Posted by Jennifer Duncan on June 29, 2006

Q: We have a mallard that has laid 9-10 eggs next to our swimming pool. We're pretty sure this is all she'll lay as she's here constantly now. How long can the mother be off the nest without damage to eggs? How do we "lead" them to other water (we have a reservoir nearby)and away from the pool once they've hatched?

Thank you.

Habitat: suburban/yard

State: Maryland

Habitat: suburban/yard

A: Thanks for sending the photo. Before incubation starts, the eggs can remain cool for quite some time without any damage. In fact, since the female duck only lays one egg a day, after the first egg is laid, it doesn't receive any heat until the last egg is laid. But, sounds as though your duck has "decided" her clutch is complete.

Once incubation begins, I really have never seen any info on how long an egg, with embryo developing, can remain unheated. My guess, and it's only a guess, is that it can cool off for an hour or so. In fact, the female will leave her nest daily to get food and water so the eggs naturally cool then. But just how long that can be, I'm not sure.

Your photo helps me note something. Your female has gotten into your pool and although that's no big deal, she may lead her young into the pool also - that's not good. Obviously, the young will find no food there and won't be able to get out either so be aware of this possibility. Of course, if it happens, you can always get in the pool and remove the young by hand. My guess, however is that your Mallard will know very well where she wants to take her young and will probably truck on down to your local reservoir or nearby waterway.

While the female is on the nest, do your best to eliminate any disturbances for her. Raccoons and skunks love eggs and if they find the nest, it's all over! Let's hope all goes well and in 26-30 days, the ducklings should hatch. Best of luck and thanks for writing.

John Wiessinger ( June 29, 2006)