Cavity-Nesting Birds

tufted titmouse at nest hole by The Natural Capital on Flicker

tufted titmouse at nest hole by The Natural Capital on Flicker (Creative Commons licence)

I’ve never thought of myself as a female Dr. Doolittle, but last June a bird “talked” to me and I understood her.

My tale began last April when our son, Dave, decided not to remove a dead oriental cherry tree trunk in his front yard. It was an eyesore, but, on the other hand, he thought it might attract cavity-nesting birds.

And so it did. Almost immediately a pair of black-capped chickadees started excavating a hole facing the woods and then deserted it and began another hole facing the guesthouse porch five feet away. Unlike most chickadees, which are secretive during the nesting period, they were exhibitionists. As Dave and I sat on the porch, they continued to dig out their nest, carrying beaks full of wood chips and dropping them nearby. Not only were they unafraid of us, but they also weren’t fazed on April 20 when several members of our Juniata Valley Audubon Society stood on the porch watching them.

Dave spent far more time on his front porch than I did and kept me informed about the chickadees’ work. Once they hollowed out an area deep in the trunk, the female started gathering material for her nest. Chickadees are supposed to use natural materials such as moss, pine needles, and possibly bark to provide a firm foundation to their nests and then they line them with finer material such as rabbit fur.

But at 2:00 p.m. on April 23, as I sat on our veranda reading several hundred feet away from and out of sight of Dave’s porch, a chickadee, presumable the female, flew in and landed on my book. By doing this, she grabbed my attention, and I watched her fly over to a piece of unraveling beige twine attached to the handle of a covered plastic bucket. She clung to the twine and pulled out strands of this material until she had crammed her beak full, and off she flew. She returned several minutes later and yanked off more, but this time her beak was only half full. She didn’t come back so I assumed she had enough lining for her nest.

 

One of the chickadee parents at the nest hole in the cherry snag

One of the chickadee parents at the nest hole in the cherry snag

The next time I saw her pulling out twine fibers was the afternoon of the Pennsylvania Migratory Bird Count on May 11. No doubt she had been back numerous times when I hadn’t seen her. According to chickadee researchers, nest-building by females can take as little as two days and as long as two weeks so this female was several days over the limit. Or maybe she was freshening her nest lining.

On the 21st, Dave and I sat and watched the chickadee male feeding the female sitting down in the nest. Neither paid any attention to us. But we were worried. Several days earlier Dave had discovered a six-and-a half-foot-long, shed black rat snake skin not far from the nest. And the previous spring he had observed a black rat snake climb up a tree at the edge of the woods and wipe out a northern flicker nest he had been watching form his porch. We hoped the chickadees would survive and raise their young, but their nest hole was much closer to the ground and the trunk much easier to climb than the mature live tree that had held the flickers.

a black rat snake in a flicker hole, just after eating the nestlings

a black rat snake in a flicker hole, just after eating the nestlings

Four days later, when I went down to check on the chickadees, one parent held a caterpillar in its beak and kept calling “dee-dee-dee” as it perched on a cherry stub above the hole, while a second chickadee flew down into the nest. Finally, it emerged and the calling bird zipped down and reappeared a few seconds later without the caterpillar. Then both parents flew off.

It looked as if they were feeding young. She must have begun incubating her eggs the day after I saw her gathering more twine because it takes 12 to 13 days for the eggs to hatch. But after the eggs hatch, according to ornithologists, the male is supposed to feed both the young and the female for several days since she is brooding the nestlings. Not only was this pair unusually bold, but they didn’t seem to be following the “rule book” either.

Day after day they continued feeding their young, most often caterpillars, which was the most common fare for chickadee nestlings, according to the work of one ornithologist in Massachusetts back in 1961. He constricted the throats of nestlings when they were fed and altogether counted 35 caterpillars, 11 spiders, 10 unidentified larvae, six termites, one white Lepidoptera, one pupa, and one fly.

On June 2 I did some more chickadee watching as they fed both caterpillars and insects to their young. Twice a parent emerged with a fecal sac and flew away with it. Sometimes parents eat these sacs, but usually they drop them far from the nest so they don’t attract predators.

After a short wait, a parent arrived with a green caterpillar, paused at the nest hole for several minutes, and finally ate the caterpillar. It flew into the nest entrance and stayed there for more than ten minutes, and I could see the nestlings below. Then the second parent arrived with another green caterpillar which it fed to a begging nestling.

Right on time, on June 8, 16 days after hatching, the chickadees fledged, but both Dave and I missed it. However, the black rat snake never found them, much to our relief, because we had gotten fond of the plucky birds. Perhaps, by building their nest close to the porch, they had gained some measure of protection from our constant surveillance.

In the meantime, the twine story developed another twist. On May 26, my husband Bruce and I sat on the veranda in the afternoon and watched a tufted titmouse fly in twice and pull out a beak full of twine strands, the second time mixing it with a little freshly cut grass. Titmice are also cavity nest builders and titmice females construct the nest, but I had no idea where her nest was. Still, I couldn’t believe how popular the twine was as nest-building material.

More than three weeks later, on June 19, as I sat on the veranda reading in early afternoon, a tufted titmouse flew in and landed on a round white table. Then she flew toward my face and over to the rim of a white chair across from me. Next she flew back to the table, then to me where she landed on my foot, which was propped on a stool, and looked up at me. This titmouse was trying even harder than the chickadee had to get my attention.

She returned to the table, hopped underneath it, and pecked a few times on the cement floor beneath her spread legs. It was then I realized that she was “asking” me to move the two large containers of potting soil I had recently placed in front of the covered bucket with the treasured twine.

“Alright,” I said to her. “I understand what you want.”

She flew off, and I moved the larger containers so the twine would be accessible. A couple minutes later, the titmouse returned and spent five minutes shredding the end of the twine and filling her beak. She looked over at me several times as if to say thank you. At least that’s how I interpreted it. Then she chirped to me as she flew away.

For the first time in my life, I felt as if I had had actual communication from a wild creature. To me it was a transcendent experience I will never forget.

A short film of the chickadees at work excavating the den hole.


Video and photos by Dave Bonta except where indicated.