2019 was the 11th year for the Tree Swallow (TRES) research project
out on the remote Middleton Island. Again, this summer the TRES-population did not get monitored during the breeding season, but thankfully Scott Hatch of the Institute for Seabird
Research and Conservation (ISRC) provided me with an overview of the nest boxes’
contents, as found on their annual inspection round after the
breeding season:
Field map containing 2019's TRES results (ISRC). Middleton is approximately 7x2 km.
Based on this information I suspect that this year about 6 nesting pairs roamed the island, four of which laid eggs and produced one or more young.
I took the time to organize box occupancy between 2009 - 2019...:
