Valentin Moser

Vertebrate activity can significantly affect forensic investigations. Trauma interpretation is impaired when vertebrates scavenge on injuries and inflict damage, and scavengers can hinder the recovery of human remains through dispersal. However, forensic scavenging research is scarce in Europe and lacking for Switzerland. We conducted a 2-month baseline study followed by a 5-month experiment with six domestic pig (Sus scrofa domesticus) carcasses in a Swiss forest during summer through fall. We monitored each three caged and uncaged carcasses with camera traps and documented vertebrate activities and taphonomic signatures on the remains and calculated the scavenging rate. Rodents (Apodemus sylvaticus, A. flavicollis, and Myodes glareolus) and red fox (Vulpes vulpes) scavenged and dispersed the remains. All carcasses and ca. 4% of the recovered bones exhibited scavenging marks, including wet bone scavenging (rodents) mainly on small bones and protruding features, and scoring (red fox) on a rib. The presence of a carcass, decomposition stage, sun exposure, and use of cages significantly influenced the number of vertebrate visits at the plots. Rodents preferentially scavenged caged, skeletonized remains at tree-covered plots and modified perimortem wounds beyond recognition. The few carnivore sightings focused on uncaged specimens. The generally low scavenger participation was likely season-related, due to the rapid maggot infestation, or human presence. Future studies should evaluate the influence of these variables, including sun exposure. Our study informs forensic casework by highlighting the importance of rodents and to a lesser degree foxes as vertebrate scavengers and dispersal agents in central European temperate forests.

Die schweizerischen Gewässer werden insbesondere im Winter und zur Zugzeit von Lachmöwen genutzt; ihr Gesamtbestand ist in Mitteleuropa und auch in der Schweiz rückläufig. Da die Lachmöwe tagsüber auch abseits der Gewässer nach Nahrung sucht, dürfte der Schweizer Winterbestand anhand der Ergebnisse der winterlichen Wasservogelzählung unterschätzt werden. Dies erschwert die Beurteilung der Bedeutung der Schweiz als Rast- und Winterquartier für diese Art. Synchrone Zählungen an Schlafplätzen sind zur Erfassung des Winterbestands vermutlich besser geeignet. Daher führten wir im Winter 2021 die erste schweizweit koordinierte Lachmöwen-Schlafplatzzählung durch. Insgesamt wurden dabei rund 39 000 Individuen erfasst, deutlich mehr als bei der kurz zuvor durchgeführten Wasservogelzählung mit rund 32 000 gezählten Lachmöwen. Somit beherbergt die Schweiz im Winter rund 1,5 % der westeuropäischen Lachmöwenpopulation. Zusätzliche Erhebungen zeigten, dass die Bestände am grössten schweizerischen Lachmöwenschlafplatz in Basel Mitte Winter am höchsten waren, während die Zahlen in Zürich gegen Februar/März noch etwas anstiegen. Letzteres könnte auf den Zuzug von weiter südwestlich überwinternden Individuen zurückzuführen sein.

1. As ecosystem engineers, Eurasian beavers (Castor fiber) modify aquatic and terrestrial ecosystems, which can benefit the biodiversity and community composition of plant and animal species. However, in contrast to aquatic taxa, beaver engineering impacts on terrestrial taxa, like bats, are so far largely overlooked. While it has been shown that bats prefer beaver-engineered ecosystems, the reason for this choice is poorly understood. We hypothesized that this preference may be associated with beaver-related changes in habitat characteristics and food availability.
2. To address this knowledge gap, we recorded bat species richness, activity and feeding activity in eight beaver-engineered ecosystems (pool) with paired control sites without beavers (control) along the same stream in Switzerland. In addition, we collected data on food availability (arthropods) with arthropod flight interception traps and characterized habitat suitability with deadwood volume and vegetation surveys, as well as assessing canopy heterogeneity based on different digital height models.
3. The nighly bat species richness increased from four to five species between control and pool sites. Bat activity increased 1.6 times and bat feeding activity 2.3 times in beaver-engineered systems compared to controls. These increases in richness and activity were explained by higher volumes of standing deadwood, higher canopy heterogeneity and higher arthropod abundance in beaver systems compared to controls.
4. Overall, the volume of standing deadwood, a critical resource for bat roosting and foraging, had a stronger effect on bat species richness than canopy heterogeneity or arthropod availability. Bat feeding guilds (short-, mid-, long-range echolocators) responded differently to beaver-engineered habitat changes, with edge-hunting mid-range species benefiting the most.
5. Our findings suggest that beaver engineering created structurally diverse habitats that supported a broader range of bat species. By modifying both habitat structure and prey abundance, beaver engineering affected bat activity, richness, and feeding activity directly and indirectly. These changes operated across aquatic–terrestrial boundaries, highlighting the cross-ecosystem influence and ecological complexity of ecosystem engineering.

Lachmöwen gehören zu den auffälligsten Wintergästen der Schweiz. Dabei nutzt die Lachmöwe für die Überwinterung wie kaum eine andere Vogelart auch urbane Lebensräume. Dies und die geringe Scheu vor dem Menschen machte die Lachmöwe seit dem Beginn der regelmässigen Beobachtungen in Städten im 19. und frühen 20. Jahrhundert zu einem beliebten Studienobjekt. Die vorliegende Untersuchung knüpft an frühere Studien an, wobei wir weitere Aspekte des Verhaltens im Winterquartier und Veränderungen über die Zeit dokumentieren. Wir haben im Raum Basel und Morges während neun Wintern 1361 Lachmöwenringe von 224 Individuen aus 21 Ländern abgelesen. Nachweise aus Brutkolonien kamen aus 17 dieser Länder, meist nordöstlicher Herkunft, schwerpunktmässig aus Polen und Tschechien. Bis zu 19 % der Überwinterer waren Jungvögel, mehr als zu Beginn des 20. Jahrhunderts. Die bei uns überwinternden Lachmöwen zeigten eine teilweise jahrelange Treue zum Winterquartier und selbst zum Tagesstandort. Über eine Saison konnten 77 % der Lachmöwen (n = 56) nur in einem Gebiet beobachtet werden, weitere 18 % in zwei Gebieten. Über die Jahre (n = 59) wurden 46 % der Lachmöwen nur an einem Tagesstandort beobachtet, weitere 34 % an maximal zwei. Dies legt nahe, dass sich Lachmöwen im Winter auf einen Futterplatz spezialisieren und diesem über Jahre treu bleiben.

Phytoplankton is an essential resource in aquatic ecosystems, situated at the base of aquatic food webs. Plastic pollution can impact these organisms, potentially affecting the functioning of aquatic ecosystems. The interaction between plastics and phytoplankton is multifaceted: while microplastics can exert toxic effects on phytoplankton, plastics can also act as a substrate for colonisation. By reviewing the existing literature, this study aims to address pivotal questions concerning the intricate interplay among plastics and phytoplankton/phytobenthos and analyse impacts on fundamental ecosystem processes (e.g. primary production, nutrient cycling). This investigation spans both marine and freshwater ecosystems, examining diverse organisational levels from subcellular processes to entire ecosystems. The diverse chemical composition of plastics, along with their variable properties and role in forming the "plastisphere", underscores the complexity of their influences on aquatic environments. Morphological changes, alterations in metabolic processes, defence and stress responses, including homoaggregation and extracellular polysaccharide biosynthesis, represent adaptive strategies employed by phytoplankton to cope with plastic-induced stress. Plastics also serve as potential habitats for harmful algae and invasive species, thereby influencing biodiversity and environmental conditions. Processes affected by phytoplankton–plastic interaction can have cascading effects throughout the aquatic food web via altered bottom-up and top-down processes. This review emphasises that our understanding of how these multiple interactions compare in impact on natural processes is far from complete, and uncertainty persists regarding whether they drive significant alterations in ecological variables. A lack of comprehensive investigation poses a risk of overlooking fundamental aspects in addressing the environmental challenges associated with widespread plastic pollution.

First records of the harvestman Lacinius dentiger (C. L. Koch, 1847) for Switzerland (Opiliones: Phalangiidae). − Until recently, the harvestman Lacinius dentiger had never been observed in Switzerland. This report presents the first national records of this species. Observations are documented by distribution maps, and the habitat and phenology are presented. Based on the results, the absence of historical records for this species in Switzerland are discussed.

Die Weberknechtart Lacinius dentiger wurde bisher in der Schweiz nicht nachgewiesen. In diesem Bericht werden die ersten nationalen Nachweise dieser Art vorgestellt. Diese Beobachtungen werden mit Verbreitungskarten dokumentiert und das Habitat und die Phänologie charakterisiert. Auf Basis der Ergebnisse wird diskutiert, warum Nachweise dieser Art bis jetzt in der Schweiz fehlten.

Premières mentions de l'Opilion Lacinius dentiger (C. L. Koch, 1847) en Suisse (Opiliones: Phalangiidae). − L'Opilion Lacinius dentiger n'avait jusqu'à présent jamais été signalé en Suisse. Cette note présente les premières observations dans le pays, documentées à l'aide de cartes de répartition, et décrit l'habitat ainsi que la phénologie de l'espèce. Les raisons pour lesquelles cette espèce n'avait jamais été signalée jusqu'à présent en Suisse sont discutées.

Prime segnalazioni dell'opilione Lacinius dentiger (C. L. Koch, 1847) per la Svizzera (Opiliones: Phalangiidae). − Lacinius dentiger non era finora mai stato segnalato in Svizzera. Questo rapporto presenta le prime osservazioni della specie a livello nazionale, documentate con mappe di distribuzione, e presenta la caratterizzazione dell’habitat e della fenologia. Sulla base dei risultati, vengono discusse le ragioni della mancanza di segnalazioni di questa specie in Svizzera.

Aim: Climate is a major driver of large-scale variability in biodiversity, as a likely result of more intense biotic interactions under warmer conditions. This idea fuelled decades of research on plant-herbivore interactions, but much less is known about higher-level trophic interactions. We addressed this research gap by characterizing both bird diversity and avian predation along a climatic gradient at the European scale.
Location: Europe.
Taxon: Insectivorous birds and pedunculate oaks.
Methods: We deployed plasticine caterpillars in 138 oak trees in 47 sites along a 19° latitudinal gradient in Europe to quantify bird insectivory through predation attempts. In addition, we used passive acoustic monitoring to (i) characterize the acoustic diversity of surrounding soundscapes; (ii) approximate bird abundance and activity through passive acoustic recordings; and (iii) infer both taxonomic and functional diversity of insectivorous birds from recordings.
Results: The functional diversity of insectivorous birds increased with warmer climates. Bird predation increased with forest cover and bird acoustic activity but decreased with mean annual temperature and functional richness of insectivorous birds. Contrary to our predictions, climatic clines in bird predation attempts were not directly mediated by changes in insectivorous bird diversity or acoustic activity, but climate and habitat still had independent effects on predation attempts.
Main Conclusions: Our study supports the hypothesis of an increase in the diversity of insectivorous birds towards warmer climates but refutes the idea that an increase in diversity would lead to more predation and advocates for better accounting for activity and abundance of insectivorous birds when studying the large-scale variation in insect-tree interactions.

1. Fragmentation of habitat, for example by intensive agricultural practices, can be detrimental to local biodiversity. However, it often remains unclear whether such biodiversity declines are caused by loss of habitat area or increased fragmentation, and how habitat quality factors into it. In our study system, vegetated vineyards are typically small, and isolated from one another, potentially limiting the distribution and dispersal of organisms.
2. In a full-factorial experiment of a priori selected vegetated vineyard patches of differing size and fragmentation, we aimed to disentangle the effects of habitat area (area of vegetated vineyards), habitat fragmentation (number of vegetated vineyards per 100 ha) and field-scale ground vegetation density on ground beetle, leafhopper and wild bee communities using a combined framework of multiscale and multispecies modelling (Hierarchical Model of Species Communities).
3. We demonstrate variable effects of habitat area, fragmentation and local ground vegetation density on the three insect groups: Increased habitat area at fine scales favours higher species richness of leafhoppers, while local vegetation density boosts species richness of both leafhoppers and ground beetles, whereas no community-level responses were detected for wild bees.
We conclude that increased ground vegetation density at both field and landscape scales (i.e. higher habitat area) favours more diverse and abundant insect communities, while fragmentation effects are highly variable and species specific. In addition, our results highlight that mainly ground beetles and leafhoppers will benefit from simple ground greening measures in vineyards, while for wild bees environmental factors other than the ones tested here may drive community structure.
4. We recommend increasing the number and area of vegetated vineyards (even at small spatial scales) requiring more nature-friendly farming practices especially regarding a reduction or renunciation from herbicide applications, while the within-field vegetation density should optimally be intermediate or high to favour a diverse insect community.