Dear Jane and Other Good Friends of Killdeers, Falcons and Ospreys,
What wonderful stories you told last week, Jane. I loved the rooftop romance of the Killdeers. And the drama only built after that! Significant that the trestle gets congested no matter how wide it is built – just like Highway 1. “When will they ever learn….”
There was a rumor circulating this last week that the fenced off stretch of the Riverwalk between Highway 1 and Water St. was because the City was doing some kind of ground squirrel eradication. Of course, all my fears about pesticides were triggered. So I packed my weapons of pen and paper and sallied forth this morning to confront the enemy, only to learn from a worker that the City was just repairing the sidewalks. Oh! In the meantime, I did a little research on Otospermophilus beecheyi, fondly known to rodent scientists as Beechies.
First, do you remember the excitement a year ago when someone reported spotting a BURROWING OWL on the east bank of the river between Water St. and Highway 1? Well – it turns out that these odd owls do like to make their homes in the abandoned burrows of Beechies. Not only that, but I ran across a scientific study, click here, that said that the Beechies actually protect the underground-dwelling owls from predators by sounding alarms before the owls themselves can pipe up. It’s too bad that we don’t have more Burrowing Owls on the levee to take advantage of all the cozy and safe burrows that lace the levee. These animals had their intra-species systems so well worked out before we came along.
I found another study, click here, that explores the kind of levee vegetation that might discourage Beechies from building their labyrinths underneath levees. The conclusion of the study was that grass and low shrubs are no good, but trees might possibly work. Do you think we could we use this study to encourage the City to plant more trees on the levee? I picked up the interesting statistic that the average ground squirrel burrow in California is 27 feet long and 30 inches deep. These numbers, according to the authors, are not long enough to completely ‘transect’ and ‘perforate’ a levee, the biggest fear. But the authors also point out that beechie burrows have been known to be as long as 872 feet (!) and as deep as 27 feet! Collapsing, water “piping” and erosion seem to be the three main problems created by all this homebuilding – not too different from the effects of our human homebuilding along the river. It is quite understandable that the City is concerned. I heard someone suggest that installing owl boxes might help. Now that’s a solution I could really get behind.
The CLIFF SWALLOWS have moved back en masse to the Water St. Bridge this year, to reclaim their old somewhat worse-for-wear nests that they abandoned in the last couple of years. Who knows what brings them back. I am glad to say that this year I have seen only one HOUSE SPARROW squatting in the swallow nests, perched brazenly in the doorway of its stolen site while the original builders dash frenetically back and forth, busily patching their broken nests. The lazy year-round House Sparrow will probably claim one of these newly patched nests next year. Harrumph! The river was swollen by rains that day, covering the muddy banks where the swallows usually gather their mud. So the resourceful creatures moved their mud-gathering operation up to little pools along the Riverwalk itself.
I have also seen quite a few NORTHERN ROUGH –WINGED SWALLOWS flying about, a few of them flying into the vents under the bridge where they nest. I’ve never actually seen the nest of a VIOLET-GREEN SWALLOW, although theses birds are so common on the river in the summer. I caught this one actually sitting still for a moment on the corner of an apartment building. I wonder if it was guarding a nest. I’ve read that they normally nest in cavities in old trees, five feet high or more. In our tree-denuded levee bank, there are unfortunately no such trees. Was this swallow forced to to settle for a rooftop nest?
I wandered down to the Tannery area, as I am wont to do these days, hungry for the woodland feeling that exists just steps from my door. I caught a glimpse of this eye-catching new art work in the process of construction – almost ready for the Ebb and Flow Festival in two weeks.
The artist is Jayson Fann and the sculpture is created entirely out of driftwood collected on the Main Beach during this year’s winter storms. Pretty wild. I like it – like that it’s a nest.
Still – nothing comes close to nature’s creations. I sat by the river for a long time this week, staring at all the natural sculptures, like this piece of stream wood. Later I stopped to relish this willow catkin, so beautifully designed to flirt with the wind and so propagate it’s kind. Nature’s art.
Incidentally, Kristin Kittleson, the champion of stream wood that I talked about in my last blog, sent me a gentle note reminding me that Wood Ducks can use stream wood for protection, but not for nesting. For nesting, the ducks need a dry cavity in a living tree that is standing – for protection from the elements and predators. Silly me. Thank you Kristin.
May you all have many good nature walks this week!