Forest Knolls, with Coyote, Great Horned Owl, and Raccoon

I love that I can walk late at night in Forest Knolls. I’ve always enjoyed these magical (though infrequent walks). Now, with social distancing, they’re better than ever; there’s hardly anyone around.

Last week, I was out a couple of times. The first night was as still and quiet as if someone had turned off the world’s sound. On my way home I saw a dark shape on the sidewalk ahead. At first, it was so still that I thought it was a small abandoned suitcase or something. But as I came closer, it moved, and the light from the street-lamp showed me a raccoon. It looked at me and dived into the roadside shrubs. I went out to the middle of the road to give it enough room. Though I was pleased to see it. With all the precautions people (including us) take with their trashcans, I thought raccoons had abandoned our neighborhood for lack of food.

Another night, the quiet was broken by one of my favorite sounds: a Great Horned Owl up in Sutro Forest. It sounded like a lone owl, and stopped after a few hoots. Later in the year, perhaps I’ll hear the duets of a pair talking to each other.

And the same night, the best sighting of all: a coyote, out on Oak Park Drive near the staircase called Glenhaven Lane. When it saw me, it retreated up the staircase, and then onto the hillside so it could escape into the bushes if I pursued it. I didn’t, of course. I gave it a wide berth, and took a few blurry pictures with my cellphone.

+

+
+
+
+ + +

Barn Owl in the Forest Knolls’ Forest

I was driving west along Clarendon Avenue, heading homeward. As I slid into the turn lane to make a right on Christopher, something white lay on the side of the road. I slowed nearly to a stop, unsure what it was. Then I recognized it as a barn owl, wings spread. My fear was that it might be injured, perhaps from hitting a car.

To my relief, it rose into the air and disappeared into the trees of Sutro Forest, a rodent clutched in the talons of its right foot. It must have just caught it.

But I was in even more luck! As I turned right, it sailed out of the forest ahead of me, looped over Christopher Dr, and flew back to a tree beside the street. Then it took off again, but only went a little deeper into the forest.

The last time I saw a barn owl in Forest Knolls was seven years ago: Evening Walk with Owl and Moon

Later, I went back. The owl was there, but difficult to see in the darkness. I heard rustling sounds that suggested it was eating the rodent it had caught. I tried getting photographs, but both my phone and camera rebelled at the darkness. This picture is an edited public domain photograph.

So if you hear hisses, screeches, and rasping noises from the forest – or around our neighborhood – it’s barn owls on rodent patrol. (Also, please don’t use rodenticides, especially slow-acting ones like brodifacoum. It could kill the owl.)

 

Forest Knolls Skunk

Sometimes, I cruise around the neighborhood at night in hopes of seeing our resident or visiting wildlife. It’s easier from a car; they get spooked by people walking.  Last night, I was rewarded with a skunk.

It was grubbing in the mulch along Christopher, the mulch that’s still there from the tree-cutting operation a couple of years ago. Grass is beginning to grow through it, but it’s a great place for beetles and grubs.

skunk in forest knolls 1

The skunk looked small, perhaps a kit that’s just gone out on its own. It wasn’t the least bothered by the headlights. I got a couple of iPhone pictures, not good ones but definitely a skunk!

little skunk in Forest KnollsI never got to see its face. When I rolled down the window, it realized I was looking at it, and it decided to move along. In a minute, it scrambled up the hillside into Sutro Forest, and all that was left was a sound of scrabbling in the bushes.

Feeling Guilty About Loving Bermuda Buttercups?

I love these yellow flowers that appear in spring in San Francisco and vanish a couple of weeks later. Many others do, too, but consider it a guilty pleasure because they think they’re bad for bees and birds and animals. Since we often have them around Forest Knolls, I’m re-publishing a shortened version of a post about oxalis from SFForest.org (with permission).

The oxalis season is over, and the perky yellow flowers have vanished for another year. These Bermuda buttercups will be back next year to herald the spring, bringing joy to those who love them, irritation to those who hate them, and Tier I herbicides targeted at them in San Francisco’s so-called “Natural” Areas.

oxalis in glen canyon feb 2011These flowers are so visible in spring that Bay Nature magazine did an article about them in March 2015: A Natural History of the Little Yellow Flower that’s Everywhere Right Now.

THOSE WHO HATE OXALIS AND WANT TO POISON IT WITH GARLON

The article quoted Jake Sigg, the retired SF Recreation and Parks gardener who is considered the doyen of San Francisco’s native plant movement. He hates oxalis pes caprae, which he considers extremely invasive. The article quotes him as saying that, without intervention, “in X many years Twin Peaks would just be one solid mass of yellow, and there wouldn’t be any other plants there…” The article suggested that an oxalis-dominated landscape “drives away coyotes, hawks and owls that feed on grassland foragers, and the situation is especially dire for endangered Mission blue butterflies, which depend heavily on native wildflowers.” Most of those ‘facts’ about oxalis are mistaken as we’ll explain below.

Mr Sigg’s theories align with those of the Natural Areas Program (NAP) of the San Francisco Recreation and Parks Department (SFRPD), which uses the herbicide, Garlon (triclopyr) to battle oxalis despite its dubious efficacy for the purpose. San Francisco’s Department of the Environment San Francisco’s Department of the Environment classifies Garlon 4 Ultra as Tier I: Most Hazardous. It’s listed as HIGH PRIORITY TO FIND AN ALTERNATIVE (their caps). Since oxalis is the main reason NAP uses Garlon, the alternative we propose is – don’t use Garlon or anything else on oxalis.

First, a little about the actual natural history of oxalis. This plant doesn’t set seed in California, and spreads entirely by sending out roots and forming little bulbils (like tiny potatoes) underground. It’s usually found where the soil has been disturbed by activities such as road-building, gardening, or trail-building. In some cases, the disturbance come from landslides or something similar. It can’t stand frost. If we do nothing, it would tend to die down rather than spreading uncontrollably.

In disturbed landscapes, it can spread fast. For this reason it can be a nuisance in gardens. People don’t want to leave their gardens alone for years to let nature take its course with the oxalis, and not every garden design includes brilliant yellow as the dominant color for a few weeks. The only way to eradicate it in the short term is to dig it out carefully every time you see it, and make sure you get most of the bulbils. Or use strong herbicides, which may not work.

In a natural landscape, though, it’s a different story and here’s why.

1) OXALIS IS GOOD FOR BEES AND BUTTERFLIES

Oxalis is actually an excellent plant for bees and butterflies. When blooming, it provides “copious nectar.” In fact, it generously gives away its nectar. Since it doesn’t set seed, it doesn’t benefit from pollinators – but it’s a food source for honey bees, bumblebees and butterflies.

In fact, a recent 2014 study shows that plant communities with exotic plants had more plant species as well as more pollinators, that pollinators didn’t prefer native plants, and that even some specialist pollinators depended on introduced plant species.

It’s true the Mission Blue butterfly needs (native) lupine as its nursery plant. (It doesn’t depend on any other native wildflowers – only three varieties of lupine. Incidentally, one of the key nectar sources for the Mission Blue butterfly is an invasive non-native Italian thistle: Carduus pycnocephalus).

Lupine has been planted on Twin Peaks as NAP attempts to reintroduce the Mission Blue butterfly there. But lupine is also a plant of disturbed areas, which means that NAP must maintain it or it will die out as the area stabilizes. An SFRPD report on the reintroduction project said “unmanaged habitat deteriorates quickly.” Presumably, they don’t use Garlon near the lupine patches, since it would likely kill that too. Despite what the Bay Nature article implies, it’s not oxalis that’s the issue. The real problem is another native plant, the coyote bush which takes over grasslands in a natural succession.

2) OXALIS IS GOOD FOR WILDLIFE

Oxalis bulbils are a food source for wildlife. Gophers and other rodents eat them. In fact, the Bay Nature article says, “Their spread is abetted by pocket gophers and scrub jays, which have been spotted carrying the bulbs and caching them in the ground—effectively planting them in new areas.”

Since gophers are a foundation species in the food web, being dinner for predators from hawks to coyotes to great blue herons, these plants actually provide habitat benefits whether or not they’re flowering, because the bulbils are there all year.

gopher-twin-peaksWhere there are gophers, the predators follow. Like the coyotes in these pictures, which clearly haven’t been driven away by a landscape dominated by oxalis.

coyote pouncing in oxalis field - copyright Janet Kessler
coyote pouncing in oxalis field – copyright Janet Kessler
coyote in oxalis field - copyright Janet Kessler
coyote in oxalis field – copyright Janet Kessler

3) OXALIS DOESN’T LEAVE THE GROUND BARE

The article says that oxalis leaves “bare ground during the six months of the year oxalis doesn’t flower.” That’s not true either.

oxalis interspersed with grasses and other plants

oxalis in glen canyon feb 2011The spectacular yellow bloom of the oxalis – valuable because it the mass of color attracts honey bees and bumblebees – gives the impression that it’s the only plant there. But though it visually takes over the landscape when it’s in bloom, it naturally grows interspersed with grasses and other plants. Like in the picture above.

In fact, oxalis tends to enrich the soil with phosphorus, which is good for grass.

So when it finishes blooming, as it has by now – you don’t get bare ground. The picture below shows the same area as the first picture in this article – but it’s after the oxalis bloom is over. It’s a grassland.

glen canyon after the oxalis season

4) OXALIS HAS LITTLE IMPACT ON “NATIVE” PLANTS

One argument – related to the ‘bare ground’ argument – is that oxalis takes over grasslands and destroys them, particularly the native grasses. However, grasslands in most of California including San Francisco are dominated non-native grasses. The change occurred over 100 years ago, when these grasses were planted for pasture. So the grassland that NAP is defending with herbicides are primarily non-native anyway.

oxalis and california poppies sm But anyway, what’s the evidence that oxalis is actually damaging native plants?

It’s true some European studies do suggest that an increase in oxalis is associated with a decrease in native plants diversity -though whether it’s a cause is unclear. It may just be benefiting from human activities that disrupt the landscape. Another study put oxalis head-to-head with a native annual grass, lolium rigidum. The native grass tended to dominate. Their conclusion: “Oxalis is a poor competitor. This is consistent with the preferential distribution of Oxalis in disturbed areas such as ruderal habitats, and might explain its low influence on the cover of native species in invaded sites.

The California Invasive Plant Council rates its invasiveness as “moderate,” considering it as somewhat invasive in sand dunes and less so in coastal bluff areas.

In San Francisco, every place where oxalis grows is already a disturbed environment, a mix of non-native grasses and plants with native plants (some of which have been artificially planted). Here, oxalis appears to grow happily with other plants – including, for instance, the native California poppy in the picture above.

5) KIDS LOVE IT AND IT’S EDIBLE

Children love oxalis, both for its pretty flower and for the sour taste of its edible stems. Even small children love gathering posies of Bermuda buttercups (though picking flowers is technically prohibited in Natural Areas). The flowers are surprisingly hardy for wildflowers, and in a glass of water last quite well as cut-flowers.

The plant is edible, and its tart leaves make a nice addition to salad. People enjoy snacking on its sour stems. Besides Bermuda buttercup, it’s also called ‘sourgrass’ and ‘soursob.’ It does contain oxalic acid (as does spinach, for instance), and so you probably wouldn’t want to make a meal of it. Though in South Africa it’s made into soup.

Adding Garlon to it is probably a bad thing.

Photo credit: Badjonni (Creative Commons - Flickr)
Photo credit: Badjonni (Creative Commons – Flickr)

From our current evidence, there’s no sign that oxalis has a negative impact on wildlife, and plenty of evidence it’s already part of the ecological food web of our city. The evidence also suggests it’s not having a negative effect on other plants in San Francisco either. Lots of people find this flower attractive; one writer described it as the city smiling with Bermuda buttercups.

[Webmaster: The original article goes on to argue that the city should not use Garlon to attack oxalis – it’s expensive, toxic, and pointless.]

 

Wild Parrots of San Francisco! – M. Bruce Grosjean

It was the book and movie, The Wild Parrots of Telegraph Hill that first drew my attention to the marvelous fact that San Francisco has parakeets. Those birds originated in South America.  They’re related to the now-extinct Carolina Parakeet, which was found in North America until the early 1900s, being declared extinct in 1939.

I was interested to learn, while reading a birding group, that there’s a different parrot in town. Parrots are very social birds, and they need company. Apparently, the stranger can recognize a parrot when he sees one, so the new bird is hanging out with the locals.

How wonderfully cosmopolitan is our city?

The story and photographs below are from M. Bruce Grosjean, and are published here with permission.

AN INTERLOPER SURVIVAL STORY – M. BRUCE GROSJEAN

Back in October 2012 I reported seeing a single Rose-ring parakeet that seemed to be trying to attach itself to the larger population of our local Red-masked parakeets. Whereas the flock itself is made up of birds that are originally from Ecuador and Peru, this Rose-ringed individual comes from Asia and Africa. The fact that he recognizes they’re all family is fascinating to me.

parrots san francisco - copyright M. Bruce Grosjean
The rose-ringed parakeet, originally from Asia and Africa – (c) M Bruce Grosjean

It was predicted by some observers that the Rose-ringed would not survive all that long, so every time we saw it over a span of about a year and a half we were surprised. But then sometime around a year ago we stopped seeing it altogether and slowly began to believe that this bird indeed couldn’t survive.

Rose-ringed parakeet surround by red-masked conures - (c) M. Bruce Grosjean
Rose-ringed parakeet surround by red-masked conures – (c) M. Bruce Grosjean

So it was a complete surprise a few days ago when I spotted him feeding with a small flock of our local Red-masked birds again. By all appearances he looks quite healthy but still doesn’t seem to get along with the other birds much better than before, and yet he survives – I’m amazed!

parrots san francisco 6 - copyright M. Bruce Grosjean
Rose-ringed parakeet and red-masked parrots at a feeder – (c) M. Bruce Grosjean

[This flock was sighted near McLaren Park. “FYI,” Bruce wrote me as he sent these pictures over, “Some time ago Mark Bittner (The Wild Parrots of Telegraph Hill) told me that he’d seen this bird on Telegraph Hill, which indicates it does get around.” Here are a few more pictures of the little flock with the outsider bird.  There are higher-resolution pictures at Bruce’s Zenfolio page, HERE.]

This slideshow requires JavaScript.

Strangers in the Night

Around midnight, it’s usually quiet in Forest Knolls, the only sounds coming from the house itself. Outside, you might hear the wind soughing in the trees and humming in Sutro Tower. But tonight, a bird chirped tentatively in the backyard. At first I thought it was just a songbird disturbed on its perch, or responding to the bright moon.

moon from forest knolls drive san francisco
But it continued, growing louder and insistent. Opening a window to listen, I wondered if a raccoon had caught a bird. It sounded distressed. I could see nothing in the dark, my yard was in shadow.

skunk 1I ran down to turn on the garden light. And then I saw it – not a bird at all, but a skunk, right up against the back fence in a corner. When I shone the flashlight on it, it emerged from the shrubbery. And then, out came another one. Mating season!

They stuck around for a while, but annoyed by my watching them, they left through a hole under the fence. There was mildly skunky smell. Love was in the air.

 

December in Stow Lake: Ducks and More

What better way to end the year than a walk round Stow Lake in Golden Gate Park? It remains one of my favorite places in San Francisco – user-friendly for people and waterbirds alike.
kid at water edge

Sbare areas with felled treeso I went down there on December 31st in the late afternoon with someone who wanted to try out a new Olympus camera. I carried my trusty Nikon Coolpix. (It’s a little less trusty now for having a strange gray line appear whenever I use the zoom; I’m going to have to fix or replace it).

Unfortunately, Strawberry Hill – the hill in the center of the lake, accessed by a bridge on either side – is a lot more bare than it used to be. They’ve been cutting down trees and removing vegetation. Before, you couldn’t even see the summit from the outside, and it always seemed green and lush.

gulls mallards coots at Stow Lake Dec 2014

We strolled around the lake,  enjoying the amazing birdlife and the clear evening light. On this trip, we saw not just the usual mallards and gulls, but a wealth of American coots…
OLYMPUS DIGITAL CAMERA
OLYMPUS DIGITAL CAMERA

This shot reminded me of a hen overseeing a flock of chicks. “Are you our mother?
Are you my mother

This gull allowed a close-up. I tried to figure out its species from my bird books, but couldn’t really narrow it down. Maybe a Thayer’s or a Glaucus-winged? Or a young Western gull? [Edited to add: A friendly bird expert thought it was probably a glaucus-winged, but just possibly could be a Thayer’s.] Gulls are confusing, the more so because some of them hybridize quite happily.

A gull

There were some Northern Shovellers amid the mallards, and I got a picture of this couple.
northern shoveler

Perched on a rock, and preening continuously, we saw this duck – I think it’s a female ruddy duck.
PC310014 female ruddy duck and coot

And there was this smart black and white bufflehead. [Edited to add: The picture shows the green/ purple iridescence, but that wasn’t clearly visible from shore without binoculars – which I forgot to carry with me.] We first saw it near the boat-house, but then it reappeared on the side near the waterfall. I couldn’t tell if it was the same individual or not, it was diving and moving quickly. There were at least two; I have another photo of them which is too blurry to publish.
OLYMPUS DIGITAL CAMERA

A Double-crested cormorant swam around, low in the water. We saw a couple of others fly off.
double crested cormorantThey always remind me of a nonsense verse I read as a kid: ” The common cormorant or shag/ Lays eggs inside a paper bag/ The reason you will see no doubt/ It is to keep the lightning out/ But what these unobservant birds/ Have never noticed is that herds/ Of wandering bears may come with buns/ And steal the bags to hold the crumbs.” (It’s by Christopher Isherwood and of course it isn’t true – but as a child I had a strong mental image of the birds creeping into brown-paper bags to nest…)

The usual Muscovy ducks (which don’t actually come from Moscow) foraged around the edges of the lake.
muscovy duck at Stow Lake

There were a few of the Canada geese (formerly from Canada, but they live here now and particularly love the new Botanical Garden, which is goose heaven).
canada goose in a pine tree

Instead of a partridge in a pear tree, I offer you a wild goose in a pine tree.

It’s a couple of days late – but wishing everyone who reads this a wonderful year in 2015!