Song structure and habitat associations of Pacific Wrens ( Troglodytes pacificus) in a temperate rainforest

I investigated the impact of ambient noise on the song structure and singing behaviour of 63 Pacific Wrens (Troglodytes pacificus) within Pacific Rim National Park Reserve, B.C., Canada. In addition, I examined the relative importance of temperate rainforest vegetation characteristics on the abundance of Pacific Wrens. Individuals located near the ocean produced songs with significantly longer and more syllables than individuals away from the ocean, presumably, in attempts to mitigate the masking effects of their noisy territories. Individuals near the ocean also had higher intra-individual variation in song duration compared to individuals recorded away from the ocean. I found that forest sites that contained trees with larger diameters at breast height (approximately ≥ 80 cm) were associated with higher Pacific Wren abundance. Pacific Wrens were not an indicator of the richness of other bird species. These findings are important for understanding the mechanism driving the decline of Pacific Wren populations.