Where in nature can we find examples of natural "hoods" - either for reducing UV / sun exposure or for providing shelter from rain?

Question

I'm in the process of designing a more functional "hood" to block UV / sun exposure and also provide shelter from rain. I believe that the best gear and products are developed by "looking to nature" for inspiration. Therefore, what solutions exist in nature to reduce the amount of UV / sun exposure or provide shelter from rain?

I am specifically (though not exclusively) interested in mimicking any hood-like features that animals exhibit, or any natural means of blocking the UV rays/sun such as the way trees in the rain forest create a natural canopy (perhaps less obvious examples will generate more inspiration). Are there are any other means of reducing UV/sun exposure or offering shelter from the rain?

Hoping to gain some inspiration here.

Thanks!

Answer 1

Protecting against UV is usually done with a covering like fur, feathers, scales, a hard shell, etc, or pigment.

Our own species is a great example of the latter. It seems we emerged on the plains of central Africa where UV exposure is a serious issue. The first humans most likely had dark skin, as humans still do that stayed in that area. Those that migrated north encountered a different tradeoff where UV exposure was less of a threat and being able to make vitamin D from sunlight more of a advantage. As a result, those with a long ancestry in more polar regions evolved light-colored skin. As people migrated to different places, the lightness/darkness of the skin evolved to suit the local conditions.

Sunscreen is something light-colored people can use to temporarily attenuate UV. Unlike the natural melanin, it doesn't also attenuate visible light, so doesn't appear dark.