Females and younger birds are less distinct, and more similar in appearance to some chaffinches. Another work of his was based on the songs of chaffinches. These include flamingos, terns, pied avocets, Eurasion wigeons, and common chaffinches. His attempts to introduce bullfinches, chaffinches, nightingales, and skylarks were not successful. This was first demonstrated in chaffinches ("Fringilla coelabs"). Chaffinches and robins are the most common species in the woodlands. Birds that can be seen in the area include, skylarks, sparrowhawks, kestrels, goldcrests and chaffinches. Chaffinches, nightingales and other songbirds can be heard in the early summer. Common chaffinches first breed when they are 1 year old. Birds found in the area include goldcrests, chaffinches, robins, black woodpeckers, and white-backed woodpeckers.