Bank Swallows nest in huge colonies like this one. Burrows are excavated in sand/clay banks [June; Douglas County, Minnesota]
![Bank Swallows nest in huge colonies like this one. Burrows are excavated in sand/clay banks [June; Douglas County, Minnesota]](https://photos.smugmug.com/BIRDS/SWALLOWS/Bank-Swallow/i-MZRzrvL/0/466d7f5b/S/Bank%20Swallow%20colony%20MN%20217_1793-S.jpg)
