Compared with the bird in South Amherst on September 3rd, which looked like a straight forward Western Kingbird, I'm still a little troubled by some of the features shown by this bird near the Brookfield Trail. The white in the outer retrices is difficult to see but certainly present. On the other hand, this evening I still had trouble seeing the gray across the upper breast. The underparts still looked extensively yellow as can be seen in the profile shots below. The bird displayed a very clear notch in the tail, rather more obvious than it was yesterday evening.

However, the six of us gathered at the site this evening heard a sharp 'kip' call repeated seven or eight times. As far as I know this is unique to Western Kingbird. This evening the kingbird came in quite late, at about 16:12 hrs, and eventually went to roost in the pines behind house #1555.

Here's a selection of three species of kingbirds from various trips in the US. All of the kingbirds were identified by a combination of range, voice and plumage.