摘要: Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make context-appropriate behavioral decisions. However, in sexually dimorphic species, males and females are expected to differ in the perceived costs and/or benefits associated with predator avoidance decisions. Recent studies suggest that male Trinidadian guppies (Poecilia reticulata) show reduced or absent responses to acute personal information cues, placing them at greater risk of predation relative to females. Our goal here was to test the hypothesis that adult (reproductively active) male guppies rely on social information to limit potential costs associated with their lack of response to risky personal cues. Adult male guppies were exposed to personal chemosensory cues (either conspecific alarm cues (AC), a novel odor, or a water control) in the presence of a shoal of three females inside a holding container that allowed the transmission of visual but not chemical cues. At the same time, we exposed females to either risk from AC or no risk, resulting in the display of a range of female behavior, from calm to alarmed, available as social information for males. Alarmed females caused male fright activity to increase and male interest in females to decrease, regardless of the personal cue treatment. These results indicate that male guppies rely more on female information regarding predation risk than their own personal information, probably to balance trade-offs between reproduction and predator avoidance.

摘要: Noise pollution has been shown to affect wild animals in various ways, but little is known about its consequences at the community level. Investigating animals' overall vocal responses to noise across multiple sympatric species can reveal the complex nature of noise impacts but is challenging. In this study, we employed social network analysis (SNA) to evaluate how anuran communities and populations vary their calling behaviors in response to aircraft noise. SNA of anuran communities revealed that conspecific individuals increase the aggregation of their spectral (i.e., minimum frequency, maximum frequency, and dominant frequency), temporal (call duration, call rate, and call effort), and overall spectral-temporal features as an airplane passes through. SNA of populations also revealed that anurans could increase the interindividual similarity of multiple call characteristics in response to airplane noise. Furthermore, our network analysis of multiple species and multiple call traits revealed an effect of noise in species whose calling behavior did not change in previous separate analyses of each species and single traits. This study suggests that noise pollution may change the pattern of combined acoustic properties at the community level. Our findings highlight the importance of integrated methods and theories for understanding the ecological consequences of noise pollution in future studies.

摘要: The gut microbiome is a key partner of animals, influencing various aspects of their physiology and behaviors. Among the diverse behaviors regulated by the gut microbiome, locomotion is vital for survival and reproduction, although the underlying mechanisms remain unclear. Here, we reveal that the gut microbiome modulates the locomotor behavior of Drosophila larvae via a specific neuronal type in the brain. The crawling speed of germ-free (GF) larvae was significantly reduced compared to the conventionally reared larvae, while feeding and excretion behaviors were unaffected. Recolonization with Acetobacter and Lactobacillus can fully and partially rescue the locomotor defects in GF larvae, respectively, probably due to the highest abundance of Acetobacter as a symbiotic bacterium in the larval gut, followed by Lactobacillus. Moreover, the gut microbiome promoted larval locomotion, not by nutrition, but rather by enhancing the brain levels of tyrosine decarboxylase 2 (Tdc2), which is an enzyme that synthesizes octopamine (OA). Overexpression of Tdc2 rescued locomotion ability in GF larvae. These findings together demonstrate that the gut microbiome specifically modulates larval locomotor behavior through the OA signaling pathway, revealing a new mechanism underlying larval locomotion regulated by the gut microbiome.

摘要: Aedes albopictus is an important vector of arboviruses and prefers small containers of stagnant water as oviposition sites. One of the mechanisms mosquitoes use to search for suitable oviposition sites is relying on odor cues from prospective sites and their surroundings. The genetic and molecular bases of this behavior are not known for Ae. albopictus. Oviposition site-searching behavior can be separated into 2 stages: container location and water detection. We applied a glue compound to the antennae and the maxillary palps of adult females to mask their ability to detect molecules that may guide them to preferred oviposition sites. Treatment of the antennae significantly reduces the location index (P < 0.001), indicating a decreased ability to find oviposition sites, whereas no significant difference was observed in mosquitoes with maxillary palps treated with the same glue compound (P > 0.05). The detection time, measured as the duration from contact with the water surface to the deposition of the first egg, was extended in mosquitoes with treated antennae or maxillary palps, supporting the conclusion that olfaction is involved in the detection of oviposition site. Transcriptomic analysis identified differentially expressed olfactory-related genes, including obp67, obp56d-like, obp19d-like and obp67-like. RNA interference (RNAi)-mediated knockdown of obp67 and obp56d-like significantly affected the location index and detection time, respectively. Cas9/guide RNA-mediated knockout of obp56d-like resulted in a prolonged detection time, compared with the wild type (P < 0.05). These findings help to elucidate aspects of the olfactory mechanisms involved in Ae. albopictus oviposition site selection, and provide a basis for the development of mosquito surveillance and control strategies.

摘要: Harvester ants are one of the most extensively studied groups of ants, especially the group foraging ants, Messor barbarus (Linnaeus, 1767), which construct long-lasting trunk trails. Limited laboratory investigations have delved into head-on encounters along foraging trails involving workers moving in opposing directions, with fewer corresponding studies conducted in the natural environment. To address this gap, we devised an in-field experimental design to induce lane segregation on the foraging trunk trail of M. barbarus. Using an image-based tracking method, we analyzed the foraging behavior of this species to assess the costs associated with head-on encounters and to figure out the natural coexistence of outgoing and returning workers on a bidirectional route. Our results consistently reveal heightened straightness and speed in unidirectional test lanes, accompanied by an elevated foraging rate compared to bidirectional lanes. This suggests a potential impact of head-on collisions on foraging behavior, especially on foraging efficiency. Additionally, Kinematic analysis revealed distinct movement patterns between outbound and inbound flows, particularly low speed and sinuous trajectories of inbounding unladen workers. The study of encounter rates in two traffic systems hints at the plausible utilization of individual memory by workers within trails, underscoring the pivotal role of encounters in information exchange and load transfer. To address the question of why outgoing and returning workers of the harvester ants, M. barbarus, do not segregate on a one-way route, we employed a novel methodology involving an asymmetrical ramp (depicted in the middle-left section of the Graphical Abstract Image). This ramp acts as a behavioral check valve, compelling workers to move within unidirectional traffic lanes.In the central portion of the graphical abstract image (A), it is evident that workers traversing the test lane (unidirectional) exhibited higher speeds compared to the control lane (bidirectional). On the middle-right of the graphical abstract image (B), workers demonstrated straighter trajectories in contrast to the control lane (bidirectional).Furthermore, outbound lane workers displayed a more direct trajectory with increased speed compared to those in the inbound lane. In the latter scenario, laden workers exhibited both higher speed and a superior straightness index.These findings, coupled with the monitoring of foraging rate and encounter rate, indicate that, overall, ants exhibit a propensity to meet during foraging, facilitating information exchange and load transfer. This tendency appears to be driven by the need for interaction rather than being a consequence of bidirectional traffic, suggesting a potential utilization of individual memory by workers within trails. image