Together the Blue-winged Warbler and Golden-winged Warbler form a species complex that isn't fully understood. Each species can breed with the other, and produce offspring hybrids that themselves can produce further offspring, leading to all kinds of variations in plumage. This unfortunately has lead to a competition that the Blue-winged Warbler is winning: it is "breeding out" the Golden-winged Warbler throughout much of its traditional range. In this part we hear the Blue-winged Warbler's respiratory-sounding "Bee-buzzzzz" song, which sounds more like buzzing than warbling. This soundscape was recorded at McMaster Forest in Hamilton, Ontario on May 11, 2019. Heard in this recording are: Blue-winged Warbler, Gray Catbird, Yellow Warbler, Chestnut-sided Warbler, Field Sparrow, American Goldfinch, Ovenbird, Song Sparrow, and more. Audio editing: Doug Welch, Rob Porter Audio sourced from the Hamilton Bioacoustics Research Project of the Hamilton Naturalists' Club. For more information, see http://hamiltonnature.org/songscapes Send in a voice message: https://anchor.fm/songscapes/message