noun
nestling; baby bird still in the nest
Refers to a young bird that has not yet left the nest. The reading すびな is a voiced variant.
木の上に巣雛が三羽いる。
There are three nestlings in the tree.
巣雛はまだ飛べない。
The nestlings cannot fly yet.
Compound of 巣 (す, 'nest') and 雛 (ひな, 'chick'). The reading すびな is a result of rendaku (sequential voicing).