Need resources, starting duck 4-H group

Hello fellow duck lovers.  I am back to this site after being away for a year. I have two 8 week old mallards, one runner, one rouen, one pekin and one 3 year old female mallard.   I now live in a rural area of Idaho and have been asked to be the duck 4-H leader.  The extension office knows nothing about ducks so I am pretty much on my own.  I need help finding resources that can answer specific questions about ducks.  I can also post specific questions one by one on the thread.  The following questions were complied at our first meetings.  My youngest member is 8, oldest is 11.  Can anyone help us with these questions?

1.  After male and female mate,  how long is she fertile?  

we had a pekin mate with our mallard.  7 days later sadly, a fox got him.  Right around that time, she started laying on her eggs and will not come off of them.  It's been more than a  month so I know none of those eggs are going to hatch.  She won't leave the next.  I need some duck sex education!

2.  Why do you see baby ducks in the wild do just fine in cold weather but domestic ducks have to be under a heat lamp?  I assume mom isn't keeping them warm the entire time.

3.  what is the average life span for a domesticated duck (assuming they don't get eaten by dogs or other critters)

4.  Why do females only have ducks in the spring?  

5.  Can females have more than one batch of babies in a year?

6.  What is the males role in raising babies (if any)

7.  why do ducks make that funny duck soup in their water?  Are they spitting up their food into the water?  I am not talking about them swimming in their water, I am talking about the massive amounts of paste that is left in the bowl.

THANK YOU so much for any advice.  The kids show their ducks on August 16 at the fair, but all of them are pets and are not going to market.

:)

Thanks for the great info.

So, much to our surprise, we now have two darling ducklings out of the eggs mom was sitting on.  I am sad when I remind myself that I gave away all those wonderful eggs she was sitting on, just sure they were going bad in the sun.  Very glad I left the two, which turned out to be our new much cherished babies.

So now, she still had about 11 eggs under her along with the two babies.  She is very protective of her eggs.  When I pick them up, i can shake them and feel lots of water moving around.  Only one or two feel solid.   I just cant bare to toss them, as I made that mistake before.... but how in the heck could any of these be fertile when the male would have been absent for more than a month.  Ideas?

Also, now my female rouen is sitting on 5 eggs.  Did she learn this from my other duck?  Unless I am crazy, there is no possible way those eggs could be fertile yet she won't come off of them and she hisses at me where as she never did before.

What kind of ducks are seasonal egg layers?  I have 1 pekin, 2 baby pekin/mallard mix,  3 mallards, 1 runner, 1 rouen.   All are female except the 2 babies ?