Below is a list of all our Vaux's Happening communal migratory roosts documented 2008 through 2014.  The spread sheet shows how many total observations are recorded for both the north and southbound migrations and the highest number of swifts recorded in each migration.  The roost sites are listed in order of most swifts recorded in both migrations.  Note that we most often document more swifts when they are going south that when they came north.  With all the first year birds there should be at least twice the number headed back south.  Also, the swifts probably are more likely to use the warm chimneys in September than May as the cool nights are longer.  We need to get some more data on that part of it.

Design:  Ana-Maria Brujban, AIS student project