19 January 2022

These high gloss eggs look like ceramic but were actually laid by members of the Tinamou family, native to Central and South America.

Tinamous are shy, secretive ground-dwelling birds that resemble chickens but are closely related to ostriches and emus. 46 species range in size from the 8’7″ small-billed tinamou (Crypturellus parvirostris) to the 16-19″ grey tinamou (Tinamus tao). No matter where they live, rainforest, savannah or shrubland, all of them lay shiny eggs in a nest on the ground.

One would think that shiny eggs would be easily found by predators, especially after researchers examined the cuticle, the egg’s outside layer, and found:

They quantified its smoothness down to the nanometer scale and measured the shininess of the mirrorlike surface, finding that tinamou eggs are up to 14 times as glossy as the average chicken egg. A spectroscopy test also revealed that the blue eggs were iridescent (the green and brown eggs were too shiny for the spectrometer to accurately measure).

— New York Times: Easter Eggs without a Kit

However, the male tinamous who build the nest, incubate, and rear the chicks are generally successful as long as their habitat is not destroyed. 80% of the species are stable.

Watch the eggs’ beauty transform in this video of elegant crested tinamou eggs (Eudromia elegans) in a captive breeding facility.

When the chicks grow up they will look like this.

Read more in the New York Times: Easter Eggs Without The Kit.

(photos from Wikimedia Commons, embedded from Tumblr and screenshot from embedded YouTube video; click on the captions to see the originals)