I got up around 5:30 this morning and headed out with my friend Roxanne to go check out parts of the Arboretum in Davis. It was another hot day today (up to 99°), so we only stayed out for a few hours. At the arboretum, we walked through part of the Peter J. Shields Oak Grove and adjoining gardens.
This grove is only one part of the Davis Arboretum. There are other gardens and collections, including a native plants garden, desert collection, redwood grove and pollinator garden. The arboretum also abuts the Putah Creek Riparian Reserve. Each facet is accessible through different streets with varying parking availability. At the oak grove, there is adequate parking and a restroom facility that is covered in detailed mosaic murals.

The last time Rox and I were here was in September of last year. What a difference in what we saw today compared to then: fewer flowers, no galls, few birds, hot temperatures. What we seemed to see the most of today was a lot of different bee species.
Among the bees we saw were a Foothill Carpenter Bees that were sleeping on different stems of the same salvia plant. Because they were dozing, it was easy to get some close up photos of them. When the male Foothill bee started to wake up, he stretched himself out between two flowers on the plant (like Tarzan going from vine to vine).
Foothill Carpenter Bee, male Foothill Carpenter Bee, female
The female bee would have slept in longer if another bee hadn’t jumped her and forced her off the plant. We weren’t sure if it was an attempt at mating (I think it was) or if it was an aggressive behavior, but the female bee just wasn’t having it.
Roxanne got this photo of them together:

Many of the carpenter bees we saw were “nectar robbing”. I know I’ve mentioned this before, but it bears repeating. Rather than working their way to the nectar through a natural opening in a flower, some bees (and hummingbirds, too) will drill a hole in the base of the flower and take the nectar from there. It’s called “nectar robbing” because the bees get the benefits of the food, but flowers don’t get any pollination action.

How do you tell the carpenter bees apart? The following is from the UCD Blog:
California has three species of carpenter bees.
The biggest is the Valley carpenter bee, Xylocopa varipuncta. It’s about an inch long. The female is solid black, while the male, commonly known as “the teddy bear bee,” is a green-eyed blond. Why teddy bear? It’s fuzzy and does not sting… “Boy bees don’t sting.”
The second largest is the California carpenter bee or Western carpenter bee, Xylocopa californica, often found in the mountain foothill areas of northern and southern California. It’s known for its distinctive distinctive bluish metallic reflections on the body… The females have dark smoky brown wings.
The smallest is the foothill or mountain carpenter bee, Xylocopa tabaniformis orpifex. The females are black with light smoky-colored wings. The male has bright yellow marks on the lower part of its face and some yellow hairs on the top front of its thorax.

We saw a family of Western Bluebirds on one of the lawns, including this youngster. I was surprised to realize that it was banded, so I reported it to the Bird Banding Laboratory. Some birds aren’t banded with numbers, only color codes, like this one. So, even if you don’t see any alpha-numeric marking on the bands, reporting the birds still helps scientists to track them.
Roxanne and I walked through the Ruth Risdon Storer Garden, and went by the Moon Garden and gazebo. At the Moon Garden, all of the flowers are supposed to be white but there weren’t many blooms at all this time of year. The gazebo was occupied by a large group of people without face-masks on, so we didn’t go in there.
On the lawn near the Moon Garden, however, we found a small flock of Mallards (mostly hybrids) stretched out in the grass in the shade, all of them in a well-spaced circle. Social distancing duck-style. Hah!
Desert Willow Shrubby Hare’s Ear One of the many oak trees Certified California Naturalist, Roxanne, with a seed head of a Star-of-Persia
CLICK HERE for the full album of photos.
Because of the heat, we walked for about 3 hours before heading out.
When we were done at the oak grove, we stopped briefly at the home of Bob Schneider. He’d invited us over to pick up copies of his new book, “Exploring the Berryessa Region: a Geology, Nature and History Tour”. He has advance copies that he’s selling, and all of the profits will be donated to nonprofit conservation organizations. (You can contact him through FB or email him at Verve2006@comcast.net), The cover art is by Obi Kaufmann.
Bob Schneider, Mary K. Hanson and Roxanne Moger.
Here’s a write up on the book from the Daily Democrat newspaper.
Species List:
- Acanthus, Acanthus sp. [like bear’s breeches]
- Algerian Oak hybrid, Mirbeck’s Oak, Quercus canariensis x Quercus robur
- Aloe Vera, Aloe vera
- Annual Honesty, Lunaria annua [“Money Plant”, “Silver Dollar”]
- Aster, European Michaelmas-Daisy, “Purple Dome”, Aster amellus
- Baby Sage, Salvia microphylla [red and white]
- Blue Germander Sage, Salvia chamelaeagnea
- Buckwheat, Red-Flowered Buckwheat, Eriogonum grande var. rubescens [pink to deep red flowering heads]
- Buckwheat, Saint Catherine’s Lace, Eriogonum giganteum
- Bur Oak, Quercus macrocarpa
- Butterfly Rose, Rosa x odoratus Mutabilis [hybrid]
- California Barberry, California Holly-Grape, Berberis pinnata
- California Carpenter Bee, Xylocopa californica
- California Goldenrod, “Cascade Creek”, Solidago velutina californica
- California Ground Squirrel, Otospermophilus beecheyi
- Calla Lily, Zantedeschia aethiopica var. Green Goddess
- Chilean Lily-of-the-Valley Tree, Crinodendron patagua
- Chinkapin Oak, Quercus muehlenbergii
- Cleveland Sage, Salvia clevelandii [purple, circles]
- Coast Live Oak, Quercus agrifolia
- Common Green Lacewing, Chrysoperla carnea [eggs]
- Common Soapwort, Saponaria officinalis [“balls” of pink flowers, look like phlox]
- Common Whitetail Dragonfly, Plathemis Lydia
- Coral Tree, Indian Coral Tree, Erythrina variegata
- Cornelian Cherry, Cornus mas
- Cypress Oak, Quercus robur f. fasigiata
- Desert Willow, Chilopsis linearis
- Dog-Rose, Rosa canina [similar to wild rose]
- Eastern Fox Squirrel, Sciurus niger
- English Oak, Quercus robur
- European Honeybee, Western Honeybee, Apis mellifera
- Field Bindweed, Convolvulus arvensis
- Foothill Carpenter Bee, Xylocopa tabaniformis orpifex
- Garden Sage, Salvia officinalis [pale purples age]
- Garnet Geranium, Pelargonium sidoides
- Indian Blanket Flower, Gaillardia pulchella
- Jimsonweed, Sacred Thorn-Apple, Datura wrightii
- Laurustinus Viburnum, Viburnum tinus [white flowers, purple-blue berries]
- Leaf Gall Wasp/ Unidentified per Russo, Tribe: Cynipidi [on Valley Oak]
- Ligated Furrow Bee, Halictus ligatus [tiny bee, b/w striped abdomen, yellow legs]
- Madeiran Germander, Teucrium betonicum
- Magnolia Tree, Magnolia grandiflora
- Mallard duck, Anas platyrhynchos
- Metallic Sweat Bees, Subgenus: Dialictus
- Mission Prickly-Pear Cactus, Opuntia ficus-indica
- Mournful Duskywing Butterfly, Erynnis tristis
- Oak Aphid Leaf-Curl Gall, Tuberculatus annulatus [on Coast Live Oak]
- Peach Leaf Curl Fungus, Taphrina deformans
- Peach Tree, Prunus persica
- Persian Oak, Quercus castanelfolia
- Peruvian Lily, White Peruvian Lily, Alstroemeria inticancha “Magic White”
- Pincushion Flower, Cream Scabious, Scabiosa ochroleuca [white/cream colored]
- Pincushion Flower, Small Scabious, Scabiosa columbaria [little, purple]
- Pink Sedum, Iceplant Stonecrop, Hylotelephium spectabile
- Purple Sage, Silverleaf, Cenzio, Leucophyllum frutescens
- Purpletop Vervain, Verbena bonariensis
- Red Coral Fountain, “St. Elmo’s Fire”, Russelia equisetiformis
- Resin Bee, Heriades sp. [nests in bee-condo block]
- Rocky Mountain Sage, Salvia lanceolata
- Rosemary, Salvia rosmarinus
- Santa Barbara Daisy, Mexican Fleabane, Erigeron karvinskianus [small yellow and white daisy-likeflowers]
- Sedge, Family: Cyperaceae
- Shrubby Hare’s-Ear, Bupleurum fruticosum [umbrels of yellow flowers]
- Silver Texas Mountain Laurel, Sophora secundiflora [dangling hard seedpods, fasciation]
- Smooth Blue Aster, Symphyotrichum laeve
- Spined Stilt Bug, Jalysus wickhami [look like tiny Craneflies]
- Star of Persia, Allium christophii [giant onion]
- Three-lined Potato Beetle, Lema daturaphila
- Tree-Anemone, Carpenteria californica [post-blooms, “yellow-green stars”]
- Valley Carpenter Bee, Xylocopa varipuncta
- Variegated Agave, American Century Plant, Agave americana
- Western Bluebird, Sialia mexicana
- Western Spotted Orbweaver Spider, Neoscona oaxacensis
- Western Sunflower Longhorn Bee, Svastra obliqua ssp. expurgata
- White Crepe Myrtle, Lagerstroemia subcostata var. fauriei
- White Oak, Quercus alba
- Yarrow, Achillea millefolium
- ?? black discoloration/gall on Valley Oak leaves
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