One way to help ensure survival of hatchling turtles is to “cage” the nest of eggs as soon as they’ve been laid – harder than it sounds…
by David Seburn
[Note: This is the second in a series of blog posts on a project of the OFNC and the Canadian Wildlife Federation. The first was Hunting for the elusive Blanding’s Turtle.]
Every June, female turtles leave their homes in swamps and marshes to lay their eggs. A turtle “nest” is a fairly simple affair: the female digs a hole in the ground in a sunny location, lays her eggs in the hole, covers up the eggs with the soil, and then she leaves. The eggs hatch in a few months and the hatchlings head to water.
That’s how the process works in theory, but in reality there are many creatures that would love to eat all of those tasty turtle eggs. A certain amount of nest predation by raccoons and other animals has no long-term effect on turtle populations, but in some areas, there are so many nest predators that they can devour almost all the turtle nests. The future of any population depends on successfully producing young, so complete nest failure year after year is a serious threat.
One simple way to help some nests survive is to cage them. A nest cage does not affect the conditions in the nest, but keeps out predators. As part of a partnership between the Canadian Wildlife Federation and the Ottawa Field-Naturalists’ Club, we have been placing nest cages on turtle nests in the city of Ottawa. The cages are roughly two feet by two feet in size and built from 2×4 lumber and hardware mesh. They are held in place with long spikes nailed into the ground to deter raccoons from pushing the cages aside. Small openings in the sides of the cages allow hatchlings to escape.
The real challenge is finding a turtle when she is nesting, so that the cage can be placed on the nest as soon as the female is finished. Finding a turtle on land before she starts to nest may simply spook the turtle and cause her to return to the wetland and nest another day. After a female has finished nesting, it is often hard to find where the eggs were laid. Nesting surveys usually have to be undertaken either early in the morning or in the evening, when turtles are more likely to nest.
If you are out exploring areas near wetlands this summer, you may find a turtle nest cage. For example, two of these cages have been installed at Britannia Conservation Area. These cages usually have a tag indicating what it is but these tags can sometimes disappear. Please do not disturb the cages, as that is the only protection the developing eggs have.
Turtles face many threats in today’s world, from traffic mortality to habitat destruction. They need all the help they can get, and caging some nests so that the eggs will hatch and produce hatchlings is one way to help ensure that turtles have a future.