Journal of the Southeastern Association of Fish and Wildlife Agencies

Handling techniques for x-raying trapped doe deer are described. Myothesia was used as an anaesthetic at the rate of 1.5 cc. per 5 pounds body weight. A portable x-ray machine with maximum output of 30 MA and 80 KV was used to x-ray eight dead and forty-eight live deer. Pictures were made of yearling deer (12-14 cm. width) at 0.5 second exposure time, 36-inch focal-film distance, 25 milliamps and 65 kilovolts. Machine settings were the same for older deer, except kilovoltage, which increased 2 kilovolts per cm. of deer width. Radiographs indicated that 52 deer contained an average of 0.83 fetus and none of the 23 yearlings were shown to be pregnant. The adult does averaged 1.5 fetuses. Aging of fetal images on the x-ray is discussed. Evidence of prenatal mortality was not found.

Three 160 acre deer enclosures were stocked with 2, 4, and 8 deer respectively. Track counts were made simultaneously on prepared surfaces in the enclosures. It was found that the track counts were not directly proportional to population size. Thus it appears that track counts are not a valid measurement of population size, if a linear relationship through the origin between population size and number of tracks is assumed. The track counts were able to detect that there were differences in population size, but it did not tell us the magnitude of this difference.

A two-year study was made of the nesting ecology of the black duck (Anas rubripes Brewster), the gadwall (Anas strepera Linnaeus), and the blue-winged teal (Anas discors orphna Stewart and Aldrich), at their southern nesting limits along the Atlantic coast. Approximate production at Pea Island was: 1959-black duck 230, gadwall 348, blue-winged teal 105; 1960-black duck 144, gadwall 457, blue-winged teal 97. Production at Bodie Island, estimated only for 1960, was: black duck 111, gadwall 28, and blue-winged teal 48. The major rearing areas were the two man-made fresh-water impoundments on Pea Island (1020 acres of water and marsh) and the brackish pond on Bodie Island (500 acres water and marsh). Estimated juvenile mortalities were: black duck 31%, gadwall 48%, and blue-winged teal 23%. Major predators were feral cats (Felis domesticus) and snapping turtles (Chelydra serpentina).

During 1961 adult female wood ducks (Aix sponsa) were removed from nest boxes on three ponds near Raleigh and banded with U. S. Fish and Wildlife Service leg bands. During the 1962 nesting season ducks were again removed from nests for banding and a large percentage of them were found to be ducks returning from the previous year. An analysis of the first two years of the banding study revealed that (1) no nests were deserted as a result of banding during late incubation, (2) survival of adults as measured by the return of nesting birds was 47%, (3) there was a high rate (70%) of return of birds to individual boxes in which they had previously nested, and (4) some females produced two successful broods in a single season.