La phase des oiseaux, un terme à bannir ?

In this article, we propose you to distinguish two birding terms often used indistinctly : « morph » and « phase ».
The Eleonora’s Falcon (Falco eleonorae) for example, can be all dark or with a white belly with black marks. Some birders speak about dark phase and light form. But if you look at the dictionary definition of « phase », you will see that it refers to a temporary state in a larger process of change. Change is thus implicit in the expression « phase ». But a dark phase Eleoonora’s Falcon is always going to stay a dark phase Eleoonora’s Falcon. It isn’t going to change into a light phase. Consequently, many birders have instead adopted the expression « morph », such as dark morph Eleoonora’s Falcon. This comes from the Greek noun « morphe », meaning « form ».