Park Week 4/19/2024

Nightbird Active by Day

Black-crowned Night-Heron (Nycticorax nycticorax)

The Black-crowned Night-Heron usually hunts by standing still and waiting for prey to approach. This bird was exceptionally active. It walked, hopped, and fluttered along the east edge of the seasonal Burrowing Owl Sanctuary, probing and poking like a very hungry bird, spending little time at any one spot. As I filmed, the heron had no luck. The tide was low, but its prey had retreated deep into the crevices between the rip-rap. Before long, the heron flew around the northeast corner and tried again on the north side, out of my view. These birds, as the name implies, are active mostly at night, avoiding competition with diurnal herons, but at times of high nutritional need, in breeding season, they are often active in the daytime, as here.

She Wins

House Finches and Golden-crowned Sparrow

Up on the north side there is a set of shrubs — a mix of Holly Oak and Coast Live Oak — where Golden-crowned Sparrows shelter when they’re not foraging on the ground nearby. As I walked by, I saw a different bird entirely on a perch at the top: a beautiful House Finch male in breeding plumage, almost bright red. But its reign at the top was short. A female House Finch unceremoniously bumped it and took over its perch. Then one of the resident Golden-crowned Sparrows got into the act. It perched inches away from the female finch, and looked like it might challenge for top spot. But after some feinting, which the finch ignored, the sparrow thought better of it and descended. The female finch remained undisputed at the top of the bush.

Feathers of the Week

Two park visitors captured the largest local members of the heron family this week. Photographer Susan Black, whose work has appeared here a number of times but has been absent for a while, is back with this lovely image of a Great Egret (Ardea alba) taking off, its huge wings fully extended, beginning a powerful downbeat. New contributor David Salk used his cellphone to catch this Great Blue Heron (Ardea herodias) wading at low tide, with a gull (probably a Western Gull, Larus occidentalis) sitting quietly in the foreground.

The most difficult ID for me this week was the American Pipit. I usually see them in the grass. I saw this bird in the rip-rap on the west side, among the drying seaweed, as if it were a stone-foraging shorebird like a turnstone, a tattler, or a Spotted Sandpiper. Just like seeing an old friend in a different context, I didn’t recognize it. Once I clicked on what it was, I remembered that this bird used to be called the Water Pipit, and that it commonly winters at the edges where wet meets dry.

The Fennel in the northwest quadrant is about knee-high now, which is very promising for Red-winged Blackbird nesting season. A few more inches of growth, and we should see the females arriving. The males are waiting impatiently, flexing their epaulets and practicing their come-hither songs.

Currant, Buckeye Saved

As regular readers of this blog are aware, the Bay Area Air Quality Management District (BAAQMD, “back-mud”) has ordered the City to rework the landfill gas collection system that underlies the park surface. One of the first steps in the project is to replace all 37 of the known extraction well heads. This will require an excavation that may be six feet or more square and about three feet deep, depending on the particular spot. Two of the extraction wells, EW7 and EW8, lie in the Native Plant Area. As it happens, a beautiful native Flowering Currant (Ribes sanguineum), about four feet tall, grows within inches of EW7. This week, Chavez Park Conservancy Volunteer Coordinator Bob Huttar, with some help, dug out the Currant and moved it about twelve feet uphill to a new location. We gave it a generous helping of water and a circle of mulch, and spoke words of hope and encouragement. This Currant has been growing vigorously and has a good chance of surviving the trauma of relocation. Then we moved to Extraction Well 8. There is a year-old California Buckeye (Aesculus californica) growing in the margin of the access path to EW8. We built a stake barrier with neon pink ribbons around this plant. The construction crews, when they come, will have no trouble seeing and avoiding this young native tree. At this time, the schedule for wellhead excavations has not been published.

Tiny Bloomers

I might not have noticed these little guys if I hadn’t kneeled on the grass to get a portrait shot of the Common Vetch (below). The tiny geranium flower is just a shade more than a quarter inch in diameter. The Lesser Trefoil is even smaller. I saw both of them almost concealed by taller grasses on the north side.

This European native is famous (in the niche of tiny geranium fans) for its power to launch its seeds with a spring-like catapult. You can see a photo in the Wikipedia article. Despite this superpower, the species rates only a “limited” invasive grade from the California Invasive Plant Council.

The Lesser Trefoil is also a European native, with a specific reference to Ireland, where it’s believed to be the original Irish shamrock. If so, old St Patrick must have had unusually good eyesight. Finding a four-leaf specimen of this miniature plant requires sharp peepers. Like the larger hop clover (Trifolium campestre), which also grows in the park, this one is said to be OK for livestock feed, although it would take a heap of them to fill a bovine.

Which Old Vetch?

The vetches have their partisans. I learned this the hard way a few years ago when I remarked to a friend that the Purple Vetch (Vicia benghalensis) wasn’t anything to write home about. On the contrary, said my friend, and would have liked a bouquet of them. Personally I much prefer the Common Vetch (Vicia sativa), which has taken a bit longer to bloom than its purple cousin. Admittedly, the sativa would struggle as a cut flower in a vase. It grows much lower to the ground here, although in other soils it can reach higher. And the sativa here isn’t as abundant. While the hairy benghalensis has overrun acres of ground in the north and northeast areas of the park, the sativa picks a few spots here and there for a more modest display. Once you see it, you might be enchanted. That color combination, with a magenta face and a deep red tongue, outclasses anything that its cousin could boast of. But those are idle aesthetic opinions. Neither of these plants is significant in the floral trade. They both serve as livestock forage and as green manure, and farmers in Australia grew more than a million acres of the sativa in recent years. The sativa has also left a record as part of the human diet in early Stone Age times.

See You at Bay Fair April 27

It’s that time of year again — time to celebrate the arrival of the Spring season on this beautiful Bay. Once again, your Chavez Park Conservancy will have a booth at the event. We’ll have the popular game that challenges kids of all ages to identify some common creatures seen in the park, and we’ll have the beautiful brochures that show two dozen birds in the park, as drawn by artist Bill Reynolds.

The event is family friendly, next door to the Adventure Playground and to a conventional playground, with boat rides, and a real park restroom (not a porta-potty) right there on site, as every park should have. And it’s totally FREE, with ample car parking, bicycle valet service, and public transport nearby.

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