Recently at our Interdam site, I was lucky enough to spot a little group of fledged chicks sitting in a tree (though I could only photograph them through binoculars). It was close to what I believe was their native nestbox, and they were being fed by a parent. It was very cute to see them sit in a row together. It’s also great to have some confirmation that they made it out of the nest safely.


Four tree swallow fledglings on a branch. Can you spot them?

Now it’s time to clean out most of the nestboxes. The last viable nestbox eggs of the year have hatched – bluebirds at the Arboretum. This box and seven other boxes will be banded by early August, and that will be it for the breeding season. Then we’ll be looking at our data and preparing for next year. I’ll be updating here soon with some final numbers from this breeding season.


Bluebird eggs and newly-hatched chicks in their nest

It was a colorful day in Winters last week when I checked and cleaned the nestboxes there. There are often hot air balloons above the town, but that day they were close overhead and landed near the creek. I also spotted a peacock on a residential street. I’ve heard there are peacocks at Lake Solano too. One of the perks of fieldwork is that I see something different nearly every day.


Hot air balloon next to Putah Creek in Winters


Peacock on the street in Winters



Late-summer nesting

Many of the nestbox birds are still busy taking care of nestlings and even laying a few new eggs. It looks like I’ve banded my last house wren for this year, but there are still bluebird nests that have new eggs being incubated.


Western bluebird nestling after banding

Left: bands for bluebirds. Right: nestbox with two cloth bags full of birds during banding.

The incubation period is also our best chance to catch adult birds, so I’ve been able to recapture more birds and put new bands on previously-unbanded parents. Recapturing banded adults lets us see that they’re still alive, and it shows us how far their nest is from the last place we saw them.


Newly banded female bluebird. She’s incubating eggs at Russell Ranch.

I recently moved the nest camera box to Russell Ranch, where there is another nest of ash-throated flycatchers. They’ve been doing very well, and they’ve just been banded. The camera will stay on them until they fledge.


Ash-throated flycatcher (ATFL) nestlings in the nest camera box. The parents laid the eggs in an old bluebird nest, with very little of the usual fur lining of ATFL nests.

We’ve seen a few rattlesnakes at our sites this season. I stepped pretty close to one once without seeing it, but thankfully it just slithered away to avoid me. I found this reminder to watch my step, a discarded snake skin, at our Old Davis Road site recently.


The weather along the creek has been hot but mostly pleasant lately. I’m hoping we don’t have any more heat waves until after the young birds are all out of the nest.


A nestbox hanging in an oak tree at Picnic Grounds


Summer updates

July is usually our last month of nesting activity overall, with just a few active boxes left to monitor in August. This season is still quite busy, though. About a quarter of our nestboxes are still active with eggs or nestlings. All of our most common species are still raising chicks, and all of our sites still have at least a few active boxes. The nestlings are doing well in general, although I worry what the coming triple-digit weather will mean for them.


House wren chicks and egg in a very deep twig nest


Tree swallow nestling during banding in Winters


One of the bluebird nests at the Arboretum had a very small egg! The three other eggs were fertilized and have now hatched, but the small one likely did not have a yolk to begin with. Runt eggs like this are rare.



Winters Putah Creek Park, one of our nestbox sites, has been having a pretty successful year. We hadn’t been able to monitor nestboxes at this site for a few years due to restoration work on the land, but now we’re back and the birds seemed to have no problem finding the boxes again — at least on the north side. The south side of the creek has less activity so far, but there were two successful nests. Each time I visit this site lately, there are many people working hard to water the new native plants and keep up the restoration work. Soon enough, the new bushes, trees, and other vegetation will grow larger along the creek and improve the habitat for wildlife.


Further up the creek, at our Interdam site near Lake Berryessa, I discovered a mallard nest hidden in the grass. The female flew out each week when I passed the spot, so I took a closer look and sure enough, there was a large nest with eggs. (I covered it again with grass and left soon after.)


Lastly, here is a photo of a bee from this morning. There are bees at many of our nestbox sites taking advantage of the abundant flowers at these beautiful places. The buzzing is a nice background sound to our work.