The common snapping turtle (Chelydra serpentina) hatchling is precocial, meaning it possesses the necessary instincts for survival immediately upon emerging from the egg. This independence is instantly tested by numerous environmental dangers. Although hatchlings are naturally programmed to care for themselves, the sheer number of threats results in an exceptionally low initial survival rate. This life history strategy relies on producing a large number of offspring, with only a tiny fraction expected to reach reproductive age.
Immediate Independence and the Perilous Journey to Water
The mother snapping turtle offers no parental care, abandoning the nest immediately after laying eggs in loose soil or sand. Hatchlings, typically emerging in late summer or early fall, must coordinate efforts to dig out of the nest chamber, which can be buried several inches deep.
Once free, the tiny turtles, often no bigger than a quarter, begin an instinctive overland migration toward the nearest water source. This journey is the most dangerous period of their early lives, exposing them to dehydration and the risk of being crushed by vehicle traffic. The trip must be completed quickly to conserve energy reserves from their absorbed yolk sac, allowing them to reach a permanent wetland area that offers water and sufficient cover.
Understanding the High Mortality Rate and Key Predators
Studies suggest that only one to two percent of all hatchlings survive to reach sexual maturity. This high mortality rate is a direct consequence of their small size and the soft, vulnerable nature of their carapace, which offers little defense against predators.
Terrestrial Threats
On land, the newly emerged hatchlings are easy targets for opportunistic mammals and birds. Mammals often locate the nests before hatching, but they readily prey on the slow-moving hatchlings attempting to reach the water.
- Raccoons
- Striped skunks
- Red foxes
- Coyotes
- Crows and various raptors
Aquatic Threats
Once they successfully enter the water, the threats shift to aquatic predators. Documented predators include large fish like the largemouth bass, wading birds such as the great blue heron, and American bullfrogs. Hatchlings must immediately seek out dense cover to avoid being consumed by these larger inhabitants.
Essential Survival Skills: Feeding and Finding Shelter
Upon reaching their aquatic nursery habitat, hatchlings immediately locate food and secure shelter. They are omnivores, feeding mainly on small aquatic invertebrates, insects, tadpoles, and carrion. Younger turtles are more active foragers compared to adults.
Their hunting strategy is primarily based on ambushing prey, remaining motionless in the substrate until a meal passes by. They seek out areas with dense aquatic vegetation, leaf litter, or soft, muddy bottoms. These locations allow them to bury themselves for camouflage and security.
This preference for shallow, cover-rich water also aids in thermoregulation. The warmer water helps them regulate body temperature, which is necessary for digestion and growth.
Surviving the First Winter (Brumation)
A major hurdle for first-year survival is successfully navigating the winter months through brumation. Triggered by falling water temperatures, hatchlings must locate a suitable location, typically burrowing into mud or soft sediment at the bottom of a wetland. They sometimes seek areas near an underwater spring where the water temperature is more stable.
The first winter is challenging because hatchlings have minimal energy reserves compared to older turtles. During brumation, their metabolism slows dramatically, and they cease breathing with their lungs. Instead, they rely on cutaneous or cloacal respiration, absorbing dissolved oxygen through their skin and specialized tissue.
In low-oxygen environments, turtles metabolize stored glycogen, which produces lactic acid. They buffer this acid by releasing calcium and magnesium from their shell and bones. This physiological adaptation allows them to withstand harsh conditions, but the energy cost makes the first brumation a significant test of survival.