ABSTRACT Urban wildlife must persist in close proximity to humans. A reduced flight initiation distance (FID) is a widely reported behavioural correlate of this exposure. FID is lower in rock hyraxes ( Procavia capensis ) near permanent human settlements than in undisturbed populations in a national park landscape, but whether similar variation exists at finer spatial scales within a single suburban site has not been tested. We measured FID in three hyrax colonies differing in distance from human dwellings at Meyersdal Eco Estate, Johannesburg, South Africa, with and without food present, in the warm and cool months. Inter‐colony distances (1.8–2.1 km) exceeded the typical hyrax home‐range size and reported dispersal distances, supporting the treatment of the colonies as independent sampling units. Colony and food treatment each accounted for a similar proportion of variance in FID ( η 2 = 0.148 and 0.150 respectively), with no evidence that the effect of food differed among colonies. The colony furthest from human dwellings had longer FID than the two closer colonies, which did not differ from each other, indicating a threshold rather than a continuous relationship with distance. The presence of food reduced FID consistently across colonies, but season had no effect. These patterns are consistent with reduced escape responses at closer proximity to humans and with feeding motivation acting as an independent, similarly weighted influence on escape decisions. However, the single colony per distance design means that the colony effect cannot be separated from other between‐colony differences. The results indicate to a multi‐factor view of urban antipredator behaviour in which exposure to people and immediate behavioural context both influence flight initiation decisions.
ABSTRACT Male parental care is a prominent and sexually selected trait in giant water bugs (Belostomatidae), where females preferentially mate with egg‐carrying males. However, females frequently encounter males that are not carrying eggs, and the criteria underlying mate choice under such conditions remain poorly understood. Here, we examined female mate choice in two closely related species, Appasus major and A. japonicus , by experimentally restricting mate‐choice assays to males that were not carrying eggs. We quantified male courtship behaviour and analysed female acceptance using a common statistical framework in both species. Female mate choice differed strikingly between the species. In A. major , female acceptance was strongly associated with male courtship behaviour, whereas male body size had no detectable effect. In contrast, in A. japonicus , courtship behaviour did not predict female acceptance; instead, females were more likely to accept smaller males. We interpret these contrasting patterns in light of species‐specific reproductive ecology. In A. japonicus , multiple females sequentially contribute to communal egg masses, and male body size may provide females—particularly early ovipositing females—with a predictive cue for how quickly males transition from mating activity to dedicated egg care. In A. major , where eggs are larger and egg care is expected to be more energetically demanding, sustained courtship may instead function as an indicator of male endurance and parental capacity. Our results demonstrate that removing a dominant parental‐status signal reveals divergent mate‐choice rules even among closely related species. These findings highlight how differences in reproductive ecology can shape the informational value of male traits and generate contrasting selection pressures on morphology and behaviour in parental‐care systems.
ABSTRACT Lighting environments are important for multiple tasks in visually oriented species, including identification of proper habitat, finding food, avoiding predators, and finding, choosing, and defending mates. Variation in lighting environments can lead to local adaptation and/or the expression of different traits as a function of developmental plasticity. Habitat choice as a function of lighting environments can theoretically alter these dynamics. Here, we examined habitat choice as a function of lighting environments in bluefin killifish, Lucania goodei , originating from different lighting environments: a clear spring and a tannin‐stained swamp. We predicted that fish would prefer lighting environments similar to their natal conditions and found partial support for this hypothesis. Killifish from the swamp population preferred red‐shifted lighting environments with yellow backgrounds over broad spectrum lighting environments with blue backgrounds, whereas killifish from the clear spring population showed no consistent preference for either lighting environment. These findings suggest that animals from narrow spectral habitats are more likely to remain in and return to those habitats, while animals from broad spectrum habitats may more readily tolerate and disperse across a wide range of lighting environments in nature.
ABSTRACT In social groups, leadership often emerges from consistent interindividual differences in behaviour. Yet how personality shapes role specialisation remains poorly understood. We investigated how personality traits (activity, aggressiveness, boldness and exploration) influence leadership roles in the ant Pachycondyla striata during tandem running, a recruitment strategy where a leader ant guides a single follower to a target destination. Using repeated behavioural assays (open field, novel object, and aggression tests) and forced emigrations, we assessed individual consistency in personality traits and recruitment roles (leader or follower). We found moderate‐to‐strong repeatability in activity, aggressiveness and exploration, and in the adoption of the leadership role during tandem recruitment. Behavioural responses changed over time: activity decreased after the first trial, suggesting familiarisation with testing contexts or diminishing novelty effects after initial exposures. Tandem runs, and in particular the adoption of the role as a follower, declined sharply in subsequent emigrations as ants transitioned to solitary navigation—a faster strategy once routes were learned. This highlights how experience alters collective decision‐making, favouring speed over recruitment. More importantly, more active, exploratory and aggressive ants were significantly more likely to become leaders, suggesting that intrinsic behavioural differences drive task specialisation. By linking personality to role specialisation, this study contributes to a better understanding of how consistent individual variation shapes collective outcomes in social groups. Understanding these mechanisms could provide broader insights into leadership emergence across animal societies.
ABSTRACT In many species, males have evolved overt aggression as a competitive strategy for resources. Due to the high costs that are associated with overt aggression, such as energy expenditure and the threat of injury or death, several mechanisms that regulate its performance have been observed. Gryllus field crickets (Orthoptera; Gryllidae) are a group of animals whose overt aggression in males is highly stereotyped and has been well studied. Previous work with various Gryllus species shows that male overt aggression can be mediated by several mechanisms that appear to be shared across species, such as suppression by experience (loser effects), reduced or delayed by life history trade‐offs (dispersal capability vs. male aggression), or increased by motor activity that modulates hormonal state (resetting of aggression via flight behavior). Here, we studied the overt aggression of dispersal polymorphic Gryllus rubens males in staged male–male interactions. We tested the three mentioned regulatory pathways to determine how they might control male aggression. We predicted that male aggression would be similarly influenced by these mechanisms as observed in males of several other Gryllus species. In contrast to our predictions and previous work, however, we found that (1) male G. rubens were highly aggressive regardless of dispersal phenotype, (2) we did not detect a loser effect, and (3) the performance of motor activity prior to an agonistic encounter had a negligible effect on aggression. Our results suggest that mechanisms that regulate aggression are not consistent across closely related Gryllus species. Moreover, G. rubens males appear to have evolved a “constant aggression” competitive strategy that is likely shaped by their specific ecology, selecting for males to compete for access to burrows under natural conditions, which are a critical resource used for attracting mates and serve as refuge against predation.
