Sara Gruen's last novel, the enchanting circus-set "Water for Elephants" in 2006, became a best-seller primarily through word of mouth, and I doubt there's a book club in America whose members haven't read it.

Expect the same sort of "you've got to read this" buzz for "Ape House," Gruen's new novel, which had me instantly enraptured with a family of bonobo apes. As in "Elephants," the animals in this book are multilingual - they "speak" bonobo and American Sign Language, and also understand English. One female, Bonzi, also can communicate via computer.

As the book opens, a family of a half-dozen bonobos is happily ensconced at the fictional Great Ape Language Lab at the University of Kansas. They're adoringly cared for and studied by Dr. Isabel Duncan, who calls them her family and tells a reporter, "Over the years, they've become more human, and I've become more bonobo."

Well, perhaps we all have. Gruen opens the book with a 1970s quote from Nim Chimpsky (the ASL-using "chimp who would be human"): "Give orange give me eat orange me eat orange give me eat orange give me you."

Then a lyric from Britney Spears, circa 2007: "Gimme gimme more, gimme more, gimme gimme more."

With that, and throughout the novel, Gruen delicately and profoundly brings life to that oft-quoted statistic: Bonobos and humans share 98.7 percent of their DNA. We're all members of the ape house. In this book, when it comes to the best human qualities - empathy, good humor, the ability to adapt, loyalty - the apes win easily.

Gruen gives each of her apes a distinct personality, and just as with people, it gets to the point where all she has to do is describe behavior, and we know which member of the pack she's talking about. She exquisitely depicts their gentleness, humor and curiosity, as well as their tendency to pettiness over such things as a deflated ball or coveted banana. (Sound like anyone's cubicle mates?)

The plot? Doesn't really matter; it involves a misguided animal-rights group, a nasty explosion and a reality-TV show. But it's truly all about the apes, the humans and their interactions and similarities - sometimes mouth-gapingly ghastly, sometimes hold-your-sides hilarious.

Gruen must have picked up a thing or two about the circus from "Elephant"; I've never seen an author more gracefully navigate the tightrope above the minefield topics of animal rights, evolution, serious vs. tabloid journalism and more. She even manages to get in a sweet-hearted plug for the much-maligned pit bull terrier.

Her wit goes a long way toward making it all palatable to a general audience. My favorite line: her description of a pair of mukluks, written by a novelist subbing as a catalog copywriter until that fabled book contract comes in: "Top notes of Ugg with a soupcon of Piperlime, and guaranteed 100 percent cat-fur free."