R Cookbook

Colophon

The animal on the cover of R Cookbook is a harpy eagle (Harpia harpyja). One of the fifty species of eagle in the world, the harpy eagle is native to the tropical rain forests of Central and South America, and prefers to nest in the upper canopy layer thereof. Both its genus and species names refer to the harpies of ancient Greek mythology—vicious creatures with the face of a woman and the body of an eagle or vulture.

On average, harpy eagles weigh about 18 lbs., are 36 to 40 inches long, and have a wingspan of 6 to 7 feet, though females are consistently larger than males. The plumage of both sexes is identical, however: slate black feathers dominate the animal’s top half, while the underside is white or light gray. Light gray-colored heads are accentuated with a double crest of large feathers, which specimens can raise when showing hostility.

Harpy eagles are monogamous, and pairs raise only one chick every two to three years. Females will usually lay two eggs at a time, and after the first hatches, the other is neglected and does not hatch. Though the chick will fledge within 6 months, both parents continue to care for and feed the chick for at least a year. Because of this low rate of population growth, the harpy eagle is particularly susceptible to encroachments on its habitat and losses from human hunting. Throughout its range, the animal’s conservation status ranges from threatened to critically endangered.

The cover image is from J. G. Wood’s Animate Creation. The ...