Overview
Project Name
Canadian Migration Monitoring Network
Access Level
By Request
Year started
1991
Year Ended
Ongoing
Dataset
Daily Migration Counts: Thunder Cape Bird Observatory
About
Dataset summary
Counts from Thunder Cape Bird Observatory (TCBO) of birds banded and observed during daily operations; plus a composite Daily Estimated Total (DET): the best estimate for each species of unduplicated number of individuals detected within the official count area during the daily monitoring period
Season(s) and frequency
Daily from last week of April into early June, and from 1 August until 31 October
Geographic area covered
Located near Thunder Bay, northwestern Ontario (48.3, -88.93). Migrants at the site originate primarily from breeding range in Manitoba and Ontario, but isotopic studies indicate that a portion of individuals of some species come from Northwest Territories
Primary species covered
Captures are primarily small passerines, but all species observed are recorded
Goals
To conduct standardized daily migration season counts and collect ancillary data on migration ecology for use in long-term biological and population monitoring of Canada’s bird species
Methods
Sampling Design
Daily capture and observation during migration seasons to generate species-specific daily totals of birds detected within each study site
Field methods
Daily operations (standardized in 1999) include 7 hours of banding (starting 45 min before sunset, using 4 passerine nets, 8 hawk nets, 8 ground traps, a J-trap and 2 Heligoland traps), and a 6-hour watch from a platform. Incidental observations are recorded for the remainder of the day
Analysis methods
See Quick Links. Population trends for ‘Regular Migrants’ at this site are based on counts from standardized methods only (numbers banded and recorded on the 6-hr watch), while trends for all other species are based on Daily Estimated Totals that include incidental observations
Advice
Any disruption to standardized operations relevant to appropriate interpretation of analytical results is noted in a regularly-updated section of the station protocol. As of 2025, the only alert to users of this dataset is that due to covid restrictions, the station was closed in spring of 2020 and fall coverage in that year was reduced.
Partners
Thunder Cape Bird Observatory
Citation
Birds Canada and Thunder Cape Bird Observatory. 2026. "Daily Migration Counts: Thunder Cape Bird Observatory". Data accessed from NatureCounts, Birds Canada. 10.71842/n2v8-2q89
