Peer into the mouth of a hungry Gouldian/Zebra Finch, you will see luminous nodules (papillae)on the sides of beaks & markings on the inside of their mouths.
The marks help parents find their chicks in a dark nest. The reflective quality of marks may help parents hone in on their chicks' mouths.
Peer into the mouth of a hungry Gouldian/Zebra Finch, you will see luminous nodules (papillae)on the sides of beaks & markings on the inside of their mouths.
The marks help parents find their chicks in a dark nest. The reflective quality of marks may help parents hone in on their chicks' mouths.