Portal:Birds/DYK/4

...that sexual size dimorphism in the brown songlark is among the most pronounced in any bird, with males as much as 2.3 times heavier than females?
...that rufous whistler birds, unlike all other whistler birds, never forage on the ground but high up in trees or other high places?
...that the bill of the magpie duck (pictured) becomes green as the bird gets older, and its black crown may go completely white?