Osprey have been around since well before man showed up, but the graceful raptors created a shiny new moment for two boys last Sunday.

“Look, they’re coming in to land,” shouted Finn Hall, 11, to his younger companion. Both sets of eyes were glued to telescopes focused on osprey pole nests several hundred yards away.

“Oh, wow, it looks like they’re going to land on each other,” the younger boy replied before racing away to report the impending cataclysm to his parents.

But Finn, a veteran of the annual osprey festival at Felix Neck Wildlife Sanctuary since the age of three, stayed with his telescope, giving updates to his dad, Ron Hall of Vineyard Haven.

The 15th annual festival, postponed for one day due to thunderstorms on Saturday, drew 250 fans to the sanctuary in the rural reaches of Edgartown.

Relaxing with an organic hot dog, Ballyhoo jamming softly in the background, Rob Bierregaard, a biology professor at the University of North Carolina at Charlotte, summed up his two days in the field counting ospreys and nests with Dick Jennings, longtime natural history guide for The Trustees of Reservations on Chappaquiddick.

Mr. Bierregaard and his team, including Mr. Jennings and Vineyard nurse Chris Weston, physician Stacie Noble-Shriver and Emily Smith, a Felix Neck visitor services assistant, recorded 61 active nests among the 135 nests Islandwide, down from 65 a year ago. Mr. Jennings said one or two additional nests may yet be occupied. The team found a new tree nest on Lake Tashmoo. Pole nests have gradually replaced tree nests on the Island, thanks to a program begun by Gus Ben David years ago.

The team’s next project aims to tag three new birds with global positioning tracking devices in late July under Mr. Bierregaard’s direction. Migratory osprey commute some 3,000 miles; this year one GPS tagged bird flew 1,490 miles nonstop over water. The bird left Billerica on Jan. 7 at 6 p.m. and flew to the southern Bahamas. The bird flew 51 hours without food or rest.

Mr. Bierregaard said the osprey population on the Vineyard is now healthy and stable, a far cry from 1969 when Mr. Ben David was working hard to preserve the two remaining pairs on the Island.

Mr. Bierregaard noted that opsreys’ habits could be a good model for humans: “We say they mate for life but really they mate with the nest and they take separate [winter] vacations, which is often good for a relationship.”

At the festival, music, food, crafts tents, face painting and several informational booths caused heads to swivel like the barn owl displayed by Emily Carreiro, a naturalist with the Blue Hills Trailside Museum in Milton. At the crafts tent, young artisans made fish prints, tern decoys, pole nests and paper ospreys under the direction of Emily Reddington, the Island coordinator for the coastal watershed bird program.

Emily Clay of West Tisbury had a trifecta — a paper osprey and its pole nest as well as a wooden painted tern decoy. She left the festival grounds chattering to her brother Ben, 11, and parents Melissa and Wayne Clay.

Sanctuary director Suzan Bellincampi surveyed the crowd with satisfaction. “Osprey festival funds go to educational programs at the sanctuary. We netted $1,000. The trailside museum raptors were a huge hit. They’ll be back. Other new events were Egg-stravaganza, which measured the strength of eggs,” she said. This year, one egg supported 17 pounds.

“The other new element was Rob’s talk on tagging and tracking on Saturday night at the Mary P. Wakeman Conservation Center in Vineyard Haven that drew 17, mostly adults,” she added.

And Mr. Jennings the osprey counter saw a silver lining in Saturday’s rain. “It’s actually easier to count when it’s raining. More uncomfortable for us, but ospreys stay home when it’s teeming rain,” he said.