Question regarding a feature on many small birds. (2 Viewers)

[beaneater]

Idk if this question´s a bit silly but why do so many small birds tend to have white "eyebrows"? (Eg - a lot of prinias and warblers). What advantage does it have for them or is it just there for aesthetics?

 

[KenM]

An interest

Idk if this question´s a bit silly but why do so many small birds tend to have white "eyebrows"? (Eg - a lot of prinias and warblers). What advantage does it have for them or is it just there for aesthetics?

An interesting question!
It appears to have been conferred on many groups, Waders, Pipits, Shrikes, Chats, Warblers and Accipiters.
Must be some evolutionary reason…albeit one that’s beyond me.

Cheers

 

[delia todd]

Similar to that is why so many birds have a white spot behind the eye... seen particularly in Hummingbirds, some Honeyeaters in Australia and quite a few other similar birds in Asia.

 

[Welsh Peregrine]

One small part of the answer to the original question is that an eye stripe or eyebrow is a relatively easy feature to evolve as it corresponds to a feather tract; alter the colour of the tract and you get a stripe. The second part of the question then becomes why is a stripe selected for? Here it is likely that there will not be a “one size fits all” answer; three explanations that spring to mind immediately are camouflage (bitterns, snipe, nightjars); anti glare (possibly shrikes, raptors) and display.