The role of facial pattern variation for species recognition in red-fronted lemurs (Eulemur rufifrons)

AbstractThe predator-predator naïveté hypothesis suggests that non-native predators benefit from being unknown to native predators, resulting in reduced intraguild interference with native predators. This novelty advantage should depend on the ability of native predators to recognize cues of non-native predators. Here, we compared ant aggression and lady beetle reaction in four native and the invasive lady beetle species Harmonia axyridis. In addition, we tested whether lady beetle cuticular hydrocarbons (CHCs) are involved in species recognition, which might explain naïveté if the invasive species has a specific CHC profile. To this end, we conducted behavioral assays confronting two native ant species with both living lady beetles and lady beetle elytra bearing or lacking CHCs of different lady beetle species. Finally, we characterized CHC profiles of the lady beetles using GC–MS. In general, the aggression of Lasius niger was more frequent than that of Myrmica rubra and L. niger aggression was more frequent towards most native lady beetle species compared to H. axyridis. The removal of CHCs from lady beetle elytra reduced aggression of both ant species. If CHCs of respective lady beetle species were added on cue-free elytra, natural strength of L. niger aggression could be restored. CHC analyses revealed a distinct cue composition for each lady beetle species. Our experiments demonstrate that the presence of chemical cues on the surface of lady beetles contribute to the strength of ant aggression against lady beetles. Reduced aggression of L. niger towards H. axyridis and reduced avoidance behavior in H. axyridis compared to the equally voracious C. septempunctata might improve the invasive lady beetle’s access to ant-tended aphids.

Download Full-text

Asymmetric interspecific competition drives shifts in signalling traits in fan-throated lizards

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.2141 ◽

2020 ◽

Vol 287 (1940) ◽

pp. 20202141

Author(s):

Amod M. Zambre ◽

Akshay Khandekar ◽

Rajesh Sanap ◽

Clairissa O'Brien ◽

Emilie C. Snell-Rood ◽

...

Keyword(s):

Interspecific Competition ◽

Species Recognition ◽

Character Displacement ◽

Social Signals ◽

Lizard Species ◽

Male Aggression ◽

Species Overlap ◽

Asymmetric Pattern ◽

Competitor Recognition

Interspecific competition can occur when species are unable to distinguish between conspecific and heterospecific mates or competitors when they occur in sympatry. Selection in response to interspecific competition can lead to shifts in signalling traits—a process called agonistic character displacement. In two fan-throated lizard species— Sitana laticeps and Sarada darwini —females are morphologically indistinguishable and male agonistic signalling behaviour is similar. Consequently, in areas where these species overlap, males engage in interspecific aggressive interactions. To test whether interspecific male aggression between Si. laticeps and Sa. darwini results in agonistic character displacement, we quantified species recognition and signalling behaviour using staged encounter assays with both conspecifics and heterospecifics across sympatric and allopatric populations of both species. We found an asymmetric pattern, wherein males of Si. laticeps but not Sa. darwini showed differences in competitor recognition and agonistic signalling traits (morphology and behaviour) in sympatry compared with allopatry. This asymmetric shift in traits is probably due to differences in competitive abilities between species and can minimize competitive interactions in zones of sympatry. Overall, our results support agonistic character displacement, and highlight the role of asymmetric interspecific competition in driving shifts in social signals.

Download Full-text

The evolution of female sex pheromones

Current Zoology ◽

10.1093/czoolo/59.4.569 ◽

2013 ◽

Vol 59 (4) ◽

pp. 569-578 ◽

Cited By ~ 22

Author(s):

Ally R. Harari ◽

Hadass Steinitz

Keyword(s):

Sexual Selection ◽

Natural Selection ◽

Sex Pheromones ◽

Species Recognition ◽

Current Evidence ◽

Social Selection ◽

Breeding Sites ◽

Female Sex ◽

Breeding Resources

Abstract The role of female sex pheromones in natural selection, particularly as a means for species recognition to avoid the generation of hybrid offspring with low fitness, has been widely explored and is generally accepted by scholars. However, the significance of sex pheromones in shaping mate choice (sexual selection) and in competition over breeding resources (social selection) has been largely ignored. The effect of sexual selection on sex pheromones as a sexually dimorphic signaling trait has been discounted because the amount of pheromone released by females is typically minute, while the role of sex pheromones in competition over breeding resources (other than mates) has not yet been considered. As a result of natural selection, variation in sex pheromones among females is expected to be low, and males are not expected to choose their mates among phero-mone-releasing conspecific females. Sexual selection, on the other hand, should drive the increase in pheromone variance among females, and males are expected to choose females based on this variation. Moreover, social selection resulting from more general social interactions, for example competition among females for breeding sites and food, should also promote variance among female sex pheromones. Here, we review the current evidence for each of the three selection processes acting on sex pheromones of female moths as an advertising trait. We suggest that the three selection types are not mutually exclusive but rather act together to promote different fitness components in diverse ecological situations.

Download Full-text

The well-tuned blues: the role of structural colours as optical signals in the species recognition of a local butterfly fauna (Lepidoptera: Lycaenidae: Polyommatinae)

Journal of The Royal Society Interface ◽

10.1098/rsif.2011.0854 ◽

2012 ◽

Vol 9 (73) ◽

pp. 1745-1756 ◽

Cited By ~ 35

Author(s):

Zsolt Bálint ◽

Krisztián Kertész ◽

Gábor Piszter ◽

Zofia Vértesy ◽

László P. Biró

Keyword(s):

Spectral Data ◽

Species Recognition ◽

Structural Data ◽

Flight Period ◽

Butterfly Species ◽

Optical Signals ◽

Butterfly Fauna ◽

Data Points ◽

Competitor Recognition

The photonic nanoarchitectures responsible for the blue colour of the males of nine polyommatine butterfly species living in the same site were investigated structurally by electron microscopy and spectrally by reflectance spectroscopy. Optical characterization was carried out on 110 exemplars. The structural data extracted by dedicated software and the spectral data extracted by standard software were inputted into an artificial neural network software to test the specificity of the structural and optical characteristics. It was found that both the structural and the spectral data allow species identification with an accuracy better than 90 per cent. The reflectance data were further analysed using a colour representation diagram built in a manner analogous to that of the human Commission Internationale de l'Eclairage diagram, but the additional blue visual pigment of lycaenid butterflies was taken into account. It was found that this butterfly-specific colour representation diagram yielded a much clearer distinction of the position of the investigated species compared with previous calculations using the human colour space. The specific colours of the investigated species were correlated with the 285 flight-period data points extracted from museum collections. The species with somewhat similar colours fly in distinct periods of the year such that the blue colours are well tuned for safe mate/competitor recognition. This allows for the creation of an effective pre-zygotic isolation mechanism for closely related synchronic and syntopic species.

Download Full-text

Adaptive evolution of facial colour patterns in Neotropical primates

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2011.2326 ◽

2012 ◽

Vol 279 (1736) ◽

pp. 2204-2211 ◽

Cited By ~ 63

Author(s):

Sharlene E. Santana ◽

Jessica Lynch Alfaro ◽

Michael E. Alfaro

Keyword(s):

Species Recognition ◽

Ecological Factors ◽

Neotropical Primates ◽

Communication Ecology ◽

Rich Diversity ◽

Mammalian Lineage ◽

The Rich ◽

Colour Patterns ◽

Adaptive Role

The rich diversity of primate faces has interested naturalists for over a century. Researchers have long proposed that social behaviours have shaped the evolution of primate facial diversity. However, the primate face constitutes a unique structure where the diverse and potentially competing functions of communication, ecology and physiology intersect, and the major determinants of facial diversity remain poorly understood. Here, we provide the first evidence for an adaptive role of facial colour patterns and pigmentation within Neotropical primates. Consistent with the hypothesis that facial patterns function in communication and species recognition, we find that species living in smaller groups and in sympatry with a higher number of congener species have evolved more complex patterns of facial colour. The evolution of facial pigmentation and hair length is linked to ecological factors, and ecogeographical rules related to UV radiation and thermoregulation are met by some facial regions. Our results demonstrate the interaction of behavioural and ecological factors in shaping one of the most outstanding facial diversities of any mammalian lineage.

Download Full-text