Bird Fact Friday – How have bird eyes evolved?

From page 66 of Bird Brain:

Compared to most mammals, bird eyes are highly complex. They contain four color photoreceptors, or cones, capable of aiding the perception of a much wider frequency range of light wavelengths. Birds are even able to see across the entire visible color spectrum, including colors in the invisible spectrum that humans cannot see unaided. There are important reasons why birds have evolved this way, and Nathan Emery describes them in Bird Brain.

Bird Brain
An Exploration of Avian Intelligence
Nathan Emery
With a foreword by Frans de Waal
Introduction

EmeryBirds have not been known for their high IQs, which is why a person of questionable intelligence is sometimes called a “birdbrain.” Yet in the past two decades, the study of avian intelligence has witnessed dramatic advances. From a time when birds were seen as simple instinct machines responding only to stimuli in their external worlds, we now know that some birds have complex internal worlds as well. This beautifully illustrated book provides an engaging exploration of the avian mind, revealing how science is exploding one of the most widespread myths about our feathered friends—and changing the way we think about intelligence in other animals as well.

Bird Brain looks at the structures and functions of the avian brain, and describes the extraordinary behaviors that different types of avian intelligence give rise to. It offers insights into crows, jays, magpies, and other corvids—the “masterminds” of the avian world—as well as parrots and some less-studied species from around the world. This lively and accessible book shows how birds have sophisticated brains with abilities previously thought to be uniquely human, such as mental time travel, self-recognition, empathy, problem solving, imagination, and insight.

Written by a leading expert and featuring a foreword by Frans de Waal, renowned for his work on animal intelligence, Bird Brain shines critical new light on the mental lives of birds.

This post is part of a series, explore additional posts here<< Bird Fact Friday – Do birds create art?Bird Fact Friday – How do birds feed themselves in the winter? >>