Nisqually NWR, 18 November 2025. While just about all of the warblers and vireos have headed south to warmer climes, our resident tiny insectivores are still active and with fewer / no leaves to obscure then, often easier to see. They have coalesced into mixed-species feeding flocks as they industriously glean insects and spiders from the branches, trunks, and remaining leaves. It is magical when you find yourself in the middle of a flock. Their delicate sounds surround you. The air is filled with their frenetic movements.
Considering that they consume the same prey, there must be advantages for joining in these larger feeding flocks. More eyes might reduce the overall predation risk from Cooper’s or sharp-shinned hawks.
A week ago, I found myself immersed in this situation at Nisqually NWR. For almost an hour, I tried to photograph these tiny, fast birds under relatively the relatively low light conditions of mid-November, especially under cloudy skies (higher ISO and slower shutter speeds…). Not unexpectedly, I discarded many pictures (thank you for digital vs. the film cameras I started with decades ago.). I have over a dozen images of empty branches where there had been a bird just a fraction of a second before or a blurred bird flying out of frame… But there were many solid ones that I thought I would share.
Chickadees, both black-capped and chestnut-backed, were the most common participants in this flock. On multiple occasions, I watched a chickadee hang from the yellow leaf of a big-leaf maple as it scanned for caterpillars or other potential food items. A black-capped chickadee (11g)
is just about the mass of two quarters (11.3g) (or two nickels = 10g). A chestnut-backed chickadee (9.7g)
is even lighter.
For the last few trips to Nisqually, Merlin’s sound ID feature has indicated the presence of golden-crowned kinglets (6g) in the crowns of the trees, hidden by leaves for the most part. But on this day, the mixed feeding flock included golden-crowned kinglets coming closer to the ground and in better photographic range.
Adding to the species diversity, there were a few ruby-crowned kinglets (6.5g) in the mix as well.
A solitary brown creeper searched up the main tree trunks.
I often encounter downy woodpeckers traveling with this mixed-flock. Today, I first heard their high-pitched squeaks deeper in the woods and then found a pair of downy woodpeckers who were chasing each other through the trees. While I do not see many nuthatches at Nisqually NWR, I have observed red-breasted nuthatches traveling with these flocks in my neighborhood.
While not traveling with these groups, species that have more limited ranges, such as song sparrows and Bewicks wrens,
appear to become more active as a mixed-species flock passes through their range. Perhaps they are more comfortable when there are so many other individuals on alert for predators.
Interestingly, I rarely find bushtits (5.3g – one quarter), another classic small insectivore, as members of these mixed flocks.
Steve
