| Full text | |
| Author(s): |
Viana, Joao Vitor de Alcantara
;
Duarte, Rafael Campos
;
Lambertini, Carolina
;
Capoccia, Felipe
;
Martins, Anna Luiza Oliveira
;
Vieira, Camila
;
Romero, Gustavo Quevedo
Total Authors: 7
|
| Document type: | Journal article |
| Source: | American Naturalist; v. 204, n. 6, p. 18-pg., 2024-12-01. |
| Abstract | |
Fire events change background color, impairing camouflage strategies. However, selection for polymorphic populations may increase camouflage and survival by reducing predation risks. We conducted experiments addressing background selection and predation pressures on the effectiveness of arthropod camouflage against predation in burned and unburned trunks. We tested color and luminance contrasts, as well as trunk preferences, in a color polymorphic grasshopper and praying mantis species with melanic and brown morphs, and a spider species with a single dark color. To expand the scope of our study, we used two distinct visual models of avian predators: ultraviolet sensitive and violet sensitive. We also performed predation experiments using theoretical prey exhibiting black and brown color and human "predators" to understand the effectiveness of color polymorphism against different trunk conditions. Melanic morphs had lower achromatic contrast in burned backgrounds for both visual systems, suggesting that melanism promotes advantages against predation over long distances. However, only spiders actively selected the low-contrasting burned trunks, indicating habitat specialization. The predation experiments showed that black models benefited from camouflage on burned trunks. Conversely, brown models elicited more time and reduced distance in predator searching compared with the black targets on unburned trunks. We suggest that postfire effects can enhance color contrasts and increase predation over color-mismatching individuals, which translates into selection pressures for color polymorphism and matching background choices. As queimadas mudam a colora & ccedil;& atilde;o dos substratos ocupados por animais, prejudicando estrat & eacute;gias de camuflagem. No entanto, a sele & ccedil;& atilde;o por popula & ccedil;& otilde;es polim & oacute;rficas pode beneficiar a camuflagem e a sobreviv & ecirc;ncia ao reduzir os riscos de preda & ccedil;& atilde;o. Conduzimos experimentos abordando a sele & ccedil;& atilde;o de substratos e as press & otilde;es de preda & ccedil;& atilde;o sobre a efic & aacute;cia da camuflagem de artr & oacute;podes contra preda & ccedil;& atilde;o em troncos queimados e n & atilde;o queimados. Testamos contrastes de cor e lumin & acirc;ncia, bem como prefer & ecirc;ncias por troncos em uma esp & eacute;cie de gafanhoto e louva-a-deus polim & oacute;rficos em rela & ccedil;& atilde;o & agrave; cor, com morfos mel & acirc;nicos e marrons, assim como em uma esp & eacute;cie de aranha com uma & uacute;nica cor escura. Para ampliar o escopo do nosso estudo, usamos dois modelos visuais distintos de aves predadoras: sens & iacute;veis ao ultravioleta e sens & iacute;veis ao violeta. Tamb & eacute;m realizamos experimentos de preda & ccedil;& atilde;o usando modelos de presas exibindo as cores preta e marrom e "predadores" humanos para entender a efic & aacute;cia do polimorfismo de cor em diferentes condi & ccedil;& otilde;es de tronco. Os morfos mel & acirc;nicos apresentaram menor contraste acrom & aacute;tico em troncos queimados para ambos os sistemas visuais, sugerindo que o melanismo promove vantagens contra preda & ccedil;& atilde;o a longas dist & acirc;ncias. No entanto, apenas as aranhas selecionaram ativamente os troncos queimados de baixo contraste, indicando especializa & ccedil;& atilde;o de habitat. Os experimentos de preda & ccedil;& atilde;o mostraram que os modelos pretos se beneficiaram da camuflagem em troncos queimados. Por outro lado, os modelos marrons exigiram mais tempo e reduziram a dist & acirc;ncia na busca do predador em compara & ccedil;& atilde;o com os alvos pretos em troncos n & atilde;o queimados. Sugerimos que os efeitos p & oacute;s-fogo possam aumentar os contrastes de cor e a preda & ccedil;& atilde;o sobre indiv & iacute;duos com cores contrastantes em rela & ccedil;& atilde;o ao substrato, o que se traduz em press & otilde;es seletivas para o polimorfismo de cor e escolhas de substratos correspondentes. (AU) | |
| FAPESP's process: | 19/01934-3 - Colour change and camouflage in coastal benthic crustaceans: occurrence, selective pressures and ecological function |
| Grantee: | Rafael Campos Duarte |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 22/00946-0 - Adapting to a changing world: how variability in predation risk and in the availability of new habitats affect colour change and camouflage in chameleon prawns (Hippolyte varians)? |
| Grantee: | Rafael Campos Duarte |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |
| FAPESP's process: | 19/08474-8 - Freshwater ecosystems under climate change: impacts across multiple levels of organisation |
| Grantee: | Gustavo Quevedo Romero |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |