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Harold D. Irby

Publications and source records attributed to Harold D. Irby.

3 recordsLinked to original sources

Whooping crane recovery plan

This plan has been prepared under the authority of the Endangered Species Act of 1973 and subsequent amendments. The Plan is designed to provide decision makers with an orderly set of events which, if carried out to a successful completion, will result in changing the status of the species from the endangered to the threatened level. It must be recognized that this Plan has been prepared 40 years after attempts to preserve the species began. As such, it covers events that have taken place, that are taking place, and that need to take place. The Plan, therefore, not only compiles in one place all whooping crane management and research efforts which are underway, but also proposes additional efforts needed for the recovery of the whooping crane. The Plan also establishes funding evels, time schedules, and priorities for each management and research effort. The Plan is organized into three parts. the first part includes an account of the whooping crane's history, biology, present status, and the factors believed to have resulted in its endangered status. Also included in this part is a synopsis of research and management activities that have taken place through 1978. The second part is a step-down pan wherein all existing and needed research and management efforts are organized into an orderly set of events. The prime objective is to move the whooping crane to non-endangered status. Minimum requirements for the attainment of this objective are the increase of the historical Wood Buffalo-Aransas population to at least 40 nesting pairs and the establishment of at least two additional, separate, and self-sustaining populations consisting of at least 20 nesting pairs each. the third part identifies the responsibility, time schedule, and cost for each element of the step-down plan.

Book

Relative toxicity of lead and selected substitute shot types to game farm mallards

The acute toxicity of lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot were tested in year-old male game farm mallards. Mallards ( Anus platyrhynchos ) were fed eight number 6 shot of each type and observed for a period of 60 days. Ducks used totaled 230 and most shot types were tested in three replicates of 8 ducks each. Mortality and losses of body weight were the criteria used for judging toxicity. Three types of plastic-coated lead shot were as toxic (93 percent) as the commercial lead shot (96 percent). The average mortality in mallards fed lead-magnesium alloy shot was less (58 percent) than that occurring in birds fed commercial lead shot. Mortality among mallards fed iron, copper, zinc-coated iron or molybdenum-coated iron shot was significantly less than in birds fed lead shot, and was not significantly greater than the conrtols.

Maryland, Pennsylvania

Breeding behavior of immature mourning doves

Some immature mourning doves ( Zenaidura macroura ) are capable of breeding in their first (calendar) year of life. The breeding activities of immatures observed in this study included calling, copulating, and nesting. Development of sexual structures such as cloacal papillae, oviduct openings, and gonads was also regarded as evidence of breeding potential. Immatures were identified principally by white-tipped wing coverts. Sexes were distinguished by behavioral characteristics. Males coo, perform flights, carry nest material, and attend nests during the day and females attend nests at night. Immatures were involved in at least ten nestings on two areas near Tucson, Arizona, in 1963. Five young fledged from these nests.

Arizona