Conservation
Species at risk
The most familiar list of species at risk is the federal one proposed by COSEWIC (the Committee for the Status of Endangered Wildlife in Canada). But several other lists exist, each with a different emphasis, depending on jurisdiction, geographic coverage, and sources of information.
COSEWIC (Committee on the Status of Wildlife in Canada) assesses how species are doing in Canada (then, separately, the Environment Minister decides whether to list them)
Nova Scotia Endangered Species Act mostly mirrors the federal listings
General Status Ranks are used forfor Nova Scotia Environmental Impact Assessments
Partners in Flight is part of the global BirdLife International, which has a list of its own
Natural Heritage / Conservation Data Centers store sightings for regions, less useful for birds than other taxa, though their rankings are cited a lot (Global, G1-5 and Subnational, S1-5)
Population trends
There's years of data on many species available on the web, collected by various methods and updated constantly. The websites vary in how user-friendly they are, but are enormously distracting once you get the hang of them.
Bird atlasses (via the maritimes atlas)
Conservation plans
Comprehensive conservation plans exist for various groups of birds (from North American Bird Conservation Initiative)
Regulations
Canadian Wildlife Service’s advice on how to not run afoul of migratory bird protections