Sunbird colors
Many species of sunbirds overlap in their environmental niches - they share location and food sources etc. This is possible through the establishment of sensory (here visual) niches, based on the color of the males and strong sexual selection by females. Under such conditions, feather patterns of male members of sunbird species have evolved to balance two differing selective forces: the need to camouflage and the need to attract. Iridescence seems to play an important role there - it is an effect created by the nano-structure of keratin, air and melanin of their feathers, which makes the feather shine under some angles but appear almost black from others.
At the same time, nest-caring females have a strong need to be well-camouflaged, which is supported by a strong sexual dimorphism, in which male members of sunbird species often display a lot of color, while females appear comparatively dull.
This is a picture of the same brown-throated sunbird I posted yesterday, here showing the signature brown throat, which to me seems the least obvious feature. Despite their impressive colors, I still find them hard to spot in the wild.
Sunbird colors
Many species of sunbirds overlap in their environmental niches - they share location and food sources etc. This is possible through the establishment of sensory (here visual) niches, based on the color of the males and strong sexual selection by females. Under such conditions, feather patterns of male members of sunbird species have evolved to balance two differing selective forces: the need to camouflage and the need to attract. Iridescence seems to play an important role there - it is an effect created by the nano-structure of keratin, air and melanin of their feathers, which makes the feather shine under some angles but appear almost black from others.
At the same time, nest-caring females have a strong need to be well-camouflaged, which is supported by a strong sexual dimorphism, in which male members of sunbird species often display a lot of color, while females appear comparatively dull.
This is a picture of the same brown-throated sunbird I posted yesterday, here showing the signature brown throat, which to me seems the least obvious feature. Despite their impressive colors, I still find them hard to spot in the wild.