Ducks minus 7

In the last couple days, half of our ducks got taken from their nest in the cattails, and their eggs all broken but not eaten. Each ducks demise can be seen on the property, as the feathers are sticking to the grass where they were devoured. Only one small webbed foot to be found as evidence that it was them. With only 7 ducks left, and only one female nesting, I pitched a small backpacking tent, and laid sentry near the nest. I'll be camping there until the eggs hatch. I could lay ambush and shoot the coyotes, but I'd rather trap them. Who knows how many long nights would pass before I shot one. If anyone has any large traps, I'd like to borrow them.