The Spring 2016 swift watches gave us some really interesting numbers.  The peak was on May 17 when Dan Williams saw 123 enter the roost. A Merlin was seen by several people harassing the swifts and keeping them from getting into the roosts. Heavy rain before normal roost time seemed to make them enter early. Thanks for your help.
I have sent in the following data to SwiftWatch Ontario at Bird Studies Canada.  Observers all across the range of the Chimney Swift in Canada will have made observations on most of these same dates so it will be interesting to see the BSC report in a few months time.
See below the table for the eBird checklists for these visits.

Chimney Swift Roost Observations for Chimney at Peterborough at 311 George St. N.

Date: May 9
Start time: 7:54
Finish time: 8:50
Observer: Chris Risley
Number entering main roost: 66
Total entering all roosts and seen: 68

Start time:
Finish time:
Number entering main roost:
Total entering all roosts and seen:

Here are the eBird checklists if you want to learn more about any of the roost counts.
May 9:
May 13
May 17
May 21
May 25
May 29
June 2
June 6
June 10
June 14

Drew Monkman

I am a retired teacher, naturalist and writer with a love for all aspects of the natural world, especially as they relate to seasonal change.