| Link | Quote | Stars | Tags | Author |
| c835c55 | Female song is uncommon in birds. | David Lack | ||
| 5b1ae57 | 'duetting' is uncommon in birds, but has been recorded for various tropical species. | David Lack |
| Link | Quote | Stars | Tags | Author |
| c835c55 | Female song is uncommon in birds. | David Lack | ||
| 5b1ae57 | 'duetting' is uncommon in birds, but has been recorded for various tropical species. | David Lack |