Executive Summary


This study examines vulnerable species inhabiting the Île à l'Aigle and Île Bouchard islands near Montreal. It also examines trends that are likely to modify habitat conditions on the islands. These islands offer a rare opportunity to safeguard biodiversity near the urban area of Montreal.

The study was conducted at the request of the proprietors, Nature Conservancy Canada (NCC), in an ongoing collaboration between the land conservation group and the Environmental Research class at McGill's School of Environment. NCC identified six vulnerable bird species and one rare plant species which were investigated: Ammondramus nelsoni (Nelson's sharp-tailed sparrow), Asio flammeus (short-eared owl), Cistothorus platensis stellaris (sedge wrenl), Coccyzus erythropthalmus (black-billed cuckoo), Ixobrychus exilis (least bittern), Sterna hirundo (common tern) and Eragrostis hypnoides (teal lovegrass). NCC also requested research on water level changes, erosional and successional processes and on the species invading the islands including: Lythrum salicaria (purple loosestrife), Phragmites australis (common reed) and Larus (gulls).

The study defined the specific ecological requirements of each species and their relationships to the trends. It suggests strategies NCC might pursue to ensure the conservation of the species on the islands. Specifically, we recommend that the habitats of these two islands be sustained at their current level of diversity. This follows from the belief that an early successional mosaic with some woods will best sustain the vulnerable species on these islands. The continuation of grazing can be explored as a method for maintaining this mosaic. Furthermore, monitoring environmental conditions, such as water level changes, erosional, depositional and successional processes, as well as controlling invasives if necessary is highly advised. Another beneficial undertaking for the NCC would be to gather as much relevant knowledge as possible on all the other species on the islands. With this knowledge the NCC can make the most informed decisions regarding management options and uphold its vision of conserving ecological refuges.