Wing Scales Aid Thermoregulation

Biological Strategy

AskNature Team

Maintain Homeostasis

When a living system is in homeostasis, it means that internal conditions are stable and relatively constant. For example, a human’s internal temperature is approximately 37 degrees Celsius (98.6 degrees Fahrenheit) unless there’s an illness. The human body maintains this temperature despite external ambient temperature. However, as with all physiological processes, maintaining homeostasis requires communication and coordination. So living systems have ways to detect changes from the norm, mechanisms to cause an adjustment, and negative feedback connections between the two. A desert lizard called the Gila monster offers a good example of maintaining homeostasis. The lizard goes from eating large meals to fasting for extended time periods. To maintain its blood sugar levels at a steady level, when food is scarce, its endocrine system releases a hormone that raises its blood sugar levels.

Search this Function

Modify Light/Color

Color in living systems comes from pigments and the interaction of light with surfaces. Color serves many purposes for living systems, such as attracting prey or mates, providing warnings, or protecting through camouflage. To create the effects needed for each purpose, living systems must control the expression or visibility of pigments and the interactions (such as reflectance and refraction) of light. To do so, they have strategies that modify color or light to increase or decrease the color’s position, intensity, opacity, and more. Male hummingbirds, for example, have brightly colored feather patches on their throats; the coloring comes from pigments, structures that refract light, or a combination of the two. When a male hummingbird hovers near a potential mate, it modifies the angle of these feathers to create a bright, colorful display. However, when it needs to mute the colors to reduce conspicuousness, such as to avoid a predator, it modifies the angle again.

Search this Function

Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

Search this Living System

The wing scales of a green birdwing butterfly help regulate body heat by using a honeycomb structure to enhance black pigments found in the wings.

Image: David Bygott /

“At the other extreme are butterflies like Ornithoptera priamus–‘ultrablack,’ [Peter] Vukusic calls it. Again, structure is key. Its honeycombed wing scales absorb more light than would a smooth surface, so the black looks blacker still. The hue helps regulate body heat and makes other wing colors stand out in mating displays.” (Holland 2007:30)

“In our previous studies, we have already discovered that structurally assisted blackness is a common phenomenon in black butterfly wings and furthermore an ideal structure for improving the blackness. Compared with the porous structures in other species of butterflies, the structure in the cover scales of the black wings of butterfly Ornithoptera goliath is mainly comprised of adjacent inverse V-type ridges, which can effectively reduce reflection, while at the same time keep transmission at a relatively low level. However, limited by the optical properties of the natural chitin/melanin composite, the effect of the structure in producing black materials is far from fully exploited.” (Zhao et al. 2010:877)

Last Updated August 28, 2020

References

Journal article

Super black and ultrathin amorphous carbon film inspired by anti-reflection architecture in butterfly wing

Carbon | February 23, 2021 | Qibin Zhao, Tongxiang Fan, Jian Ding, Di Zhang, Qixin Guo, Masao Kamada

embedly preview

AskNature