Washington ? The four-pound cub lies next to Mei Xiang’s huge head, a study in black-and-white geometry. The National Zoo’s giant panda mother licks him, noisily, in slow motion, as they doze.

A few inches away, Claudia Tejada Riley watches intently. She cranks up her speakers and enlarges the webcam picture until it spreads across the full screen of the computer in her office. “It’s so intimate,” she says.

It reminds her of her own early weeks of motherhood. She and another mother, who also works on the ninth floor of the Defenders of Wildlife building, sometimes compare notes about the panda, and themselves. Remember in the beginning, they say, when the baby was your entire world and you were conscious of every little thing your newborn was doing?

Riley clicked on the webcam from the National Zoo’s Panda House two days after the cub was born July 9 and has been hooked ever since. At home at night in Waldorf, Md., where she lives with her husband and year-old son, Owen, she checks on the pandas. Only her commute, 90 minutes each way, is bear-free.

The pandacams, operated by Friends of the National Zoo volunteers who zoom in and out depending on what is happening, are on all the time. An Animal Planet spokeswoman said the pandacam remains the most popular area of its Web site, with more than 1.1 million page views. The pandacam also is on the National Zoo Web site, but that link can accommodate only about 600 people at a time and is often impossible to see during the day. Until the Panda House’s reopening, scheduled for October, this is the only way for most people to watch the mother and her cub, although the outdoor yard is open when it is not too hot and the cub’s father, Tian Tian, can sometimes be seen there.

Some women, like Riley, watch Mei and her baby in their small den because they enjoy seeing another mother do a good job on her own without relying on how-to books. The pandacam also offers a distraction for people under stress: The zoo received an e-mail from an employee of a defense contractor in Iraq who said that everyone in her office is working tense, 12-hour days and “crazy in love” with the mother and her cub.

Riley, whose job as a national grass-roots legislative advocate involves spending the day on issue-oriented e-mail to and from Defenders of Wildlife members, is among a coterie of a half-dozen panda watchers on her floor. They call or message each other when someone sees something good.

Another member of the ninth-floor panda club, Inga Sedlovsky, says watching the webcam is a bridge between “what we do and what we want to do.” Her job title is executive assistant, but her mission is to save wildlife. So she peeks at the pandacam after answering an e-mail or making a phone call, to remind herself what her life is all about.

Riley, who was born the year before Richard Nixon’s 1972 visit to China that resulted in the gift of Ling Ling and her mate, Hsing-Hsing, did not know about this history. She came to Washington in 1993, after the mating drama had ended.

“Such a nice thing to have,” Sedlovsky says of the pandacam before heading back to her desk. “It’s a little voyeuristic. … We get this peek into this world we never normally see.”

On screen, Mei Xiang barks. A few minutes later, the cub flails on his back, squealing. And there’s a gentle chime to tell Riley that she has mail.