The colony of rare African penguins has happy feet, shiny feathers, and a lot more pep now that the $2 million upgrade to their home has been completed at Adventure Aquarium in Camden.

To create a setting that better mimics the natural environment of the 40 penguins, the aquarium spent the last year renovating the outdoor exhibit, which opened in 1998. Workers tucked heating elements beneath new rock-like structures to warm the penguins' tiny feet and filled their 17,000-gallon pool with saltwater to improve their health and well-being.

The workers also created grottoes that offer shade and privacy.

A happy penguin is, after all, an entertaining penguin. And penguins enjoy wide appeal because of their endearing charm, cuteness, and funny antics.

Michele Pagel, the aquarium's curator of birds and mammals, said the penguins have noticed the changes, which were completed a few weeks ago when Penguin Island reopened.  "They're more active," she said as a few dove into the pool.

The hope is that their attractive new home will spark fresh interest in the African penguin, which is endangered in the wild. Without conservation efforts, Pagel said, the species could become extinct within 10 years. Fewer than 25,000 breeding pairs remain in the wild.

The penguins are native to South Africa, where their habitat is threatened by development and pollution, Pagel said. Adventure Aquarium holds public awareness events and raises funds to promote the penguin's survival in the wild, she said.

The playful creatures are also known as jackass penguins because their call is similar to the braying of a donkey.  On a warm afternoon this week, one puffed out his black-and-white throat and bellowed.

Unlike their more common cousins in the Anarctic, these penguins are accustomed to a temperate climate that can dip below freezing or rise to 100 degrees, much like that found in their urban home in Camden.  "People ask all the time if they're hot," said Pagel. "It's the number-one myth we hear each day."

Adventure Aquarium has joined with zoos and other aquariums across the country to increase penguin populations through selective breeding, or matchmaking, and to help with the species' survival. Pagel, who has cared for the penguins since the first few arrived at the aquarium two decades ago, said a new nesting area in an expanded room behind the exhibit is designed to encourage the penguins to mate and breed.

A month ago, two chicks were born there.

Deanna Sabec, the aquarium's public relations manager, said the fuzzy brown babies won't be introduced to the public until the middle of the summer.  They each weighed about two ounces at birth and are still being nurtured by nesting parents that generally mate for life.

Before that, four chicks arrived in December. The males are named Nick and Carson, in honor of Eagles quarterbacks Nick Foles and Carson Wentz.  Their females are named Taco and Shelley.

The sleek steel-gray feathers of the four juveniles made them stand out among the pack of black-and-white penguins that stood and stared motionless during a lull in the action one day this week. The appearance of a bird, and then a dragonfly, caused them to jerk their heads in unison and follow the flight path in the sky until the winged creatures disappeared from view.

Sienna Repka, 5, of Warminster, waited patiently for a little more action.

"I like when the penguin is slipping," she said, then demonstrated by dropping onto her belly and wiggling — and giggling.

Gray Mason, also 5, of Folsom, liked watching them eat tiny fish.

The hippos, the sharks, and the little blue penguins at the aquarium also draw crowds, but the African penguins still rule, Pagel said.  "They're feisty," she said.

Now, with rocking chairs conveniently placed next to the 20-foot underwater viewing window, and a shade canopy above, even more visitors are flocking to Penguin Island.

"We love them," said Nicole Henry of Cherry Hill, who visited this week with her children, Khloe, 4, and Delaney, 2.  "This is our favorite thing."