ORCID Profile
0000-0001-7769-0845
Current Organisation
University of Freiburg
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Publisher: Elsevier BV
Date: 11-2020
Publisher: Wiley
Date: 02-2021
DOI: 10.1111/CSP2.364
Publisher: Elsevier BV
Date: 03-2023
Publisher: Wilson Ornithological Society
Date: 09-2015
DOI: 10.1676/14-087.1
Publisher: Wiley
Date: 11-2022
DOI: 10.1002/ECE3.9492
Abstract: Prey species may display anti‐predatory behavior, i.e., flight, increased vigilance, and decreased feeding, in response to the true presence of a predator or to the implied presence of a predator through, e.g., acoustic cues. In this study, we investigated the anti‐predatory reactions of moose ( Alces alces ) to acoustic stimuli related to hunting, at saltlick stones, a known attractant. In before‐during‐after‐control‐impact experiments, we compared the behavioral responses of in iduals to: (i) two hunting‐related acoustic stimuli—hunting dog barking and human speaking (ii) nonpredatory acoustic stimuli—bird sounds and and (iii) no acoustic stimulus (control). We asked: (1) How does the probability of moose leaving the site differ depending on the stimulus they are exposed to? (2) What affect do the acoustic stimuli have on the amount of time moose spend vigilant, feeding, or away from the site? and (3) What affect do the stimuli have on the time between events at a site? We found that when exposed to the human stimulus, moose left the sites in 75% of the events, which was significantly more often compared to the dog (39%), bird (24%), or silent (11%) events. If moose did not leave the site, they spent more time vigilant, and less time feeding, particularly when exposed to a dog or human stimulus. Furthermore, moose spent the most time away from the site and took the longest to visit the site again after a human stimulus. Moose were also more likely to leave the site when exposed to the bird stimulus than during silent controls. Those that remained spent more time vigilant, but their behaviors returned to baseline after the bird stimulus ended. These findings suggest that acoustic stimuli can be used to modify the behavior of moose however, reactions towards presumably threatening and nonthreatening stimuli were not as distinct as we had expected.
Publisher: Public Library of Science (PLoS)
Date: 10-03-2021
DOI: 10.1371/JOURNAL.PONE.0247400
Abstract: Traffic disturbances (i.e. pollution, light, noise, and vibrations) often extend into the area surrounding a road creating a ‘road-effect zone’. Habitat within the road-effect zone is degraded or, in severe cases, completely unsuitable for wildlife, resulting in indirect habitat loss. This can have a disproportionate impact on wildlife in highly modified landscapes, where remaining habitat is scarce or occurs predominantly along roadside reserves. In this study, we investigated the road-effect zone for insectivorous bats in highly cleared agricultural landscapes by quantifying the change in call activity with proximity to three major freeways. The activity of seven out of 10 species of bat significantly decreased with proximity to the freeway. We defined the road-effect zone to be the proximity at which call activity declined by at least 20% relative to the maximum detected activity. The overall road-effect zone for bats in this region was 307 m, varying between 123 and 890 m for in idual species. Given that this road-effect zone exceeds the typical width of the roadside verges ( m), it is possible that much of the vegetation adjacent to freeways in this and similar landscapes provides low-quality habitat for bats. Without accounting for the road-effect zone, the amount of habitat lost or degraded due to roads is underestimated, potentially resulting in the loss of wildlife, ecosystem services and key ecosystem processes (e.g. predator-prey or plant-pollinator interactions) from the landscape. We suggest all future environmental impact assessments include quantifying the road-effect zone for sensitive wildlife, in order to best plan and mitigate the impact of roads on the environment. Mitigating the effects of new and existing roads on wildlife is essential to ensure enough high-quality habitat persists to maintain wildlife populations.
Publisher: Elsevier BV
Date: 08-2017
Publisher: Wiley
Date: 08-2023
DOI: 10.1002/ECE3.10431
Abstract: Selective browsing by deer on young trees may impede the management goal of increasing forest resilience against climate change and other disturbances. Deer population density is often considered the main driver of browsing impacts on young trees, however, a range of other variables such as food availability also affect this relationship. In this study, we use browsing survey data from 135 research plots to explore patterns of roe deer ( Capreolus capreolus ) browsing pressure on woody plants in mountainous forests in central Europe. We fitted species‐specific generalised linear mixed models for eight woody taxa, assessing the potential effects of understory characteristics, roe deer abundance and lying deadwood on browsing intensity. Our study reveals conspecific and associational effects for woody taxa that are intermediately browsed by roe deer. Selective browsing pressure was mediated by preferences of plants, in that, browsing of strongly preferred woody taxa as for ex le mountain ash ( Sorbus aucuparia ) and of least preferred woody taxa, for ex le Norway spruce ( Picea abies ) was not affected by the surrounding understory vegetation, while browsing pressure on intermediately browsed species like for ex le silver fir ( Abies alba ) was affected by understory characteristics. Contrary to our expectations, roe deer abundance was only positively associated with browsing pressure on silver fir and bilberry ( Vaccinium myrtillus ), while all other plants were unaffected by deer abundance. Finally, we did not find an influence of lying deadwood volume on the browsing pressure on any woody‐plant species. Overall, our results indicate that patterns in browsing preference and intensity are species‐specific processes and are partly affected by the surrounding understory vegetation. Current management strategies that aim to reduce browsing pressure through culling may be inefficient as they do not address other drivers of browsing pressure. However, managers also need to consider the characteristics of the local understory vegetation in addition to deer abundance and design species‐specific plans to reduce browsing on woody plant taxa.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JENVMAN.2022.114992
Abstract: Wildlife-train collisions can have deleterious effects on local wildlife populations and come with high socio-economic costs, such as damages, delays, and psychological distress. In this study, we explored two major components of wildlife-train collisions: the response of wildlife to oncoming trains and the detection of wildlife by drivers. Using dashboard cameras, we explored the flight response of roe deer (Capreolus capreolus) and moose (Alces alces) to oncoming trains and explored which factors, such as lighting and physical obstructions, affect their detection by drivers. In a majority of cases, roe deer and moose fled from an oncoming train, at an average flight initiation distance (FID) of 78 m and 79 m respectively. Warning horns had unexpected influences on flight behaviour. While roe deer initiated flight, on average, 44 m further away from the train when warned, they usually fled towards the tracks, in the direction of danger. FID of moose, however, was unaffected by the use of a warning horn. As train speed increased, moose had a lower FID, but roe deer FID did not change. Finally, detection of wildlife was obstructed by the presence of vegetation and uneven terrain in the rail-side verge, which could increase the risk of collisions. Our results indicate the need for early detection and warning of wildlife to reduce the risk of collisions. We propose that detection systems should include thermal cameras to allow detection behind vegetation and in the dark, and warning systems should use cues early to warn of oncoming trains and allow wildlife to escape the railway corridor safely.
Publisher: Springer International Publishing
Date: 2020
Publisher: Wiley
Date: 23-08-2023
DOI: 10.1002/WLB3.01117
Abstract: Carrion is a valuable resource in forests, providing sustenance for vertebrate and invertebrate scavenger communities and contributing to ecosystem functions, such as nutrient cycling. Intensive ungulate hunting, and thereby extraction of carcasses, removes large quantities of potential carrion from the system, denying a valuable resource from scavenger fauna. It may be possible to reduce the loss and negative consequences to forest bio ersity by retaining evisceration residues from hunted deer, where full carcasses cannot be retained. However, what roll evisceration residues play as a resource for scavengers in temperate forests is not well understood. In this study, we exposed 47 carrion s les from hunted roe deer, in front of triple sets of camera traps, to examine how hunting remains are removed and fed upon by vertebrate scavengers. Overall, 70% of the s les were completely removed from experimental sites by vertebrates. We detected twelve vertebrate taxa feeding on evisceration residues, including martens ( Martes spp.), red kites Milvus milvus and garden dormice Eliomys quercinus . Common buzzards Buteo buteo and Eurasian jays Garrulus glandarius were the most frequent feeders on carrion s les, while red foxes Vulpes vulpes displaced the largest proportion of s les. Finally, we found a range of insectivorous bird and mammal species using hunting remains as a source for invertebrate prey, while not scavenging on the remains directly. We demonstrate that evisceration residues can be a valuable resource for a wide range of taxa and suggest that viscera retention from hunted game may contribute to resource provisioning for scavengers in forest ecosystems.
Publisher: Frontiers Media SA
Date: 06-12-2022
DOI: 10.3389/FENVS.2022.991551
Abstract: Wildlife-vehicle collisions (WVC) cost millions of euros each year in loss of life and damages. Wildlife crossing structures and fencing are commonly implemented mitigation strategies to reduce WVC and increase landscape connectivity for wildlife. Typically, crossing structures are over- or under-pass structures that allow animals to safely cross the road, while separating them from the road and traffic. An alternative strategy could be an at-grade fauna passage coupled with a Roadside Animal Detection System (RADS). At-grade fauna passages are designated locations where a gap in fencing allows animals to cross over the road, while RADS alert drivers of animals at the upcoming passage, so that they can adjust their driving behaviour accordingly and avoid collisions. In this pilot study, we investigated the use of one at-grade fauna passage by roe deer ( Capreolus capreolus ), red deer ( Cervus elaphus ) and wild boar ( Sus scrofa ) in southern Sweden, and compared changes in the number of WVCs before, during and after the construction of the passage. We collected a total of 326 wildlife crossings from 722 in iduals over 1 year of monitoring (24 January 2020–24 January 2021). We found that crossing events tended to be dominated by the time animals spent in the roadside verge from which they approached the at-grade fauna passage, particularly for roe deer that spent a lot of time browsing in the roadside verge during dusk. We also found that animals spent longer in the passage if vehicles were present. In our 1 year of surveys, we only recorded three accidents, and when comparing the annual collision statistics before, during, and after construction of the at-grade fauna passage, we demonstrated an overall reduction in collisions by 66%. While our pilot only evaluates a single site, it does provide promising preliminary results that suggest that at-grade fauna passages can help in efforts to reduce collisions, while maintaining connectivity over medium-sized roads for large ungulates.
Publisher: Wiley
Date: 27-12-2019
DOI: 10.1002/ECE3.4609
Publisher: Elsevier BV
Date: 05-2020
Publisher: Wiley
Date: 24-10-2019
DOI: 10.1111/COBI.13193
Publisher: Wiley
Date: 13-09-2022
DOI: 10.1002/WLB3.01055
Abstract: Carrion of wild ungulates is an important resource for microbes, invertebrates and vertebrates, and affects local plant communities and soils. Most wild ungulates in central Europe, however, are intensely hunted and removed from the ecosystem, thus not available as carrion. This study explores the use of evisceration residues as a resource by necrophagous insects in a temperate mountainous forest in Germany. We experimentally compared the relative abundance of necrophagous insects between sites of caged roe deer carcasses and evisceration residues of roe deer using pitfall‐traps. While evisceration residues were used by necrophagous insects, significantly more in iduals were s led at entire deer carcasses when corrected for biomass, however, no significant difference in abundance for Coleoptera groups was found. Overall, evisceration residues were used earlier and for a shorter period than entire deer carcasses. Leaving evisceration residues on site where game animals are obtained might help maintain specialized necrophagous insect communities, although their ecological role cannot completely replace that of whole carcasses of wild ruminants.
Publisher: Pensoft Publishers
Date: 25-03-2022
No related grants have been discovered for Manisha Bhardwaj.