scholarly journals Habitat structure drives the evolution of aerial displays in birds

2018 ◽  
Author(s):  
João C. T. Menezes ◽  
Eduardo S. A. Santos

Physical properties of the environment may shape signalling traits by determining how effective the signals are in affecting the behaviour of other individuals. Evidence abounds of signalling environment driving the evolution of colours and sounds, but little is known about its influence upon gestural displays. Here, we performed a continent-wide phylogenetic comparative analysis to test the hypothesis that habitat structure drives the evolution of aerial sexual displays in passerine birds. We found that aerial displays are seven times more likely to evolve in open habitats than in forests, likely as a result of physical properties that allow aerial displays to transmit more broadly in open habitats. Our results provide an emblematic example of how environmental factors may help predict the direction of evolution of otherwise unpredictable sexual traits. The broader range of aerial displays in open habitats may also mean that females can sample more males, potentially leading to more intense sexual selection over open-habitat, aerial-displaying males.

Author(s):  
Devi Stuart-Fox ◽  
Katrina Rankin ◽  
Adrian Lutz ◽  
Adam Elliott ◽  
Andrew Hugall ◽  
...  

Carotenoid-based colours are a textbook example of honest signalling because carotenoids must be acquired from the environment. However, many species produce similar colours using self-synthesised pteridine pigments. A compelling but untested hypothesis is that pteridines compensate for low environmental availability of carotenoids because it is metabolically cheaper to synthesise pteridines than to acquire and sequester carotenoids. Based on a phylogenetic comparative analysis of 11 pigment concentrations in skin tissue of agamid lizards, we show that pteridine concentrations are higher and carotenoid concentrations lower in less productive environments. Both carotenoid and pteridine pigments were present in all species, but only pteridine concentrations explained colour variation among species. Furthermore, pigment concentrations were uncorrelated with indices of sexual selection. These results suggest that variation among species in pteridine synthesis compensates for environmental availability of carotenoids and challenge the paradigm of honest carotenoid signalling in vertebrates with complex colour production mechanisms.


2020 ◽  
Vol 287 (1923) ◽  
pp. 20200167 ◽  
Author(s):  
J. R. Hodge ◽  
F. Santini ◽  
P. C. Wainwright

Conspicuous coloration displayed by animals that express sexual colour dimorphism is generally explained as an adaptation to sexual selection, yet the interactions and relative effects of selective forces influencing colour dimorphism are largely unknown. Qualitatively, colour dimorphism appears more pronounced in marine fishes that live on coral reefs where traits associated with strong sexual selection are purportedly more common. Using phylogenetic comparative analysis, we show that wrasses and parrotfishes exclusive to coral reefs are the most colour dimorphic, but surprisingly, the effect of habitat is not influenced by traits associated with strong sexual selection. Rather, habitat-specific selective forces, including clear water and structural refuge, promote the evolution of pronounced colour dimorphism that manifests colours less likely to be displayed in other habitats. Our results demonstrate that environmental context ultimately determines the evolution of conspicuous coloration in colour-dimorphic labrid fishes, despite other influential selective forces.


2019 ◽  
Vol 15 (9) ◽  
pp. 20190257 ◽  
Author(s):  
Maider Iglesias-Carrasco ◽  
David A. Duchêne ◽  
Megan L. Head ◽  
Anders P. Møller ◽  
Kristal Cain

Urbanization leads to a rapid and drastic transformation of habitats, forcing native fauna to manage novel ecological challenges or to move. Sexual selection is a powerful evolutionary force, which is sometimes predicted to enhance the ability of species to adapt to novel environments because it allows females to choose high-quality males, but other times is predicted to reduce the viability of populations because it pushes males beyond naturally selected optima. However, we do not know whether or how sexual selection contributes to the likelihood that animals will establish in urban areas. We use a comparative analysis of passerine birds to test whether traits associated with pre- and post-mating sexual selection predict successful colonization of urban areas. We found that plumage dichromatism was negatively associated with urban tolerance, but found no relationship with sexual size dimorphism or testes mass relative to body mass. While we cannot determine the exact reason why species with high plumage dichromatism occur less in cities, it is likely that urban areas increase the costs of expressing bright coloration due, for instance, to dietary constraints, limited male parental care or increased predation.


Author(s):  
L.Z. Khalishkhova ◽  
◽  
A. Kh. Temrokova ◽  
I.R. Guchapsheva ◽  
K.A. Bogаtyreva ◽  
...  

Ensuring the sustainable development of agroecosystems requires research into the justification of the impact of environmental factors on the formation of territorial agroecosystems and identifies ways to take them into account in order to justify management decisions and ensure environmental safety. The main goal of the research within the article is to identify the most significant environmental factors in predicting the formation of agroecosystems. Provisions are devoted to the study of the laws governing the functioning of agroecosystems in order to increase their stability. The methods of comparative analysis, generalization, abstraction, logical analysis are applied. A number of provisions are formulated regarding ways to account for the influence of factors on the formation of key elements of agroecosystems.


2021 ◽  
Vol 13 (10) ◽  
pp. 5445
Author(s):  
Muyun Sun ◽  
Jigan Wang ◽  
Ting Wen

Creativity is the key to obtaining and maintaining competitiveness of modern organizations, and it has attracted much attention from academic circles and management practices. Shared leadership is believed to effectively influence team output. However, research on the impact of individual creativity is still in its infancy. This study adopts the qualitative comparative analysis method, taking 1584 individuals as the research objects, underpinned by a questionnaire-based survey. It investigates the influence of the team’s shared leadership network elements and organizational environmental factors on the individual creativity. We have found that there are six combination of conditions of shared leadership and organizational environmental factors constituting sufficient combination of conditions to increase or decrease individual creativity. Moreover, we have noticed that the low network density of shared leadership is a sufficient and necessary condition of reducing individual creativity. Our results also provide management suggestions for practical activities during the team management.


2012 ◽  
Vol 81 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Menno Schilthuizen ◽  
Martin Haase ◽  
Kees Koops ◽  
Sylvia M. Looijestijn ◽  
Sigrid Hendrikse

The Southeast-Asian tree snail subgenus Amphidromus s. str. (Gastropoda Pulmonata: Camaenidae) is unusual among all gastropods for its genetic antisymmetry: populations consist of stable mixtures of individuals with clockwise (dextral) and counterclockwise (sinistral) coiling directions. Although previous studies in A. inversus suggest that this genetic dimorphism is maintained by sexual selection, it cannot be ruled out that environmental factors also play a role. Adult shell shapes in A. inversus are known to show subtle differences between both coiling morphs, and it is known that in snails in general, shell shape is under environmental selection, thus creating the possibility that micro-niche use of both coiling morphs differs. In this paper, we first confirm that hatchlings also differ in shell shape. We then proceed with field studies to compare dextral and sinistral juveniles and adults for (i) direction and rate of dispersal within the vegetation and (ii) micro-niche occupation. However, we failed to detect any difference in both ecological traits. In addition to earlier data that show that there is no clustering of morphs in the field and that both morphs suffer identical predation pressure, these new data do not provide any evidence for a role for environmental factors in maintaining the coil dimorphism in this species.


2019 ◽  
Vol 286 (1902) ◽  
pp. 20190226 ◽  
Author(s):  
Patrick Joye ◽  
Tadeusz J. Kawecki

Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton–Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila —but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters’ resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the ‘general immunocompetence’ hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.


2015 ◽  
Vol 112 (43) ◽  
pp. 13290-13295 ◽  
Author(s):  
Ben Ashby ◽  
Michael Boots

Parasites are thought to play an important role in sexual selection and the evolution of mating strategies, which in turn are likely to be critical to the transmission and therefore the evolution of parasites. Despite this clear interdependence we have little understanding of parasite-mediated sexual selection in the context of reciprocal parasite evolution. Here we develop a general coevolutionary model between host mate preference and the virulence of a sexually transmitted parasite. We show when the characteristics of both the host and parasite lead to coevolutionarily stable strategies or runaway selection, and when coevolutionary cycling between high and low levels of host mate choosiness and virulence is possible. A prominent argument against parasites being involved in sexual selection is that they should evolve to become less virulent when transmission depends on host mating success. The present study, however, demonstrates that coevolution can maintain stable host mate choosiness and parasite virulence or indeed coevolutionary cycling of both traits. We predict that choosiness should vary inversely with parasite virulence and that both relatively long and short life spans select against choosy behavior in the host. The model also reveals that hosts can evolve different behavioral responses from the same initial conditions, which highlights difficulties in using comparative analysis to detect parasite-mediated sexual selection. Taken as a whole, our results emphasize the importance of viewing parasite-mediated sexual selection in the context of coevolution.


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