Concealing Coloration in Animals

by Judy Diamond, Alan B. Bond

Overview

The biological functions of coloration in animals are sometimes surprising. Color can attract mates, intimidate enemies, and distract predators. But color patterns can also conceal animals from detection. Concealing coloration is unusual because it is an adaptation not only to the visual features of the environment but also to the perceptual and cognitive capabilities of other organisms. Judy Diamond and Alan Bond bring to light the many factors at work in the evolution of concealing coloration.

Animals that resemble twigs, tree bark, stones, and seaweed may appear to be perfect imitations, but no concealment strategy is without flaws. Amid the clutter of the natural world, predators search for minute, telltale clues that will reveal the identity of their prey. Predators have remarkable abilities to learn to discriminate the fake from the real. But prey have their own range of defensive tactics, evolving multiple appearances or the ability to change color at will. Drawing on modern experimental evidence of the functional significance of animal color strategies, Diamond and Bond offer striking illustrations of how the evolution of features in one organism can be driven by the psychology of others.

Concealing Coloration in Animals takes readers on a scientific adventure that explores creatures inside mats of floating seaweed, mice and lizards on desert rocks and sand, and rare parrots in the rainforest of New Zealand. Color photographs extensively document the mind-boggling array of deceptive strategies animals use to blend in, mislead, or vanish from view.

Product Details

ISBN-13:	9780674074231
Publisher:	Harvard University Press
Publication date:	04/09/2013
Sold by:	Barnes & Noble
Format:	eBook
Pages:	283
File size:	34 MB
Note:	This product may take a few minutes to download.

About the Author

Judy Diamond is Professor and Curator at the University of Nebraska State Museum.

Alan B. Bond is Research Professor of Biological Sciences and Co-Director of the Center for Avian Cognition at the University of Nebraska–Lincoln.

Read an Excerpt

Chapter 2: Mistaken Identity

Some of the most unusual animals in the ocean live just below the surface in gigantic, entangled mats of free-floating kelp, called sargassum. These creatures appear exactly like pieces of the intertwined stems, floating bladders, and fronds that make up their habitat. They look very little like their relatives from closer to shore. Drawn together by the convergence of ocean currents, this underwater forest covers a highly variable area, depending on time of year and prevailing winds. In some places, there are just scattered patches; in others the stuff is so thick it can slow sailing vessels. Patches of sargassum are found in the Indian Ocean and in the Western Pacific, but by far the largest one is in the North Atlantic. It is called the Sargasso Sea.

An early explorer of the Sargasso Sea was a young clergyman and botanist, Peter Osbeck. Aboard the merchant vessel, Prince Charles, Osbeck set sail from Sweden in 1750, bound for China and the East Indies. Osbeck was a disciple of Carl Linnaeus, the founder of biological classification, and his primary assignment was scientific exploration. Linnaeus had encouraged the young man to make the trip and had recommended him for the position. In return, Osbeck lavished attention on the natural history of the regions he passed through, bringing back numerous specimens of oriental plants and ultimately producing a detailed narrative of the voyage.

On the trip home, while his ship passed through the eastern edge of the Sargasso Sea, Osbeck eagerly trolled his nets through the mats of seaweed. He collected, among other exotic creatures, several specimens of the sargassum fish, a small and bizarrely colored member of the frogfish family. Osbeck was surprised to see that the fish’s whole body was covered with small leaf-like projections. He was, after all, a botanist, so he likened the projections to little sargassum leaves, and went on to speculate, “Perhaps Providence has clothed this fish with fulcra resembling leaves, that the fishes of prey might mistake it for sea-weed, and not entirely destroy the breed” (Osbeck, 1771, 113). Osbeck’s note on this unusual fish was one of the first published accounts of object resemblance, a form of protective coloration in which an animal adopts the detailed appearance of an inedible object.

Open-water predators such as dolphin fish and yellowtail amberjacks forage around the mats, and the sargassum fish’s resemblance to a wad of seaweed may help it to avoid detection. But sargassum fish have additional means of escape: Both their pectoral and their pelvic fins are shaped more like hands than paddles, allowing them to climb deep into the tangles of the mat. In addition, like all frogfishes, their gill openings are restricted to small circular holes just behind the pectoral fins. When under attack, they can rapidly expel water through these holes and zip away by jet propulsion.

Table of Contents

Contents Preface I. Concealment 1. Disappearing Acts 2. Mistaken Identity 3. Pepper and Smoke 4. Obscured by Patterns II. Perfection 5. Colors in the Mind 6. The Beholder’s Eye III. Isolation 7. Desert Islands 8. Flowing Genes IV. Detection 9. Telltale Signs 10. Psychology of Search 11. Distinctively Different 12. Limits to Invisibility Guide to Common and Scientific Names Notes References Acknowledgments Index

Editorial Reviews

Reading this book stimulated me to think about aspects of my own work in new ways and I would recommend it to all those interested in animal coloration. There is no book that I am aware of that competes with this one… One aspect of this book that distinguishes it from others is the focus on, and insight into, the role of predator cognition in the evolution of concealing coloration. Alan Bond has no equal in this field.

Copeia - Devi Stuart-Fox

This book is a lovely survey, for the general public, of all that is known about concealing coloration, and very nicely weaves the history of the subjects with the facts.

John A. Endler

It is a beautifully written exploration of the extraordinary variety of ways in which animals can make life difficult for the visual systems of their predators and prey in order to gain advantage in a natural world red in tooth and claw… Evolution is interwoven throughout the book.

Current Biology - Graeme D. Ruxton

I wish that many school, college, and university teachers read this book because it gives a very appealing collection of exciting stories of true scientific process and progress… Diamond and Bond show how hidden creatures made evolution recognizable.

Ecology - Johanna Mappes

If you want to read a scientific thriller then this is your book. Do not expect that, like Hercule Poirot’s cases, you will have a final answer on the last page. You may finish the book with more questions than when you started. That is the fun! This book opens your mind so you will never ‘see’ the world the same way again.

Canadian Field-Naturalist - Roy John

The authors have read, and are on top of, an immense amount of literature, making a student of coloration like myself envious… I am delighted that I have this volume on coloration in my collection.

Quarterly Review of Biology - Tim Caro

Diamond and Bond do an excellent job of discussing the evolutionary mechanisms and processes in a simple yet powerful way that should be accessible to nonexperts. They make the subject come alive by telling us not just what we know about camouflage today, but also where the field has come from, and equally importantly the work that has been done to get us here.

Animal Behaviour - Martin Stevens

How differences in coloration within a species reveal new dimensions in the operation of natural selection. "Studying animal coloration is an exercise in time travel, illuminating the conditions of the past that have produced the diversity of the present," write Diamond (Curator/Univ. of Nebraska State Museum; World of Viruses, 2012, etc.) and Bond (Center for Avian Cognition/Univ. of Nebraska), who follow their earlier collaboration (Kea, Bird of Paradox: The Evolution and Behavior of a New Zealand Parrot, 1999) with this exploration of how the coloration on bird feathers, fish scales and fur are a response to a complex array of factors. Primary among these is the extent to which coloration allows prey to deceptively merge into the background, providing an edge against predators in the struggle for survival. Equally important is patterning, "the arrangement of splotches, speckles, stripes, and shading that make up an animal's visual appearance." In a fascinating sidelight, the authors examine how Abbott Henderson Thayer, a prominent American landscape painter, applied his observations about animals to the problem of military camouflage during World War I. Diamond and Bond cover modern research on the change in the numbers of light and dark moths in response to the amount of air pollution and explain how fish have evolved darks scales on top and light underbellies to create the appearance of a flattened object. The deceptive practices of prey also affect the cognitive evolution of predator species, which learn to closely observe their targets, detecting small motions and searching for giveaway signs in order to detect them. This in turn provides an evolutionary advantage to prey that can learn to hide distinguishing features and maintain a still posture. Combining a naturalist's eye with scientific rigor, the authors report on modern experiments on the mechanisms of the selective process that support these observations. An intriguing study encompassing "a convergence of disciplines ranging from population ecology and animal behavior to genetics, molecular biology and biophysics."

Kirkus Reviews