How can i tell if i have fertile duck egg?

Question

I have a female and a male duck living with us. The female has laid about 10 or 12 eggs and im not sure if they are fertile... is there a way for me to tell if they are or are not fertile?

Answer 1

is she sitting on them? if she is not then they are prob duds.but if its like a chicken egg, you could try candling.

Answer 2

Domestic ducks will lay an egg most days, that is what they are bred to do, even if there isn't a male duck present they will lay, just like hens do.

The eggs your duck is laying are most probably fertile if you have a duck and a drake together.  However they will only hatch into ducklings if the duck goes broody ie hormonally she wants to be a mom, she has no choice over this it just happens, usually in late Spring.  

She will sit tight on any eggs she has. It takes 28 days for the eggs to hatch and she won't move much off the nest, just to have feed and a drink. She will be fierce and peck you if you try to take the eggs away.  There is no guarantee the eggs will hatch, you can "candle" them in a dark room with a torch at about 10 days or so to see if you can see a duckling developing but it isn't a foolproof method and you could drop/damage the egg in the process so I leave it to the duck and nature to sort out if any hatch.

If she isn't broody but just laying eggs every day or so and then wandering off for the day then this is normal duck behaviour. You take the eggs away each day and eat them without fear of a duckling being inside.  

All our duck eggs are potentially fertile but the ducklings only develop if there is a continuous source of heat ie the mom duck sitting on them or if I put them in an incubator.