I haven't been to Erie Bluffs State Park in quite a while. I've decided to come here today because park naturalists have invited the public to go on a special hike. We're going to learn some things today!

22 bird boxes are located throughout a large grassy area at the park. They were placed here by park staff to be temporary homes for what are called cavity nesting birds. Specifically, bluebirds, tree swallows and wrens. Today, I'm with a group of other nature lovers. We are allowed to tag along as environmental education specialists Ray Bierbower and Sara Wettekin check the boxes.

"Our boxes are visited once a week either by a volunteer or by park staff. We document what is going on on every single box,” says Ray.

This is exciting. We do not know exactly what we will find in each of the 22 boxes. We do know that we will have to walk a mile and a half to check out every bird house. Here's number one. Tree swallows have built a nest in this box and there's four tiny white eggs!!! The adult tree swallows are not far away. We must be prepared for one of the hazards of the job.

"The tree swallows are notorious for buzzing us,” says Ray. “So they'll come by really close. You'll feel and hear the wind by your ears. They click their beaks as they go by. So far, nobody's ever been hit by one of them. But, they're trying to protect their nest."

We move on. The second box we check has a nest with three bluebird eggs. Appropriately, the eggs are blue. The third box we check contains a wren's nest. It's built with sticks, while the other bird nests are mostly made of grass. As we move along, we come across our first box with live baby birds in the nest. They will soon be flying off. Ray says the time between when the eggs are laid and when the babies fly off is only 18 to 21 days.

"So it's a very rapid process once it begins,” says Ray. “It goes quickly."

We see a number of boxes where the nests have been abandoned after the babies have flown off. Ray removes the nest. The box will be cleaned and then will be ready for the next nest to be built.

This experience has been great so far!  But, half way through our hike, we get a special highlight.  A nest with newborns, only one or two days old. They look like creatures that have landed on a spaceship. Ray calls them “little aliens.”

“They're born featherless. and they're blind,” he says. “Their eyes are all closed up and everything. But they grow very quickly."

Wow!  Another great experience at a Northwestern Pennsylvania state park.  By the way, a mother bird will give birth to a group of babies two to three times between the months of April and July. And don't worry about adult birds abandoning their offspring if the babies are touched by humans. Ray says that's an old wives' tale.