Goldcrest
Goldcrest [Regulus regulus]
Gary Chalker / Getty Images
The goldcrest's scientific name is Regulus regulus, and regulus means "prince, little king." This species is in the kinglet family and is the smallest of all the birds in Europe. It measures only about 3.3 to 3.7 inches in length and weighs a minuscule 0.16 to 0.25 ounces. The species may be small, but it is mighty and doesn't mess around when it comes to raising young. As many as a dozen eggs incubate at once, and sometimes a female will have two broods a season.