BY LUKE MACKAY, ENVIRONMENTAL EDUCATION INTERN
It is currently the peak of egg laying season for Common Snapping Turtles (Chelydra serpentina). These omnivorous turtles’ breeding season is from April to November; they lay eggs primarily in June and July.
Females strive to find sandy soil and will dig a hole to deposit 25-80 eggs each year. She will then cover these holes with sand for protection and will make extra empty nest holes to confuse predators. At the Linda Loring Nature Foundation property, we have a plentiful population of snapping turtles and sandy nest pits can be frequently found on our trails, especially the eastern part of the property where there are numerous wetlands.
It is important to be wary of these incubation holes so as to not disturb the safety of these eggs. This is especially true because the literature says that and other predators will look to eat snapping turtle eggs. Nantucket is very limited with small mammalian predators so the primary predators tend to be birds, rats, feral cats, or possibly snakes. When setting a turtle trap on the eastern part of the LLNF property, we discovered some broken eggs and a deposit that had been destroyed by a predator. With various predators in the area, we couldn’t determine exactly what preyed upon the snapping turtle eggs. So we decided to investigate…
To unmask the perpetrator we set up a trail camera directly adjacent to an egg incubation deposit. While we waited and debated for a couple days before checking the trail cameras, a certain predator returned to the scene of his previous crime. We speculated that it could have been a deer, especially because there are so many deer trails around the property and it would have been easy for one to inspect it through digging. Another possible perpetrator was a feral cat. There are many of these cats around the island and on the property, and although we didn’t see any cat tracks in the sand, they were certainly a suspect. One of our volunteers, George, was dead set on the predator being a crow because of how intelligent and crafty they are. That said, an Osprey most likely would have also seen the snapping turtle mother laying her eggs and could easily have swooped down and eaten them. What do you think it was?
Well, George happened to be spot on. The trail camera footage revealed what had disrupted the nest and eaten the snapping turtle eggs to be a pair of American Crows. The included photo reveals how these clever birds not only are able to locate the egg incubation site, but stick their heads into the holes to uncover eggs.
The predators caught in the act!
Crows can identify people who have previously posed a harm to them and can use gestures for communication. Once crows successfully figure out how to get their food, they will keep trying over and over because they know it worked once. From there, these birds will teach their offspring and other crows how to obtain this food. In addition, crows have such a wide variety of food in their diet and eggs are often at the top of that list. These highly intelligent birds are major predators to snapping turtle eggs. That said, in and around Long Pond there are many snapping turtles and undisturbed egg deposits are very common.
So, if you’re on the trail on our property or anywhere near a wetland or pond this time of year, keep your eyes peeled for a snapping turtle nest!