Mama duck hasn't come back...not good...not at all good!
What's our next step??
Wednesday morning update: Mama still hasn't returned.
I should have told you that the ducklings are well protected in the completely enclosed courtyard of our school - flying is the only way in or out, unless humans intervene. This isn't the first time a duck family has inhatibed our courtyard, but it is the first time a mama has abandoned her babies. In previous years, when it was time, mama and her babies were led through the school to the stream that's close by.
There's a big cement area in the middle of the courtyard, but all around the edges there are extensive gardens with plenty of pacasandra and shade for them to hide and find bugs in. The ducklings are also stuffing themselves with the duck food and chopped veggies that are being provided. The gal that's in charge of the ducks has called every imaginable place she can think of - the Nature Center, the zoo in Bridgeport, wildlife rehabbers, etc. - and has gotten a different answer from each of them. I think what will happen is when the Nature Center's wildlife rehabber/rescuer returns from her vacation, she will come get the ducklings. I'll certainly let you know what happens. And thanks for all the suggestions!