Part 3

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.

At least two nests on the Lavallette Marsh were destroyed by predators in the course of the breeding season of 1955. One nest of the Seaside Sparrow was empty when I checked it on July 3; on July 2 it had contained four young, three days old. On July 21 I found a dead Sharp-tailed Sparrow, approximately three days old, lying on a patch of matted grass. A hole was in the flank of the bird and blood was present about the bill. This nestling was not from a nest under observation.

PASSERINE ASSOCIATES

On the Lavallette marshes the only passerine associates of the two species of Ammospiza were Song Sparrows (Melospiza melodia atlantica) and Long-billed Marsh Wrens (Telmatodytes palustris palustris). Two pairs of Song Sparrows and less than six pairs of marsh wrens nested on the study area. One Song Sparrow nest was found and is plotted on the map (pl. 1, fig. b); the other pair nested somewhere along the east shore of the island. The Song Sparrows at the east end of the island obtained most of their food from the grounds of the Lavallette Yacht Club across fifty yards of water to the east. The pair that nested in the western portion of the island fed along the sand fill or along the bases of the marsh-elder. Their nest was built in the most extensive area of these bushes; it was placed approximately one foot above the ground in a small dead bush and gained support and concealment from the surrounding black grass. Three of the four eggs hatched on June 30, and the young left the nest on July 11. Both parents fed the offspring.

The marsh wrens fed and nested in the cattails. I never saw these wrens away from the cattails.

WINTER STATUS AND SPRING MIGRATION

Ocean County is ten miles south of the area treated in Cruickshank's regional work (1942). He considers both species as rare to casual winter residents. Concerning the spring migration of the Sharp-tailed Sparrow he says (p. 456) "The first widespread wave never comes before April 25, however, and most of the birds arrive in May." He mentions that late May is the height of migration and that stragglers are passing through up to the middle of June. The arrival of the Seaside Sparrow in spring is similar (p. 458): the first widespread movement is in early May, the peak is reached in the third week of the month, and stragglers have been recorded through the second week in June.

I was in the field in Ocean County almost daily all spring and found no Seaside Sparrows and only two Sharp-tailed Sparrows north of Barnegat Inlet, Ocean County, before May 5. I waded through the marshes at Chadwick, Lavallette, and Island Beach State Park on April 27 when high tides covered all of the dense vegetation and saw no sparrows of the Genus Ammospiza. If many had been present on this date I would have seen them. On May 5 both species were plentiful on the Chadwick marshes. Furthermore, the Seaside Sparrows were defending territories. The absence of the two species the previous day indicates a large nocturnal flight.

It was during the second and third weeks in May that the sparrows of this genus were most abundant. In this period many unbanded Seaside Sparrows were in the patches of cattails that were being defended by the resident males from other territory-holders.

One Ammospiza caudacuta subvirgata (G. E. W. 545) was taken in the course of the study. It was a female (ovary: 7 x 5 mm.) weighing 15.3 grams ("moderate fat"), taken on June 8, 1955, on a marsh near the mouth of the Manasquan River on the Monmouth-Ocean County line. This marsh is decidedly less brackish than the Lavallette and Chadwick marshes. The specimen was the only Ammospiza seen there and was probably a migrant, despite the late date; this subspecies is known to occur late along the Atlantic Coast south of its breeding range. Cruickshank (1942:454-455) considers the peak of spring migration for this subspecies to be reached in late May.

To find A. c. subvirgata in a marsh seemingly not saline enough for the nominate race is not surprising. A. c. subvirgata breeds in marshes, along the coast of New England, which are almost fresh water (Montagna, 1942b:256). A. c. caudacuta is only casual away from salt water.

TERRITORY

In a general treatise on the subject of territorialism, Nice (1933:98), summarizing Howard, stated: "Territory implies in the male bird isolation, advertisement, fixation, and intolerance." I concluded from my observations that all four requirements are exhibited by male Seaside Sparrows while none of them is well developed in male Sharp-tailed Sparrows. This subject is discussed separately for the two species.

Tomkins (1941:38-51) studied populations of Ammospiza maritima macgillivrayii near the mouth of the Savannah River in South Carolina and Georgia and concluded that this form is not territorial. In support of his conclusions, he quoted Nice (1933:90-91) as follows: "Territory cannot mean just the nest spot when the adults feed in common; this may be 'nest territory,' but it is a very different matter from a territory in its strict sense to which parents confine themselves during the breeding season. Again, the very essence of a territory lies in its exclusiveness; if a bird's range is not defended, it is not a territory."

The feeding and nesting grounds of breeding Seaside Sparrows are often separated by a portion of the marsh which is not used by the birds. This complicates study of the territorial habits of the species. It does not mean, however, that the species is not territorial.

The birds studied by Tomkins had separate feeding and nesting grounds. Concerning this, Tomkins (1941:43) states that "The Seaside Sparrows of this locality [Savannah River area] often live where the two requirements [adequate feeding grounds and suitable nesting cover] are not always together or even meeting, but also where the feeding grounds and the nesting place are separated by a short distance."

Six of the eight original pairs of breeding Seaside Sparrows of the Lavallette colony fed in areas separate from those in which they nested. I found the eight nests of the original residents and banded and dyed all of the adults. The owners of two nests did not have separate nesting and feeding areas. One nest was built within fifteen feet of the south shore of the island, adjacent to the feeding area. The other was built within a few feet of the north shore. The female of this nest obtained food along the shore in the immediate vicinity of the nest. Her mate was absent; in all probability it was the singing male which I took from a nearby bush, before I found it advantageous to use the island as a study area.

The remaining six pairs flew to the south or west shores of the island in order to feed. None of these six nests was more than 100 yards from the feeding grounds (pl. 1, fig. b).

It was comparatively easy to see that the males defended an area surrounding the nest. It was more difficult to see that the pairs fed on separate plots of shoreline, each defended by the male, but I am convinced that this was the case.

The nest area was defended by the males through singing and chasing. I saw no instances of a female entering into territorial disputes; nevertheless, I did see a female chase a Sharp-tailed Sparrow away from the vicinity of her nest.