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Some of my favorite studies in animal anatomy center around coloration. How animals are colored - for example, pigment versus structural coloration - can lead to “next questions” about why they are colored as they are. Two of my recent paintings highlight very different strategies in avian coloration.

The Nicobar pigeon is amazingly flashy. The head and neck are a soft blue-grey with long, tapered feathers, but the rest of the plumage ranges through metallic and iridescent greens, autumn tones, blues and violets. I assumed that Nicobar pigeons would be sexually dichromatic, as is common in birds, but the female’s coloration is only slightly more subdued. Both sexes wear essentially the same spectacular palette.

Nicobar Pigeon, watercolor on paper

The grey morph Eastern Screech Owl I painted represents a very different approach. Rufous, brown and grey morphs are all masters of camouflage. Their false “ears” are actually feather tufts that can be flattened against the head or erected when the bird assumes a vertical pose. Mottled plumage breaks up the owl’s outline, while the dark streaks on its chest can resemble fissures in tree bark.

Screech Owl Grey Morph, watercolor on paper

My assumption was that the different owl color morphs live in different environments or have very different lifestyles, but this proved to be a wonderfully nuanced subject. Researchers have investigated how the frequency of the different morphs changes with climate. In Eastern Screech Owls, the rufous morph is associated with warmer environments, including urban microclimates that are warmer than surrounding areas.

Both species were fun to paint, but both also raised interesting next questions. Why are Nicobar pigeons so flashy if males and females wear a similar color scheme? And research into screech owl color morphs introduced me to Gloger’s rule: the tendency for populations of some warm-blooded animals in warm, humid environments to be more heavily pigmented. Which, naturally, left me wondering: what other animals follow this pattern?