This time of year, you see mixed flocks of birds, known as guilds, foraging among the trees for insects. You might catch a glimpse of yellow on a small, grayish bird, which has patches of yellow on chin, flanks and back. It is appropriately named the Yellow-rumped Warbler. I affectionately call them Butter Butts. These five-and-a-half inch guys are one of the easiest warblers to see because of their habit of sitting at the end of prominent twigs exposing their yellow rumps and flitting up to catch flying insects. I learned their name as Audubonís Warblers named after you-know-who, but years ago Audubonís was lumped with the Myrtle Warbler, which also has the yellow rump, although the adult Myrtle has a white throat and a distinct white eye-line. They were lumped with the Yellowrumped when it was discovered that some interbreed in the north and are hybrids, a mix of the two. So the Myrtle and the Audubon are known as subspecies of the Yellow-rumped Warbler. Both of these groups are seen here at this time of year but the Myrtle returns north to breed and has the distinction of being Canadaís most common warbler. So I hope youíll look up and catch a glimpse of these Butter Butts.