A few weeks ago I posted a birder’s challenge question where I asked you to tell me how the Riverside Wren (Thryothorus semibadius) was positioned in its nest (go to the archived story here). Here is the recap and your responses.
Since Riverside Wrens are known at times for roosting inside their nests during all seasons of the year with sometimes two or three individuals at a time we wondered about this particular wren when our neighbors Jim Tamarack and Cheryl Chip showed us this photo. It was taken at night during the month of December. Its position wasn’t immediately obvious so I thought I would pose the question to you. What is this bird doing and how is it positioned in the nest?
Everyone agreed that the black-and-white striped feathers are the breast feathers and that the rufous part at the top is the head facing back and to the side while keeping an eye on, well…Jim and Cheryl’s camera for starters. It was also the general consensus that, due to the photo session taking place, this posture was a likely a defensive one as well as a protective camouflage while in the vulnerable place it was in inside the nest. One person commented that they could actually see the feet perching on the branch and that the bird is standing up (sort of) with its belly facing the door. If you zoom in you can see the feet.
On a lighter note someone suggested that it was either a defensive posture or the bird practicing some yoga. For many people who visit the Osa Peninsula on vacation this wouldn’t be out of the question, but Riverside Wrens…?
I think that everybody had it right but it also begs the question; how many species build roosting nests or use old breeding nests to roost in later? It is not uncommon for cavity nesting birds to also roost in the cavity during the non-breeding part of the year. For birds that build covered nests here in the tropics it could actually be a good way to shelter from the often times torrential downpours we have here in the winter rainy season. It is an interesting question and one to look into a bit further.
Keep an eye out next week for a little bit about the Turquoise Cotinga.