All Around Yolo County, 05-28-21

I got up at 5:30 this morning and met up with my friend/fellow naturalist Roxanne to go see what was out and about in Yolo County. We had planned to go to the Putah Creek Riparian Reserve somewhere along the line, but we got waylaid by other sights and destinations, and then it got too warm for us to be walking around outdoors.

We went along Roads 105 and 30 to look for the hawks and other birds that had been reported in the fields there, then we went to the Yolo Bypass Wildlife Area, then we headed over toward the Putah Creek access, but ended up in the Häagen-Dazs Honey Bee Haven instead. At every place stopped, we saw something interesting and unexpected, and that’s always fun.

Roads 105 and 30 in Yolo County

On our way to Road 105, we saw a large, flat-faced, light-colored bird fly across the highway in front of us. We assumed by its GISS [general impression, shape and size] that it was an owl, possibly a barn owl, but we didn’t know for sure.

Rox had been in the area the day before, so knew where to look for the birds in the fields along Road 105. We pulled up onto Road 30 (where the traffic was practically nil), and got out of the car to take some photos and video.

We found a sizable collection of birds in one field, and although they were all pretty far away from us (and we didn’t want to trespass into the field itself) we were able to identify the species of the birds. 

Along with lots and lots of Swainson’s Hawks (all of them sitting down, partially hidden by the grass), we could see Great Egrets, Snowy Egrets, Black-Crowned Night Herons, Cattle Egrets, Great Blue Herons, crows and ravens, Red-Winged Blackbirds and Brewer’s Blackbirds all standing or flying in close proximity to one another.

There had been lots of reports of large gatherings of birds in the ag fields lately because some of the fields were being flooded, and that caused all the ground-dwelling mice, voles, and insects to come up in order to flee the water…then had to run the gauntlet of hungry birds. Swainson’s Hawks take both small rodents and insects, so their sitting on the ground was not uncommon for them. They’ll actually run on the ground after prey if they have to. 

And it was just Swainson’s Hawks out there, no other species. I think that’s because the Swainson’s often gather in large flocks which may be intimidating to other hawks. In one spot alone, I counted 18 Swainy’s.

According to Cornell: “…These elegant gray, white, and brown hawks hunt rodents in flight, wings held in a shallow V, or even run after insects on the ground. In fall, they take off for Argentine wintering grounds—one of the longest migrations of any American raptor—forming flocks of hundreds or thousands as they travel…”

In the field, the various birds on the ground seemed to be fine with their nearby neighbors.  The hawks didn’t bother the herons or egrets and vice versa. There was one young Swainson’s Hawk, however, who had somehow aggravated a group of blackbirds and a tenacious Kestrel, and was being chased back and forth and around the field. The hawk was crying all the while it flew, as though begging for help, but none of the adult hawks came to its rescue. It eventually landed in a tree on the edge of the field and hid itself among the leaves.

CLICK HERE for the full album of photos.

As we were walking along the edges of the field, I found an owl pellet… and also saw one of the female Brewer’s Blackbirds take some grass to her nest in the top of a tree.

To try to see more of the birds in the field from a different angle, Rox drove further down Road 30.There we saw a solitary female Wild Turkey, and some young crows going through/coming out of a major molt.  “…When crows molt, the old feathers can appear brownish or scaly compared to the glossy new feathers…” And some of these looked very brown.

We then turned the car around and drove down the other end of Road 30, almost to where the paved road gave way to dirt and gravel. We were surprised to find that some of the folks who lived nearby did some “native plant planting” along the edges of the ag fields.  There were a couple of very nice stands of Showy and Narrow-Leaf Milkweed plants, most of them just starting to bloom. Along with the honeybees, we saw a Green Lacewing, and lots of Blue Milkweed Beetles.

The beetles are a dark metallic cobalt blue with black legs and antennae. They live on or around milkweed throughout their lifecycle, eating the leaves (and sometimes the roots of the plant), having sex, and laying eggs. The larvae can “skeletonize” the leaves of the plant, but that action doesn’t kill it. It simply goes dormant until the next season. Although these beetles have the ability to launch themselves (like click-beetles), none of that did that while we were looking at them… not even when we brought them close to the eyes of our cellphone cameras.

We found a couple of the honeybees that had been trapped by the milkweed and died. Milkweed plants are interesting in that they have a variety of unusual boobytraps built into them that other plants do not. Besides their sticky latex (the white sap that drips from the plant when it is damaged) which can trap a variety of insects, the milkweed flowers themselves can also be dangerous for pollinators.  

Rather than offering up its pollen on upright visible structures called “stigmas”, the milkweed flower has its pollen hidden inside special little crevices called “stigmatic slits”.  When a pollinator, like a honeybee, lands on the flower and walks over its surface to drink the flower’s nectar, the bee’s feet slip inside theses stigmatic slits.  Pollen inside the slit affixes itself to the bee’s feet, and when the bee moves to another flower, it carries that pollen with it. Transferring the pollen and putting its feet into the stigmatic slits of different milkweed flowers completes the process of pollination.

Occasionally, however, the bee’s foot may get caked in so much pollen that it simply cannot get its foot out of the slit. (Think of putting your hand into a jar with a narrow neck so you can grab a handful of candy at the bottom of the jar. Your candy-filled hand may then be so full and wide, it cannot get through the jar’s neck, and your hand gets stuck inside the jar.)  

A dead honey bee caught in the slits of a milkweed flower. Note the pollen sac attached to the foot it managed to get out.

Some bees actually amputate the trapped foot in order to escape. But if the bee is unable to do that and cannot manage to get its foot out of the stigmatic slit, it will eventually succumb to starvation and dehydration and die.

When we turned the car around again to head back to Road 105 (and onward toward the wildlife area), we found that the hawks had taken to the air in a swirling, dense kettle of over 50 birds. I’d never seen anything like that. It was amazing to witness. Flying in huge kettles is not uncommon for the Swainson’s Hawks.

According to Cornell: “…When it comes to forming kettles, Swainson’s Hawks are overachievers: they form flocks numbering in the tens of thousands, often mixing with Turkey Vultures…[other hawks and kites)…”  These giant kettles, of course, are during their migration to Argentina, but still… Wow!

We then went to the Yolo Bypass Wildlife Area. There is virtually no water on the ground right now, so there was “nothing” to see. There were doves in several locations, but they were really the only birds, besides finches that we saw out there. It would have been a totally boring and disappointing stop had it not been for the dodder. We had never seen dodder in bloom before, so when we realized the stuff at the bypass was dense with flowers, we were super-excited.

CLICK HERE for the full album of photos.

Roxanne did a write-upon the stuff for Facebook which was excellent, so I’m quoting her here: “…Ah, Dodder. It’s the golden, orangey or reddish silly string of the plant world. That’s right: a plant. Dodders have roots (temporary), leaves (often reduced to scales), flowers and seeds. Dodder is parasitic. Although it sprouts from seed, it mostly or completely lacks chlorophyll. Consequently, the new sprout must find a host between 5 and 10 days from sprouting or it dies. The sprout swirls around as it grows and once it touches a host plant it buries haustoria (knoblike organs along the shoot) into the host stem, drawing water, carbohydrates and minerals at the expense of the host plant. As well as “starving” the host plant, dodder is also implicated in the transmission of certain bacterial and virus diseases. Thus nourished, the dodder’s roots die and the dodder spreads out in a mat moving from plant to plant, branching as it goes. Broken bits can continue to thrive if haustoria are attached to the host plant. Animals, humans, or equipment moving across a dodder mat can thereby spread dodder to new areas.

            “Flowering dodder can produce thousands of seeds that can live in soil for up to 10 years. In many native habitats dodder is not considered particularly harmful. But in an ag context dodder can cause significant economic harm, especially to alfalfa, asparagus, citrus, clover, beans, melons, peppers, potato, tomato, safflower, sugarbeet, field bindweed (Convolvulus arvensis), lambsquarters (Chenopodium album), and pigweed (Amaranthus species). It is easy to see why Dodder has enjoyed a variety of common names including love vine, goldthread, devil’s-guts, devil’s-ringlet, devil’s-hair, hellbine, hairweed, beggarweed, scaldweed, strangle tare, strangleweed, and witch’s hair.

            “CalFlora lists 31 species of dodder in CA, and only 5 are non-native (often arriving here in contaminated seed or in horticultural soils). Dodders can be found in California ag fields, forests, canyons, salt marshes, deserts, beaches and mountains up to 8200’. CalFlora lists two species here in the valley, Cuscuta campestris (Field dodder) and Cuscuta pentagona (Western field dodder) but several more species can be found in the Bay Area and into the foothills north and east of Sacramento. My frequent naturalist partner, Mary Hanson, and I first spotted a hillside of dodder two years ago in the lupin and poppy along Wilbur Springs Road about half way between the bridge and the gate to Wilbur Hot Springs. The next year we found less there but a whole hillside along Bear Valley Road not far from the bridge intersection. We ID’d this as Cuscuta californica (California Dodder) but now I’m not so sure. More study for distinguishing species is needed.

            “…Not far along the auto tour near the marsh viewing stand is a largish patch of golden yellow-orange dodder on the right side of the road in the Small Melilot (Melilotus indicus), Prostrate Knotweed (Polygonum aviculare), Bisnaga (Visnaga daucoides), and Fennel (Foeniculum vulgare). This is the first time we’ve seen the dodder in the bypass and the first time flowering. The shape of the tiny pale flowers grow in clusters and their shape and growth pattern help distinguish species.

            “Look for dodder when you are out and about and see if you can also spot the hautoria and tiny flowers. I’d be interested in hearing where else naturalists are finding it. FYI, dodder seeds are considered an herbal remedy, especially in Chinese and Korean herbal medicine. A quick Google search revealed lots of sources for seeds, extract powders, and tinctures…” Sooooo informative.

Charlie Russell, one of my former Certified California Naturalist program graduates and plant guru noted: “Dodder spreads vegetatively, so when they grade the ponds in the Yolo Bypass it spreads quite readily. Some years there can be multiple acres of solid dodder out there…”   Whoa!

There were Cabbage White butterflies all over the place. They’re “nervous fliers”, which means trying to get a still shot of one of them is tricky. The species was “accidentally introduced” in the late 1800’s. I got several photos of one foraging on mustard (Brassica rapa).

Studies seem to indicate “…some flowers, like Brassica rapa, have a UV guide for aiding nectar search for the butterfly where the petals reflect near UV light, whereas the center of the flower absorbs UV light, creating a visible dark center in the flower when seen in UV condition. This UV guide plays a significant role in foraging…” Cool, huh?

After the bypass drive, we went on to the Häagen-Dazs Honey Bee Haven, which was right in route to the Putah Creek access area. Because the pollinator garden is only an acre and the paths are well drawn, it’s easy to walk around it. The street on which the garden is situated has a lot of tall olive trees along it, so there are a lot of shady places to park.  The garden is open from dawn to dusk year-round and admission is free. Rox had never been there before, and there were picnic tables in the shade of one of the old olive trees there, so we stopped for lunch and walked the grounds for a bit.

CLICK HERE for the full album of photos.

All through the garden are paintings, sculptures and mosaics (most of them by local artist Donna Billick) that have been donated to the garden from local artists and from the art department at UC Davis.  For art students who need science class credit to graduate, they can take an art-and-science fusion class that lets them do something creative for the garden while they learn about the bees.  So there’s something new in the garden every year. The standout sculpture is of the giant “Miss Bee Haven” bee.

According to author Kathy Keatley Garvey: “…Miss Bee Haven [was built] using rebar, chicken wire, sand, cement, tile, bronze, steel, grout, fiberglass and handmade ceramic pieces. The project took [Billick] four months to complete… Anchored with 200 pounds of cement and with six bronze legs drilled into the pedestal, this worker bee is destined to stay put… Billick used lost wax bronze casting to craft the six legs, which extend from the thorax to rest on a ceramic purple dome aster, fabricated by Davis artist Sarah Rizzo.  The purple dome aster is among the flowers in the garden…”

The garden offers suggestions of what to plant in your own yard, how much water each species of plant needs, when they grow, etc. I was most impressed this time around by the lavish kiwi vines covered in their large leaves. Something of a surprise was seeing a Turkey Tangle Fogfruit plant covering an entire planter and flowing down onto the ground. I’d never seen one that was so prolific. Usually, when we come across the plants, they’re relatively small, maybe less than a hand’s breadth. So, to see one this big was kind of shocking.

Turkey Tangle Fogfruit, Phyla nodiflora

Among the flowering plants, we found several species of bees there including carpenter bees, honey bees, mason bees, leafcutter bees and sweat bees. We also saw a few Flame Skimmer Dragonflies. 

By the time we’d finished walking the acre, we were tired… and it was getting too hot for us to walk anymore, so we headed home. We were out for about 5 hours, and I counted today’s trek as hike #48 in my #52HikeChallenge.

Species List:

  1. Alfalfa Leafcutter Bee, Megachile rotundata
  2. Alfalfa, Medicago sativa
  3. Alkali Mallow, Malvella leprosa
  4. American Kestrel, Falco sparverius
  5. Apple, Malus pumila
  6. Baby Sage, Salvia microphylla [red, or red/white]
  7. Black Mustard, Common Wild Mustard, Brassica nigra
  8. Black Phoebe, Sayornis nigricans
  9. Black-Crowned Night Heron, Nycticorax nycticorax
  10. Black-Tailed Jackrabbit, Lepus californicus
  11. Bladderpod, Peritoma arborea [kind of looks like Jerusalem sage but gets bladder-like seed pods]
  12. Blessed Milk Thistle, Silybum marianum
  13. Blue Milkweed Beetle, Cobalt Milkweed Beetle, Chrysochus cobaltinus
  14. Bluebeard, Caryopteris x clandonensis
  15. Brewer’s Blackbird, Euphagus cyanocephalus
  16. Bristly Oxtongue, Helminthotheca echioides
  17. Broadleaved Pepperweed, Lepidium latifolium
  18. Brown-Headed Cowbird, Molothrus ater
  19. Cabbage White butterfly, Pieris rapae
  20. California Buckwheat, Eriogonum fasciculatum
  21. California Ground Squirrel, Otospermophilus beecheyi
  22. Cat, Felis catus
  23. Catmint, Nepeta x faassenii var. “Walker’s Low”
  24. Cattle Egret, Bubulcus ibis
  25. Cheeseweed Mallow, Malva parviflora
  26. Chicory, Cichorium intybus
  27. Chinese Wisteria, Wisteria sinensis
  28. Climbing Prairie Rose, Rosa setigera
  29. Common Checkered Skipper, Burnsius communis
  30. Common Spikeweed, Centromadia pungens
  31. Crambid Snout Moth, Family: Crambidae
  32. Crow, American Crow, Corvus brachyrhynchos
  33. Curly Dock, Rumex crispus
  34. Desert Cottontail Rabbit, Sylvilagus audubonii
  35. Dodder, California Dodder, Cuscuta californica
  36. Eastern Fox Squirrel, Sciurus niger
  37. Eucalyptus Trees, Eucalyptus sp.
  38. European Honeybee, Western Honeybee, Apis mellifera
  39. Fennel, Sweet Fennel, Foeniculum vulgare
  40. Field Bindweed, Convolvulus arvensis
  41. Flame Skimmer Dragonfly, Libellula saturata
  42. Foothill Carpenter Bee, Xylocopa tabaniformis orpifex [light eyes]
  43. Goldenrod Crab Spider, Misumena vatia
  44. Great Blue Heron, Ardea herodias
  45. Great Egret, Ardea alba
  46. Green Lacewing, Chrysoperla rufilabris
  47. Gumweed, Grindelia integrifolia
  48. Harding Grass, Phalaris aquatica [a type of canary grass]
  49. Hollyhock, Alcea rosea
  50. House Finch, Haemorhous mexicanus
  51. House Sparrow, Passer domesticus
  52. Interior Sandbar Willow, Salix interior
  53. Italian Thistle, Carduus pycnocephalus
  54. Japanese Wisteria, Wisteria floribunda
  55. Khella, Bisnaga Weed, Toothpick Plant, Bishop’s Weed, Ammi visnaga [ a kind of carrot, invasive, “Bazinga”]
  56. Kiwi, Actinidia deliciosa
  57. Lollipop Verbena, Verbena bonariensis var. “Lollipop”
  58. Lupine, Golden Lupine, Lupinus densiflorus
  59. Marsh Wren, Cistothorus palustris
  60. Mourning Dove, Zenaida macroura
  61. Mum, Chrysanthemum, Chrysanthemum sp.
  62. Narrowleaf Cattail, Typha angustifolia
  63. Narrowleaf Milkweed, Mexican Whorled Milkweed, Asclepias fascicularis
  64. Olive Tree, Olea europaea
  65. Pennyroyal, Mentha pulegium
  66. Poison Hemlock, Conium maculatum
  67. Prostrate Knotweed, Polygonum aviculare
  68. Raven, Common Raven, Corvus corax
  69. Red-Shouldered Hawk, Buteo lineatus
  70. Red-Winged Blackbird, Agelaius phoeniceus
  71. Ring-Necked Pheasant, Phasianus colchicus
  72. Rio Grande Wild Turkey, Meleagris gallopavo intermedia
  73. Shasta Daisy, Leucanthemum maximum
  74. Showy Milkweed, Asclepias speciosa
  75. Slender Vervain, Verbena rigida
  76. Sneezeweed, Rosilla, Helenium puberulum
  77. Snowy Egret, Egretta thula
  78. Stinking Chamomile, Anthemis cotula
  79. Sunflower, Common Sunflower, Helianthus annuus
  80. Swainson’s Hawk, Buteo swainsoni
  81. Tree Swallow, Tachycineta bicolor
  82. Tripartite Sweat Bee, Halictus tripartitus
  83. Tule, Common Tule, Schoenoplectus acutus
  84. Turkey Tangle Fogfruit, Phyla nodiflora
  85. Turkey Vulture, Cathartes aura
  86. Western Fence Lizard, Blue Belly, Sceloporus occidentalis
  87. Western Kingbird, Tyrant Flycatcher, Tyrannus verticalis
  88. White Tailed Kite, Elanus leucurus
  89. Yarrow, Achillea millefolium
  90. Yarrow, Golden Yarrow, Eriophyllum confertiflorum
  91. Yellow Starthistle, Centaurea solstitialis
  92. ?? little red-eyed fly