Two major drift lines were present on the island: one within a few feet of the waterline consisted mostly of dead eel grass (Zostera marina), and the other, situated close to the cattail strip, contained a variety of flotsam (pl. 2, fig. a).
FLORA
The vegetation on the island consisted chiefly of smooth cord-grass (Spartina alterniflora), black grass (Juncus gerardi), cattail (Typha sp.), and marsh-elder (Iva frutescens). Other plants identified on the area were: common reed grass (Phragmites communis) and slender grass wort (Salicornia europea). Black grass grows on the inner, dryer portions of the marsh, and cord-grass prefers the wetter portions, growing to the edge of the water. The marsh-elder bushes mostly are restricted to the mounds of earth dug from the ditches. Cattails, in general, grow in a narrow band paralleling, but back a few yards from, the shoreline. Areas of mixed black grass and cord-grass occurred.
REPTILES
Diamond-backed terrapins (Malaclemys terrapin) were the only reptiles recorded from the study island. Several were taken on land, but the majority were seen in the waters about the marsh.
On June 27 a black snake (Coluber constrictor) was seen in a bushy area bordering a marsh on the mainland side of Barnegat Bay. A few Sharp-tailed Sparrows were seen in the same locality and a singing male (G. E. W. 559) with testes 14 x 8 mm. and a female (G. E. W. 558) with a brood patch were collected.
MAMMALS
Only two species of mammals, both abundant, were present on the study island: the meadow vole (Microtus pennsylvanicus) and the muskrat (Ondatra zibethicus). The muskrats dug burrows beneath the level of the water into the banks of the island, used the ditches as routes to the interior of the marsh and built some small houses, mostly from cattail stems.
PREDATORS
Unless the above named mammals preyed on the sparrows, all of the enemies of the colony at Lavallette were avian. Both Crows (Corvus brachyrhynchos) and Fish Crows (Corvus ossifragus) visited the local marshes frequently as did a Marsh Hawk (Circus cyaneus). I watched the Marsh Hawk make many passes at what I thought were sparrows, but the only animal I ever saw caught by the hawk was a Microtus. The sparrows were alarmed when the hawk appeared, quickly and silently disappearing into the grass.