Park Week 5/24/2024


Black-crowned Night-Heron, Great Blue Heron, and Snowy Egret

First I saw the big one, the Great Blue Heron. It stalked around in a relaxed way on the mud exposed by low tide at the foot of the Open Circle Viewpoint. Then I saw what looked like its sidekick, a Snowy Egret. The two acted like they were friends. Maybe more than friends — the egret wanted the Blue all to itself. A second Snowy flew in. Acting like a bully, the first chased its conspecific out of the area. Then a Black-crowned Night Heron flew in. For a few moments, all three of them stood near one another. A photo op! A trifecta! But it didn’t last. The Snowy advanced toward the Night-Heron. The heron took off. Then the big bird had enough. It strode north, leaving its jealous sidekick behind. On the rip-rap on the east side of the seasonal Burrowing Owl Sanctuary, one more Night-Heron flew in, and then a third. That’s more Night-Herons than I’ve seen at one time maybe ever.

Bird Seed

Lesser Goldfinch (Spinus psaltria) eating Purple Sage (Salvia leucophylla)

The Purple Sage in the meadow of the Native Plant Area is mostly done blooming and has set seed. That’s the dinner bell for this Lesser Goldfinch, a male. With great energy and enthusiasm, the bird tears off a seed, quickly discards the outer husk, gobbles the kernel, and on to the next. The bird only weighs around ten grams. He must have eaten more than twenty seeds; if each weighed half a gram, the bird doubled its weight. These finches are 98+ percent vegetarian, eating more than 50 varieties of seeds, berries, fruits, flowers, and leaves. They’re the only bird I’ve seen in the park that will eat thistle seeds, but they don’t eat enough, as thistles are booming this spring.

As I learned the next day, finches aren’t the only critters that love sage seed …

Squirrel Seed

California Ground Squirrel (Otospermophilus beecheyi)

In the very same Purple Sage bush where the goldfinch had foraged on seeds, the next day I saw a Ground Squirrel doing the same thing. Of course, it’s in their name: Otospermophilus means the eared seed lover.

There was nothing bird-like about the squirrel’s table manners. It tore off a whole cluster of seeds and chewed through them, not bothering with petty details like discarding the husk. Clearly it helps to have four legs, with the front two available with talented paws that can feed the face.

Both the bird and the rodent went at the seeds with enthusiasm, as if they couldn’t get enough. Despite these raids, the plant showed no sign of damage. Seed of sage must be delicious. I’m tempted to try some. Will it make popcorn?

This isn’t strictly on topic, but photographer Susan Black caught this very new Ground Squirrel pup hiding behind a screen of thistle, and it’s just so cute I can’t resist posting it. It is that time of year when the next generation of Ground Squirrels emerges from its underground shelter and learns the ways of the world at the surface. Is there an analogy here to the Fallout series?

Good Blackbird News

The photo above left is great news. It’s a female Red-winged Blackbird with an insect in its beak. That means it has built a nest, laid eggs, and at least one has hatched and the chick is hungry. I saw possibly two other females flying by at some distance. That’s better than none. But it’s still far below the boom years of 2018-2019 when the whole northwest quadrant of the park, with its dense Fennel forests, sounded like bedlam with the cries of the competing males.

Also Probably Nesting

I’ve written before about the Song Sparrow (Melospiza melodia) holding forth on the north side of the park. I saw and heard him there again this week, and moments later I saw another little feather bundle diving into a dense bush of Fennel. It emerged for just a few seconds, long enough for a snapshot that the Merlin bird ID app says is also a Song Sparrow. My guess, flavored with a streak of hope, is that this is a female and the attraction in the Fennel is a nest.

Birds Also Seen

I saw up to about fifty of the big grebes on the North Basin at midweek. The same as last week, it was a mixed flock of Clark’s and Western grebes, without any discernible pattern to their gatherings. A flock of four Ruddy Ducks kept them company. A few Brown Pelicans were active around the park without any signs of distress. One pelican squatting on a rock just seemed to be resting.

Black Birders Week May 26 – June 1

EBRP Photo

The East Bay Regional Parks, in  collaboration with Park District naturalist staff, Park District Black Employee Collective members, and local Black-led organizations invites the public to safe spaces for guided discussions about Black experiences and the outdoors, while exploring and enjoying the parks of the East Bay. This year, we will be kicking the week off with a conference in celebration of Black people in the STEM field with speakers and tables hosted by local organizations.

All programs are free. Coffee, snacks, binoculars, and birding books are provided. Everyone is welcome. Details and schedule are at this link.

Blooms of Note

Conservancy volunteers planted five of the six plants shown here. The other is Yarrow. We did plant Yarrow in the Native Plant Area, but I chose to show a patch that has been here for many years, slowly spreading without human help next to a dirt trail on the north side of the park.

Meeting on Trail, Restroom

The City’s advertised meeting to get public input on plans to rebuild the perimeter trail and to build one permanent restroom in the park took place on Zoom as scheduled at 5 pm on May 23. About 25 people attended, including Public Works and Parks staff and contractors. Nelson Lam, a City engineer with Public Works, chaired the session.

A ten-minute slide show on the perimeter trail indicated that the entire trail would be repaved in asphalt, as at present, and that a two-foot shoulder of crushed granite would be built on both sides, for runners. The funds would also upgrade trailside amenities including benches, some signage, and waste receptacles. In the public discussion, two bicycle advocates wanted painted lines to keep pedestrians on one side so that fast bicycles could have their own right of way. There was strong opposition to this proposal and some uncivil exchanges ensued.

On the bathroom proposal, staff indicated that they had interviewed four vendors of prefab park bathrooms, two of which advertised that they were self-cleaning. Three of the offerings cost in the range of $210-260k; the fourth was higher. All will require additional cost for foundation and utility hookup. The four vendors included Green Flush Restrooms, whom I’ve written up here in the past for their sewer-free designs. One popular option, Portland Loo, was not on the City’s list. The City still does not have a consultant to manage the project, and currently does not project completion until the spring of 2026. Comments from the audience favored a solar-powered design, suggested a water fountain with dog dish, and expressed doubts about “self-cleaning” designs. One park visitor said she had been coming to the park since 1996 and had never used the porta-potties. I spoke and argued for replacement of all the porta-potties, not just the one.

The meeting concluded at 6:10 pm. Apart from the clash over bicycles, the event was civil. Additional meetings are scheduled for the fall.

Landfill Gas Rework Doubles Down

Two backhoes operating simultaneously in northwest quadrant of park on Thursday

SCS Engineering, the landfill gas contractor, brought in a second backhoe and crew this week to try to bring the project up to the goal of two or three wells per day. The work has gone more slowly than scheduled because the wells have different configurations and several excavations have had to go deeper than anticipated.

The holes now being dug are wider than during the previous rework project in 2015-2016, when excavations generally ran four to six feet wide. Holes this time must accommodate a ten-foot square plastic membrane spread over the bottom.

The rework project only begins once the hole is dug. Crews must then manually clear the well shaft, the shaft for the control valve, and the horizontal connector between them. For reasons that must have seemed compelling at the time, the original well shafts were separated from the valve shafts by a horizontal connector of about six feet, requiring two separate access boxes at the surface. The new valve assembly may need only one box.

The six-minute video below shows the main steps in the valve replacement work. The crew first cuts out and removes the existing steel valve, the plastic connector between the valve and the well shaft, and the top of the well shaft. The backhoe operator then excavates a deeper hole around the well shaft. The crew places a plastic mold about two feet in diameter around the well shaft, and fills that with bags of sodium bentonite. Bentonite is a naturally occurring clay used as a sealant. The crew then hoses the bentonite with water, which causes it to swell and form an airtight seal around the well shaft. With the mold pulled out, the crew levels and tamps down the bottom of the excavation. Workers then prepare the ten-foot square plastic membrane by cutting holes for the two vertical shafts, and fitting the holes with sleeve seals called “witches hats.” Workers then spread the membrane, tape and clamp the seal sleeves, and do the plumbing to hook up the new valve assembly. The underground lateral pipes are HDPE (High Density Polyethylene), which needs to be hot-welded, a relatively slow process requiring an elaborate electrically powered rig. The well shaft is ordinary PVC which can be glued like garden irrigation pipe. Final assembly at both ends of the new valve assembly is with hose clamps. That done, the backhoe operator refills the hole and installs the access box. The new well head has a plastic control valve and several ports for installing gauges to measure gas pressure (vacuum), composition, and temperature.

New valve assembly. Red plugs cover vents for gauges.

The well in the video was relatively uncomplicated because the system lateral pipe sloped away from the well. In some other wells, the lateral slopes toward the well, which requires a different valve configuration that allows condensation from the lateral to drip into the well shaft. In this case, two separate surface access boxes are required. These and other differences in the existing wells have slowed the project.

The finished sites are not uniform. One backhoe operator leaves a clean, level, tamped-down surface. Another leaves a rough mess. The area of disturbed ground around each excavation may be some 50 feet in diameter. This forms a magnet for opportunistic invasive weeds. An appeal has been made to staff to seed the disturbed areas with native grasses.

Once all the extraction wells are fitted with the new valve assemblies, anticipated toward the end of June, testing will begin to determine whether the lateral lines that connect the well heads to the flare station are clear. If there are obstructions, there will be trenching to replace them. The lateral pipes may run seven or eight feet below the surface. This means that if the laterals need replacing, the required trenches will be much bigger than if the pipes ran one or two feet down.

Crew of SCS Engineers working to install new valve assembly in a landfill gas extraction well

Despite pressure from regulatory agencies and from alarmed members of the public, the City as of this publication date has not published plans to scan the park for possible radioactive materials buried in the former landfill. The reasons for the City’s silence are unknown. There is speculation that projects are on hold due to the resignation of the City Manager, effective July 10. Separately, nothing has been heard so far from the Langan consulting firm, hired to evaluate whether SCS Engineering, the contractor that operates the landfill here, has been doing a competent job.

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