On the way to Lake Solano Park for our second Certified California Naturalist field trip of the summer, I stopped to put some gas in my car, and I was treated with the sight of some hot air balloons floating over the city of Winters and its surrounding fields. One of the balloons was either dragging or coming in for landing because it got REALLY low over downtown. I could see the people in the basket.  I was kind of surprised to see the balloons at all considering that it was already about 62° when I got to Winters.  Hot air balloons only work if the air around them is cooler than the air in the balloon (so they fly more successfully in the fall-to-spring time period than they do in the summer.)

I was the first one in our group to get to the park and pulled up into one of the upper parking lots because the lot nearest the park itself was still closed.  Technically, the park doesn’t open until 8:00 am, so I was there before the all-gates-open time. The rangers weren’t too pleased that I was in the upper lot before 7:30 am, but they didn’t say anything – until AFTER 8:00 am and my students had arrived, and we were in the park area itself.  I’ll know better next time not to get there early.

The reason for trying to get my group there earlier in the day, though, was to try to beat the heat. It got up to 79° by 10:30 am. So, we cut the trip a little short to get everyone back in their air-conditioned cars before we all overheated. Along with my co-worker Bill and most of the students in the class, Greg Ira (the Director of the Certified California Naturalist program at the University of California) joined us for our walk.

CLICK HERE for the full album of photos.

One of the first things we pointed out to the group was the difference between the native Black Walnut trees and the English Walnut trees. English Walnut trees don’t generally do good in California, so they’re grafted onto the native Black Walnut root stock. We were able to show the students the graft mark in one of the trees (with the Black Walnut on the bottom and the English Walnut on top) and showed them that even through the tree itself was now primarily English Walnut, they could still see some shoots of Black Walnut stems and leaves growing up out of the root stock.

We seemed to hear more birds than we put eyes on, and my student Alison K., who like our student Ken E., is a birding expert, helped us with the sound IDs.  Alison also told the group about the sap wells we were seeing in the bark of some of the trees, created by Sapsucker birds who drill the wells not so much to suck the sap, but to attract insects they can eat.  On one tree we found several clear samples of the wells, along with some hefty outpourings of the sweet sap.

We also came across a large juvenile Great Blue Heron that was sitting in a tree adjacent to the trail.  It posed for some photos, pooped into the river and then flew off with a deep-throated croaky squawk. I guess he told us what he thought about us. We also came across a small creche of Peahens with their fledgling poults. A group of three moms were taking the babies to the edge of the river to get a drink.

 I myself was focused more on finding galls than seeing birds on this trip, however, and was able to point out newly budding examples of Pumpkin galls, Roll Gall Midge galls, Erineum Mite galls, Cluster Galls, Spiny Turbans, Two-Horned galls and Flat-Topped Honeydew galls. Most of the galls were just starting to emerge and weren’t their full size yet.  Give them another week or two and they should be spectacular.

 Our group also found quite a few different orb-weaver spiders included Spotted Orb Weavers and Long-Jawed Orb Weavers. And we spotted a variety of butterflies, dragonflies and damselflies including: California Pipevine Swallowtail butterflies, a sleepy Buckeye butterfly, a Painted Lady butterfly, and a Tiger Swallowtail butterfly on the wing; Widow Skimmer dragonflies, Flame Skimmers, Four-Spotted Skimmers, Pond Skimmers and Blue Dasher dragonflies, plus several damselflies that looked like they’d just emerged and weren’t colored-up yet.

Along with imparting some of what I know to the class, I always learn something new on these field trips or add to knowledge I already have, so it’s always fun and exciting to me. I found two galls I hadn’t seen before and found out that even the experts were having trouble properly identifying them. One was a gall made by the Roll Gall Midge (whose species is known but not its genus) and it took the form of rolled edges along the leaves of Live Oak trees.  The other was an odd tubular “prick” on the leaf of a Valley Oak tree. At first, I thought I was just looking at a weird anomaly on the leaf, but then I saw the exact same structure repeated on leaves of different Valley Oaks, so I took some photos and looked it up when I got home.  Experts recognize it as a wasp-induced gall but they don’t know what species it’s associated with yet, and think it might be a second-generation gall for an already identified gall wasp.  Everything I found on it called it a “Leaf Gall Wasp” gall but with the species listed as “Unidentified”. How neat!

 As we were looking at some California Wild Grape vines, Greg asked for the term for the process by which tendrils wrap around things. None of us could remember it at the time. Of course, when I got home, it came to me: “THIGMOTROPSIM”! Cool word, huh?  You can read more about it here: http://biology.kenyon.edu/edwards/project/steffan/b45sv.htm

Another word that wouldn’t come to mind yesterday when we were out on the field trip… We saw a lot of damselflies that had apparently just emerged and weren’t “colored up” yet, and I couldn’t remember the term for that state.  It’s “TENERAL“: the state of an insect immediately after molting. At this time the insect’s exoskeleton has not hardened and it may be pale in color.

A little further along our walk, some of the students noticed frothy ooze coming out of the base of a Valley Oak tree. It looked something like Sudden Oak Death (SOD) to me, but it was a lot more frothy, and I’d never seen SOD near the bottom of a tree before. So, I looked it up when I got home.

 The foam is from a bacterial infection in the tree called “Alcoholic Flux” or Foamy Canker. It usually affects trees in the summer that have been stressed in some way. Bacteria infects the tree and ferments some of the sap. The fermentation is expelled by the tree in a frothy slime that kind of smells like sour beer. Unlike SOD, alcoholic flux isn’t usually a permanent or fatal kind of infection. It’s usually gone by the end of the summer.

We’d also seen a lot of small gnats around the ooze, and I’m not sure, but I’m going to infer that they were getting buzzed on the fermented juice. Hah!

By 10:30 it was already too hot to keep people out in the sun, so the group broke up and we all headed back to our cars by different routes.

Species List:

1. Acorn Woodpecker, Melanerpes formicivorus,
2. Alcoholic Flux bacteria, Foamy Canker, Slime Flux,
3. American Bullfrog, Lithobates catesbeianus,
4. Belted Kingfisher, Megaceryle alcyon,
5. Black Phoebe, Sayornis nigricans,
6. Black Walnut, Juglans nigra,
7. Blue Dasher, Pachydiplax longipennis,
8. Blue Elderberry, Sambucus cerulea,
9. Box Elder Tree, Acer negundo,
10. Bull Thistle, Cirsium vulgare,
11. California Pipevine Swallowtail Butterfly, Battus philenor hirsuta,
12. California Pipevine, Aristolochia californica,
13. California Scrub Jay, Aphelocoma californica,
14. California Wild Grape, Vitis californica,
15. Canada Goose, Branta canadensis,
16. Common Buckeye Butterfly, Junonia coenia,
17. Common Merganser, Mergus merganser,
18. Convoluted Gall Wasp, Andricus confertus,
19. Eight-Spotted Skimmer, Libellula forensic,
20. English Plantain, Ribwort, Plantago lanceolata,
21. English Walnut, Juglans regia,
22. Flame Skimmer, Libellula saturate,
23. Flat-Topped Honeydew Gall Wasp, Dishopcaspis eldoradrnsis,
24. Great Blue Heron, Ardea herodias,
25. Green Shield Lichen, Flavoparmelia caperata,
26. Hoary Rosette Lichen, Physcia aipolia,
27. Indian Peafowl, Pavo cristatus,
28. Interior Live Oak, Quercus wislizeni,
29. Leaf Gall Wasp, Unidentified
30. Painted Lady Butterfly, Vanessa cardui,
31. Poison Oak, Toxicodendron diversilobum,
32. Pumpkin Gall Wasp, Dryocosmus minusculus,
33. Roll Gall Midge, Contarinia sp.,
34. Spiny Turban Gall Wasp, Antron douglasii,
35. Spotted Orb Weaver Spider, Neoscona crucifera,
36. Sunburst Lichen, Xanthoria elegans,
37. Two-Horned Gall Wasp, Dryocosmus dubiosus ,
38. Valley Oak, Quercus lobata,
39. Walnut Erineum Mite Gall, Aceria erinea,
40. Western Pondhawk, Erythemis collocata,
41. Western Tiger Swallowtail Butterfly, Papilio rutulus,
42. Widow Skimmer Dragonfly, Libellula luctuosa,
43. Woolly Aphid, Prociphilus sp.,