Avifauna inventory and monitoring at Glen Canyon National Recreation Area [progress report]

Spence, John

This progress report documents initial tests of the bird inventory methods developed for the Glen Canyon National Recreation Area (NRA) avifauna inventory and monitoring project (see Spence 1998a). The NRA has a rich (285 species) but incompletely studied avifauna (LaRue eta!. 1998). Data from three well known and inventoried habitats at Glen Canyon NRA are analyzed to determine levels of effort needed to find 90% of the species that occur in each type. These habitats are the Colorado River from Glen Canyon Dam to the Lee's Ferry area (breeding riparian birds, waterfowl) and Lake Powell (overwintering and migratory aquatic species). First, preliminary progress on the project is presented, including discussion of different methods that are being tested. Then, each of the bird data sets is discussed, including the inventory methods used. Then the analytic techniques used in this report are presented, and results detailed. Finally, the results are discussed and recommendations made for the program. Appendices with data forms and species lists are included.