It’s the middle of breeding season for western snowy plovers at the Point Reyes National Seashore, and park ecologists say this season has been the most productive in years. So far, population numbers are up from last year due to a high survival rate for breeding adults and juveniles that remained in the park. In years past, plovers have struggled to survive heavy winter storms, so this year’s survival is exciting. The success is also attributed to the use of new exclosures, or wire fences surrounding plover nests to protect from predators and disturbances. They are smaller than years past—2 feet compared to 4 feet—to keep ravens, raptors and other predators from entering while allowing plovers to exit and take flight faster. “Exclosures in general have been shown to dramatically increase nest success for plovers,” said Matt Lau, the park’s snowy plover ecologist. “If we leave them un-exclosed, nest success drops to somewhere around 20 percent compared to 80 to 90 percent.” Snowy plovers were declared a federally threatened species in 1993 due to habitat loss from beach development, invasive plants, human disturbance and predation. The seashore has partnered with Point Blue Conservation Science since 1995 to conserve plovers and their habitat. Breeding season, from March to September, typically coincides with peak visitation, which makes plovers vulnerable to disturbance. The park’s annual beach closure to protect plovers affects the north end of North Beach to Abbotts Lagoon every weekend and holiday from May 28 through Sept. 5. Snowies, as they are sometimes called, are only 6 inches long and nest in open or sparsely vegetated areas of sand. They lay two to three eggs in shallow depressions known as scrapes, and males and females incubate eggs for around 28 days. Once hatched, the chicks are monitored by males for another 28 days until fully fledged. Nineteen nests have been found on Point Reyes beaches, including five on Limantour, three in the Abbotts Lagoon area, and an additional 11 between Abbotts and the North Beach parking lot. Six nests have hatched. Dave Press, the park’s acting natural resources program lead, reported a fledge count of 22 at the end of breeding season last year, which was the highest count since 2017, and this year’s numbers are projected to surpass it. Mr. Lau added that nest success is typically low in the first half of the breeding season and increases toward the end. This year, though, ecologists have been able to locate nests early on, allowing them to protect nests more quickly than in years past.