Katherine Applegate often lets her readers see the world and its troubles through the eyes of nonhuman creatures. Most famously, there was Ivan the gorilla, who tells the story of captive wild animals in “The One and Only Ivan.” A giant oak named Red shares an unusual perspective about discrimination in “Wishtree.” “Endling: The Last,” the first book in Applegate’s new series, is about endangered species and features a new twist: It’s narrated by an animal you’ve never met — a creature called a dairne.

“I really wanted to make a talking dog,” said Applegate, who spoke by phone with KidsPost during a trip to London, England. “I love dogs.”

Byx is a doglike animal who stands upright. She has fingers, a pouch and the ability to glide like a flying squirrel. (Dairnes are one of six highly intelligent species that govern the kingdom of Nedarra.) Not far into the story, her family is killed and she becomes an “endling,” a word that inspired the books, Applegate said.

“My daughter came across [it] on Reddit,” she said. “I don’t think you’ll find it in most dictionaries. It was coined to define the last of a kind.”

Being the only surviving dairne is sad and scary for Byx, who was the baby of her family and the one her parents worried about most. At first she wishes she had died with the pack. Then she is resigned to being a prisoner. But help from two young humans — and from a comical wobbyk and a ferocious felivet — make Byx realize that her

life can have a purpose. She can help stop more of Nedarra’s governing species from becoming endlings.

“I wanted to write a classic underdog,” Applegate said. “It was fun to have her grow very gradually. . . . As she sort of creates this new family, she has to step up for her friends and for herself.”

The new family is an uneasy grouping, however. Gambler the felivet (a great cat) admits to having eaten wobbyks. Khara helps guide hunters, and Renzo is a thief. There’s suspicion all around.

“Having an apparent poacher in the middle of it was to make it an unsteady element,” she said. “You don’t want everyone to be best friends initially.”

The author said she also didn’t want all humans in the story to be villains. Although Khara and Renzo start out as fairly self-centered people, they don’t want to see entire species wiped out.

But Applegate doesn’t shy from blaming humans for animals’ troubles in Nedarra or the real world. She said it’s easy to become depressed seeing photos of polar bears floating on tiny pieces of ice, an image used to show how climate change is shrinking the animal’s Arctic habitat.

Talking to kids gives her hope for the future of polar bears, gorillas and other animals that are disappearing, she said.

“When you go to the schools . . . they are so idealistic,” Applegate said. “I tell them that I write better when I write about things that make me angry. Their parents and I haven’t handled things well as being stewards of the Earth.”

Applegate hopes the series will inspire readers to step up for these real-life endlings. She has partnered with the Animal Welfare Institute to share information about how readers can do that.

The kids she meets know a lot about animals, Applegate said, but she encourages each one to become an expert on a single species.

“I remind them it doesn’t have to be cute and cuddly,” she said. “It can be an armadillo.”

If readers want to learn more about dairnes and the other creatures of Nedarra, they’ll have to wait a bit. Applegate said she has finished the second book, “Endling: The First,” which will be published next spring. In 2020, “Endling: The Only” will bring the series to an end.