Relationships between nesting bald eagles and selective logging in south-central Oregon

Bald eagles (Haliaeetus leucocephalus) often use tall, large-diameter trees to nest, and so the potential for conflict with forest management exists. Responses of bald eagles to forest management practices, particularly selec tive logging, have not been investigated thoroughly. We present a case stud y describing relationships between territory occupancy and productivity of bald eagles and selective logging of a mixed-conifer forest in the Klamath Basin in south-central Oregon. Selective logging was implemented across mor e than 3,000 ha of mixed-conifer forest in the Doak Mountain Management Are a (Doak), 80% of which occurred in territories of bald eagles. Fifty-seven known nest trees and 5,040 trees suitable for immediate and future nesting by bald eagles were retained and protected during operations. Within the ma trix of nest and replacement trees, operators also retained 153-753 trees/h a ((x) over bar= 373, SE= 103.2) across a range of diameters (10 to 110 cm DBH; (x) over bar 27.7, SE=2.3) among 4 species of trees. We determined ter ritory occupancy and productivity from territories of bald eagles at Doak a nd in reference areas within the Klamath Basin and throughout Oregon prior to (1978-1992) and following (1993-1999) selective logging. Mean territory occupancy increased in all areas during the post-treatment period, rising n early 10% at Doak ((x) over bar =90.1%, SE=2.38, n=15 pre-treatment; (x) ov er bar =98.9%, SE=1.10, n=7 post-treatment). Mean difference in territory o ccupancy between Doak and all reference areas was higher and indicated impr ovement post-treatment compared to pre-treatment. Productivity of bald eagl es was lower at Doak ((x) over bar =0.73, SE=0.04, n=15) compared to all ot her areas during the pre-treatment period, but increased at Doak and other territories on Upper Klamath Lake during the post-treatment period. Differe nces in mean productivity between Doak and Upper Klamath Lake were not sign ificantly different post-treatment compared to pre-treatment and reflect co mparable productivity of eagles at Doak during the post-treatment period. O ur results indicate that territory occupancy and productivity of bald eagle s can be maintained in conjunction with careful forest management planning and implementation.