Unique nano-structures present on the eggshells of guillemot eggs are at least partially responsible for the egg’s extreme resiliency, according to new research from the University of London.
Guillemot eggs are often left by their mothers completely unprotected on exposed seaside cliffs — with no nests — until this new research it hadn’t been completely clear what stopped the eggs from simply falling off the cliffs, and what protected them from their exposure to saltwater and guano. But now, the new research has found cone-like nano-structures on the surfaces of the eggs that act as ‘self-cleaning guardians of the eggs’ — enabling survival even in their extreme environment.
Lead researcher, Dr Steven Portugal of the Royal Veterinary College, University of London, explained: “This work was started by accident. A water spillage over an egg collection revealed how differently water droplets acted on the guillemot eggshells in comparison to other species. The water droplets stayed as a sphere on the eggs, typically an indication of a hydrophobic surface.”
After discovering the nano-structures on the guillemot eggs, the researchers did a comparative study with the eggs of over four hundred different species, including those closely related to the guillemots — the newly discovered nano-structures are completely unique to guillemot eggshells.
The Society for Experimental Biology continues:
They performed engineering tests on the eggshells and found that those of the guillemot have several unique proprieties due to these nano-structures: higher water contact angle (which means they were more hydrophobic), rougher surface (which helps prevent the egg from falling off the cliff or the parents feet) and higher rate of gaseous exchange (which helps them cope with the high salt content from the sea spray).
Similar hydrophobic nano-structures have already been found before — in the Lotus Leaf — and researchers have already begun working on replicating the structures in the lab. Such water-repelling structures could be of great use in a wide-variety of capacities/materials. The new findings may help in the creation of such materials.
A bit of background on the species:
The Common Guillemot — also known as the Common Murre — is a species of large auk that is found throughout the low-Arctic and boreal waters of the North-Atlantic and North Pacific. It spends almost all of its time at sea, only coming to land to breed — mostly on rocky cliffs or islands. While it’s not the most agile bird in the air it is an incredible over — capable of diving down underwater to at least 600 feet. The birds typically lives in large colonies consisting of hundreds to thousands of individuals, or larger.