Cezário, R. R., Gorb, S. N., & Guillermo-Ferreira, R. (2022). Camouflage by counter-brightness: the blue wings of Morpho dragonflies Zenithoptera lanei (Anisoptera: Libellulidae) match the water background. Journal of Zoology, vol. 317, pp. 92– 100. https://doi.org/10.1111/jzo.12955
From mammals to bugs, a number of animals (and even vegetation) exhibit putting iridescent colors. Iridescence, an optical phenomenon of structural origin (i.e., micro- and nanostructures on the floor of an animal), is characterised by its color altering with viewing angles. Furthermore, the brightness of the iridescent colors displayed by animals rely upon the visible background and ambient gentle situations the place they reside.
Therefore, animals could exhibit particular behavioural shows in particular circumstances to reinforce the visibility of their colors, whether or not to draw mates or push back rivals. Moreover, though counterintuitive, iridescence could operate to keep away from predators by background matching. Birds, fishes, reptiles and, particularly, the Morpho dragonfly Zenithoptera lanei (Anisoptera) profit from this protecting operate of iridescence as they grow to be much less distinctive (i.e., cryptic) from glossier backgrounds.
As an example, Z. lanei, a Neotropical dragonfly inhabiting the Brazilian savannah (i.e., Cerrado), mix their brilliant iridescent colors with a novel wing-clapping show. Each wing surfaces of the Morpho dragonfly exhibit a remarkably brilliant iridescence, UV-blueish on the dorsal floor, whereas black-reddish on the ventral floor. Moreover, Z. lanei can fold their wings dorsally (the one different anisopteran able to folding their wings dorsally is the Australian Cordulephya).
After observing this distinctive behaviour, in addition to the colors of Z. lanei, we requested ourselves if (i) the iridescent colors of Z. lanei wings operate as a visible technique to cut back wing detection by their brightness matching the background; and (ii) the detection of the wings towards vegetation and water varies in response to their predators, prey, and conspecifics.
By mathematically modelling the visible system of avian predators, dipteran prey, and conspecifics, we discovered proof that Z. lanei males are in a position to exhibit their angle-dependent iridescence in a spatiotemporal dynamic method.
The angle-dependent iridescence of the wings of Z. lanei males match the brightness of the background they’re naturally discovered through which disrupts their silhouette for predators, prey and rivals. Nonetheless, by displaying particular behaviours (such because the wing-clapping) towards particular backgrounds and light-weight situations, Z. lanei is ready to management when and the place to point out its colors.
To our information, that is the primary examine exhibiting that animals could possibly match, as an example, the brightness of inland-water backgrounds. Specifically, the iridescent colors of Z. lanei wings, which additionally exhibit diffuse reflection, permit males to keep away from undesirable conspecific interactions and detection by prey in addition to by visual-oriented chicken predators.