@article{HoffmannHoelkerEccard2022, author = {Hoffmann, Julia and H{\"o}lker, Franz and Eccard, Jana}, title = {Welcome to the dark side}, series = {Frontiers in ecology and evolution}, volume = {9}, journal = {Frontiers in ecology and evolution}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-701X}, doi = {10.3389/fevo.2021.779825}, pages = {11}, year = {2022}, abstract = {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.}, language = {en} } @article{HoffmannHoelkerEccard2022, author = {Hoffmann, Julia and H{\"o}lker, Franz and Eccard, Jana}, title = {Welcome to the Dark Side}, series = {Frontiers in Ecology and Evolution}, volume = {9}, journal = {Frontiers in Ecology and Evolution}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-701X}, doi = {10.3389/fevo.2021.779825}, pages = {11}, year = {2022}, abstract = {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.}, language = {en} } @article{EccardSchefflerFrankeetal.2018, author = {Eccard, Jana and Scheffler, Ingo and Franke, Steffen and Hoffmann, Julia}, title = {Off-grid}, series = {Insect conservation and diversity}, volume = {11}, journal = {Insect conservation and diversity}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {1752-458X}, doi = {10.1111/icad.12303}, pages = {600 -- 607}, year = {2018}, abstract = {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.}, language = {en} } @article{SchirmerHoffmannEccardetal.2020, author = {Schirmer, Annika and Hoffmann, Julia and Eccard, Jana and Dammhahn, Melanie}, title = {My niche}, series = {Proceedings of the Royal Society of London : B, Biological sciences}, volume = {287}, journal = {Proceedings of the Royal Society of London : B, Biological sciences}, number = {1918}, publisher = {Royal Society}, address = {London}, issn = {0962-8452}, doi = {10.1098/rspb.2019.2211}, pages = {9}, year = {2020}, abstract = {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.}, language = {en} } @article{HoffmannPalmeEccard2018, author = {Hoffmann, Julia and Palme, Rupert and Eccard, Jana}, title = {Long-term dim light during nighttime changes activity patterns and space use in experimental small mammal populations}, series = {Environmental pollution}, volume = {238}, journal = {Environmental pollution}, publisher = {Elsevier}, address = {Oxford}, issn = {0269-7491}, doi = {10.1016/j.envpol.2018.03.107}, pages = {844 -- 851}, year = {2018}, abstract = {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.}, language = {en} } @article{HoffmannSchirmerEccard2019, author = {Hoffmann, Julia and Schirmer, Annika and Eccard, Jana}, title = {Light pollution affects space use and interaction of two small mammal species irrespective of personality}, series = {BMC Ecology}, volume = {19}, journal = {BMC Ecology}, publisher = {BioMed Central}, address = {London}, issn = {1472-6785}, doi = {10.1186/s12898-019-0241-0}, pages = {11}, year = {2019}, abstract = {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.}, language = {en} }