Fecal Sac Being Removed

Let’s delve into the mysterious world of the Eastern Bluebird and their fascinating fecal sac extraction process. Observe, as a male Eastern Bluebird, with the precision of a seasoned pro, removes a fecal sac from the nest box.

Eastern Bluebird Removing Fecal Sac
Eastern Bluebird Removing Fecal Sac

Yes, you read that right. The Eastern Bluebird nestlings have the unique ability to signal to their parents, by pointing their posterior in the air, that they have produced a fecal sac and require removal. The parent bird then soars off into the distance, to discard the sac and maintain nest hygiene.

But what is a fecal sac, you might ask? A fecal sac is an enigmatic, mucous membrane, usually white or transparent in appearance, that envelops the feces. This remarkable sac makes the removal of fecal matter from the nest, a simple and efficient process for parent birds.

Intriguingly, nestlings create a fecal sac within mere seconds of being fed, and from our observations, the parents remove one or two every hour. A feast for the eyes, as well as the soul, to witness such avian efficiency in action.

So, how did I manage to capture this scintillating scene? This photographer, stationed inside a vehicle, used a Fujifilm X-T3 camera equipped with a Canon EF 100-400 mm f/4.5-5.6L IS II lens, with a Fringer EF-FX Pro adapter. The camera and lens were perched on a bean bag, draped over an open window, and captured the moment with a shutter speed of 1/220 of a second, at f5.6 and ISO 2500, with white balance set to auto.

And now, let us delve into some fecal sac facts. Did you know that not all bird species produce fecal sacs? Some parent birds consume them, as it is believed to provide a nutritional benefit. Additionally, young birds usually stop making fecal sacs shortly before they fledge. The removal of fecal material not only enhances nest hygiene but also decreases the chances of predators discovering the nest, by sight or scent.

In conclusion, the Eastern Bluebird’s fecal sac extraction process is a testament to the avian world’s efficiency and adaptation. For a deeper understanding of this intriguing subject, I recommend this article from the Audubon: “What Are Fecal Sacs? Bird Diapers, Basically.”

You can see my setup here – My Eastern Bluebird Photography Setup