Great Basin Naturalist


The relative abundance and habitat affinities of breeding and migratory waterfowl were documented for a 16,556 ha (40,880 acre) area of the Navajo Indian Reservation, San Juan County, New Mexico. The objective of the 1973–1974 study was to obtain baseline data for use as part of an environmental assessment for coal gasification plants and an associated strip mine proposed for an area not previously described in ornithological journals.

Roadside breeding-bird surveys resulted in the observation of 26 species of birds, of which the horned lark was most abundant. Additional breeding-bird observations were made during afternoon reconnaissance surveys around stock ponds and arroyos, and by a helicopter survey of cliff-nesting raptors. Nine of 30 raptor nests located were active.

Migratory waterfowl surveys were made in September and November at four stock ponds and a marsh on the study area. Peak waterfowl numbers were present in September, when teal and shovelers were the most abundant species.

The importance of stock ponds to breeding and migratory birds and the significance of cliffs to nesting raptors were discussed. Details of observations made for five species of birds designated "threatened" or "status undetermined" were presented.