Acoustic communication plays a central role in the reproductive and social behaviour of anurans, influencing not only mate attraction and male–male interactions but also the spatial structure of breeding assemblages. Because sound propagation is constrained by environmental factors, the effective communication range determines how individuals perceive one another across the landscape. While the acoustic properties of frog calls have been studied extensively, less is known about how the receivers behaviourally respond to calls simulating different source distances. We examined how the simulated call distance and weather conditions affect behavioural responses in two ecologically and acoustically contrasting amphibians: the European tree frog ( Hyla arborea ); and the Common spadefoot ( Pelobates fuscus ). Both species were tested under semi-natural conditions using playback experiments in which conspecific advertisement calls were broadcast at levels corresponding to various source distances. Individual positions within an arena were recorded over time as angular absolute deviations from the loudspeaker sector, with low deviations indicating attraction while large deviations indicated avoidance behaviours. The behavioural data was analysed using generalised linear mixed models with Gamma and binomial error structures. For H . arborea , the angular deviations from the loudspeaker significantly increased with the temperature but not with the simulated distance, time nor the humidity. For P . fuscus , no significant relationship between the position of an individual relative to the playback source was detected, nor with the distance, time, temperature and humidity, which is consistent with the limited importance of acoustic competition in this fossorial species. We observed the immobility of several individuals of P . fuscus , which stayed in the centre of the experimental arena. The probability of the occurrence of this behaviour increased with the air humidity. These findings, contrary to our expectations, suggest that a frog’s movement behaviour depends on environmental conditions rather than on the social context and spatial scale.
Chestnut ( Castanea sativa Mill .) forests represent structurally complex ecosystems that sustain high levels of insect diversity, yet the coleopteran assemblages in these habitats remain poorly documented in Türkiye. We assessed the beetle diversity and trap efficiency using a multi-trap approach (window, pitfall and red sticky traps) across coastal (Karacabey, 0-300 m), mid-elevation (Y??ld??r??m, 300-600 m) and high-elevation inland (Osmangazi, 600-900 m) chestnut stands in Bursa Province during 2024. A total of 2,244 individuals representing 188 species belonging to 144 genera and 33 families were recorded. The trap type significantly affected the species richness, diversity and evenness (generalised linear mixed models, p < 0.001 in each case), although not the abundance, and explained 50.3% of the variation in the assemblage composition (PERMANOVA, pseudo-F = 14.77, p = 0.0001) compared with 12.3% for the study site. Window traps yielded the highest richness (127 species; Shannon H’ = 4.49), while pitfall and sticky traps captured distinct subsets of ground-dwelling and trunk-associated taxa. All three of the trap types differed significantly from one another in their composition, and 35 species proved to be significant indicators of a single method. The most effective single method recovered only 67.6% of the total observed richness, so a reliance on one trap type would have missed approximately one third of the species present. Diversity patterns varied with the forest structure: open-canopy coastal stands supported a higher aerial diversity; whereas over-mature inland stands promoted saproxylic and ground-active assemblages. Because each altitudinal zone was represented by a single forest, differences among the sites were reported as case-specific patterns rather than as general altitude-diversity relationships. Our findings demonstrate that no single method adequately represents the beetle diversity in chestnut forests; instead, a multi-trap strategy is essential. From a management perspective, maintaining structural heterogeneity, including canopy variability, mature stands and deadwood resources, is critical for sustaining biodiversity in temperate deciduous ecosystems.
Two new Paramecium strains were isolated from an artificial pond on a university campus located in Tokyo, Japan. Morphological observations and molecular phylogenetic analyses based on partial sequences of heat shock protein 70 and cytochrome b gene sequences identified both strains as Paramecium pentaurelia , one of the sibling species within the Paramecium aurelia species complex. This represents the first confirmed record of P . pentaurelia in Japan. Although this species has rarely been reported on a worldwide basis, the phylogenetic analyses showed that the Japanese strains shared identical or nearly identical sequences with multiple P . pentaurelia strains from geographically distant regions, suggesting that this species may have a wider, possibly cosmopolitan, distribution than has currently been recognised. The limited number of records may reflect the infrequent occurrence of this species in environmental samples, which may hinder its detection.
Exogenous bacterial species, which mainly populate the intestines of Helix pomatia snails, also affect various biological processes that are crucial to the survival of the host. However, the microbiota undergoes changes during overwintering, as feeding is suspended, leading to serious health consequences for the host. This study aims to investigate whether the food supplementation of snails with a microbiological inoculation containing bacterial strains isolated from the intestines of overwintering snails could improve their cold tolerance in summer. The experiment was conducted on two groups: a control group without supplementation; and an experimental group given the microbiological inoculation. The supercooling point (SCP) of their body fluids was measured to assess the effects of supplementation on the cold tolerance of wild snails in the summer. The results showed that the SCP for the snails in the experimental group was statistically significantly lower than for the snails in the control group, with a mean SCP value of -1.73 degrees C compared to -0.97 degrees C (p < 0.05). These findings confirm that the microbiota has a significant impact on cold tolerance in snails, and the microbiological inoculation had a positive impact on lowering the supercooling temperature of H. pomatia in the summer. This sheds new light on the mechanism of this species' adaptation to cold, which still remains a mystery.
Land-use changes are a major driver of biodiversity shifts in Southeast Asia, particularly within human modified landscapes. Understanding how migratory species use habitats during the non-breeding season is important for assessing their tolerance to environmental changes. We examined the non-breeding habitat associations of the Brown Shrike ( Lanius cristatus Linnaeus, 1758) in Laos by analysing 139 field-detected occurrence sites and comparing them with an equal number of randomly selected background points. Three landscape variables were most strongly associated with the detection of shrikes: road area (positive relationship), and the extent of built-up areas and forest cover (both negative relationships). Brown Shrikes were most frequently recorded in semi-open environments within agricultural mosaics, where structural elements such as perches and open foraging spaces were maintained. Our findings suggest that modified landscapes can provide suitable conditions for the species when structural habitat elements are retained. Our study provides the first fine-scale assessment of the non-breeding habitat associations of Brown Shrikes in mainland Southeast Asia and highlights the importance of maintaining mosaic agricultural landscapes for migratory insectivorous birds.
