Our mission is to share the wonders of the natural world by publishing books from experts in the fields of gardening, horticulture, and natural history. Grow with us.

Crypsis: Nature’s camouflage

by Timber Press on August 13, 2014

in Natural History

A camouflaged looper hides from its enemies by fastening petals of the blazing star (Liatris spicata) to its back with silk. This strategy has earned this caterpillar its common name and ensures that it will always perfectly resemble its background, no matter what flower it feeds on.

A camouflaged looper hides from its enemies by fastening petals of the blazing star (Liatris spicata) to its back with silk. This strategy has earned this caterpillar its common name and ensures that it will always perfectly resemble its background, no matter what flower it feeds on.

Chances are your garden is full of life that you have never seen. Don’t feel bad; there is an excellent reason these animals are difficult to see. Any animal that is easy to find quickly becomes a predator’s next meal.

A mother bird that must find thousands of caterpillars in just a few days to feed her young becomes very good at finding caterpillars. Over the eons, this has made caterpillars equally good at looking like their background, a condition known as crypsis. Insects that come to resemble a decayed section of leaf, a conifer needle, the bark they are resting on, and so forth are more difficult to locate than insects that contrast with their background. Often that’s all it takes to discourage a bird from searching for cryptic insects.

The varied textures and shades of tree bark provide excellent opportunities to “disappear” from sight. Here a nocturnal waved sphinx moth goes undetected by foraging birds by remaining motionless by day amid the lichens on this tree trunk.

The varied textures and shades of tree bark provide excellent opportunities to “disappear” from sight. Here a nocturnal waved sphinx moth goes undetected by foraging birds by remaining motionless by day amid the lichens on this tree trunk.

Birds must hunt quickly and efficiently; they must find lots of food to feed their hungry chicks and they must do it as quickly as possible to minimize their own exposure to predators. If a caterpillar looks just like a twig, a bird would have to look closely at every twig to find it. Looking like a twig, then, elevates the cost of searching beyond what the bird can afford both energetically and ecologically.

Few caterpillars blend in with their food plant as well as the curve-lined angle. This specialist on juniper (Juniperus virginiana) resembles the needles it eats so well that even sharp-eyed birds have difficulty seeing it.

Few caterpillars blend in with their food plant as well as the curve-lined angle. This specialist on juniper (Juniperus virginiana) resembles the needles it eats so well that even sharp-eyed birds have difficulty seeing it.

Fortunately, gardeners can learn to find even the most cryptic species themselves by learning where to look, when to look, and what to look for. The rewards are great from this investment, for cryptic insects are true marvels of evolutionary design.

Yellow-flowered legumes such as partridge pea (Chamaecrista fasciculata) and various Senna species provide the perfect backdrop (and food) for larvae of the cloudless sulfur butterfly. As long as they stay within a flower, these caterpillars are very difficult to see.

Yellow-flowered legumes such as partridge pea (Chamaecrista fasciculata) and various Senna species provide the perfect backdrop (and food) for larvae of the cloudless sulfur butterfly. As long as they stay within a flower, these caterpillars are very difficult to see.

All images by Doug Tallamy.

__________

RD_authorphoto_by Ralph VituccioRick Darke is a landscape design consultant, author, lecturer, and photographer based in Pennsylvania who blends art, ecology, and cultural geography in the creation and conservation of livable landscapes. Darke has studied North American plants in their habitats for over three decades, and his research and lectures have taken him to Africa, Australia, Brazil, Costa Rica, Chile, Japan, New Zealand, and northern Europe. His books include The Encyclopedia of Grasses for Livable Landscapes, The American Woodland Garden, and In Harmony with Nature. You may also be interested in the author’s own Web site, RickDarke.com.

DT_authorphoto_02_by Jon Baldivieso CROPPEDDoug Tallamy is currently professor and chair of the department of entomology and wildlife ecology at the University of Delaware in Newark, Delaware, where he has taught insect taxonomy, behavioral ecology, and other subjects. Chief among his research goals is to better understand the many ways insects interact with plants and how such interactions determine the diversity of animal communities. Doug won the Silver Medal from the Garden Writer’s Association for his book, Bringing Nature Home. You may also be interested in the author’s own Web site, plantanative.com.

__________

Click image for a look inside this book:


“Two giants of the natural gardening world, Rick Darke and Doug Tallamy, have collaborated on their best work yet.”—The New York Times

{ 0 comments… add one now }

Leave a Comment

Previous post:

Next post: