It just occurred to me this morning, after catching sight of a cardinal in my yard, that there are quite a few birds with significant amounts of red, yellow, black, blue, orange and white in their plumage. But there don’t seem to be many with green, at least in temperate climates. In the tropics, you have many species of parrots, quetzals, jays and others. In the temperate zone, you have some hummingbird species.
Why are birds with significant amounts of green on them so rare in temperate areas?
Pasadena Parrots: they are distinctly green. They are non-native, of course, but they seem to have flourished for decades, and you see small flocks of them around the area quite often. I am not sure if Southern California exactly counts as “temperate”, but it is not tropical.
Green herons aren’t particularly green, to the point where you look at them and ask “Why are they called green herons?” Certainly not lorikeet green which is probably what the OP was asking about.
I’d guess it’s that a bright green bird would stand out too well during the six months of the year that the leaves are not green. Although that doesn’t explain the lack of bright green migrating passerines. So…I dunno. Pretty good question.
I have noticed that the yellow birds such as gold finches and yellow warblers blend into the local underbrush extremely well. So maybe it’s just that brown and yellow are fractionally better colors for avoiding predators up here in the frozen north.
The Perfect Master touched on the source of green coloration in birds in this column. In most species it requires a particular microscopic structure for the feather (to make blue) along with an overlaid yellow pigment layer. Since green coloration requires two simultaneous adaptations, my WAG would be that it’s just the luck of the draw that very few North American species ended up with them both.
From the sounds of it, our equivalent here in Chicago would be the Monk Parakeets/Quaker Parrots. The University of Chicago area (Hyde Park and Washington Park) is kind of famous for them. They have a very distinct call, too.
Define “temperate climes”? There are lots of green birds in South Africa, for instance, and they run the gamut of greens - turacos, white-eyes, parrots, sunbirds (really pretty - check out this one), greenbuls… Last I checked, South Africa was mostly temperate. Of course, a lot of that is evergreen foliage, so that might tie in with chacoguy’s theory.