Here are some options if you find a turtle nest and are worried that the nest will get destroyed:
- Make a chicken wire mesh and put over the nest site, then ignore and see whether turtles will hatch. You can make a wood frame to make it sturdier and keep the dogs and other predators away from eventual hatchlings. If this is in a lawn, don't mow around the nest, and don't walk on the area.
- Dig up, take indoors, incubate, then let babies go when they are a few weeks or months old.
- Relocate nest. This is tricky, since turtles eggs should not be turned over once layed. Also, picking a good nest site can be tricky, too. You'd have to take out the nest with quite a bit of dirt, and then "repot" it at the new site. However, if you think this will improve the turtle's chances, why not give it a try. Pick a site that does not soak, drains well, does not completely dry out, gets some sun, and make sure you don't turn over the eggs during digging and transport.
- Do nothing. This sounds heartless, but only a small number of nests survive predation in the wild, and only a small number of hatchlings survive to adulthood.
- Instead of incubating the eggs yourself, find someone who would take them.
You can use something like this to make a protector.
Put a heavy brick or stepping stone on top, or stake it down!
These are good basic incubators for a decent price. I've had mine for over ten years.