This report outlines the results of joint Porcupine Caribou investigations from summer 1982 to winter 1986, between the U. S. Fish and Wildlife Service (funding agency) and the Yukon Department of Renewable Resources (personnel). In December 1983, the senior author joined the Canadian Wildlife Service and all three parties agreed that the project would continue with the same personnel. The project was initially designed to provide information to the funding agency on both the juvenile mortality of the herd and on the possible impact of petroleum development on the range use of the herd. Two mortality projects were initiated. The first, on neonatal mortality, was the prime responsibility of the U. S. Fish and Wildlife Service and the Alaska Department of Fish and Game. In Canada, support for this project was in the form of radio-tracking flights to monitor the mortality collars and to monitor the movement patterns and distribution of animals in Canada. As well, when mortality signals were detected in Canada, the collars were retrieved and the ca--use of death investigated. Mortality of juvenile caribou, other than neonates, was the focus of the second study and Canadian personnel took the initial lead role in the study. Similar arrangements with monitoring and collar retrieval were negotiated with Alaskan biologists. Two aspects of caribou range use in relation to petroleum development were investigated. The spring range use of bulls in northern Yukon was studied via radio-monitoring and ground camps (see attached report entitled - Distribution, activity and range use of male caribou in early summer in northern Yukon, Canada). The second project is designed to provide baseline information on the range use of the herd in summer, with particular reference to the use of insect relief areas. This project has one more year of field work until completion and will not be reported here. Both of these projects are the primary concern of the Canadian Wildlife Service.
