On Friday, two days before Earth Day, an egg appeared. One of the ospreys living in a nest at Hammonasset Beach State Park sat hunched over, occasionally ruffling its feathers, protecting the speckled sphere. And Lorrie Shaw probably got a lot of emails.

Shaw is the treasurer of the Menunkatuck Audubon Society, and the administrator of the live video stream that shows, 24 hours a day, the activity in an osprey nest in the park that will serve as the nursery to osprey eggs and later fledglings.

The nest of twigs, branches, seaweed and grass is home to two adult ospreys who, perched on a man-made platform, have returned after a winter in South America to continue the work of rebuilding an osprey population that decades ago seemed on its way to extinction.

Shaw encourages the emails; her address is listed with a prompt for watchers to tell her if they see something interesting — right under the disclaimer that "this is a wild osprey nest and anything can happen."

A report by the Connecticut chapter of the Audubon Society suggests that ospreys continue to thrive in Connecticut, particularly along the shoreline, where the fish-eating birds can flourish.

Hundreds of volunteers identified almost all the osprey nests in the state last year and found nearly 400 actively used by osprey pairs, which mate for life and return to the same spot each March to lay eggs and raise their young before returning south.

"New ones are popping up all the time," Connecticut Audubon Society Executive Director Patrick Comins said.

The comeback of ospreys, driven to near extinction by the widespread use of the pesticide DDT, is an environmental success story. Before the banning of DDT, the local osprey population plummeted from about 200 pairs in 1950 to about 25 pairs two decades later and less than 10 soon after that. The pesticide, absorbed by the fish that osprey ate, caused the birds' eggshells to weaken and crack prematurely, killing the chicks.

When DDT was banned in 1972, Connecticut had only seven active osprey nests. The combined efforts of government agencies, conservation groups and volunteers who built platforms for osprey nests in the communities helped bring the population of mating osprey pairs active in Connecticut back up into the hundreds, and the number is still rising.

The Menunkatuck Audubon Society installed a camera on an osprey nest in a New Haven Park several years ago. They installed the camera at Hammonasset in March with the blessing of the Department of Energy and Environmental Protection, in hopes of educating people and inspiring them to join in conservation efforts benefiting ospreys and other species.

The group bought a state-of-the-art weatherproof camera that films the birds eating, sleeping and swiveling their feathered heads all day and night, thanks to infrared capability.

By Saturday night, almost 30,000 people had watched the live stream.

"It's very popular," Shaw said. "It's a great way for people to learn what goes on there."

While the osprey population has almost bounced back to levels before the introduction of DDT, the birds still face risks, Comins said. Some — like former Congressman Ron Paul — have suggested bringing back DDT to fight mosquito-borne illnesses. Bald eagles, whose population has grown alongside the ospreys', like to steal food from their osprey neighbors. And the ospreys could simply get crowded as more nesting areas fill up.

Knowing where nearly all the osprey nests are will help Connecticut Audubon scientists better determine how the birds' populations are changing — whether that means further growth or a decline, Comins said. The growing numbers in past years may have reflected the growing number of volunteers available to count them.

"Statistically speaking, any growth further from here is going to be real growth of population and not just increased effort," he said.

The osprey show has an engaged audience, Shaw said. People watching for an egg to appear have commented on the live stream almost every day since the camera was installed in March, and Shaw gets regular emailed updates from viewers.

Sometimes the viewers' investment can be misguided, though well-intentioned. They worry about plastic that blows into the nests or other birds harassing the occupants. One hawk fledgling at the New Haven nest last year was getting more food than its sibling, and viewers concerned about the baby birds urged Shaw to intervene.

"I had to keep telling (them) we couldn't do that," Shaw said. The birds are protected under federal law and approaching their nests is illegal as well as dangerous.

"As much as we'd like to, it's not good practice to interfere," she said. "That's not what you're supposed to do."

m.shanahan@theday.com