Lesser Goldfinch

I have been watching a Lesser Goldfinch nest for the last three and half weeks. The nest is neatly tucked in a cluster of leaves at the end of an oak branch. There are two baby birds still in the nest.

It is thought that goldfinches are late season nesters in order to take advantage of all of the seeds. The parents regurgitate a mushy seed-porridge to the babies during nesting. Also, I imagine that the timing is beneficial for the juvenile birds to have a bountiful crop of seeds to eat when they leave the nest.

The meadows around the pavilion are full of grass seeds that the goldfinches love. It is fun to watch them forage. They will land on a grass stalk and move towards the seed head. This bends the stalk over where they can access the seeds and they can often be seen hanging upside down eating. Birds are acrobatic creatures.

You have to be observant and moving slowly to catch the goldfinches nibbling on seeds. They practically disappear in the dry meadow colors and the dappled sunlight under the oak trees. It is not uncommon for me to flush them out of the grass as I walk along. Many times they won’t go far and are usually fairly tolerant of my presence as I slowly inch closer to watch them.

Hope you are getting in some good birding this summer. Thanks for reading my blog.

Western Wood Pewee Sunning & Preening

In the early warmth of the morning sun, I watched this Western Wood Pewee sunning and preening. It spent most of the time with its back to the sun with its tail feathers spread out and its wings slightly open and away from its body. After a five minutes or so of sunning, it would have a session of preening that lasted approximately five minutes. Sometimes when it preened, it would flip around and have its other side exposed to the sun.

Occasionally an irresistible insect would fly by and it would swoop out, catch it, return to the perch, and continue preening. To my surprise, this lasted for around an hour.

I wrote about this sunning and preening last year, observing it in Robins and Steller’s Jays (Sunning, Feb. 28, 2024): This maintenance behavior isn’t completely understood but seems to be largely associated with removing parasites, such as lice, living on their skin and feathers. Studies have shown that exposing the feathers to direct sunlight can allow them to heat up enough to kill some of the lice. In addition, lice might move to escape the heat possibly making it easier to clear them away during preening, which often follows a session of basking in the sun.

Happy Birding!

Sweet Dreams

I was out walking around the arboretum the other evening enjoying the cool air and a slight breeze as the day was coming to a close. I was walking along the incense cedar trail and could hear the ethereal notes of brown creepers flowing through the forest. I stopped to listen and saw one swoop down to the base of a tree. I watched it for a little while as it sang and moved around on the furrowed trunks of old incense cedars looking for food. I lost sight of it in the waning light, but I could still hear it singing in the canopy. Suddenly it swept down to the base of an incense cedar in front of me. It went up the tree and came to a small cavity in the bark where a tree limb used to be. It hopped into the entrance and perched there. I watched as it sat there looking around. After about five minutes or so, I saw it nestle a little more into the old knot hole. I occasionally saw it gently close its eyes for a moment and then reopen them. I began to wonder if this was where this brown creeper was going to spend the night. I decided to sit down, wait for night to fall, and see if it stayed. I watched it over the next forty-five minutes or so, occasionally glancing up to see if it was still there. The last time I looked up there I saw that it had tucked its head inside, and I imagined that it had nodded off to sleep. So I said goodnight, quietly stood up, and walked on to go home and do the same.

Great Horned Owl - Thermoregulation

In the later part of spring, there was a hot weekend where the temperature got up to around 90 degrees Fahrenheit. It was the first day of the year where it had become that hot and it felt like summer had suddenly arrived in a blast of heat. I felt a bit drained from the surge in temperature and was staying in the shade as I walked around the arboretum. I was at the beginning of the zigzag trail when I heard a robin alarming on the hillside and went to check it out. I found two great horned owls—a parent and a juvenile. They were briefly on the same branch together and then the parent flew a little ways down the hillside. The juvenile stayed behind and I could see that it was eating a northern flicker. As it sat on the branch, it was occasionally making a screeching call that seemed to be a begging communication to the parent and to me, a possible signal that it was uncomfortable in the heat.

To remedy the stress from the heat It was perched in the deep shade of the hillside where it was coolest. It was also cooling itself by holding its wings open to allow the air to circulate over its body. I could also see that it was holding its mouth open and vibrating its neck. Some birds will perform a version of avian panting called gular fluttering where they open their mouths and vibrate their neck muscles to try and remove excess heat. Basically, opening their mouth and fluttering their neck muscles (in the throat or “gular” region) increases blood flow and moves air across the moist membranes in their mouth and esophagus, resulting in evaporative cooling.

As the daytime highs are consistently rising into the 90’s, I recommend fluttering your feet around in the river. Stay cool everybody. I hope to see you out there!

Resources
How Birds Keep Their Cool | Audubon. 1 Aug. 2012, https://www.audubon.org/news/how-birds-keep-their-cool.

How Do Birds Keep Cool in the Summer? | U.S. Fish & Wildlife Service. 11 Jun. 2021, https://www.fws.gov/story/how-do-birds-keep-cool-summer.

Western Wood-Pewee Nest

The nest of the Western Wood-Pewee is so elegant. It is tightly woven out of fine plant fibers and held together by spider webs. It is a work of art. I love watching the parent sitting on the nest as the branch gently sways in the breeze.

As I sit and watch this nest, it all seems unbelievable. This little bird flies all the way from South America to nest here at the arboretum! The range maps have them breeding in Western Canada and up into Alaska. The migration of birds is truly miraculous. I can’t even imagine all of the landscapes and obstacles this bird had to navigate to get here. And by the end of the summer, they will be on their way back along with the new hatchlings! That is a long way from here. This blows my mind!