NPS
Habitat Range of the Violet-green Swallow
Violet-green Swallows are also known to go into a hibernation-like state of inactivity called torpor. During unseasonably cold and cloudy weather, they may not be able to find enough insects to maintain their energetic lifestyle, so to conserve energy, they become dormant. If you encounter a swallow that appears to be only semiconscious, the best thing you can do is to leave it alone. If the bird is in a location where it might be injured or disturbed by a careless visitor, carefully move it (gently pushing an index finger into its chest until it steps up on to your finger--in the same manner you would a parakeet or other pet bird) to a safer spot where it can warm up in the sun. In a few hours it will become fully alert and resume its fast-paced lifestyle.
When and where to see at Bryce:
Violet-green Swallows are easily seen anywhere along the Rim Trail and are especially common at Sunset Point. Look for them from early April through September.
Further Reading:
Dunn, John L. 1999. The National Geographic Field Guide to Birds: 3rd Edition. National Geographic, Washington D.C.
Erlich, Paul R. et al. 1988. The Birder's Handbook: a field guide to the natural history of North American Birds, Simon and Schuster/Fireside Books, New York
Ryser, Fred A. 1985. Birds of the Great Basin: A Natural History. University of Nevada Press
Sibley, David Allen. 2001. The Sibley Guide to Bird Life and Behavior. Knopf Publishing