of two species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius). We analyzed effects combined with individual boldness score. Both species reduced their activity budget during daylight hours. While under natural light conditions home ranges were larger during daylight than during nighttime, this difference vanished under ALAN. Conspecifics showed reduced home range overlap, proximity and activity synchrony when subjected to nighttime illumination. Changes in movement patterns in reaction to ALAN were not associated with differences in boldness score of individuals. Conclusions: Our results suggest that light pollution can lead to changes in movement patterns and individual interactions in small mammals. This could lead to fitness consequences on the population level. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 749 KW - Nighttime illumination KW - Rodents KW - Outdoor enclosure KW - Animal personality KW - Interspecific interactions KW - HIREC Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436307 SN - 1866-8372 IS - 749 ER - TY - JOUR A1 - Eccard, Jana A1 - Scheffler, Ingo A1 - Franke, Steffen A1 - Hoffmann, Julia T1 - Off-grid BT - solar powered LED illumination impacts epigeal arthropods JF - Insect conservation and diversity N2 - 1. Advances in LED technology combined with solar, storable energy bring light to places remote from electricity grids. Worldwide more than 1.3 billion of people are living off-grid, often in developing regions of high insect biodiversity. In developed countries, dark refuges for wildlife are threatened by ornamental garden lights. Solar powered LEDs (SPLEDs) are cheaply available, dim, and often used to illuminate foot paths, but little is known on their effects on ground living (epigeal) arthropods. 2. We used off-the-shelf garden lamps with a single ‘white’ LED (colour temperature 7250 K) to experimentally investigate effects on attraction and nocturnal activity of ground beetles (Carabidae). 3. We found two disparate and species-specific effects of SPLEDs. (i) Some nocturnal, phototactic species were not reducing activity under illumination and were strongly attracted to lamps (>20-fold increase in captures compared to dark controls). Such species aggregate in lit areas and SPLEDs may become ecological traps, while the species is drawn from nearby, unlit assemblages. (ii) Other nocturnal species were reducing mobility and activity under illumination without being attracted to light, which may cause fitness reduction in lit areas. 4. Both reactions offer mechanistic explanations on how outdoor illumination can change population densities of specific predatory arthropods, which may have cascading effects on epigeal arthropod assemblages. The technology may thus increase the area of artificial light at night (ALAN) impacting insect biodiversity. 5. Measures are needed to mitigate effects, such as adjustment of light colour temperature and automated switch-offs. KW - Artificial light at night (ALAN) KW - Carabidae KW - illuminance KW - light pollution KW - light spectrum KW - nocturnal epigeal insect KW - phototaxis KW - solar powered light-emitting diode KW - spectral irradiance KW - white light Y1 - 2018 U6 - https://doi.org/10.1111/icad.12303 SN - 1752-458X SN - 1752-4598 VL - 11 IS - 6 SP - 600 EP - 607 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hoffmann, Julia A1 - Palme, Rupert A1 - Eccard, Jana T1 - Long-term dim light during nighttime changes activity patterns and space use in experimental small mammal populations JF - Environmental pollution N2 - Artificial light at night (ALAN) is spreading worldwide and thereby is increasingly interfering with natural dark-light cycles. Meanwhile, effects of very low intensities of light pollution on animals have rarely been investigated. We explored the effects of low intensity ALAN over seven months in eight experimental bank vole (Myodes glareolus) populations in large grassland enclosures over winter and early breeding season, using LED garden lamps. initial populations consisted of eight individuals (32 animals per hectare) in enclosures with or without ALAN. We found that bank voles under ALAN experienced changes in daily activity patterns and space use behavior, measured by automated radio telemetry. There were no differences in survival and body mass, measured with live trapping, and none in levels of fecal glucocorticoid metabolites. Voles in the ALAN treatment showed higher activity at night during half moon, and had larger day ranges during new moon. Thus, even low levels of light pollution as experienced in remote areas or by sky glow can lead to changes in animal behavior and could have consequences for species interactions. (C) 2018 Elsevier Ltd. All rights reserved. KW - Myodes glareolus KW - Light pollution KW - Chronic stress KW - Survival success KW - Artificial light KW - LED Y1 - 2018 U6 - https://doi.org/10.1016/j.envpol.2018.03.107 SN - 0269-7491 SN - 1873-6424 VL - 238 SP - 844 EP - 851 PB - Elsevier CY - Oxford ER -