An aerial view of the marshes at Chadwick (upper left) and Lavallette (lower left). The Atlantic Ocean appears in the upper right of this photograph.
Table 2—Linear Measurements in Millimeters of Adult Seaside Sparrows and Sharp-tailed Sparrows Captured or Collected Within Two Miles of Chadwick, Ocean County, New Jersey, Between May 6 and June 27, 1955.
| Ammospiza maritima | ||
| 14 males | 3 females | |
| wing (chord) | 64.14 (60-66) | 58.33 (58-59) |
| tail | 55.28 (54-59) | 51.00 (49-53) |
| tarsus | 23.00 (22-25) | 22.17 (21-23) |
| culmen | 15.18 (15-15.5) | 14.50 (13.5-15.0) |
| Ammospiza caudacuta | ||
| 33 males | 15 females | |
| wing (chord) | 58.79 (55-61) | 55.67 (54-58) |
| tail | 49.48 (46-53) | 46.93 (45-50) |
| tarsus | 20.91 (20-22) | 20.30 (20-21) |
| culmen | 13.67 (13-14) | 13.23 (12.5-14.0) |
In the first 24-hour period after hatching the soft "peep" note is heard frequently. The young are better able to right themselves, and many feather papillae show distinctly through the skin.
On the second day young are capable of moving short distances by using their wings and feet. A thick ridge of tissue forms over the eyeball where the eyelids later delaminate. The call is now a double version of the "peep" note described above.
When the young are three days old the eyelids open, but only slightly. In the next three days the young become better co-ordinated and the eyes open fully. The egg tooth was last seen on a young bird on the sixth day. All incoming feathers remain sheathed until the seventh day.
On the seventh day young show the first signs of cowering. Previously, they all begged when I came to the nest. The remiges remain sheathed, but the body feathers emerge from the tips of the sheaths. A quiet reedy call replaces the "peep" note. A quiet, but squealing distress call was also first noted on the seventh day, when the young were handled.
On the eighth day the remigial sheaths become gray (previously they were dark blue) and begin to slough off. When removed from the nest, the young attempt to escape. Begging is less frequent and cowering is the predominant attitude towards intruders.
The first young of both species left the nest on the ninth day. It must be remembered, however, that this remark, and succeeding remarks, concerning departure of young from nests pertains to young that were disturbed daily by me. The others climbed to the edge of the nest when they were left alone, but remained in the nest when they were all replaced. Gaping was recorded once on the ninth day. Stuart W. John watched two Sharp-tailed Sparrows on my study area leave a nest. They climbed out and immediately hid in a tussock of grass a few inches behind the nest.
On the tenth day when I parted the branches over one Seaside Sparrow nest, the four young jumped from the nest and scattered in the grass. One of these birds gave a chipping note similar to the distress call of adults. No bird remained in a nest longer than ten days. Four young left the nest after nine days, seven young left on the tenth day. When the young leave the nest they are able to run rapidly through the dense grass. The young are fed by the parents for approximately 20 days after they leave the nest. Twenty-three days after one young Seaside Sparrow left the nest it was netted at the opposite end of the island, 300 yards from the territory of its parents.