Cygnets and Goslings, 04-26-20

I got up at 6 o’clock this morning and headed out with my friend Roxanne to the Mather Lake Regional Park by 6:30 am.  We were hoping to walk the full length of the trail along the far side of the lake (the less manicured side) and wanted to check in on the swans to see if they were off their nests yet.

CLICK HERE for the full album of photos.

The first thing we saw when we got into the park were several families of Canada Geese and their goslings.  One pair was looking after 30 (yes, 30) of the fuzzy babies.  Most of the geese have up to 8 goslings, so, when you see a large group of them (like 30) it’s a group of goslings from different parents (called a creche) that are being overseen by babysitters while the parents go off to feed. Creches usually occur where a lot of geese nest in a small area.

A very chubby Canada Goose, Branta canadensis, gosling

Except for the creches and the parenting behavior we saw among the geese, in which the male steps forward to protect his babies while the female herds the kids away to another location, we also saw a lot of “rule by tyranny” behavior with the nonbreeding adults posturing, honking at, and threatening others who came near them.  Once the breeding season is over, the flocks are less apt to be so aggressive.

Canada geese mate for life, but will take a new partner if their spouse dies.  The goslings are remarkable. They leave the nest within 24 hours of hatching, and can walk, feed, swim and dive without parental supervision.  But they do still need their parents for warmth and protection.

Because there were so many baby birds around, I was constantly being distracted by them and their fluffy cuteness, and I wasn’t being a very observant naturalist,s o I’m sure I missed tons of stuff along the trail.  I know that I missed the specimen of Dog Vomit Slime Mold that Roxanne saw and photographed. D’oh!  Still, I managed to get about 70 species on my list for today.       

We saw and heard several Great-Tailed Grackles along the trail. The males are singing and posturing for the females right now, so they’re very vocal. Some of their calls are quite loud and carried all the way across the lake.

Another unexpectedly loud creature was a Mute Swan who, without babies, was harassing the geese and other swans in the water.  It would run across the surface of the water in the direction of whomever it was focused on, slapping its feet and smacking its wing tips against the water, making a great noisy, splashing display obviously designed to intimidate.  Cornell calls this a “Foot-Slapping Display” and is usually related to territory.  “The sound produced by this display can be heard several hundred meters away,” says Cornell.  That’s for sure!  I could hardly believe how noisy it was. “Although both sexes can show aggressive behavior, it is more common and dramatic with males.”

I liked this photo of one of the parent Mute Swans (which actually are not mute). This posture is referred to as a “busk”; it’s a threat posture. Depending on how aggressive the bird is feeling the busk can take on more dramatic forms, with a deeper tuck of the neck and higher arch of the wings. This swan had babies with her, and she wasn’t thrilled when another swan came near them.

As I think I’ve mentioned before, Mute Swans were introduced into the US in the 1800’s as decorative accents to city parks and rich people’s homes.  In California, they’re considered an invasive species and it’s illegal to own them without a permit.  The “feral” ones in this park, though, are seemingly left to breed at will. 

The males are called “cobs” and the females are called “pens”. There were a lot of both on the water today, and several of the pairs had broods of cygnets (between 6 and 10).  I had never seen live cygnets before, so I was captivated by them and their white fuzziness. I watched as the moms reached down deep into the water to pull up aquatic plants for the babies to eat. 

About 80% of the swans’ diet is made of water plants, and because of the way they feed – roots to tips — they can completely tear out all of the very stuff they need to live on. The rest of their diet can include small fish, larger dead fish, and ripe berries (like blackberries).

You’ll note that some of the swans look like they have rusty-looking feathers on the top of the head. This is not any special kind of coloration. In fact, Cornell says: “…Plumage entirely white. Feathers of head and upper neck may become stained green, brown, or rust color from foraging among various substrates (MAC)…”

We also saw some of the swans basking in the warm morning light and a pair of adults sitting across the lake with their cygnets all gathered up in the nest.

As we walked along the trail, kind of chasing after the swans from the shore, we were inundated by a minty smell all around us.  It took us a moment to figure out where the smell was coming from, but then we decided that it was all the Pennyroyal around and under our feet.  None of it was in bloom yet, so we didn’t recognize it right away.

Pennyroyal mimics spearmint, but it’s actually poisonous. Although it’s been used in herbal medicines, ingestion or absorption through the skin can cause severe liver damage; it’s often used as an insect repellent.  Because it’s not regulated by the U.S. Food and Drug Administration, though, people still use and abuse it.

We were attacked by ticks all day, more so than anywhere else we’ve walked lately, and I swear some of them were just falling out of the trees onto our heads and limbs. I got rid of three of them during our walk, and found three more in my hair after I got home. CHECK FOR TICKS! 

American Dog Tick, Dermacentor variabilis

Among the other insects we saw were some female Valley Carpenter Bees (the largest bees in California; about the size of your thumb) and several species of damselflies (including Sooty Dancers, Pacific Forktails, and Northern Bluets).  We also found a small Sweat Bee rolling around in Hawksbeard flowers and its entire body was caked in yellow pollen. Hah!

In the lake was got to see quite a few Gallinules (but none of them came very close to the shore) and lots of Pied-Billed Grebes.  We could hear and see the grebes calling to one another, but whenever I got my came up ready to video them, they’d go quiet.  We saw a pair of three of the grebes, one smaller than the other two, and speculated about what could cause the distinct size difference.  We threw out the idea that maybe it was a set of parents and a juvenile because all of the birds had their adult breeding coloring on. So we settled on the group as being two large males and a smaller female.

Elsewhere in the lake, we watched one of the grebes catch and eat something.  From our distance, we couldn’t tell what it had caught, but I got some video of it and discovered it was a crayfish.  I was amazed that the little bird could swallow that big hard-shelled creature whole.

There were a lot of Tree Swallows around the lake, and we were able to get photos of some of them in and near their nesting cavities.  We also saw a pair trying to mate in a tree, but it seemed like the male just couldn’t get into the right position.  He’d light on the female, flutter off, light on the female flutter off.  She didn’t seem to be trying to get away from him or drive him off; in fact, she just kind of sat there. The mess-up was all on the male’s part; he just couldn’t get his act together.

The most exciting sighting of the day, though, was as we were heading back to the car.  Roxanne mentioned that she’d love to be able to see the muskrat again, and almost as soon as she said that, I spotted the muskrat in the water close to where we were walking.  It swam away from the shore, dove under the water, and came back up with a mouth full of water plants.  Then it swam straight at us, toward the shore, and disappeared under the water again… but I was still able to see it for a few seconds as is swam under the surface.  So neat!  [If you watch the video, just ignore my  gleeful squee-ing.]

Muskrat, Ondatra zibethicus

We were out for about 5½ hours.

When we headed back home, we stopped at a drive-through to get some iced coffee and grilled cheese sammiches, and while we were waiting in line, we saw some House Sparrows going to and from the nest they had setup in one of the drain holes near the roof of the building. Nature adapts.

Species List:

  1. American Coot, Fulica americana
  2. American Dog Tick, Dermacentor variabilis
  3. American Robin, Turdus migratorius
  4. Anna’s Hummingbird, Calypte anna
  5. Azolla, Water Fern, Azolla filiculoides
  6. Black Bean Aphid, Aphis fabae
  7. Black Phoebe, Sayornis nigricans
  8. Blessed Milk Thistle, Silybum marianum
  9. Brewer’s Blackbird, Euphagus cyanocephalus
  10. California Black Oak, Quercus kelloggii
  11. California Brome, Bromus carinatus
  12. California Ground Squirrel, Otospermophilus beecheyi
  13. California Poppy, Eschscholzia californica
  14. California Quail, Callipepla californica
  15. California Scrub Jay, Aphelocoma californica
  16. California Scrub Oak, Quercus berberidifolia
  17. Canada Goose, Branta canadensis
  18. Common Gallinule, Gallinula galeata
  19. Common Green Lacewing, Chrysoperla carnea [larvae]
  20. Cork Oak, Quercus suber
  21. Cottonwood Leaf Gall Aphid, Pemphigus populivenae
  22. Cottonwood Petiole Gall, Poplar Petiole Gall Aphid, Pemphigus populitransversus
  23. Coyote Brush Bud Gall midge, Rhopalomyia californica
  24. Coyote Brush Rust Gall, Puccinia evadens
  25. Coyote Brush Stem Gall moth, Gnorimoschema baccharisella
  26. Coyote Brush, Baccharis pilularis
  27. Crimson Clover, Trifolium incarnatum
  28. Curly Dock, Rumex crispus
  29. Eurasian Collared Dove, Streptopelia decaocto
  30. European Starling, Sturnus vulgaris
  31. Filamentous Green Algae, Spirogyra sp.
  32. Fremont’s Cottonwood, Populus fremontii
  33. Great Blue Heron, Ardea Herodias
  34. Great Egret, Ardea alba
  35. Great-Tailed Grackle, Quiscalus mexicanus
  36. Green Heron, Butorides virescens
  37. Hairy Vetch, Winter Vetch, Vicia villosa ssp. villosa 
  38. Hare’s Foot Inkcap, Coprinopsis lagopus
  39. Hawksbeard, Smooth Hawksbeard, Crepis capillaris
  40. House Sparrow, Passer domesticus
  41. House Wren, Troglodytes aedon
  42. Italian Thistle, Carduus pycnocephalus
  43. Jersey Cudweed, Pseudognaphalium luteoalbum
  44. Jointed Charlock, Wild Radish, Raphanus raphanistrum
  45. Killdeer, Charadrius vociferous
  46. Mallard duck, Anas platyrhynchos
  47. Mediterranean Praying Mantis, Iris Mantis, Iris oratoria [very narrow ootheca]
  48. Mediterranean Stork’s-Bill, Erodium botrys
  49. Mourning Dove, Zenaida macroura
  50. Multiflora Rose, Rosa multiflora
  51. Muskrat, Ondatra zibethicus
  52. Mute Swan, Cygnus olor
  53. Nuttall’s Woodpecker, Picoides nuttallii [heard]
  54. Pacific Forktail Damselfly, Ischnura cervula [males blue, 4 dots on thorax]
  55. Pennyroyal, Mentha pulegium
  56. Pied-Billed Grebe, Podilymbus podiceps
  57. Popcorn Flowers, Plagiobothrys sp.
  58. Rabbitfoot Grass, Polypogon monspeliensis
  59. Red-Eared Slider Turtle, Trachemys scripta elegans
  60. Red-Winged Blackbird, Agelaius phoeniceus
  61. Ribwort Plantain, Plantago lanceolata
  62. Rio Grande Wild Turkey, Meleagris gallopavo intermedia
  63. Scarlet Pimpernel, Lysimachia arvensis
  64. Slender Path Rush, Juncus tenuis
  65. Sooty Dancer Damselfly, Argia lugens
  66. Stork’s Bill, Big Heron Bill, Broadleaf Filaree, Erodium botrys
  67. Tree Swallow, Tachycineta bicolor
  68. Tripartite Sweat Bee, Halictus tripartitus [tiny, striped abdomen]
  69. Turkey Tangle Frogfruit, Phyla nodiflora
  70. Turkey Vulture, Cathartes aura
  71. Unidentified Willow, Salix sp.
  72. Valley Carpenter Bee, Xylocopa varipuncta
  73. Water Milfoil, Myriophyllum triphyllum
  74. Western Fence Lizard, Blue Belly, Sceloporus occidentalis
  75. Western Kingbird, Tyrant Flycatcher, Tyrannus verticalis
  76. Western Polished Lady Beetle, Cycloneda polita
  77. White Tailed Kite, Elanus leucurus [kiting high overhead]
  78. Wild Mustard, Sinapis arvensis
  79. Yellow-Headed Blackbird, Xanthocephalus xanthocephalus