■ Hirundinidae 

 Purple Martin 



Progne subis 



1991-95 = 1; 1995 

 n = 19 



- QLL 12B 



Tree Swallow 



Tachycineta bicolor 

 1991-95 = 205 



Violet-green Swallow 



Tachycineta thalassina 

 1991-95 = 146 



Northern Rough-winged Swallow 



Stelgidopteryx serripennis 

 1991-95 = 106 



t 

 t t t t 



t - t - - - - t 



t ----- b b t - 



t t - - t - - - - 



74 



