Best new children’s and young-adult books released this month

Brendan Wenzel’s “Hello Hello” (Chronicle, Ages 3-6) is exuberant and captivating, even if this ode to the wonderfully diverse but fragile world of animals has a solemn underlying message. The bright palette is delicious — the colors seem to vibrate and glow with warmth. Wenzel's animals, made with oils, pastels, pencils and digitally, have a slightly manic quality, with their large round eyes and expressions that suggest laughter. Echidna, narwhal, cockatoo, giraffe — each seems familiar, with eyes, a mouth, fingers, legs — and each is extraordinary as well. The book shows how we share the planet with some astonishing creatures — from black-and-white animals to those with bright color and those with surprising numbers of arms or spines or spots. Even the endpapers emphasize the bounty and variety of the animal world: Inside the front cover are empty silhouettes of nearly 100 animals; inside the back cover those same animals are transformed into a gorgeous and colorful array. An author's note points out that habitat loss and climate change threaten many to most of these, some quite seriously. But, adds Wenzel, “the more that people know about these creatures, the better chance they will share this planet with us for many years to come. It starts with saying hello.” Pick up this marvelous book for Earth Day, and celebrate.

How do you capture some of the world's most ferocious creatures? You put them in a book so kids can study and admire them from a huge historical distance. Fun and informative, “In the Past” (Candlewick, Ages 3 to 7) also offers a variety of startling visual perspectives. Young readers will turn from the rare sight of a contemplative T. rex to a battle between the largest-ever snake and a massive snapping turtle. Matthew Trueman's mixed-media illustrations and David Elliott's playful poems pay tribute to some very formidable animals, starting with the relatively small Trilobite, Astrapsis, and Eurypterus, which was perhaps the first to venture out of the ocean. The sequential zoological parade continues with an emphasis on sharp pincers, claws, and incisors but also includes intriguing glimpses of long-ago landscapes. The feathered dinosaur Yutyrannus, for instance, throws a tantrum in what is now China. Elliott's rhyme-filled odes and explanatory endnotes pack information into the small spaces the towering creatures leave available. Spanning two pages, Quetzalcoatlus looms menacingly above his poem: “Unrepentant./Carnivore./Largest of all/flying things./How the timid/must have trembled/in the shadows/of your wings.” Young readers looking for themselves in this book will find a few humans on the last page, alongside a concise elegy for the woolly mammoth.

Veera Hiranandani opens her powerful epistolary novel “The Night Diary” (Dial, ages 8-12) on her protagonist's 12th birthday in July 1947. Nisha is writing in the journal she's received from her Hindu family's beloved Muslim servant, who told her she “needs to make a record of the things that will happen” in India. But Nisha also uses the diary for oneway correspondence with her mother, who died in childbirth a dozen years before. Nisha yearns for a strong, loving guide into womanhood: “What would your hand feel like holding mine?” she asks her mother. In the coming weeks, the quiet girl writes almost every night, sharing her thoughts and feelings as India's freedom from British rule leads to partition into the republics of Pakistan (for Muslims) and India (for Hindus, Sikhs and Christians). Like 14 million others, Nisha and her family must swiftly relocate to the country now assigned them by religion. Nisha and her twin brother, father and frail grandmother set out by foot for the border 100 miles away, amid increasing violence on both sides. They brave extreme heat, dehydration, scorpions and riots. Hiranandani drew on her father's childhood experience to create this wrenching, ultimately hopeful story. Like the poetic novels “Inside Out & Back Again,” by Thanhha Lai and “The Year of Goodbyes,” by Debbie Levy, “The Night Diary” personalizes the effect of historic events. With Nisha, readers experience the fear and danger of displacement, take joy in a soothing rain and small bowl of lentils and try to imagine a new, safe home in a faraway place. “THE GATE KEEPER” by Charles Todd; Harper Collins (320 pages, $26.99)