Tree Swallows

Last week, I saw about a dozen tree swallows flying together in Winters. I was replacing broken nestboxes, and a couple of them even inspected and sat near one new box for a bit! It’s still very early in the year, and I don’t expect them to start nesting until late March or early April. However, I’ve heard that some nestbox trail monitors in other states are also seeing early box visitors this year.


Tree swallows zooming through the air in Winters

We’ve recently received some lovely new nestboxes for the year from Ron and Sara Ringen. They have donated handmade nestboxes to our project for the past several years. Replacing and repairing old nestboxes makes our nestbox trails safer and more effective for the songbirds.


A fresh batch of nestboxes

Other animals like to hang around the nestboxes in winter. I recently found a couple of boxes full of walnuts, presumably stored by a squirrel. I’m not sure if it would have been able to remove the nuts again through the small box entrance. We’ve also had a lot of woodpecker damage. I caught a northern flicker in the middle of pecking a large hole in one nestbox last week. The drumming is really loud on a hollow nestbox!


Walnuts stored in a nestbox


A nestbox with an entrance hole that has been enlarged by a woodpecker

There aren’t many boxes left to replace or repair now. In about a month I’ll start checking for nests. Hoping for a great nesting season for our native songbirds!


Lush grass at our Mace Boulevard site


Preparing for Spring


Putah Creek near the city of Winters, January 2020

The 2020 breeding season has yet to begin for our cavity-nesting songbirds, but pretty soon it will be time to start repairing, re-hanging, replacing, and cleaning out the nestboxes. Most of the species that use these nestboxes tend to start scoping them out pretty early in the spring or late winter, so it’s important that we have everything in good condition and in the right locations at that point. However, if Putah Creek floods within the next couple of months, some boxes could still be swept away or become damaged. If only I knew how bad the rain and flooding are going to be this year.

Before we know it, spring will come and we’ll be spending hours each week checking nests and recording data. It leaves little time for catching up on other tasks, so now is the time to make all of our preparations.


A Few Site Visits

Between the bouts of rain, I spent time at some of our sites to make sure our bird survey areas were marked. It’s also a good opportunity to check if the nestboxes are still up. After the strong winds and rain we’ve had this fall, I wasn’t surprised to find a few tree branches and boxes had fallen. I was able to put some of them back up nearby, while others will need to be moved or replaced.


The sites look quite different in December, now that the trees are mostly bare and the new grass is just coming up among the fallen leaves. There’s not much to block my view or my path, although the low light and fog can make it a little bit harder to spot birds.

The Audubon Society’s annual Christmas Bird Count will start this weekend. Birders throughout North America and beyond will be organizing groups to go out and see as many birds as we can. The local Yolo Audubon Society will be surveying Putah Creek. Hope we all see a lot of birds!

Siblings after fledging

A male banded Western Bluebird was seen recently near the UCD Equestrian Center, and this one was the brother of the banded female I posted about last time! Both birds were banded with the same color combo in June of 2018 in the Arboretum. This seems to be our only record of two bluebirds from the same brood being seen again after fledging from the nest. [Correction: One other pair of broodmates have been seen again, both from the Arboretum as well. One was seen there again two years later while the other was found further west at our Picnic Grounds site.]


Adult Tree Swallow with silver leg band visible, May 2019.

Since Tree Swallows have been easier to catch than bluebirds, we do have several records of multiple Tree Swallows of the same brood identified again after fledging. Some were found near each other in the same area, and others moved far apart to different sections of Putah Creek. Broodmates on Putah Creek are rarely both/all seen again in the same year.

Speaking of bird families, an interesting nest camera video was recorded by researchers in Pennsylvania this year showing interspecies parental care. (Click the above link and scroll down to see the video.) Sometimes birds of one species are found feeding another species’ nestlings. In this case, an Eastern Bluebird was helping a Tree Swallow pair take care of their offspring. I don’t believe we’ve ever observed this sort of behavior on Putah Creek.


Campus bluebirds

I recently spotted two bluebirds in a parking lot on the UC Davis campus – and one was banded! I was able to see its color band combo and find it in our records. She was banded as a nestling in June of 2018 in the Arboretum. I could only get a photo of the other bluebird, though, and it didn’t have bands.


Western bluebird in a tree on the UC Davis campus

It’s tricky to get useful (let alone high-quality) photos of songbirds. If a better, bulkier camera isn’t an option, a phone camera used with binoculars can work pretty well. There are also affordable telephoto phone lens attachments out there, which is what I’ve been trying out lately. I’m hoping it’ll be a more portable option for quick bird photos.


October changes

As bird surveys continue into October, I had the opportunity to go see how the Winters Putah Creek Park is changing. The new plants are growing nicely, giving a better idea of how this site will look next spring when our birds start nesting again.



A banded juvenile bluebird, possibly the same one as in the last post, was seen this past weekend again in Northstar Park in Davis. White-crowned and golden-crowned sparrows are also around Davis in large numbers now that we’re further into fall. Hopefully the birds that are still migrating will be alright through this week’s windy weather.


Juvenile bluebird

Kelli O’Neill recently saw one of our banded bluebirds foraging in Northstar Park, where Alison Ke monitored the new nestbox trail this year. This juvenile western bluebird came from one of those boxes. After checking its leg band combo with our records, I found out that it hatched on about July 17th and was banded on July 30th. It came from a brood of four total nestlings, the second brood in that box this year. Both broods were very successful. It’s great to know that this bird is still doing well and taking care of itself!


Juvenile western bluebird catching bugs in the grass. Its metal and plastic leg bands, partially visible in the photo, were used to identify it. Photo by Kelli O’Neill.

We’ve mostly been busy looking at our data in the office lately, but we’re still doing avian surveys as the fall migration period continues. I’m looking forward to the cooler weather and hopefully seeing a lot of birds.