Saturday, March 12, 2011


The trailhead for Hellhole Canyon in Anza Borrego State Park sports this sign: "People have died on this trail." Well... that seems a little melodramatic... but in summer it certainly could apply, when the temperature can climb to 124º!

Even though today's temperature is a mellow 80º, hikers year-round do need hats and plenty of water on this 5-mile trek. Also Mountain Lions do roam here... and perhaps those of us who live with lions and rattlesnakes grow too accustomed to them, and careless.

Brittlebush (Encelia farinosa) adds sunny splashes to the wildflower display. (All photos by Narca)

Beautiful Desert Hibiscus (Hibiscus denudatus) is in the mallow family.

The trail is fairly level and well-maintained, as it mounts the wide bajada at the foot of Hellhole Canyon. Many flowers are peaking just now, and the wide fan is aflame with the reds of Chuparosa. Shortly after the canyon walls close in, a small stream of water cuts the trail, and in the distance I see a stately grove of California Fan Palm, the only native palm in the southwestern US.

California Fan Palm (Washingtonia filifera) at Hellhole oasis

California Fan Palms grow only at desert oases, where fault lines along the mountains' roots allow water to flow to the surface. Anza Borrego must have gotten a good recent rain, for the flow today is strong, and the sand on the open bajada is still damp below the surface. Ocotillo always flowers after a good, soaking rain, and it is in flower today, and fresher than the Ocotillo was yesterday in Plum Canyon.

Several of the fan palms show scars from a fire, but many have survived. Trunks are scorched, and their long skirts of old fronds are now miniskirts, no longer brushing the ground. I scramble over a boulder with a bedrock mortar, evidence that Native Americans gathered here to grind acorns and other seeds, in the cool shade of the well-watered canyon.

Bedrock mortar at Hellhole Canyon, still holding water from the last rain

California Sycamore (Platanus racemosa) in flower

I'm early, and the sun hasn't yet topped the ridge, so I must wait for its warmth if I'm to see any butterflies. Only a single Mourning Cloak flies before the sun has hit the canyon bottom. A few Orange-crowned and Yellow-rumped Warblers forage in the palms and California Sycamores. Lesser Goldfinches are very conversational this morning, as they gather to drink and bathe.

Male Lesser Goldfinch (Pen-and-ink by Narca)

As soon as the sun hits, the Sara Orangetips fly––dozens of them, the only abundant butterfly today. Variable Checkerspots energetically zoom past, alighting occasionally to bask. On the return trail, only the orangetips and a few blues venture to flowers on the alluvial fan, beyond the water.

Variable Checkerspot (Euphydryas chalcedona hennei)

Like butterflies, lizards emerge with the sun's warmth. Several Side-blotched Lizards scurry away as I return downhill.

A Side-blotched Lizard (Uta stansburiana) has the confidence of a dinosaur, its small size notwithstanding!

One change is very striking: a new plant has invaded the low desert, which I didn't notice on my last visit, and it is already a scourge. The Saharan Mustard. The Arizona-Sonora Desert Museum's website gives a lot of information:

This very fast-growing invader is self-pollinated, so every flower sets seed––as many as 16,000 seeds on a single plant! Seeds disperse from broken, tumbling, wind-blown plants. This mustard smothers native plants, and quickly overruns a region with up to 100% coverage. It can form impenetrable stands up to 5 feet high. Then, adding insult, it carries fire into desert communities that don't normally experience fire and can't tolerate it. I probably pull up 100 of the plants growing right along the trail to Hellhole Canyon, but can see many more.

Seed pods of Saharan Mustard (Brassica tournefortii)

Back at the car, Noel has been photographing a pair of Loggerhead Shrikes as they return every couple of minutes to feed their four hatchlings. It is the second shrike nest we've found on this trip. This pair has so far outwitted a pair of Common Ravens that are malingering here, no doubt aware that the shrikes have a nest somewhere nearby. Nestling ravens grow up on a diet that consists largely of the young of other birds. These shrikes are wary of the ravens, though, and, with continuing alert parental care, the four nestlings stand a good chance of surviving. In general, shrike productivity is high. Noel says that a major issue causing declines of Loggerhead Shrikes throughout their range is collision with cars.

Loggerhead Shrike in its dense thicket of a nest shrub

Common Ravens are among the most intelligent of birds.

Shrikes are fascinating birds. Their display is unique: they don't sing complex melodies, or flash brilliant colors to woo a mate. Instead, they build a larder by impaling grasshoppers, lizards, mice and other prey on the thorns of mesquite, the points of agave leaves, or the spikes of barbwire, thus proving to potential mates what good providers they are. (The only Pygmy Mouse that Alan and I have ever seen was one spotted by Arnie Moorhouse in a shrike larder!)

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