Naturalist and author defines the role of colour in nature

Jan 21, 2010

Naturalist, author and professor Michael Runtz

Bursts of colour seem hard to come by in mid-January but naturalist and author Michael Runtz put an end to that on Jan.17 at his presentation on the role of colour in nature titled Sex, Survival, and Success.

Presented as a partnership between the Nature Lover’s Bookshop in Lanark and the Mississippi Madawaska Land Trust Conservancy (MMLTC), Runtz’s talk was the first in the bookshop’s winter workshop series.

Runtz has been a naturalist all of his life and has published nine books on natural history. He currently teaches natural history and ornithology at Carleton University.

A lively and entertaining speaker, Runtz captivated the large audience that gathered at the Lanark Legion and began his talk/slideshow by stating that “Just about every single colour under the sun can be found in nature.”

Next he challenged the audience’s preconceptions on the topic, stressing the fact that plants use colour to exploit insects and other animals. Focusing on flowers in particular, he stressed that the gorgeous colours found on a wide variety of flowers exists “for the eyes of the insects that the flower wants to exploit for its own purposes” (reproduction and proliferation).

For example, the colorful patterns found on the Canada violet and wood sorrel flower are known as nectar guides. These guides act like runway lights at an airport directing the insect to nectar and pollen, thereby guaranteeing the plants’ future chance at survival.

In the same way blueberry plants exploit bears, attracting them to their ripe, swollen fruit which they consume and later excrete, spreading the plants’ seeds.

In the animal world Runtz pointed out how colour functions for a variety of reasons. Male creatures are often brightly coloured to attract a mate. Female mallard ducks, for example, are known to choose their mates by the brightness of the green on their heads.

Coloration can also function as camouflage. The female spruce grouse, whose vivid feathered patterns match the sunlit patterns of the surrounding forest, demonstrated this function perfectly.

A slide of the sphinx moth showed how colour can act as a weapon. When the moth opens its wings, a striking pattern of two wide, brightly coloured glaring eyes functions to startle a potential predator.

Certain animals like the tree frog and the snowshoe hare will change colours at varying rates to blend in with their environments, protecting them from predators.

Insects and animals use two different kinds of mimicry to fend off predators. The first is called Batesian mimicry, named after Henry Bates, an English entomologist. In this case a harmless animal will mimic the coloration of a harmful one the way a viceroy butterfly mimics the colouration and patterning of a monarch butterfly. The latter is poisonous in its caterpillar form. A second example is the harmless hover fly that in coloration and pattern closely resembles its bee stinging cousin.

Mullerian mimicry, named after German zoologist Hans Muller, occurs when multiple species resemble each other and are all harmful. The yellow and black coloration of many stinging species of bees and wasps are an example of this type of mimicry.

Runtz’s talk was entertaining and educational which is something that he aims for. “I’m hoping to educate people and turn them onto nature by creating an interest in it. If people want to preserve something like they do with MMLTC, there first has to be an interest. For me, understanding inspires interest and interest inspires the need to preserve and conserve.”

Store owner Mary Vandenhoff was thrilled to have Runtz as a presenter for their winter series of talks and said, “We are delighted to have him. He really loves and values nature and is committed to it for the long term which reflects the feelings and aims of our store and the land trust.”

Michael Runtz’s books are available at the Nature Lover’s Bookshop.

Next in the series is a talk by artist Blair Paul titled “On the Edge of Discovery” at the bookshop on Saturday January 23 from 2-4pm. This event is free