Our study further suggests that oral tests of House Sparrows, House Finches, and Northern Cardinals
, three common urban or suburban species, might be efficiently used to survey for WNV in some areas where corvid populations have been diminished by WNV (11) or are uncommon for other reasons.
Ninety-five northern cardinals, 59 song sparrows, and 86 dark-eyed juncos were collected during the three winters; 45 white-throated sparrows were collected in the winter of 1982-83.
Conversely, Ambrosia occurred in a lower proportion of northern cardinals than in the other three species.
Combined, Croton and Datura comprised approximately 64 and 43% of the weight of seeds in the digestive tracts of northern cardinals collected on the Nacogdoches County and Angelina County study areas, respectively.
Ambrosia occurred more frequently in white-throated sparrow and song sparrow food availability samples than in those of northern cardinals, and Digitaria was recorded in higher percentages of song sparrow and dark-eyed junco than white-throated sparrow food availability samples.
Both Ambrosia and Panicum seeds were less available to northern cardinals than to the other species.
Callicarpa, Croton, Datura, Galactia, and Phytolacca comprised 90% of the seeds consumed by northern cardinals in Nacogdoches County during the winters of 1981-82 and 1982-83 (Table 4); Croton, Datura, and Galactia were consumed in excess of availability.
Although identifiable seeds comprised relatively small proportions of digestive tracts, this study provided strong evidence that northern cardinals, song sparrows, dark-eyed juncos, and white-throated sparrows selected seeds of some genera over those of others.
The two most abundant species encountered in all seasons and surveys were northern cardinal and Carolina chickadees; American robins and eastern meadow-larks were most abundant during the winter and spring surveys.
The 11 most abundant birds seen during summer surveys on Aquilla Lake included northern bobwhite (Colinus virginianus), northern cardinal, Carolina chickadee, yellow-billed cuckoo, dickcissel, killdeer (Charadrius vociferus), lark sparrow (Chondestes grammacus), eastern meadowlark, northern mockingbird (Mimus polyglottos), mourning dove and painted bunting (Passerina ciris).
tested Anseriformes Canada Goose 253 Wood Duck 120 3 additional species 35 Columbiformes Mourning Dove 11 Rock Dove (b) 20 Galliformes Chukar (b) 22 Domestic Chicken (b) 63 2 additional species 16 Passeriformes Cedar Waxwing 5 Blue Grosbeak 2 Indigo Bunting 28 Northern Cardinal
129 American Crow 157 Red-winged Blackbird 39 Brown Thrasher 19 Gray Catbird 72 Ovenbird 32 House Sparrow 185 American Robin 79 Swainson's Thrush 32 45 additional species 422 Strigiformes Great Horned Owl (b) 9 2 additional species 3 Other (5 orders) 10 species 31 Total (10 orders) 81 species 1784 Order Common name No.