The Cliff Swallow (Petrochelidon pyrrhonota) species is one of six swallows that we find during summer in Carver County.
Barn Swallows are often seen in the same area because they join Cliff Swallows in building mud nests under bridges and in culverts. Bank Swallows and Rough-winged Swallows live in burrows in sand banks. Purple Martins and Tree Swallows nests are placed in tree cavities and man-made Martin houses. The swallow family species all spend most of the daylight hours in flight, with wide-open mouths capturing insects.
About 5 ½ inches long, with wings 13 ½” long, they are masters of the air above areas with water or where insects may swarm. This can include agriculture fields during plowing, when the insects are disturbed.
The presence of diverse and available insect food means Cliff Swallows are found across most of North America and nest throughout Carver County. They are long-distance migrants, travelling northward in April, building nests in May, and raising young in June and July. Then in August and September, they head south to their wintering homes throughout South America.
Their dependence on insect abundance also means their arrival date in Minnesota and even in Capistrano, California, is never fixed on the calendar. If our weather is cold and wet, their nesting will be delayed, and early arrivals may not survive. The ground must be thawed for the small balls of mud to be collected and constructed into nests under our overpasses and against the sides of buildings and cliffs. They usually live in colonies that may contain hundreds of nests. Each nest may contain 900 to 1,200 individual pellets of mud collected in the beaks of both sexes.
Finding Cliff Swallows on the banks of streams and ponds is the easiest way to identify them, because they aren’t moving at 20 miles per hour! They have dark backs and white bellies. At the base of their tail, behind the edge of the wing, their rump will be pale or tan. Their heads will be black on the top, with a white forehead and tan and dark-brown throat. The end of their tail is squared-off, differing from the other mud nest builder – the Barn Swallow – which has a split tail that is pointed or spread, but not flat.
While in the air, swallows can be challenging to identify; look for the tail shape, white forehead and tan rump. They are superb aerialists and can maneuver inches above a lake’s surface or climb to a hundred feet in a matter of seconds. You might find them in a racetrack flight pattern – matching the edge of the water then flying a return route to start the path again a few seconds later.
Cliff Swallows are easy to find while in the air feeding and are fun to watch from our trails through the underpasses where they nest. Their nest-building, egg incubation, then feeding nestlings can be seen while not causing disturbance to the swallows’ lives. They are good neighbors to have for a few months of our summers!
For more information:
- The Sibley Guide to Birds, David Allen Sibley
- Birds of Minnesota, Robert B. Janssen
- Breeding Birds of Minnesota, Pfannmuller, Niemi and Green
- The Audubon Society’s Encyclopedia of North American Birds, John K. Terres
- Birds of the World, Cornell Lab of Ornithology
- Online: All About Birds, Cornell Lab of Ornithology LINK
- Online: Minnesota Breeding Bird Atlas
