You can tell when the person you're talking to is passionate about a subject. Their eyes sparkle. Their speech pattern changes, either slowing down to make sure you don't miss a detail, or speeding up to share as much information as quickly as they can. It almost feels as if you're talking to a different person. The transformation is a joy to watch.

One is likely to imagine Susan Orlean's eyes sparkling as she composed the essays in "On Animals," a compendium of works, most of them written for the New Yorker, that showcase her curiosity about a wide range of animals, from mules to mice, from Rhode Island Reds to Welsh springer spaniels, from homing pigeons to one of the box-office superstars of 1990s cinema: a killer whale.

"I was always a little animalish," she writes at the outset. After a 1980s move from Manhattan to a farm in the countryside, she was able to keep chickens, ducks, Black Angus cattle and guinea fowls, two of whom were named Prince Charles and Camilla. Their house, she writes, "bears a resemblance to a three-ring circus."

The pageant of animals in these pieces is equally spectacular, as is the writing. In an essay on chickens, she notes that she had "no pre-existing chicken condition," but after seeing a "mouth-to-beak resuscitation" in a documentary, she developed a passion that led to the day when the four Rhode Island Reds and plastic coop she had ordered arrived at her post office. The amused clerk told her, "You have a package here, and it's clucking."

Orlean strikes a perfect balance between hilarious and informative. An essay about an "intentionally mysterious" New Jersey woman who keeps more than 24 tigers on her compound reveals that more than 15,000 tigers are in the U.S., "more than seven times the number of registered Irish setters or Dalmatians."

Similar insights appear in essays on donkeys in Morocco; the "lion whisperer" in South Africa who forged such trusting relationships that lions "with paws the size of dinner plates" could harmlessly gnaw on his head while he checked his phone; and Keiko, the orca chosen to star in "Free Willy!" and the subsequent fight over whether to keep him profitably captive or set him loose.

Throughout, Orlean has a gift for the indelible detail, as when she notes that pandas produce the world's tiniest babies relative to the mother's size: "a 250-pound panda delivers a cub that is about the size of a stick of butter."

Lines like that are too numerous to mention here, but readers fond of seemingly effortless writing about animals will savor this book. One can imagine a sparkle in their eyes as they turn the page.

Michael Magras is a freelance book critic. His work has appeared in the Economist, Washington Post, Pittsburgh Post-Gazette, Kirkus Reviews and BookPage.

On Animals
By: Susan Orlean.
Publisher: Avid Reader Press/Simon & Schuster, 288 pages, $27.