Fig. b. The nest of a Sharp-tailed Sparrow viewed from above. Stems of black grass were parted to take the picture. The outer rim of this nest (lower right) is made of living stems of black grass.
COPULATION
In late June at the Lavallette area there was an influx of unbanded Seaside Sparrows. Certain of these new arrivals established territories in areas unoccupied by the remaining original residents. These new residents were birds that probably had unsuccessful nestings elsewhere. Because of tropical storms that almost covered the island with water in August, I doubt that any of these late nestings were successful. On July 7 at 8:30 a.m., while watching a pair of these new arrivals, I recorded my only observation of copulation in the Seaside Sparrow. The female seemed to be searching for a nest site when copulation occurred. The female crawled about in a marsh-elder bush seemingly testing the various forks in the branches for size. The male followed her, remaining a few inches above and behind. Several times the two birds disappeared in the lower branches and were hidden by the surrounding black grass. Finally, while the female squatted on a branch the male mounted. He fluttered his wings before mounting and continued to do so as coition took place.
I began observations at Lavalette on June 16, too late to observe copulation of the early residents. All the nests contained eggs by that time. At Chadwick, pair formation seemingly never occurred, at least with the males I was studying. The territories established by males at Chadwick contained few marsh-elder bushes. Possibly females, finding no suitable nest sites, refused to accept these territories.
Copulation in the Sharp-tailed Sparrow was observed several times. It occurs most frequently in the course of, or immediately following, a fight between several males. I do not know what instigates the gathering of several males into these groups; it may be a certain behaviorism of a female, or possibly, merely the appearance of a female. Montagna (1942a:117) was convinced that females of A. c. subvirgata were present in these fights. On the other hand, in two instances with A. c. diversa where he collected all the birds in the group, no females were present. Twice, at Chadwick, my observations indicated that females of A. c. caudacuta were not always involved in these groups. In these instances all the birds in the group had previously been banded and diagnosed as males. Possibly a female was the original stimulus of these groups, and she may have disappeared while the males were fighting with each other. I found it difficult to distinguish fighting males from a copulating pair. On June 3, however, a banded pair was observed. Copulation occurred on the ground. The male fluttered his wings as he mounted and the female remained motionless. Copulation lasted approximately three seconds; immediately thereafter the male flew to a nearby cattail stem and the female climbed a tussock of grass and chipped quietly. This same female was seen to copulate with other males, and males were observed copulating with several females.
A. m. maritima is monogamous, the pair-bond being maintained throughout a breeding cycle. A. c. caudacuta is promiscuous, relations between the sexes being limited to copulation. For A. c. subvirgata a relationship other than promiscuity has been intimated (Lewis, 1920:587-589). Concerning observations of the nest he found at Yarmouth, Nova Scotia, Lewis wrote: "The nest was found after I had quietly watched the parent Sparrows for about an hour, while they were bringing food to their young.... The male sang from time to time from a piece of driftwood on the marsh about 30 feet distant from the nest. When I was examining the nest and the young birds, the parents made no demonstration for some minutes, but later they came near and uttered chip's, much like those of Savannah Sparrows."
NESTS