Guillemot Eggs Possess Self-Cleaning Nano-Structure Guardians

Guillemot eggs can be found perched on exposed cliffs, at the mercy of the elements without the benefit of a nest. Now, scientists have discovered exactly how these eggs survive such harsh conditions. It turns out that unique nano-structures in the eggs act as self-cleaning guardians, preventing the eggs from falling and keeping them from salt and guano exposure.

Guillemots are seafaring birds. Usually found around rocky coasts, they possess the ability to dive into the water to capture prey. While underwater, these creatures use their wings to help swim, steering themselves toward fish or crustaceans. Yet these birds also lay speckled eggs that can often be found perched on cliffs, blasted by sea spray and wind.

"This work was started by accident," said Steven Portugal, one of the researchers, in a news release. "A water spillage over an egg collection revealed how differently water droplets acted on guillemot eggshells in comparison to other species. The water droplets stayed as a sphere on the eggs, typically an indication of a hydrophobic surface."

In order to find a little bit more about the adaptations seen in the eggs, scientists conducted a comparative study of over 400 species in total, including birds nesting in similar environments and those closely related to guillemots. They performed engineering tests on the eggshells, closely analyzing the properties of different egg species.

What did they find? It turns out that guillemot eggs have an edge over other birds'. Nano-structures in the eggs gave the shells a higher water contact angle, rougher surface (which would prevent the egg from falling off of cliffs) and a higher rate of gaseous exchange. This last property helps the eggs cope with the high salt content from sea spray.

The study gives researchers a new understanding of these eggs and explains exactly why they're so adept at surviving an oceanic environment. Yet the findings also have practical applications. More and more components of industry are employing biomimicry, which is the process of copying "designs" found in nature. By "copying" the guillemot egg's hydrophobic nano-structures, scientists could help create new materials that are better suited for wet environments.