I got up at 5:30 this morning and headed over to the Gristmill Recreation Area, getting there around 6:00 am. It was 59° when I arrived there, but it warmed up to 70° before I left.
I walked over to where I normally see the Western Screech Owl, and was happy to see her — but she ducked down immediately when a loud Scrub Jay flew down in front of her.

I then walked on the longer trail on the opposite side of the parking lot. I hadn’t been on that one before, so I didn’t know what to expect, really. It was more “wild” than the other trail with lots of trees, plants, and wildflowers (some still surviving in the heat) that are not seen on the shorter trail. It was also flatter with direct access to the river in a few spots.

I was surprised to see so many Elegant Clarkia flowers still in bloom. And it looks like there had been several stands of a kind of phacelia (caterpillar flowers) there — which I’ll have to keep an eye out for next year.

There was much of anything on the water, although I did see a Great Egret and the mama Merganser with her red-headed babies. She’s still got her four little ones, so she’s been pretty successful in keeping them alive and safe.

I found quite a few galls on the trees including those of the Black Walnut Pouch Gall Mite and the Willow Rosette Gall Midge. The rosette galls, this time around, were new ones, still all shiny and green. New-to-me galls included those of the Smooth Petiole Gall Sawfly and Willow Fold Gall Sawfly.





As their names suggest, the petiole galls were at the petiole (the point where the leaf attaches to the plant) of the willow leaves, and the fold-galls were, well, folded. In some of the fold-over galls, I found aphids being tended by ants. I think the aphids were secondary dwellers, though, having taken over the folds after the sawfly larvae hatched out. I’m not sure, though.

On one of the cottonwood trees, I saw a collection of about a dozen “things” hanging down from the branches. They looked like bushtit nests or maybe masses of bees, but I could tell they weren’t. They were made of plant material. But they weren’t like any of the hanging seed pods, and there weren’t any of them on any of the other trees. They were — and still are — a bit of a mystery to me. I think they might be panicles of seedpods that have been taken over by some kind of fungus or insects — like large leafy galls. More research is required…

Among the insects, I found a single specimen of a tiny planthopper, Agalmatium bilobum. It’s an “adventive” species, which means it’s not native but also not very well established yet.

I also found several examples of what I think is a kind of “moth leaf tier” on an Arroyo Willow. They were collections of leaves with a dead leaf in the center surrounded by several live leaves — and I think they hid moth caterpillars of some kind.

I opened up a couple of them, and found that whatever had been inside the leaves was now long gone, leaving just plant material and old webbing behind. I’m still searching for a more specific ID. The construction of the things was really interesting to see, though.
CLICK HERE for the full album of photos.
Although I didn’t get any really good photos of it, the most interesting moment on the trail today was seeing a female Nuttall’s Woodpecker foraging in the bark of a tree, while below her, near the ground, was a female Downy Woodpecker foraging on Mugwort plants.
Nuttall’s Woodpecker, Picoides nuttallii
I’d never seen a woodpecker foraging on plants before, so I had to look it up. For the Downy Woodpecker, it’s rather unusual (used only about 2% of the time). I assumed the bird was looking for ants more than plant matter itself.
Fun fact according to Cornell: “…Percussion not a means of securing prey, but rather a means of locating prey by rapidly tapping along a branch or trunk, presumably in order to hear resonance produced when tapping is above tunnel of a wood-boring insect…”
I was out on the trail for about 3 hours and then headed back to the car…and it was from the car when I got photos of House Finches and Lesser Goldfinches. Always have to keep my camera at the ready. This was hike #50 of my #52HikeChallenge.
Species List:
- Anna’s Hummingbird, Calypte anna
- Aphid, Family: Aphididae
- Arroyo Willow, Salix lasiolepis
- Bewick’s Wren, Thryomanes bewickii
- Black Locust Tree, Robinia pseudoacacia
- Black Phoebe, Sayornis nigricans
- Black Walnut Pouch Gall Mite, Aceria brachytarsa
- Black Walnut, Eastern Black Walnut, Juglans nigra
- Black-Tailed Jackrabbit, Lepus californicus
- Blue Elderberry, Sambucus nigra cerulea
- Boxelder, Box Elder Tree, Acer negundo
- Bushtit, American Bushtit, Psaltriparus minimus
- California Manroot, Bigroot, Marah fabaceus
- California Mugwort, Artemisia douglasiana
- California Scrub Jay, Aphelocoma californica
- California Wild Grape, Vitis californica
- Canada Goose, Branta canadensis
- Coast Live Oak, Quercus agrifolia
- Common European Greenbottle Fly, Lucilia sericata
- Common Merganser, Mergus merganser
- Conical Trashline Orbweaver, Cyclosa conica
- Dog, Canis lupus familiaris var. Golden Retriever
- Downy Woodpecker, Dryobates pubescens
- Elegant Clarkia, Clarkia unguiculata
- European Earwig, Common Earwig, Forficula auricularia
- European Praying Mantis, Mantis religiosa
- Exclamation Damselfly, Zoniagrion exclamationis
- Fennel, Sweet Fennel, Foeniculum vulgare
- Fremont’s Cottonwood, Populus fremontii
- Goldwire, Hypericum concinnum
- Goodding’s Black Willow, Salix gooddingii
- Great Egret, Ardea alba
- Green Lacewing, Chrysoperla rufilabris
- House Finch, Haemorhous mexicanus
- House Wren, Troglodytes aedon
- Issid Planthopper, Agalmatium bilobum
- Killdeer, Charadrius vociferous
- Lesser Goldfinch, Spinus psaltria
- Mallard Duck, Anas platyrhynchos
- Moth Leaf Tier on Willow, Order: Lepidoptera
- Mourning Dove, Zenaida macroura
- Narrowleaf Willow, Salix exigua
- Northern Catalpa, Indian Bean Tree, Catalpa speciosa
- Northern Mockingbird, Mimus polyglottos
- Nuttall’s Woodpecker, Picoides nuttallii
- Oak Apple, California Gall Wasp, Andricus quercuscalifornicus
- Oak Titmouse, Baeolophus inornatus
- Phacelia, Caterpillar Scorpionweed, Phacelia cicutaria [white]
- Pied-Billed Grebe, Podilymbus podiceps
- Red-Shouldered Hawk, Buteo lineatus
- Smooth Horsetail, Equisetum laevigatum
- Smooth Petiole Gall Sawfly, Euura sp. [willows]
- Spotted Towhee, Pipilo maculatus
- Stink Bug, Trichopepla sp.
- Tree Swallow, Tachycineta bicolor
- Turkey Vulture, Cathartes aura
- Valley Oak, Quercus lobata
- Western Boxelder Bug, Boisea rubrolineata
- Western Ragweed, Ambrosia psilostachya
- Western Screech Owl, Megascops kennicottii
- White Horehound, Marrubium vulgare
- Willow Fold-Gall Sawfly, Phyllocolpa sp.
- Willow Rosette Gall Midge, Rabdophaga salicisbrassicoides
- Wood Duck, Aix sponsa
- ?? growth on cottonwood trees
- ?? soft blobby “eggs” on oak leaf
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