Beaver activity and red squirrel presence predict bird assemblages in boreal Canada.

This article investigates how beaver activity and the presence of American red squirrels (Tamiasciurus hudsonicus) influence bird assemblages in boreal wetlands of northern Quebec, Canada. Using automated acoustic recordings at 50 ponds (beaver ponds and peatland ponds) during 2018–2019, the study detected 96 bird species grouped into four taxonomic guilds based on habitat successional requirements. Results showed that beaver ponds supported higher bird species richness, particularly benefiting early successional species, while the presence of red squirrels was associated with lower occupancy for about a quarter of bird species, likely due to nest predation. Additionally, late successional species’ occupancy increased with surrounding forest cover, and species richness declined with increasing latitude. The study highlights the ecological role of beavers in shaping bird communities through habitat modification and suggests that red squirrel presence negatively affects certain bird guilds in boreal ecosystems.