Keep an eye out for those protective dogs! They really can get themselves in trouble if a snapper does decide to come across your yard--they won't have any preconditioning, intinctual or otherwise, to realize the danger that poses to them. As the daughter of a vet, I grew up seeing almost daily examples of pet owners assuming their dogs/cats "knew" stuff that was totally foreign to them and ended up hurt or dead. I will admit, that became one of my pet peeves as I became an adult.
And about the nest building stuff? You'll know!!
Wait till you see Barry start carrying every branch/twig/clump of grass--from everywhere he can find it. Then, if he's like my Samson, he'll have to rearrange everything a thousand times before he finally decides it's just right!! Samson cracks me up as he literally hunkers down and the long neck moves like a crane (the machine, not the bird)--back and forth--as he transfers clumps of grass from an area over towards where he's building the nest.
So that's what we do--all the spring-cleaning type yard stuff gets tossed into their area! We give them some straw (much of my reading doesn't recommend it, however, because it's slippery) but lots of other stuff to mix in so it's not as bad with the slippery aspect. (Think of sliding eggs and later little cygnets not being able to get back in the nest). He does amazingly well with sticks and twigs!
This goes on for a couple of weeks, usually, and all the while Delilah is out on the water bathing and preening and her body language literally is like "I am the queen" while Samson does all the work! But I think it is so cool because once the eggs are all laid and she starts to sit, that's it. Almost no more swimming, very little food and water--just sit and be patient for the next 34 days. I'll see her get up a few times during the incubation period, but never more than 10 minutes as a time and it's really rare. Therefore, it seems only fair that she get that "pampered" time before. Samson pitches in big-time with watching the little ones as soon as they hatch and it really seems like he is purposefully giving her a break. He also never stops patrolling the whole time she's on the nest .....that will probably be the end of your sweet and tame Barry for a while !! We usually have to carry a broom to keep him back when we try to put food in the feeder that's closer to Delilah during that time.
Hope this helps!
Beth