One of my favorite spring sights is watching our bluebirds set up their nests. We have active nests near the Discovery Center, at the edge of the meadow, near the Hydrangea garden, and probably in the other boxes, too. I haven't had time to check them all, but I see the male bluebirds standing watch on the boxes, and the female bluebirds foraging.
And a peek in the box along the loop drive in front of the Discovery Center (waiting for rotations of first-graders) revealed several nestlings. I didn't have my handy automotive mirror handy to check on their numbers, but it made a good interpretive point for the classes!
Leaving the Garden in late afternoon, a phoebe was foraging near the Geology Museum. Last year, a female built a nest above the Museum porch, and I wondered if this might be the same one -- they often come back to the same nesting site.