Galls, Swallows, and Baby Killdeer, 04-28-21

I got up around 5:30 this morning, so I could get out by 6:00 and join my friend and fellow naturalist Roxanne Moger for walks at the American River Bend Park, West Davis Pond, and the Yolo Bypass. We were hoping to see owls, but didn’t find any.

At the River Bend Park, the Great Horned Owl owlets had all fledged and moved on. There wasn’t a sign of any of them or their mom. So we continued on to Davis. We looked for Burrowing Owls along Road 104, and didn’t see any of them either. So the beginning of the trip was something of a bummer.

Rye, Secale cereale

But on Road 104, next to fields of rye, we got to see Killdeer, Western Kingbirds, Mourning Doves, blackbirds, and an American Goldfinch among a few others. When we were  done looking around there, we went on to the West Davis Pond.

The “pond” is actually a stormwater retention basin in the city of Davis, with varying levels of water in it depending on rainfall. This year, rainfall was practically nonexistent, so the pond was practically empty… so, no waterfowl or ducks with babies. Sigh. But in the butterfly garden we got to see a lovely assortment of plants (all grown for pollinators), several different galls, some Rose Weevils, and all sorts of bees.

On the rose plants (which were practically overridden by Japanese Honeysuckle vines) we found three distinct galls, two of which I’d never seen before.

One looked like spiky balls on the leaves of the plants, another looked like leafy rosettes and is called a “Leafy Bract Gall”.  The third one was in its final stages when we found it. It just looked like a shriveled chunk charcoal-looking stuff on the stem of the plant. When it’s new, the gall looks like a collection of fine greenish-red hairs (and is called a “Mossy Rose Gall”). Eventually, the gall loses its hairs and goes “bald” but retains some thin spiny projections. This is usually a summer gall, which is why we’re not seeing new ones yet. Might be worth a trip back in June to check them out.

We also saw galls on Coyote Brush plants and their relatives, the Mule Fat plants. I’ve seen galls on Coyote Brush lots of times (stem and bud galls), but had never seen the blister-like ones on the Mule Fat before.

Although finding new-tome galls is always exciting, the most fun thing at the garden was watching the bees. There were the typical honeybees, of course, but we also saw several species of carpenter bees, including the thumb-sized Valley Carpenter Bee, and the smaller Foothill Carpenter Bee.  The carpenter bees were “nectar robbing”, drilling a hole in the side of the flower to get at the nectar rather than going through the front of the flower.

Clinically speaking, “…Nectar robbers are frequently described as cheaters in the plant-pollinator mutualism, because it is assumed that they obtain a reward (nectar) without providing a service (pollination). Nectar robbers are birds, insects, or other flower visitors that remove nectar from flowers through a hole pierced or bitten in the corolla…”

Foothill Carpenter Bee, Xylocopa tabaniformis orpifex. You can see it pulling nectar from the side of the flower.

We were seeing the honeybees, which aren’t usually nectar robbers, follow after the carpenter bees to feed on nectar through the holes the carpenter bees chewed into the flowers. Smart little guys. I’d never noticed that behavior before.

After taking photos and video snippets, we left the garden and went for a drive around the auto tour route at the Yolo Bypass Wildlife Refuge. Not a lot to see there, because of the distinct lack of water. We were waylaid for a little while, watching and photographing the Cliff Swallows living under the freeway bridge. 

According to Cornell: “…The Cliff Swallow is one of the most social landbirds of North America. These birds typically nest in large colonies, and a single site may contain up to 6,000 active nests… The Cliff Swallow’s highly colonial life style has led to the evolution of some complex behavioral traits. For instance, Cliff Swallows brood-parasitize neighboring nests both by laying parasitic eggs and by moving eggs from their own nest into others; they have a sophisticated vocal system for distinguishing their own young from the offspring of many other individuals within a colony; and they observe each other’s foraging success and learn from other colony residents the locations of food… In addition, the species is closely associated with an endemic vector-borne virus that has led to insights into how changes in hosts drive the evolution of different pathogen strains…”

And besides being cool, they’re also beautifully colored, and distinguished by a white “aviator goggles” strip over the eyes (in the adults). Their eye color has been described as “dark claret brown”.

They build mud nests, one little mud pellet at a time, and the nests can overlap, sometimes as many as eight nests deep depending on the size of the colony.

Cornell says: “…Both sexes build the nest, although the male may initiate construction before he attracts a mate. Birds gather mud in their bills along the bank of a stream, lake, or temporary puddle… A bird brings a mud pellet back to the colony and molds it into the nest with a shaking motion of the bill. The shaking causes a partial liquefaction of the mud, disperses moisture, and allows fresh mud to overrun small air spaces, resulting in a stronger structure when dry… A newly built nest begins as a narrow mud ledge affixed to the wall. Birds add to the ledge until it is a crescent shape…”

Then the wall and ceiling are built up until there is only a small hole for the entrance. Dried grass is brought in to line the nest. Slapdash repairs to the nest may continue throughout the breeding season.  The birds will reuse nests from one season to the next, but around here, old nests are knocked down by humans after the nestlings have fledged.

Sometimes House Finches and House Sparrows will parasitize the nests, laying their own eggs in them.  We saw House Sparrows under the bridge. They were nesting inside the drain holes, watching the swallows work hard on their own nests.

CLICK HERE to see the full album of photos.

We saw a few Snowy Egrets, Great Egrets, and Great Blue Herons. One of the Great Blues had something sticking out of its throat. It looked like it was coming from the inside out, like the bird had jabbed at something to eat among sticks and impaled itself.  The stick (or whatever it was) didn’t seem to interfere with the bird’s ability to move around and turn its head, but we couldn’t tell if it would interfere with the bird’s ability to feed itself.

After she got home, Roxanne contacted the people she knew at the Yolo Basin Foundation (the organization that oversees the bypass wildlife area) to let them know about the bird. She got the impression that they were indifferent to the bird’s distress and probably weren’t going to do anything. I understand the whole “circle of life” thing, but I believe that if you’re paid to manage a wildlife area and are in a position to help an injured animal, you should do what you can… otherwise, what are you “managing”?  The dirt? It frustrates me.

Downingia, Flatface Calicoflower, Downingia pulchella

Two surprises on the trip included seeing patches of purple-blue downingia growing in a few dense clumps in the otherwise dry pond areas, and finding baby Killdeer. Those little things are so danged cute! They’re little striped fuzz balls with disproportionately long legs that run all over the place.  I was trying to video one of them and could barely keep it in view. Hah!

The chicks are precocial (able to fend for itself almost immediately) and nidifugous (able to leave the nest) almost immediately after hatching.

We were out for about six hours before heading home. I counted this as hike #39 of my #52HikeChallenge.

Species List:

  1. ?? Stink Bug Eggs
  2. Aleppo Pine, Pinus halepensis
  3. Almond Tree, Prunus dulcisaloe
  4. American Goldfinch, Spinus tristis
  5. Aphid, Family: Aphididae
  6. Baby Sage, Salvia microphylla [red, or red/white]
  7. Bird’s-Foot Trefoil, Lotus corniculatus
  8. Bird’s-Eye Gilia, Gilia tricolor
  9. Black Mustard, Common Wild Mustard, Brassica nigra
  10. Black Phoebe, Sayornis nigricans
  11. Black Sage, Salvia mellifera
  12. Black Walnut, Eastern Black Walnut, Juglans nigra
  13. Blessed Milk Thistle, Silybum marianum
  14. Blue Blossom, Ceanothus thyrsiflorus thyrsiflorus
  15. Brown-Headed Cowbird, Molothrus ater
  16. Bur Clover, Medicago polymorpha
  17. California Flannelbush, Fremontodendron californicum
  18. California Poppy, Eschscholzia californica
  19. California Wild Grape, Vitis californica
  20. California Wild Rose, Rosa californica
  21. Callery Pear, Pyrus calleryana
  22. Carmel Ceanothus, Ceanothus griseus
  23. Cheeseweed Mallow, Malva parviflora
  24. Cleveland Sage, Salvia clevelandii [purple, circles]
  25. Cliff Swallow, Petrochelidon pyrrhonota
  26. Coast Redwood, Sequoia sempervirens
  27. Common Vetch, Vicia sativa [pink flowers]
  28. Coyote Brush Bud Gall midge, Rhopalomyia californica
  29. Coyote Brush, Baccharis pilularis
  30. Cranefly, European Crane Fly, Tipula paludosa
  31. Crow, American Crow, Corvus brachyrhynchos
  32. Curlycup Gumweed, Grindelia squarrosa
  33. Double-Crested Cormorant, Phalacrocorax auratus
  34. Downingia, Flatface Calicoflower, Downingia pulchella
  35. European Honeybee, Western Honeybee, Apis mellifera
  36. Foothill Carpenter Bee, Xylocopa tabaniformis orpifex [light eyes]
  37. Fortnight Lily, Dietes grandiflora
  38. Giant Needle Grass, Celtica gigantea
  39. Goldenrod Crab Spider, Misumena vatia
  40. Great Blue Heron, Ardea herodias
  41. Great Egret, Ardea alba
  42. Harding Grass, Phalaris aquatica [a type of canary grass]
  43. Hoary Rock-Rose, Cistus creticus
  44. Hollyhock, Alcea rosea
  45. House Finch, Haemorhous mexicanus
  46. House Sparrow, Passer domesticus
  47. Japanese Honeysuckle, Lonicera japonica [white flowers turn yellow]
  48. Khella, Bisnaga Weed, Toothpick Plant, Bishop’s Weed, Ammi visnaga [ a kind of carrot, invasive species]
  49. Killdeer, Charadrius vociferous
  50. Lavender, Topped Lavender, Lavandula stoechas
  51. Leaf Footed Bug, Leptoglossus zonatus
  52. Leafy Bract Gall Wasp, Diplolepis californica [rosette gall on rose bush]
  53. Lupine, Yellow Lupin, Lupinus luteus
  54. Mallard Duck, Anas platyrhynchos
  55. Marsh Wren, Cistothorus palustris
  56. Mason Bee, Osmia sp.
  57. Mock Strawberry, Potentilla indica
  58. Mossy Rose Gall Wasp, Diplolepis rosae
  59. Mourning Dove, Zenaida macroura
  60. Mule Fat Blister Mite, Aceria baccharices
  61. Mule Fat, Baccharis salicifolia
  62. Pacific Forktail Damselfly, Ischnura cervula [males have 4 spots on thorax]
  63. Paper Wasp, Black Paper Wasp, European Paper Wasp, Polistes dominula
  64. Parasitoid Wood Wasps, Family: Orussidae
  65. Pineapple-Weed, Matricaria discoidea
  66. Pinkladies, Oenothera speciosa
  67. Poison Hemlock, Conium maculatum
  68. Potato Mirid Bug, Closterotomus norwegicus [yellow-green bug]
  69. Rabbitfoot Grass, Polypogon monspeliensis
  70. Red-Winged Blackbird, Agelaius phoeniceus
  71. Ring-Necked Pheasant, Phasianus colchicus
  72. Rose Weevil, Merhynchites sp.
  73. Rye, Secale cereale
  74. Saint Catherine’s Lace, Eriogonum giganteum [a kind of buckwheat]
  75. Showy Milkweed, Asclepias speciosa
  76. Snowy Egret, Egretta thula
  77. Spiny Leaf Gall Wasp, Diplolepis polita [on rose leaves]
  78. Spurge, Mediterranean Spurge, Euphorbia characias
  79. Stinking Chamomile, Anthemis cotula
  80. Tidytips, Frémont’s Tidytips, Layia fremontii
  81. Toyon, Heteromeles arbutifolia
  82. Valley Carpenter Bee, Xylocopa varipuncta
  83. Valley Oak, Quercus lobata
  84. Western Kingbird, Tyrant Flycatcher, Tyrannus verticalis
  85. Western Meadowlark, Sturnella neglecta
  86. Western Redbud, Cercis occidentalis
  87. White-Faced Ibis, Plegadis chihi
  88. Willow Dock, Rumex salicifolius
  89. Yarrow, Golden Yarrow, Eriophyllum confertiflorum
  90. Yellow Sweetclover, Melilotus officinalis