1988-04-11_PERMIT FILE - C1981008A (29)

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The waterfowl species of actual or potential occurrence in the Nucla East study area are listed in Table 5. Probably all the species listed from the Canada goose through the ruddy duck are frequent migrants in the Nucla area (Denver Museum of Natural History 1982), although nearly half were not recorded during the baseline studies. Small numbers (less than five broods of each species) of the mallard, cinnamon teal, and ruddy duck were observed. The majority of the broods were observed at the Nucla sewage lagoons. It appeared that several non-breeding individuals of mallards and cinnamon teal summered in the study area. The results of the seasonal small bird censuses for the farmsteads/orchards, Swale, and rangeland habitats are presented in Table 8. The Swale habitat supported the lowest richness/diversity index of the three habitats during both sampling periods. Eight species were recorded in the spring and 15 were recorded in the fall. The spring (and summer) breeding bird composition in areas of the Swale habitat typified by cattails and willows is dominated by yellow warblers, common yellowthroats, and red-winged blackbirds which comprise 3.5 percent, 3.9 percent, and 88.3 percent of the total bird density, respectively. Sparrows of several species made up 36 percent of the total fall density. The farmsteads/orchards habitat supported the highest bird densities during both census periods and the highest richness/diversity index in the fall (Table 8). European starlings made up 45.8 percent of the total spring density and mourning doves comprised 18.7 percent. European starlings, white-crowned sparrows, dark-eyed junco, and Brewer's blackbirds comprised 30.1 percent, 18.3 percent, 8.2 percent, and 129.4 percent of the total fall density, respectively. The rangeland habitat supported total densities comparable to the farmsteads and orchards (Table 8). This habitat supported the highest richness/diversity index in the spring as well. Spring densities were dominated by black-billed magpies (7.3 percent), European starlings (15.4 percent), Brewer's blackbirds (7.3 percent), brown-headed cowbirds (6.2 percent), and pine siskins (6.2 percent). Species predominating the fall censusing were the ruby-crowned kinglet (10.3 percent), American robin (15.9 percent), European starling (10.3 percent), yellow-rumped warbler (18.6 percent), and red-winged blackbird (9.7 percent). The overall densities and species composition of the farmsteads/orchards and the rangeland habitats are similar. Bark gleaning, foliage gleaning, and sallying species are present 11-2-31 Revised 04/11/88