Friday, December 30, 2011

Crucifixion Thorn

While wandering through the desert during the annual Christmas Bird Count south of the Gila River near Buckeye, Arizona the other day, we came across one of three species of crucifixion thorn. All three are  mean spiky shrubs, with green stems and branches that take on the job of photosynthesis where leaves are mostly absent, except in very young plants. Out on the creosote flats of Robbin's Butte Wildlife Area, the lone specimen of Castela emoryi we found is the perfect place for resident loggerhead shrikes to impale their prey. This brand of crucifixion thorn is one of three Castela species native to the Sonoran Desert, but the only one found in Arizona wildlands; the others are found in Mexico. Over in southern California there is a Crucifixion Thorn Natural Area, dedicated to a healthy forest of this somewhat rare Castela. Like its better known cousin, Quassia, stems of Castela are sometimes used medicinally for their bitter tonic and intestinal parasite purging benefits.
The other two types of crucifixion thorn found in Arizona include Canotia holocantha, a very common tree-like shrub with long, flexible spine tipped branches, that grows mostly in the central uplands; and Koeberlinia spinosa, a well-armed shrub endemic to southwest deserts, ranging from California to Texas. None of these species, however, are native to the holy lands, where Jesus is said to have bore the corona de cristo for which these plants are named. The plant most likely to be referenced in biblical stories is Zizyphus spina-christi. We also have a thorny species of Zizyphus in Arizona, but we call it gray-thorn, among other things, in these parts.  Whichever you encounter, it's best to handle carefully with leather gloves, lest you draw blood!

Thursday, December 22, 2011

Alligator juniper

For tonight's solstice fire, we burned a bundle of juniper wood that I picked up from a fuel wood market in downtown Phoenix. I could tell by the scaly bark that it was from an Alligator juniper (Juniperus deppeana). The man I bought it from told me that it was  harvested from a clear cut up near Williams, AZ. Although I shudder to think that these amazing old trees are being clear cut, we could at least feel that these limbs were burned with reverence. The wood burns clean and smells so sweet.

A couple of months ago we visited an ancient alligator up near Flagstaff. This one has seen many centuries, and undoubtedly many young boys in its limbs over the years.
Happy Solstice!

Wednesday, December 21, 2011

Desert Snails

These spiral beauties are the shells of talussnails (Sonorella spp.), a type of land snail that survives in between rocks in Arizona deserts and canyons, grazing on mosses, lichens, and leaf litter. I haven't figured out which species. If you want to be a land snail biologist, and want to identify the species, you need to get a good look at their penises. Unfortunately, I haven't come across a live one yet, in order to determine the shape and size of their gonads. This, plus the details of shell morphology, are the most important characters used to distinguish between them. All snails have a penis, since they are hermaphroditic, which is very handy for reproduction, since both individuals can become pregnant when they copulate. At least if I do find a live one, the sex won't matter!

Although there are over 200 species of snails native to Arizona, we know very little about most of them. Many are considered very rare, with populations limited to isolated mountain ranges. Threats from mining and recreation have raised enough concern from biologists to petition for protection under the Endangered Species Act, as with the Rosemont Talussnail and Sonoran Talussnail. Others, are considered pests, such as the New Zealand Land Snail, which has inspired annual conferences to discuss how to eliminate them.  

Most snail reports are heavy with measurements and description, but I did find a few lines referring to snail intelligence and behavior buried inside a 69 page report, where two biologists came eyestalks to eyes with a snail:

"With its eyestalks still turned towards us, the snail appeared to increase its traveling speed across the boulder and attempted to go down the side of the boulder and out of our sight. We considered this to be evasive behavior."  Schmalzel and Archer, 2010

They didn't say if that one escaped, or if it became one of the many sacrificed for taxonomic analysis. I hope it got away!

Monday, December 19, 2011


When you look closely at the flowers of tamarisk (Tamarisk ramosissima) it is easy to understand why folks brought them to North America for their ornamental value.  Eight different species have been introduced from Asia for both aesthetics and erosion control. Today, they are reviled by many, because they do very well here. So well that they have become the dominant vegetation in many river corridors of the southwest deserts. After nearly 200 years, we should probably accept that they are now a permanent member of our regional flora. But millions of dollars and thousands of hours of human effort are spent every year in an attempt to eliminate them, using chemicals, fire, insects and other weapons of mass destruction. This particular specimen, however, is a well cared-for tree growing in one of my neighbors yard, planted intentionally for its shade and beauty. 

Sunday, December 18, 2011


We've had a lot of clouds this week. I love clouds! Here are a few of my favs from the cloud files. 
Plus, our families own Word Cloud for 2011. 
Another nebulous year has drifted by......

Merry Christmas and Happy New Year to All! Thanks for following Kat Tracks!

Friday, December 9, 2011

Turf Wars

One of the grandest features of the neighborhood I live in is a ~3 acre park, a vast swath of bright green that brings visual relief to what is sometimes a stark desert landscape.  On just about any day of the year it is warm enough to walk across the field barefoot, fly a kite, toss a football, or just lay down under a mesquite tree and take a nap. On a clear night, it's a great place to do a little stargazing. 

The park is actually a retention basin, a required element of any development around here, meant to help with flood control during monsoon season. It works: when the rain pours, the park becomes a lake. Not all retention basins are lined with turf. Our Homeowners Association has elected to maintain the lawn here, at considerable expense. In Phoenix, keeping a decent looking lawn is a fine art that requires not only an elaborate irrigation system, weekly mowing, and a lot of fertilizer, but also a twice a year conversion from heat tolerant Bermuda grass to cool season rye grass. For this park alone, which is the largest of 6 parks in the hood, we run an annual water bill of about $100,000. Most people think it's worth it.
However, some residents believe that the good green grass should only be admired and not played on. No golf, lest there be divets; no loose dogs, lest there be lawn sausage; and, good Lord!, no games, lest there be skid marks! Our HOA meetings have oft been dragged down by turf wars: endless arguments about who should be able to enjoy the field, and how to regulate the enjoyment thereof. Some advocate that security services be hired to run off any cleat bearing soccer players. Others would like to promote neighborhood ultimate frisbee tournaments. A few curmudgeons would like to see the whole dang thing covered with gravel to eliminate all the expense of turf management and wasteful use of water. 

Here is my vision: wouldn't it be cool if we all got together and made it into a cooperative farm?! We could probably produce enough fruits and vegetables to feed all ~5000 people that live in the neighborhood, AND provide fresh food to the elementary school across the street! We could even allow some chickens, add a fish pond or two, and we'd have the whole food pyramid! Probably a bit too forward thinking for this community, but, heck, it's a great back-up plan!

Thursday, December 8, 2011

Pit Pond

A few miles south of Lake Pleasant, on a patch of land where burros eek out a living in Peoria, Arizona, there is a huge rectangular pond. You won't see it on most maps, but it does show up on Google Earth. The lake is a recent addition to the landscape,  a wetland created by filling in a giant gravel pit. In the evenings, thousands of water birds congregate there: coots, ducks, geese, herons, egrets and the occasional swan. We caught the sunset from the cattail-rimmed shore last week, and a flock of ducks on the wing.
Whenever I find these places in the otherwise ultra-arid Sonoran desert, I am reminded that life loves heat. 
You just have to add water!

Tuesday, December 6, 2011

City Lights

If you really want to gain an appreciation for just how vast the Phoenix metropolitan area is, you really need to get up in the air, preferably at night. Two nights ago, I had the window seat as we flew in at 11:00 pm to this dazzling display, which to a very minor degree, is probably enhanced by holiday lights. The city lights stretch out beyond the horizon as you descend into Sky Harbor airport, with patches of darkness marked by several mountain preserves, and long black ribbon winding through all of it that is the Central Arizona Project canal.

This constant illumination was my bane last spring while experiencing chronic insomnia. Convinced that the light beaming into my bedroom at 2:00 a.m. was to blame, I decided to drive around the neigborhood one night and find out what nefarious activities were at the source, or at the least, what mid-night highway project was being done so as not to inconvenience daytime commuting. Much to my dismay, there was nowhere not lit, save for the clear sky above, whose stars are nearly obliterated by the glare from below. The shopping centers, churches, parking lots and two schools within a mile of our home, the freeway, every street, every cul-de-sac, and most people's homes were literally burning midnight oil. There was no construction project. I went back home to bed and laid awake wondering: How much energy could be saved if we convinced the various folks who control all these lights to just shut them off for even one hour each night?