Reptiles and amphibians can be found in nearly all of Sagamore Hill’s vegetative communities, from dry upland forests to salt marshes. Many of the amphibian and reptile species of the park exhibit complex life-cycles that require complex habitat mosaics for reproduction and over-wintering. Species such as wood frogs and spotted salamanders (a locally uncommon species) spend only a short time within the park’s ponds during the breeding season and utilize adjacent forested upland for the remainder of the year. Aquatic species - such as painted and snapping turtles - likewise depend upon well-drained upland forests and fields for nesting.
Terrestrial species such as the eastern red-backed salamander, common garter snake, and box turtle extensively utilize Sagamore Hill’s mixed deciduous forests, with the box turtle in particular depending upon large, roadless patches. Heron and Woodpile ponds constitute the only freshwater wetland sites within the park, but they exhibit the highest species diversity of amphibians and reptiles. These sites are critical for obligate vernal-pool breeders, such as wood frogs, spotted salamanders, spring peepers, and grey treefrogs.
The northern diamondback terrapin, though the most abundant reptile at Sagamore Hill, is found exclusively within the park’s estuarine habitats. These turtles are found primarily in Eel Creek and Cold Springs Harbor and nest on the adjacent beach. Though small, the maritime complex at Sagamore Hill is a vital part of the larger Oyster Bay and Cold Springs system, which supports one of the larger diamondback terrapin populations in the state.