zygodactyly

(from the article `reptile`) ...tails capable of supporting most of the weight of the animal or used habitually for grasping—for clinging to their aerial supports. For this ... ...have long (sometimes extremely long), graduated tails, usually with the individual feathers tipped with white. The legs vary from medium to rather ... ...
Found on http://www.britannica.com/eb/a-z/z/13

zygodactyly

zygodactyly An arrangement of digits in birds, with two toes facing forward (digits two and three) and two back (digits one and four). This arrangement is most common in arboreal species, particularly those that climb tree trunks or clamber through foliage. Zygodactyly occurs with woodpeckers, flickers, nuthatches, and parrots. ...
Found on http://www.wordinfo.info/words/index/info/view_unit/614/11
No exact match found