MATERIALS AND METHODS

The adult sparrows were captured and banded, and sometimes the nestlings were banded. The standard funnel trap, baited with seeds, proved useless for capturing birds of the Genus Ammospiza, although migrant Savannah Sparrows (Passerculus sandwichensis) readily entered. A Japanese bird net, twenty-five feet long, was used successfully. Eighty-five Sharp-tailed Sparrows and forty Seaside Sparrows were banded at two localities.

All of the adult sparrows were banded with United States Fish and Wildlife Service numbered bands and colored celluloid bands. The colored bands I used were obtained from the Hinton Supply Company of New York City, which manufactures them for cage birds. The firm makes them in seven colors, sold at reasonable prices. With seven colors, the number of combinations, using only one colored band and one aluminum band per bird, is forty-two.

In addition, I dyed many adults and all nestlings. Alcoholic solutions of Victoria Blue B S concentrate and Alizarine Red S concentrate were used. The males were dyed red, the females blue; various areas of the body were colored in order further to individualize the birds. Although the dyes disappeared in less than a month, the markings were helpful on many occasions.

When an adult bird was captured I always sexed it and ordinarily weighed and measured it. The nestlings were weighed and measured daily at intervals of 24 hours. I built a corral of hardware cloth around one Sharp-tailed Sparrow nest in order to measure the young after they left the nest. The sex of any adult was ascertained by examining the cloacal area, as described by Salt (1954:61-75). Sex as determined by this method was corroborated by internal examination of the specimens collected.

A pan balance accurate to one-tenth of a gram was used for weighing. The adults were weighed in a cloth sack, the sack being weighed each time to prevent error owing to variable moisture and other factors.

Dragging the marsh with a rope was ineffectual in finding nests. The birds flushed long before the rope neared them. I found nests of the sparrows by using a blind. From a blind I would determine the approximate location of a nest by watching the movements of the adult birds. Then I would either make a direct search of the vegetation or move the blind closer to find the actual site.

Many hours were spent in blinds. I had two in operation throughout the breeding season, and it was from these that most of the data on behavior were accumulated. Observations were made by means of a 7 x 50 coated binocular and on occasions by means of a 19.6x spotting telescope.

DESCRIPTION OF THE AREA

The intensive work was carried out on the marshes west of the town of Lavallette in Ocean County, New Jersey. Further observations were made at other localities in the county, in particular at the Chadwick marshes (plate 6), one mile north of the Lavallette site, where many of the Ammospizas were banded. The breeding Ammospizas of the localities are the nominate races, A. c. caudacuta (Gmelin) and A. m. maritima (Wilson).

Characteristic of the sand beaches of the Atlantic coast of the United States are offshore bars which, when exposed, form long bays parallel to the coastline. These bays become surrounded by marshes that in turn are inhabited by the two species of Ammospiza. The birds prefer the marshes closest to the ocean (plate 6). I made trips to the marshes on the mainland side of upper Barnegat Bay and found only a few Sharp-tailed Sparrows and no Seaside Sparrows in residence.

The island of the Lavallette marshes that I worked on was approximately 1400 feet long and 600 feet wide. One-third of the east central end of the island was covered with sand fill, pumped there several years before the study was begun (plate 1, fig. b). The island was also ditched. The four east-west ditches are spaced 125 feet apart; the two ditches perpendicular to these are 340 feet apart and are situated in the western portion of the island. These ditches, originally dug as a means of decreasing the mosquito population, are one foot wide and almost three feet deep. The excavated earth is deposited in a row paralleling the ditch. The entire island, excluding the sand fill is not more than two feet above normal high tide. In August, 1955, abnormally high water, a result of hurricane "Connie", rose four to five feet and covered all but the tops of the bushes and a few mounds of sand. Low tides expose no mud flats for the edges of the marsh are nearly vertical banks and the water along the edges is more than one foot deep.

The average temperature for July, compiled over a 34 year period at the Asbury Park weather station is 72.6°F. The average precipitation from May through August, acquired over the same length of time, is between 3.5 and 4.5 inches per month.

In spring and summer the prevailing winds are from the south and southwest. Therefore, the south and west shores of the island are subject to greater inundations by water. The fact that the island is unprotected by neighboring islands from the open expanse of the bay on this side is also of importance in this respect. The north and east shores, on the lee side of the island, are guarded from the open bay by nearby land. The exposed southern shores, where there was open mud and sparse patches of cord-grass, were the preferred feeding areas of the Seaside Sparrows. Lack of exposed and open feeding areas may account for the absence of this species in areas that otherwise seem to fulfill the requirements of the species.

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.