Thursday, June 30, 2022

Small Ground Finch

My last post gave a short description of Charles Darwin in the Galapagos Islands and the medium ground finch. 
The Highlands on Santa Cruz Island. 

This post is on the small ground finch, another of Darwin's finches. The small ground finch is found on every island in the Galapagos except for Genovesa, Wolf and Darwin islands. It is abundant and widespread and most common in arid coastal and transitional areas, but moves into the highlands following the breeding season. 
Urbino Bay on Isabela Island. 

Its beaks is short and pointed, with a slightly curved culmen (the upper ridge of the bill). Its beaks is smaller than that of the medium ground finch, but there is overlap in size between them, particularly on islands where only one of the two species exists. Where both species compete directly, the difference between their beaks is greater. The male is black with white-tipped undertail coverts and the females and young are brown with streaked underparts. Those found in the highlands have larger and more pointed beaks, smaller feet and smaller claws, compared to the lowlands.

1 comment:

  1. I wonder what the advantage/disadvantage is between the beak sizes and shapes. Any idea?