Yellow-billed loon at Lake McConaughy

On 8 August 1998 we observed a Yellow-billed loon (Gavia adamsii) at lake McConaughy in Keith County, Nebraska. We arrived at the pull-off on the south end of the dam at 6:25 p.m. and soon spotted a distant loon off the dam. On the basis of the yellow bill, head pattern, and large size, we concluded the bird was a Yellow-billed loon. We studied the bird until 7:33 p.m. and again from 9:03-9:45 a.m. on 9 August. Compared to a Common loon, this bird was huge and large-headed. The neck was very thick with an almost puffy appearance. The bird was also conspicuously dark-backed and pale-necked. The bill was long, thick, and dull yellow. The bill and head were held upturned and a slight angle. The head and neck were pale except as follows: the forehead was dark, the crown was very pale, and the nape and back of neck were light brown. There was a darker auricular patch. There was also a third dark mark on the side of the chin. The age of the bird was problematic. It was clearly not an adult because of the facial markings and pattern of the upperparts. Similarly, the very early August date suggested the bird was not a juvenile. After some study, we concluded the bird was probably in first-alternate plumage (see Appleby et al. 1986). On the basis of the bird\u27s behavior around boats, we strongly suspect that it had spent the entire summer at this location