I saw a flock of them land in tall alfalfa, where they disappeared to hunt for grasshoppers and other insects and the moving alfalfa looked like it had been hit by a strong wind.
Sighting of the Month and ABQ a Bird Sanctuary City
It is the largest swallow in North America and is not supposed to live in the South Valley of Albuquerque, so it is not listed in A Field Guide to the Plants and Animals of the Middle Rio Grande Bosque (UNM Press, 2008).