The Houston Zoo is celebrating a baby boom this summer with the biggest newborn of all expected soon.

Two red river hogs were born to first-time mom Luna on Tuesday, June 27. The unnamed hoglets made their public debut Monday as they frolicked with Luna and two other adult hogs, Neptune and Vidalia.

This is the first litter of red river hogs to be born at the Houston Zoo since they were brought to Texas in 2015 for Gorillas of the African Forest. Gorillas and red river hogs share the same forest lands in Africa, but Houston has the only zoo where they share a habitat.

Photos: Baby boom at Houston Zoo

Cali, a California sea lion, gave birth to her first pup on June 26. Cali and her pup began to bond immediately, zookeepers say. Cali’s sister Kamia gave birth to TJ in 2016.

In the zoo’s aquarium department, five white blotched river stingrays were born on Sunday, June 18. Baby stingrays are left on their own after birth. They get nutrients from a yolk sac until they’re able to eat worms and shrimp on their own. Each white blotched river stingray is unique; no two have the same spot pattern.

Two Palawan peacock-pheasant chicks recently hatched in the zoo’s Birds of the World habitat. This small threatened pheasant species is only found on the island of Palawan in the Philippines.

On June 11, 10 African bush vipers were born inside the zoo’s Reptile and Amphibian House. They were born live instead of hatched from eggs like most types of snakes. They tiny vipers weight only two grams and will grow up to two feet long. Bush vipers vary in color, mostly shades of green, but can also be bright yellow, grey, even red.

The Houston Zoo will welcome a 250-300-pound Asian elephant calf later this summer. Expectant mom Shanti is mom to the zoo’s youngest calf, 3-year-old Duncan, along with 7-year-old Baylor.