Pet birds can experience a prolapsed cloaca, so I imagine hummingbirds could, too. There are more than a few things that can cause this, including nutritional deficiencies and parasites. How sad. Unfortunately, I don't think there is anything that could be done to help a wild bird. But I admit to not being very knowledgeable about this serious condition; someone else may be able to provide more insight. Or even have a different theory as to the hummingbird's problem.

I am the RI cousin of backyardmama and am posting the picture of the abnormal protrusion that is still there 4 weeks later on my brown hummingbird visitor. He still visits often, flys well and feeds vigorously. The protrusion seems to be narrowing at his body, otherwise remains unchanged. Any ideas what it could be?