Monday, April 23, 2007

Western Fence Lizard - Super Hero

Spring doesn’t just warm up the ground for seeds to grow and flowers to bloom. The sun heats the rocks and gravel and invites the lizards to emerge from their winter hiding spots. The most visible lizards in our yard are Western fence lizards (Sceloporus occidentalis). There is a pair in the herb garden and this large individual in the driveway. They seem to prefer elevated basking sites where they can keep an eye on their territory and watch for insects.

The female in the garden frequently jumps up several inches to catch flies. She’s an efficient insect eliminator and fun to watch.

You may know these lizards as “blue-bellies.”
Males, especially, have bright patches of blue on their bellies and sometimes at the throat. The fence lizard does push-ups displaying his bright breeding colors to admiring females. The brighter the blue, the healthier and more attractive the male is as a mate.

We haven’t always had lizards in our yard. When we first moved in, garden snails infested the African daisy planted along our front hillside. Blindly, we used the box of “snail bait” poison left behind by the previous homeowners. Did it get rid of the snails? No. It would decrease them for a while, but then they would multiply and return in greater numbers.

When the poison ran out, we tried beer traps, copper strips and a variety of organic methods. After several years of “Earth friendly” snail deterrents, we began to notice there were fewer snails but it wasn’t because of anything we were doing. Something was eating them.

Now that our snails were “clean” and tasty, predators were picking them off. A skunk was crunching them on the porch and alligator lizards (Gerrhonotus multicarinatus) moved in to dine as well.

As we remove the African daisy and replaced it with native plants, we have less and less non-native garden snails. The snails don’t like the thick waxy leaves of the ceanothus or the aromatic taste of sage. But these native plants have attracted native insects.

In May of 2004, we spotted the first western fence lizard in the yard.
Since then, there has been at least one batch of youngsters. Rock piles and concrete walls soak up the sun’s rays and create warm stopping places for lizards. The nooks and crannies between the rocks make it easy for a lizard to hide from a hungry red-shouldered hawk.

A place to live and a safe food source were all the lizards needed to move in.
Western fence lizards patrol the herb garden, eating a variety of bugs. They warm themselves on the driveway and run up the walls, clinging with their long strong toes.

But these western fence lizards are doing something else for us besides insect patol. You see the western fence lizard is a Super Hero. Not only can they run straight up a wall, they fight disease.

Lyme’s disease has made its way to Southern California from the east coast. But this debilitating illness is less of a threat to humans here than in other places. Why? Because of the western fence lizard. The tick’s that carry Lyme’s disease are small, tiny actually. These ticks will hop on a western fence lizard as easily as a mouse or a person. And here is where the Super Hero comes in: If a tick carrying Lyme’s disease bites a western fence lizard, something in the the lizard’s blood neutralizes the disease. When the tick leaves the western fence lizard it is no longer a carrier of Lyme’s disease.

If you have western fence lizards as neighbors, they are protecting you from potential disease. What other wonders are these lizards capable of? Who knows. Perhaps they carry a natural antibiotic in their blood like Komodo dragons or American alligators that could be beneficial to humans.

For now, I’m happy to watch them basking in the garden. And to inspire them to stay we’ve created a few more rock piles and added some novel resting places. The female fence lizard has moved into a dark-colored, resin gargoyle-shaped drain spout. For a lizard it’s a cool place to live.

Monday, April 16, 2007

Hummingbird Soap Opera

Well, there is no doubt about it. Having the scrub jay frequenting the yard made our little female Allen's hummingbird reevaluate the nest she created on top of her mother's deserted nest from last year. (See the nest)

She stayed away and abandoned the tiny lone egg. When I checked the nest late Tuesday night, there was no mother incubating and the cool temperatures were too much for the egg to survive.

When I checked the nest Wednesday morning, the egg was gone and the side of the nest was slightly torn–probably by a bird larger than a hummingbird sitting on the edge.

Some nests are made in unsuccessful locations. This was the second batch of eggs lost in this one specific nest site.

The fascinating thing to me is this tiny hummingbird with a brain the size of this "O" realized she had made an untimely choice. Rather than fight against brutal odds, she abandoned her hard work rebuilding the nest and the resources committed to the egg. She let it go.

Then she disappeared for three days. Where did she go?

I think she went off to mate again. She's back now and fervently trying to drive off her last batch of youngsters. She's also building a new nest somewhere in the holly cherry shrubs. I haven't spotted it yet. This time she is being very secretive.

Monday, April 09, 2007

Of Mourning Cloaks and Hummingbirds

The more I watch the life dramas that play out in my backyard the more aware I am of how interconnected life is.

Spring has come barreling across the Southern California landscape. Plants that survived the frost leafed out in record time.

The Chinese elm went from leafless to brilliant green in five days. The first hummingbird babies of the season took to the air March 23.

With her first brood of youngsters out of the nest, Alena, a one-year-old Allen’s hummingbird, began renovating a nest her mother, Hummy, built last year. This location, in a downward hanging elm branch, was not successful for her mother. Hummy’s second brood was discovered and eaten by a predator, probably another bird. (See Hummy on original nest)

When Alena chased off a group of bush tits that were eyeing the potential building materials available in this old nest, I thought she was anxious about the activity near her fledglings. I had no idea Alena had decided to build her second nest on top of her mother’s old nest.

If you look at the picture, you can see the cone-shaped bottom of the old nest. The rounded, upper half of the nest is new construction.

Enough with the background.

The real story begins with frass. That’s right, frass, the poop from insect larva. If you’ve ever grown tomatoes and had tomato worms, actually tobacco hornworms (Manduca sexta) you know what large-caterpillar frass can look like–tiny chunks of black charcoal. You may not see a tobacco hornworm or a cabbage looper but the trail of leaf damage and frass will lead a discerning eye right to the munching, pooping source.

Well, there was a lot of frass on the patio under the elm tree. Something was up there munching away on the new green leaves. Something that was numerous and rapidly getting larger.

For the past three years, western scrub jays have been infrequent visitors to our yard. West Nile virus has decimated the scrub jays, mockingbirds and American crows in our neighborhood several times since its arrival. But suddenly Saturday morning, a scrub jay was making a racket as it made it’s way through the trees.

Spiny elm caterpillars, the larva of mourning cloak butterflies (Nymphalis antiopa), were marching down out of the elm tree across our patio and up the walls of the house. Some of them were done eating and pooping and they were looking for a safe place to enter the chrysalis stage of their development. The jay had found a banquet .

While searching for roving caterpillars, the jay stumbled across another delicacy–hummingbird nestlings. From the far side of the yard a second female Allen’s hummingbird frantically voiced alarm calls. The scrub jay had found her nest in the eucalyptus tree. Alena and two other female Allen’s hummingbirds came to their cohorts aid. The foursome buzzed the jay and tried to drive it off, but it was too late. The jay consumed one youngster and flew off with the second. It was probably taking the morsel back to its own offspring.

The next morning, Alena laid an egg in her new nest.

But now the nest that seemed safe is in a dangerous place. Caterpillars continue to march down out of the elm and this morning two scrub jays were on the prowl.

The hummingbird egg sits quietly alone in the nest. Alena is not sitting on it.

Is she staying away so as to not draw attention to the nest? Has she decided to abandon the egg, realizing the nest is not in a safe location?

If the caterpillars hadn’t been so successful and their numbers so great, the jay might not have spent any time in the yard. The hummingbird nests might have been safe all summer. If Alena had made her second nest in a different tree or avoided the location that was probably raided by a jay last year, brooding her second clutch might have been as easy as the first.

Now everything is more complicated.

Life is a delicate dance. The living constantly effect each other. The weather benefits some and challenges others. No action or inaction is without effect.

Monday, April 02, 2007

A Desert Cottontail

We had a neighborhood rabbit–a desert cottontail to be exact. She would trot through the hillside planter in the morning or graze the driveway grass in the evening.

Sometimes we went days without seeing her and I would worry that one of the hawks or owls had caught her. A lone rabbit only has two eyes and two ears to watch out for danger.

I wondered how she came to be in our neighborhood. We are adjacent to the Santa Monica Mountains, but several lanes of houses barricade us from the majority of the mountain residents. We do not have deer, quail were a first time excitement this September after 14 years. The coyotes, however, do frequent the streets even though we are only two short blocks from one of the San Fernando Valley’s busiest boulevards.

When the rabbit first appeared about two years ago, it was small–a youngster. It grew up wandering between several houses. It must have been crossing the street, but it seemed to have found a way to do so safely.

Unfortunately, a neighbor just came pounding on my door. His dogs had caught the bunny in his backyard. Could I come and see if anything could be done? I rushed over with him.

There was my morning friend laying quietly on her side. I felt for a heart beat. There was none. The soft fur was still warm with her last breath. Life was easing away. I stroked her gently and hoped her passing was quick.

For a wild rabbit she had lived an unusual life, solitary, virginal and fairly long. She had avoided predators and suitors. She was healthy and loved by the humans who’s homes she visited. Did she eat my garden lettuce to the ground? Yes. But there were a few fancy greens she didn’t like and therefore left those for us. She also hopped casually between the ferns and made the yard a calmer more beautiful place.

One small wild rabbit has returned to the Earth and for many of us there is a small empty place in the world.