Saturday, February 26, 2011

Carolina Wren - Nesting

Carolina Wrens (Thryothorus ludovicianus) are cavity nesters.  In the wild, they nest in places like a woodpecker hole, the open crotch of a tree or tangled roots of an uprooted tree.  Birdhouses 101 says the male begins nest construction with sticks and then follows with softer materials like grass, moss and bark strips.  The male may start several nests so the female can choose the one she prefers.  After the female makes her choice, she often tosses out some of the material collected by the male and finishes the nest with her own choices of interior decor.

Carolina Wrens are monogamous.  The male often brings food to the female while she incubates their eggs.  Both feed the young after the eggs hatch.  One hardcopy field guild we have said males will sometimes finish raising a brood while the female begins incubating another clutch of eggs on another nest.

Birdhouses  101 says, "Carolina wrens prefer natural nesting sites located in woodlands, thickets, brushy hollows, and swamps and along the banks of streams where there is plentiful cover."  The site continues, "Due to the growing density of human population Carolina wrens do not always have the option to build nests in wild spots like that. However, Carolina wrens do not have a really difficult time adapting to their environment and are fairly tolerant of human activities. In fact they often use man-made objects..."  Both of the statements are true, but I tend to disagree with the word "prefer" in the first sentence.  We live in a very rural area with abundant natural nesting locations for the wrens.  While I'm sure many wrens do choose natural nesting sites, others seem determined to use man-made locations.

The jar-style bird feeders Jo makes are one of the Carolina Wren's favorite nesting sites.  We only feed the birds during the winter.  There is often a time lag between the time we stop feeding and when we get around to taking down and cleaning the feeders.  Wrens often take advantages of the empty feeders.

We'd watch a wren building a nest in this feeder and thought the nest was nearing completion.  As it turned out, we'd been watching a male preparing a nest for his mate's inspection.  She accepted this bird feeder nest, but then immediately began remodeling it to her satisfaction.

Once the female wren got the materials of her choice arranged the way she wanted them, she laid her eggs and incubated them.

The eggs hatched and the young wrens were fed by their parents until they successfully fledged.

The bird feeders obviously mimic the woodpecker cavities wrens might choose for nesting in the wild, but wrens also nest on the ground in dense undergrowth.  As far as wrens are concerned, a fern growing in a hanging basket is a suitable substitute for "dense undergrowth".

In this case, we'd missed seeing the wrens' nest building and remodeling activities.  Jo became aware of the nest because of the female's indignant response when watered.  Subsequently, Jo carefully watered around the wrens and these young birds also fledged successfully.

While it's easy to understand that a bird feeder mimics a tree cavity and a fern in a hanging basket seems like dense undergrowth, it takes a bit more imagination to visualize pots sitting atop a stereo speaker resembling a tree crotch or tangle of roots.

The speaker, pots and nesting wren are over in Jo's pottery studio.  "Studio" is a glamorous sounding word for an Arky cabin that was in pretty bad shape when we bought this place.  Its condition hasn't improved in the past thirty years.  The wrens can easily get into and out of Jo's studio even when the door is closed.

In past years, wrens chose to nest inside the pots.  This pair decided to build a nest among the pots.  Wrens are very tolerant of a human presence.  They fuss a little and make you feel guilty for bothering them, but don't abandon their nest or neglect feeding their young.  Jo enjoys watching wrens come and go while throwing pots.

This previous post provides more species details about Carolina Wrens and photos of a wren feeding at our suet feeder this winter.

Post photos of your favorite critters and share the link at Camera Critters.



Birdman said...

These shots and your text are quite enlightening. Always wondered about the wren

eileeninmd said...

Great post and photos of the Carolina Wren. They are one of my favorite yard birds.

swamp4me said...

Chinese take-out container, empty turtle shell, teapot, lamp globe, cast iron ladle, raincoat hood, mason jar, shoe, old mailbox, canoe bow...I could go on, but you get the idea. So I agree with you, I don't think these wrens "prefer" natural sites :)

KaHolly said...

Such a timely post for me! All my books are back home and I was wondering about the nesting habits of the Carolina Wren. (I'm still a dinosaur and I much prefer my books to the internet!) You post is hysterical. Does Jo sell her wares?? ~karen

TexWisGirl said...

Loved this post. They are one of my favorite birds. We get them here and I SO enjoy their songs and their antics. We've had the nesting in a barrel barbecue (using the vent hole as access), the lamp globe, and a piece of PVC pipe sitting on a shelf. Love that they nested in your feeders! SO CUTE!

Rebecca said...

Great photos and post.. I also have a Carolina Wren couple that seems to prefer making a nest in my garage. After reading this, I have a new respect for the wren male..What a great dad!

Pat - Arkansas said...

I very much enjoyed this post, Marvin. Your photos are wonderful and the text informative. I've seen a few Carolina Wrens around my feeders, but have no idea where they nest. I'm going to start looking; perhaps they've built in my own yard.

Scott Laurent said...

Wonderful detailed post. I'll keep my eyes open for wrens in strange places. Thanks.

Mike B. @ said...

Great post! Love the chick photos. To bad we don't have these wrens out here.

Lisa at Greenbow said...

How fun to have several Carolina Wrens nesting in your garden. You have some great shots here Marvin.

Anonymous said...

It's nice that the wrens have adopted you. I think it would be cool to be working in the studio and watching them come and go.

Willard said...

An excellent article and photographs.

Arija said...

A wonderful documentation of your friendly neighbours.
I do wish that you would add this post to World Bird Wednesday so that others could enjoy it too. You can reach the site by clicking on the Logo on my side-bar.

I had to leave my 'studio' door open last spring as the swallows had decided that it was a good spot to nest there.

I used to be a potter before a massive forest fire destroyed our historic house and garden as well as y studio. Even my kiln was no longer usable. All part of living and learning to let go so it is easier in the end to let go of everything.

Happy days!