Publications

No abstract available.

No abstract available.

Birds imported into the United States in 1971 are tabulated by species. Total numbers for the period 1968-1971 are given for the more commonly imported taxa. The number of birds imported in 1971 increased only slightly over that for.1970. In 1971, 750 species were imported, of which 194 had not been imported in the previous 3 years; since 1968, approximately 1,445 species have been imported. P

No abstract available.

Seventy-seven radio-tagged wolves (Canis lupus), including members of 12 adjacent packs, were located more than 3000 times, and observed on 1337 occasions, from 1968 through mid-1973. Projected population estimates for the 4203 square-mile Forest were 405 plus or minus 20 for winter 1971-72, and 388 plus or minus 14 for winter 1972-73.

No abstract available.

No abstract available.

Back-mounted radio packs of three weights were attached to 30 captive mallards (Anas platyrhynchos) and 30 blue-winged teal (A. discors), and physical condition of the birds was evaluated for 12 weeks. All groups with radio packs lost more weight than did control groups. Feather wear often followed by skin irritation occurred in the axillary region of the wings on 90 percent of the treated birds w

Reproductive performance was measured for 126 days in twelve pairs of ring doves (Streptopelia risoria) fed a diet containing 40 ppm of p,p'-DDE and in twelve other pairs given untreated food. The DDE-treated doves took an average of 2 1/2 times longer to renest than controls, produced 13·5% fewer eggs/clutch, had 10% thinner eggs, and experienced twice as great mortality of young; all these diffe

Black duck (Anas rubripes) hens fed 10 ppm dry weight (approximately 3 ppm wet weight) of p,p'-DDE in the diet laid eggs with shells 22 percent thinner at the equator, 30 percent thinner at the cap, and 33 percent thinner at the apex than those of controls. Natural incubation increased shell cracking more than fourfold as compared with mechanical incubation. Hens removed cracked eggs from nests, a

The current widespread presence of chlorinated insecticides, polychlorinated biphenyls (PCB's) and herbicides in world waterways has elicited much interest in the mechanisms of their toxicity in fishes. Inhibition of Na+,K+-activated adenosinetriphosphatase (NaK-ATPase) and Mg++-dependent ATPase (Mg-ATPase) by DDT, endosulfan and dicofol has been demonstrated in gill, brain and kidney microsomes o

A night vision scope was used during 1969-71 to study the nighttime feeding behavior of ducks on prairie wetlands of south-central North Dakota. Adult and immature ducks were observed feeding between 9:00 PM and 4:00 AM, predominantly on midges (Chironomidae) and mayflies (Ephemeroptera). The emergence pattern of these insects appeared to be a major factor influencing duck activity and feeding beh