Ethology最新文献

Duetting, a cooperative vocal behaviour performed by mated pairs, is a distinctive vocal behaviour among many species in specifically primates and birds. Yet, the exact features of duets that may make them a stronger territorial signal are still not well understood. One hypothesis is that the precision of duet coordination can indicate the quality of a pair bond or dedication of a pair, and thus the degree of threat posed to a rival pair. To address the implications of duetting precision in a territorial context, we here determined to what extent the antiphonal duetting behaviour in the chirruping wedgebill (Psophodes cristatus), a territorial, socially monogamous passerine, is affected by the precision of fine-level duet coordination. We tested this with playback experiments where we broadcast coordinated and uncoordinated duets at mated pairs, predicting that pairs would exhibit stronger responses to coordinated duets than to uncoordinated ones and sing more coordinated after the simulated intrusion. We found that neither response intensity nor coordination of either sex differed in responses to playback of coordinated and uncoordinated duets. Since chirruping wedgebills did respond consistently to playback, we suggest that either (1) fine-level coordination of duetting does not hold a function in joint resource defence in this species, (2) playback stimuli were too threatening for them to adjust their coordination on a level we could detect or (3) they do not discriminate between our coordinated and uncoordinated playback treatments. We highlight the notion that there may be variety in functions of duetting at play within and across avian species, and that different aspects of duets such as coordination and intensity may hold different functions.

Vickers, M. E., M. L. Heisey, and L. A. Taylor. 2025. “Do Green Lynx Spiders (Peucetia viridans) Change Color in Response to Their Backgrounds?” Ethology 131: e13558. https://doi.org/10.1111/eth.13558

In the originally published article, an error in data labeling swapped the variable labels “red chroma” and “green chroma.” This has been corrected in the text, as well as in figures 4–6 of the article, and the supporting material. The authors have made some minor text adjustments in the Discussion section to align with these changes. They have reanalyzed the data and confirm that the main conclusions reported in the article remain unchanged.

We apologize for this error.

The way individuals respond to novel stimuli may provide insight into their ability to thrive in different situations, or into their role, for example during reproduction. Here, we analyze variation in the behavioral response of common terns (Sterna hirundo) when confronted with such novel stimuli. We quantify the latency to return to the nest upon facing a novel stimulus, and test for short-term repeatability, whether variation in this trait is explained by sex, age, and reproductive phase, and whether there is evidence for assortative mating with respect to this trait. We find a repeatability of 32% across the responses recorded during incubation and chick-rearing. Moreover, females take a longer time to return to the nest than males, and this latency is longer during incubation than during early chick rearing. Variation in this trait is not related to age, and responses are not correlated between the two members of a breeding pair. We suggest the sex effect reflects role differences during parental care, while the vulnerability of the offspring may dictate the effect of reproductive phase. Finally, we assess exploratory behavior during the incubation phase, and find that it does not vary with sex, age, or the response to the novel stimulus. Further work should assess the long-term repeatability of the two traits we assessed, as well as elucidate whether connections to other repeatable behaviors observed in these birds exist.

Animal behavior is an important component of individual, population, and community responses to anthropogenic habitat alteration. For example, antipredator behavior (e.g., vigilance) and animal movement behavior may both be important behavioral responses to the increased density of habitat edges and changes in patch connectivity that characterize highly modified habitats. Importantly, edge density and connectivity might interact, and this interaction is likely to mediate animal behavior: linear, edge-rich landscape features often provide structural connectivity between patches, but the functional connectedness of patches for animal use could depend upon how edge density modifies animal vigilance and movement. Using remote cameras in large-scale experimental landscapes that manipulate edge density (high- vs. low-density edges) and patch connectivity (isolated or connected patches), we examined the effects of edge density and connectivity on the antipredator behavior and movement behavior of white-tailed deer (Odocoileus virginianus). Deer vigilance was 1.38 times greater near high-density edges compared to low-density edges, regardless of whether patches were connected or isolated. Deer were also more likely to move parallel to connected high-density edges than all other edge types, suggesting that connectivity promotes movement along high-density edges. These results suggest that increases in edge density that accompany human fragmentation of existing habitats may give rise to large-scale changes in the antipredator behavior of deer. These results also suggest that conservation strategies that simultaneously manipulate edge density and connectivity (i.e., habitat corridors) may have multiple effects on different aspects of deer behavior: linear habitat corridors were areas of high vigilance, but also areas where deer movement behavior implied increased movement along the habitat edge.

Group formation in animals can arise from two primary mechanisms: individuals aggregating over resources, or individuals socially benefiting from interacting with conspecifics. Distinguishing between these mechanisms allows us to infer the drivers of group formation, which is of considerable importance for informing management strategies of invasive species. Lionfish (Pterois volitans) are a teleost predator native to the Indo-Pacific but invasive in the Western Atlantic Ocean. Lionfish are often observed sheltering in refuges on their own or in groups, with previous research suggesting these groups form due to attraction towards preferred habitats rather than having a social function. Here, we find that lionfish were more likely to shelter with a conspecific rather than choosing to shelter alone. Lionfish were also more likely to shelter with larger conspecifics. Our findings demonstrate that lionfish are socially attracted to one another, which has implications for the control and management strategies of this invasive species.

Deimatic displays are visually conspicuous behaviours designed to prevent predation by scaring off predators. Animals that exhibit deimatic behaviours often show other secondary defences as well, but the factors that influence which defences are expressed are poorly understood. Because prey are expected to deploy multiple defences strategically, conspicuous deimatic displays could be performed later in the predation sequence after primary or other secondary defences have failed. Their expression could additionally depend on the state of the performer, especially if deimatic behaviours are costly to produce or involved in a functional trade-off. Here, we investigate female defensive responses to escalating attacks involving non-tactile and tactile stimuli by a human model predator using the springbok mantis, Miomantis caffra. We found that all defensive behaviours were expressed only after mantises were physically provoked, indicating a counter defence rather than a pre-emptive one. Most females responded to initial tactile contact with non-deimatic behaviours—most commonly fleeing, but also striking with raptorial forelegs and freezing. When predator attacks escalated and tactile contact increased, females mostly produced deimatic behaviours, including raising forelegs, flaring wings, exposing jaws and/or swaying from side to side. Females that were heavier for their size and therefore closer to oviposition were also less likely to flee and more likely to strike and display, although this pattern depended on the level of predator threat. Our results suggest that the expression of deimatic displays is prompted by the repeated failure of non-deimatic defences to ward off escalating predator attacks, which may be why deimatism has gone unnoticed in M. caffra until now. Our findings also suggest an important role for fight-or-flight trade-offs in the expression of antipredator behaviours in this species: heavier egg-loads appear to compromise females' ability to flee, triggering more aggressive and deimatic responses instead.