As energy development expands into Alberta's boreal forest, sources of chronic industrial noise also increase. I found that many passerine species are present in lower densities in areas impacted by chronic industrial noise; over one-third of species analysed had lower abundances in these areas. Passerines as a whole had a 37% reduction in density near compressor stations. Male Ovenbirds ( Seirus aurocapilla ) were 15% less likely to successfully pair with a female in noise-affected areas. There was an 18% increase in the number of first-year breeders in noisy areas, implying that competition with older birds may be forcing younger birds out of optimal, quieter habitat. Finally, if birds learn to alter their song's frequency in areas with substantial background noise these effects may be minimised; Swainson's Thrush ( Catharus ustulatus ) appears to have this ability although the Ovenbird and Red-eyed Vireo (Vireo olivaceus ) do not.