Students at the Westwood Integrated Preschool are getting a hands-off science lesson from a pair of birds nesting in their school playground right behind the swing set.

The birds are killdeer, a type of plover that typically builds shallow nests on the ground, and they’re sitting on four speckled black-and-white eggs that are expected to hatch in early June, said the preschool’s director, Aprile Albertelli.

Protecting the birds from 50 preschoolers has been a challenge, Albertelli said, but also a tremendous learning experience for students and staff.

The youngsters practice their counting, color identification, and cooperation skills, while the adults have become experts, of sorts, in ornithology.

“We think the male is doing most of the sitting,’’ Albertelli said. “The mother bird is much more petite — and she does all the squawking.’’

Killdeer facts are now in the preschool’s curriculum. Known more formally as charadrius vociferous, the birds were once endangered but are now common all over Massachusetts. The Audubon bird atlas describes the killdeer as “larger, louder, and more numerous by far than its cousin, the piping plover.’’ They migrate south for the winter, are about the size of a grapefruit, and have white chests, brown backs, and black bands around their neck. Their name derives from their distinctive cry of “killdee, killdee’’ and an occasional nervous “dee dee dee.’’

While they are shore birds, they often build their nests at the edges of farm or soccer fields, golf courses, airports, gravel pits, flat roofs, and — yes — playgrounds. They’ll nest just about anywhere that’s open and away from tree cover, which often puts them in conflict with dog walkers, soccer players, and the like, according to Joan Walsh, director of bird monitoring for Mass Audubon.

But the birds will pluckily remain by their nests, despite the intrusion of humans. “Their spunk is something you just have to admire about killdeer,’’ Walsh said.

A teacher found the creatures at the Westwood preschool on May 13, when she saw what looked like a wounded bird fluttering around. Turns out that killdeer also are famous for their “broken wing’’ act of flapping on the ground to draw attention away from their nests.

“They’re really dramatic,’’ Walsh said. “Watching them, you’d think you had to call 911 for the bird ambulance.’’

The preschool staff held off calling 911 and, instead, discovered a single egg laid on bark mulch behind the playground swings.

By Monday, there were four eggs and the playground had become science central for the preschool. The building and grounds staff built a protective fence for the birds out of orange fencing and surrounded it with traffic cones.

The preschool, which has 3- and 4-year-olds both with and without special needs, operates full- and half-day sessions next to Westwood High School. Albertelli said the youngsters are excited about the birds in their backyard, although some seem more interested in the traffic cones.

One group of girls was spending so much time at the area near the nest that the speech therapist went to see what they were doing. “They told her they were speaking bird,’’ said teacher Kelly Fitzgerald.

Fitzgerald said another group of children sat in a circle around the nest as the male and female birds appeared to noisily negotiate whose turn it was to sit on the eggs. “We watched the switch-over; it was like a small movie going on,’’ she said.

Fitzgerald said that her class had been talking about what animals do in the spring — including a discussion of birds building nests — and made a giant nest out of cardboard boxes in her classroom. The creation fits up to six children and is decorated with peacock feathers from a staff member’s flock in Wrentham, and is filled with plastic eggs.

“Some people are saying [the killdeer] came because we built the nest inside,’’ Fitzgerald said. The cause-and-effect may be iffy, but there’s no doubt about the education carryover, she said.

“The kids are definitely enjoying it,’’ she said.

For her part, Walsh is enjoying the preschoolers’ reaction to their new playground partners.

“These are people managing to live with wildlife in suburban settings,’’ she said. “They’re learning to live with it, and love it, and magic will happen. If you don’t find a baby chick coming out of an egg magic, well, I don’t know what to tell you. I still find it magical after 40 years.’’

Walsh said the young killdeer will be able to run soon after they’re hatched, and the family probably will stick around for about three weeks until the hatchlings can fly.

She cautioned, though, that the preschoolers shouldn’t expect all the hatchlings to make it to adulthood.

“The rule of thumb is for every 100 eggs laid of any one species, maybe five or fewer will become adults,’’ she said. “There are all sorts of perils out there, and that’s why it’s important for us to make room for wildlife and eliminate as many perils as we can.’’

Johanna Seltz can be reached at seltzjohanna@gmail.com.