Well, the readers have spoken! I received so many emails requesting one final column on house wrens that I simply couldn’t ignore them. I did try to stagger the wren columns with something else in between stories, but there is simply no way that I would disappoint so many people who were so emphatic that one more column on these tiny birds would be a good idea. So this one is for all who love wrens!
On June 24, my sister popped over to my house for a spontaneous visit, and among the many delights that we observed was the status of the wrens in my wren box. I pulled the pin on the roof, rotated it out of the way and saw that the house wren nestlings were fully feathered. Because they were at the age when careless activity near the box could trigger a premature fledging event, I quietly closed the roof of the box and retreated as quickly and quietly as possible.
Three days later, the nest was empty. However, I think I need to modify that last statement. The nest no longer contained any chicks, but it was full of clues that pointed to the successful fledging of all seven of the little buggers.
The nest, still perfect in its shape, was a little “dirty.” There was poop visible in the bedding of the nest, but the place wasn’t completely plastered. I opened up the front of the box so that I could remove the entire nest, and in doing so, I discovered — as one hopes to discover — that the foundation was absolutely full of a flaky, grayish-white powder. This was all that remained of the feather sheaths that had once covered every feather on each of the seven chicks. Most importantly, there were no dead chicks in the nest. Everyone made it out!
And now, I suppose that I should explain a little more about feather sheaths. Feathers are remarkable structures that are strong, pliable, lightweight and amazingly complex in their structure. Feathers are assembled by cellular processes that require an active blood supply to deliver the necessary building materials. To protect them as all of this is going on, each feather is encased in a pliable waxy casing that is made primarily of keratin. Keratin is the same material that human hair and finger nails are made of.
As each feather is extruded from the skin, the sheath surrounding it eventually dries up and breaks apart into tiny bits when the bird preens itself. Adults generally produce a light dust that blows away on the breeze, but nestling birds — especially seven of them! — produce so much keratin dust that it settles into the nest. When removed from a nest box, every successful bird nest is loaded with dust. I know that there is a joke about feather dusters here somewhere, but I’ll save that for another time.
With the nest box empty, that meant that there were suddenly an additional seven house wrens zipping around my yard. The amazing thing about that is the fact that they seemed to simply melt into the undergrowth. House wrens can be very loud, but when caring for their fledgling chicks they seemed to be surprisingly quiet. I have a feeling that this is mostly driven by the fact that the adult birds are no longer tied to the nest box and are free to roam about the estate as they search for food. Instead of delivering food to the chicks in the nest, the adults are now followed by a swarm of chicks.
As luck would have it, I did manage to cross paths with a house wren fledgling back in 2023 while I was holding my camera. The little bird was loafing around in the branches of a dead white pine, engaged in a little of the preening that produced all of that dust in the nest. As is often the case with very young birds, this little charmer showed no fear of me whatsoever. I think the little bird was alert and aware of my presence, but it allowed me to approach much closer that an adult might have. I was able to stand and watch the adorable little creature for quite a while and I collected many photographs.
I chose this one because of the interesting pose. The blue arrow points to the corner of the little wren’s mouth and draws you attention to the yellow color of the skin at that location. As was the case with the photo of the red-bellied woodpecker fledgling last week, this yellow skin is a remnant of a much larger flap of skin that surrounded the baby bird’s mouth. This makes a larger target for adults who must shove food into the mouths of their offspring. As the fledgling continues to grow, the extra skin slowly diminishes until it eventually disappears altogether.
I shall keep my eyes peeled for the fledglings, but I have already discovered that the male has started a second nest and he is singing like crazy. Even in the sweltering heat, he has been hard at it and, with luck, the female will start a new clutch of eggs. In the meantime, the fledglings will slowly start to take responsibility for themselves, which will free up the adult male to care for the new nest.
The young birds may fan out across the landscape as they look for food without any sort of responsibility. There is plenty of evidence to suggest that a few of them will eventually make it down into the meadow, where they will come close to me as they explore world. Receiving the “stink eye” from a baby wren is always a joyous occasion, but it is extra special when I know the baby wrens in question.
Bill Danielson has been a professional writer and nature photographer for 28 years. He has worked for the National Park Service, the US Forest Service, the Nature Conservancy and the Massachusetts State Parks and he currently teaches high school biology and physics. For more information visit www.speakingofnature.com, Speaking of Nature on Facebook, or the Speaking of Nature Podcast.