Watching the Boise downtown Peregrine Falcon eyasses. By this time, there may be three that have hatched today. I have only seen two, but several reports of watching an egg hatch. And here is the definition of eyas or the plural, eyasses.
Definition of EYAS
: an unfledged bird; specifically : a nestling hawk
Origin of EYAS
Middle English, alteration (by incorrect division of a neias) of neias, from Anglo-French niais taken in the nest, from Vulgar Latin *nidax nestling, from Latin nidus nest — more at nest
First Known Use: 15th century [New Merriam Webster Dictionary]