Glorious green on St. Paddy’s Day

In celebration of what is to come in the not too distant future…a shock of green to help you think “spring!”

The verdant California oak savannah, in all its spring glory.

Fern fronds are one of the first to unfurl in the spring.

Gray Tree Frogs (that can also turn green) love to sit on the leaves of my raspberries where they can find all sorts of pollinators coming to the flowers.

Green Iguanas (which can be green, gray, and orange-brown as they control the dispersal of pigment in their chromatophores) are very common in Mexico and Central America — so common that they are hunted and “taste like chicken”.

Many members of the parrot family sport green feathers. But there is no green pigment, so how is the color produced in the bird’s plumage?

In elementary school we learned that to get green color you mixed yellow and blue — and that’s just what birds do. There is no blue pigment in birds’ feathers either, but incoming light scattered off air pockets in the feather structures can be reflected to our eyes and appear blue. By adding this reflected light to the yellow light reflected from underlying (carotenoid) pigments in the feathers, the birds are doing just what we did in mixing our paints. This is illustrated below by a Broad-billed hummingbird as it approaches a feeder.

The light angle changes as the hummer approaches the feeder, so that we first see mostly the blue reflected light from structural elements of the feather, and then a mix of the yellow light reflected from carotenoid pigments plus the blue reflected light, which makes the sitting hummer look green.

Many insects, both predators and prey, are green, which is usually good camouflage, but in the case of this praying mantis completely misses the mark.

But this is what we are really waiting for — the first multicolor blooms of spring, like this wild columbine from the backyard.

As they say in Eire-land

“May your blessings outnumber the shamrocks that grow. And may trouble avoid you wherever you go.” –Irish Blessing