Biology subjects

Keynan, O.

Publications and source records attributed to Keynan, O..

3 recordsLinked to original sources

bioRxiv2026

A two-signal, two-receiver signalling system: Snake mobbing in the Arabian babbler

Mobbing is a collective antipredator behaviour in which animals approach and harass a threat while coordinating signals to alert conspecifics, recruit allies, or deter predators. In group-living Arabian babblers (Argya squamiceps), snake mobbing relies on two signals that differ in receivers: acoustic "zwick" calls inaudible to the snake and visual wing-lift displays perceived by both conspecifics and the snake, raising the question of whether each signal has one receiver or involves a more complex structure. We elicited snake-mobbing events with dummy vipers and recorded babbler groups using a synchronized acoustic camera enabling individual caller identification and postural analysis. We examined mob formation, the effect of group size on signalling, and the interplay between the two signal types. First signalling (recruitment) order was independent of sex, age and rank. Individual call rate decreased as group size increased, supporting the hypotheses of social buffering and predation risk dilution. Mobbing individuals responded faster (with signalling) to a joint visual-acoustic conspecific display and the onset of a visual display than to an acoustic-only signal. When coupled, wing-lifts significantly altered vocal characteristics, decreasing peak frequency and increasing call rate, thus strengthening the acoustic signal. Moreover, calls emitted toward the end of the wing-lift display exhibited a stronger drop in peak frequency. Together, these findings demonstrate the multi-functional role of multimodal mobbing signals during a risky cooperative task balancing social communication and predator deterrence.

animal behavior and cognition↗

bioRxiv2025

The double-edged sword of wildlife biodiversity in the agricultural matrix: a case study of reptiles in vineyards

The global pervasiveness of agriculture and its profound effects on biodiversity increasingly mandate developing sustainable agricultural methods to support healthy ecosystems within agricultural landscapes. However, increasing the attractiveness of agricultural landscapes for wildlife may negatively impact biodiversity if animals or their reproduction are adversely affected in such habitats. While the effects of agricultural practices were investigated across various crop types and wildlife species, reptiles remain largely overlooked. Additionally, although reptiles in croplands were monitored throughout the farming season, little attention has been directed towards the effects of harvest at the seasons end. To illustrate the potential impacts of mechanical harvest on wildlife in permanent crops, we present a case-study concerning reptiles in vineyards. We scanned the waste of a medium-sized winery over four nights and found 105 reptiles, 69% of them chameleons. Though chameleons are considered carnivorous, approximately half had consumed grapes, potentially attracted by them. Vineyards, like many crops, offer resources including sugar, water, and shelter, likely attracting many wildlife species. However, mortality during mechanical harvest may be high, potentially rendering such crops an ecological trap. For chameleons the effects may be particularly devastating, as harvest closely precedes the egg-laying season. While our case study focuses on reptiles in vineyards, its implications extend to many species in permanent crops. Ultimately, ecological traps affect biodiversity by attracting animals to habitats in which their fitness is impaired. While preference has been widely discussed in determining trap severity, our case study highlights that considering the traps fitness impact is also crucial. HighlightsO_LIAgricultural landscapes may attract wild animals while increasing their mortality C_LIO_LIMonitoring biodiversity in agriculture must account for the effects of harvest C_LIO_LIChameleons are likely attracted to vineyards but killed just before reproducing C_LIO_LIAgricultural methods and life history interact to determine ecological trap severity C_LIO_LIEcological trap severity is affected both by preference and by fitness effects C_LI

ecology↗

bioRxiv2023

Living fast, dying young: anthropogenic habitat modification influences the fitness and life history traits of a cooperative breeder

Modification of natural habitats can lead to an ecological trap, as animals can maladaptively select lower-quality habitats over natural landscapes. Modified habitats reduce group size and prevalence, the success of dispersing individuals, and breeding success. However, little is known about how these effects on fitness affect the sociality of cooperative breeding species, which may be particularly susceptible to habitat modification. Here we show that the selection of anthropogenically modified habitats negatively affects the fitness, which has consequences in the life history traits of a cooperative breeder. We used data collected during six years from a monitored population of Arabian babblers (Argya squamiceps) and found that groups living in modified habitats breed more than those in natural habitats but that juvenile and adult survival in modified habitats was lower. Individuals living in modified habitats acquired dominance earlier than individuals from natural habitats. Males in modified habitats also dispersed earlier than those from natural habitats. Our results suggest that modified habitats entail an ecological trap for Arabian babblers, which adjusts their life history traits as a response. Understanding the adaptation of social and cooperative breeding species to habitat modification is the first step for mitigating the processes behind human-related population declines.

ecology↗