A little before noon Tuesday, the Hawaiian monk seal pup Loli‘i lay still and quiet on the sand of Kaimana Beach just above the waterline, his round black shape difficult to distinguish from the rock-rubble groin he’d sidled up to.

“It’s so sad! We’ve all been crying for an hour,” said Kelly Lim, one of a half-dozen spectators who stood at the required 150-foot distance from the endangered-species pup under the supervision of a volunteer with Hawaii Marine Animal Response.

The reason for their tears was that the first time in his life, the pup was alone, without the constant nurture of his mother, RK96, known as Kaiwi, who had borne and nursed him on the beach before suddenly swimming away Tuesday morning and leaving him behind.

But this was nothing to be sad about, for her abrupt departure was natural and expected weaning behavior by a monk seal mother, said Angela Amlin, Hawaiian monk seal recovery coordinator for the National Oceanographic and Atmospheric Administration Fisheries Pacific Islands Region.

“On Monday, Loli‘i turned 6 weeks old, and monk seal mothers usually wean their pups between five to seven weeks, while in the past we know Kaiwi usually weans her pups at approximately 42 days,” Amlin said at a news briefing in Kaimana Beach Park.

The next step, she added, was to wait until it was certain the mother would not be coming back, and then remove Loli‘i to a safe, remote location unfrequented by human beings.

NOAA had called the briefing to inform the public about the weaning and imminent move, and to remind folks to keep at least 150 feet away from the mother and pup.

“Loli‘i’s very curious and impressionable, hard to resist, but if young pups are reinforced with attention from humans early on, they will seek it out,” Amlin said, “and when they get bigger they can be a danger — they can bite divers’ fins or wrap their flippers around people and drop like a stone.”

Sometimes, after its mother departs, “a pup will call out a few times, but it won’t last long,” Amlin said, remembering that when Kaimana, born in 2017 at Kaimana Beach, the first monk seal known to have been born in Waikiki, was left by her mother, Rocky, “she did vocalize, and people on the beach were concerned.”

But the abrupt weaning is the seals’ nature — “not sad, it’s a success,” she said.

It was also necessary for the survival of the mothers, who, because they don’t forage while nursing, lose up to a third of their body weight, “and Loli‘i’s ready, he’s so nice and fat.”

Still, as they watched the pup sleep, Lim and Michele Sullivan recounted a wrenching scene earlier that morning.

“Loli‘i was swimming, diving, floating on his back, foraging and coming up with stuff in his mouth, so happy — then she left,” Sullivan said.

“She circled back once, looked at him, and then she took off.”

But Kaiwi came back several more times, other observers said at sunset, as Loli‘i lay sleeping at the other end of the beach, his nose pointing toward Michel’s Restaurant, where nearly every table was full.

“Kaiwi came back at 1:25 p.m.,” said Shiu Mei Bassette. “They were snuggling, very affectionate, and she took him out for a swim, then she left again.”

The mother returned twice more, barking as she swam, but missed the pup as he swam and played in front of the Elks’ Club and, later, as he slept on the beach, Bassette said.

Throughout the six weeks, people have largely kept a respectful distance from the endangered animals, said Jon Gelman, president of Hawaii Marine Animal Response.

He and Amlin thanked their partners the state Department of Land and Natural Resources and Honolulu Ocean Safety, Honolulu Police Department and the city Department of Parks and Recreation, and the public, for their kokua.