Chemistry of Birds

The Chemistry of Birds (22): UV Protection

November 30, 2025 by Kai Pflug No Comments

Like humans, birds can be affected by intense UV radiation. It can cause cancer, damage skin and feathers, and suppress the immune system. Staying in the shade is not always an option, particularly for birds in the tropics or at high altitudes, and the availability of avian sunscreen products in these locations is also very limited. So, what kinds of UV protection do birds utilize instead?

Mostly chemical ones, and not just because chemistry is the overall topic of this series of posts.

Substantial UV protection is delivered by the feathers:

Keratin, the protein feathers are made of, absorbs part of the UV spectrum.

Melanin pigments in the feathers (eumelanin: black/brown, pheomelanin: reddish-brown) are a group of heterogeneous conjugated polymers synthesized by the birds via the oxidation of tyrosine. The irregular conjugated structure of melanin means its electrons can absorb radiation across a broad range – UV, visible, and even near-infrared. The messy structure of the pigment also means that the electrons have many pathways to lose the energy and turn it into heat.

Melanin

Carotenoid pigments (found in red, yellow, and orange birds and obtained from the avian diet) are antioxidants. They neutralize free radicals formed by UV radiation before these free radicals can cause damage.

The skin also plays a role in UV protection. Like human skin, bird skin contains melanocytes producing melanin. Areas with bare skin, which require particularly good UV protection (such as the heads of vultures), therefore tend to be dark.

Finally, preening oils also contain antioxidants and therefore may contribute to UV protection.

Photo: White-backed Vulture, Hluluwe, South Africa, November 2018

“Melanin” by ClickChemist is licensed under CC BY-SA 4.0.

Written by Kai Pflug
Kai has lived in Shanghai for more than 21 years. He only started birding after moving to China, so he is far more familiar with Chinese birds than the ones back in his native Germany. As a birder, he considers himself strictly average and tries to make up for it with photography, which he shares on a separate website. Alas, most of the photos are pretty average as well. He hopes that few clients of his consulting firm—focused on China’s chemical industry—ever find this blog, as it might raise questions about his professional priorities. Much of his time is spent either editing posts for 10,000 Birds or cleaning the litter boxes of his numerous indoor cats. He occasionally considers writing a piece comparing the two activities.