A second egg should start to hatch soon, too.

Eagle watchers online went wild with the news. The eaglet’s parents — known as Mr. President and Lotus, for “Lady of the United States” — have their own Twitter handle, and 24/7 eagle webcams track their every move.

Five-year-old Lotus, a first-time mom, laid one egg Feb. 17 and the other three days later. Eagles take turns incubating their eggs, which take about 34 to 36 days to hatch.

Dan Rauch, a wildlife biologist for the District, said experts ideally want eagle eggs to hatch “as close as possible” to each other in terms of timing, because that reduces sibling rivalry. “The first one out gets first dibs,” he said.

Eagles grow fast. After hatching, they reach their full size in 13 weeks, so having the webcams gives the public a rare insight into what happens “all the time in the wild,” Rauch said.

“It’s pretty awesome,” he said. “We have an insider view of how nature operates.”

One recent video showed what appeared to be one leg peeking out of the first egg, as one of the eaglet’s parents stood in the nest eating part of the yoke sack that sustains the eaglet during its incubation period.

The eagles at the arboretum make one of 20 nests in the D.C. region, according to Rauch. Of those, five are new within the past year.

Mr. President and Lotus have had a tumultuous history, even by Washington’s standards for scandal.

Mr. P and his first partner, known as the First Lady, made history in the fall of 2014 when they bonded and began building a nest at the arboretum together. It was the first time there had been a nest at the site since 1947.

The pair had their first set of eaglets in 2015 and went on to have a total of seven hatch in their nest, the last coming in 2018 before it died of West Nile virus. But Mr. P and the First Lady had troubles producing offspring for three seasons thereafter; eventually, the First Lady left the nest, and other bald eagles visited. Lotus ended up taking the First Lady’s spot, as she and Mr. P hit it off.

Lotus is known for her striking appearance, with a heavy-brown streaking on her tail and head that’s matured over the past year into the full-white look emblematic of bald eagles. She has another distinctive trait: a pigment dot on her iris.

Mr. P and Lotus went through the usual eagle courtship — she’d nuzzle his neck; they’d share dinner, often a dead rodent or fish — and rearranged the twigs of their nest. When Lotus laid her first eggs in February, wildlife experts were thrilled.

In the past few decades, bald eagles have made a comeback nationwide after being decimated by harmful pesticides, poor water quality and loss of habitat, experts said. Eagles have learned to adopt and now are known to make nests in suburban and urban areas.

In the D.C. region, the arboretum and spots along the Potomac and Anacostia rivers make good homes for eagle nests because of the nearby trees, access to water and availability of plenty of small mammals for food.

In the past month, the eagle pair at the arboretum were spotted on camera as they took turns protecting the nest and incubating the eggs. Once, when a hawk came too close to the nest, one of the eagle parents called to the other to come back and defend it. In a March 12 storm with rain and snow, the pair sat together nuzzled on their eggs.

“They’re both invested in these eggs,” Rauch said of Mr. P and Lotus. “They’ve both put a lot of time and energy into these eggs.”

“We’ve been lucky,” he said. “These two are good mates, and they’re very well matched. They’re good adults and good parents.”