Metamorphosis

The other morning while out on an early morning walk before school, Orion and I stopped to look at a Queen butterfly perched on a desert milkweed. She let Orion put his hand under her, and perched on his finger. Looking more closely at the milkweed, we also saw a freshly opened chrysalis. Could this butterfly be the one that had just emerged? Then we found another chrysalis still waiting to hatch, a porcelain like pod exquisitely decorated with fine black lines and dots of gold.

Fascinated, Orion looked around and also saw a caterpillar, the kind that Queens metamorphose from. I explained to Orion that Queen butterflies usually lay their eggs on milkweeds so that when the caterpillar hatches out, it has it's favorite food to eat right there. Milkweeds have toxins that the caterpillars can eat, but that make them poisonous to birds and other creatures that might want to eat the caterpillar, so the caterpillar is usually avoided by predators. We didn't find any eggs, but just the three stages all on one plant blew Orion's mind so much that he just sat down right there on the sidewalk and watched for a long time. After a while, he got up and said, "Nature sure is amazing! Wait till I tell the kids at school about this!"

Yes, these are the moments I live for!

The Adventures of Lizzy

This summer we adopted a new pet, a green anole lizard. She is six inches long, from her nose to the tip of her tail. In her short lifetime, this tiny creature has traveled farther than many people do. She has also survived being attacked by crickets, two nights of camping out in freezing temperatures, and a visit to the second grade at my sons school.

Lizzy came to us from a friend who rescued her when she was found in a roll of sod that had been trucked from east of Colorado Springs up to Crested Butte Colorado. How she got to the sod farm is still under investigation, but from what I've read, these lizards are native to southeastern United States, from Florida to Oklahoma. They have not yet been documented in the wild in Colorado. But, it's not impossible that they are either expanding their natural range or perhaps establishing wild populations from escaped pets in areas where the climate is compatible with their native habitat.

The coolest thing about Green Anoles is that they change colors from a drab brown to bright turquoise green. In response to what is hard to determine, but it seem like she either likes the warmth of our hands or is completely stressed out when handled, which is usually when she turns green. Camouflage has little to do with it as far as we can tell. They also have bulging eyes that move around a little bit to check out whatever is going on. Lizard eyes have a certain wiseness about them.

Green anoles are marketed widely as "starter pets," something small that doesn't require a lot of space or time to take care of. But any child ready to embark on a relationship with a lizard will have had to sell a lot of lemonade to support the equipment and food necessary to keep a lizard alive in a cage. Pet stores have an impressive line of Anole products, ranging from dried mealworms and reptile vitamins, to special basking lights meant to replicate the sunlight that they are now deprived of in captivity. Creating the warm humid environment she is adapted to was a challenge in the poorly insulated house I was renting in Colorado, which cooled down to 50 F at night, 20 degrees cooler than recommended for Lizzy, so her cage was also outfitted with not one, but two special heating pads that helped warm her tank 24/7. Here in Phoenix we have dispensed with the heating pads, but continue to spritz her cage with water several times a day to keep up the humidity.

If you have a pet lizard, you wind up with pet crickets, which also need to be fed. We had a hard lesson in the relationship between crickets and lizards when we took Liz out of her cage one morning to find her guts hanging out. I had put more crickets in the cage than the lizard could eat, so the crickets started to eat her! Horrified, I cleaned out the entire cage, and started her on a diet of mealworms, which presumably would not be quite so carnivorous. Lizzy's gaping wound was miraculously healed without so much as a dab of Neosporin within two weeks, although she is a bit asymmetrical with a hunk of muscle missing in her abdomen.

During our move from Colorado back to Phoenix, we camped for a couple of nights in near freezing temperatures. Without a plug-in for heating pads, we improvised by putting boiling water into water bottles and putting them next to the cage, then wrapping the cage in our down jackets. Wild anoles in the south probably survive cold winter nights, but as adoptive parents, we were feeling a little over-protective, especially after the harrowing cricket incident.

Visiting the second grade may have been even more terrifying for Lizzy then being eaten alive by crickets. Imagine being her size and having two hundred hands reaching out to touch you. She stayed green throughout the experience, which supports the "green when stressed" hypothesis. But, she didn't jump or dart from Orion's hands in an attempt to escape as he carried her from classroom to classroom. Another survival strategy is to stay still so predators won't see you.

All of this has been intriguing to me because it illuminates the quixotic desire of we humans to keep creatures in captivity, despite the complexities, and sometimes cruelty, of taking animals out of the wild. In this case, there was some kind of altruistic instinct in play when she was first discovered in the sod. As a pet she teaches us about her kind and gives Orion a sense of how to care for the needs of others. Some people surround themselves with pets like these. Creating terrariums becomes an art and obsession.

Someday though, I would like my son to see anoles in the wild, or at least living independently in the suburbs of Texas, where crickets are free, the sun is their source of light and they survive the coldest months by hunkering down in a hole in the ground. And there are other lizards like her to mate with.

Where There is Water

....there is life! We took a field trip to Spur Cross Ranch Conservation Area north of Cave Creek the other morning in search of sedges. I had just returned from "Sedge Boot Camp," a plant identification workshop offered through the Jepson Herbarium of UC Berkeley for anyone interested in learning to recognize sedges, especially members of the genus Carex. If this sounds esoteric to you, it is. But, sedges are a very important component of wetland and riparian ecosystems around the world. Since these habitats are some of the most affected by human activities, botanists and ecologists like to pay attention to what grows in them. A workshop like this is a huge draw for botanists, in this case over forty people gathered to learn about these fascinating plants.

But, I digress. The workshop was in California, in an area where we could walk into a meadow and find a dozen species within fifty feet. Here in the Sonoran Desert, sedges are not quite so plentiful. In fact, mostly absent in the uplands. But, wherever there is water, you are likely to find some kind of sedge. And we did! Growing in great abundance around pools along Cave Creek we found American bulrush (Scirpus americanus) growing three and four feet high.

These languid pools exist in magnificent contrast to the Sonoran uplands where giant saguaros and cholla cactus dominate. Along the creek, cottonwoods and sycamore shade the banks. Cattails, cocklebur, sunflowers and common reed (Phragmites australis, a twelve foot tall cane grass) flourish. Leopard frogs and dace stir the muddy pools. A garter snake slithers by. Hot pink Centaury, a tiny wildflower with spiral shaped anthers, peeks out among the rushes. Queen butterflies glide through the rushes in search of fresh sunflower nectar. Dozens of dragonflies cruise the creek, perching on bulrush tips and dipping abdomens in the creek to lay eggs (the female ones). A bear-sized javelina snorts and huffs as it circles to make a resting place at the base of a cottonwood. Water striders skim the pools, creating four-spotted shadows. A Cooper's hawk rests, eyeing a flock of black throated sparrows. The sparrows and a family of gilded woodpeckers call loudly to alert their neighbors.


Nearby, the mesquite bosque has been burnt recently, blackened stems and scorched earth splattered with red fire retardant that was broadcasted from helicopters earlier this summer. But with a the creek nearby, the mesquite and bursage are sprouting new growth already. Where there is water, there is life!

Summer Skies and Scorpions

According to Greek legend, the venomous sting of a scorpion killed Orion, the great hunting god. One of many stories about Orion’s fate tells that the Greek goddess Artemis cursed him with the fatal sting because she was jealous of his courting Dawn, the goddess of morning. During the summer, the constellation Orion can be seen lying down on the eastern horizon, greeting his lover just as the sun rises. At the same time, the constellation Scorpius sets to the west. Likewise, Orion is most visible in the night sky in mid-winter, opposite Scorpius, which some say is because they are carefully avoiding each other.

During mid-summer, stars that make up the sweeping spiral tail and claws of the constellation Scorpius dominate the southern night sky. These are clearly visible even around the light drenched city of Phoenix. At the heart of Scorpius shines Antares, a huge star 300 times the size of our sun. The name Antares is Greek for “rival of Mars,” because they both glow red and are about the same size to our eyes when viewed from Earth. However, if Antares were the center of our solar system, it would swallow Mars and reach almost to the planet Jupiter!

Summer nights are also the most likely time that you will see a living scorpion in the desert, since they are nocturnal and more active during warmer months. Scorpions have been very successful, having survived over 350 million years on our ever-changing planet. Of the 1500+ species known world wide, 90+ are found in the U.S.; about thirty live in both wild and tamed regions of Arizona. Three of these are common, and likely to be seen in the Phoenix area if one cares to look for them. The most spectacular but least common of the three is the giant hairy desert scorpion, a dark-skinned beast that grows up to six inches long. Although frightening to look at, this species is not very toxic to humans. But if you were an insect, lizard, spider, or other scorpion, you would definitely want to stay out of their way.

The less intimidating striped devil scorpion grows to less than three inches long, and is blonde or tan with broad dark stripes down the length of their backs. This species is also not life threatening to humans, though the sting can be very painful.

The bark scorpion is the only one in our area that is highly toxic to humans. They are also blonde and similar in size to the striped devil, but lacking the stripes. A well-aimed sting from a bark scorpion can immobilize a 250-pound man, and could be fatal to a small child, unhealthy adult or small pet. The powerful neurotoxin causes numerous symptoms including a sharp tingling sensation, numbing, uncontrolled breathing, muscle spasms, and general aching. Some people suffer allergic reactions to the sting as well. These are the kind that are most common in our neighborhood.

My friend Christy was kind enough to bring me the above photographed specimen that she caught in a jar in her back yard. The wildlife watching was fun for the family until one morning when 22 baby scorpions appeared on momma's back. Something about all that neurotoxin freaks most people out. But I am delighted to have a friend who cares enough to show me local wildlife rather than just flushing it down the toilet as most people would do in this case!

Fortunately, scorpions are not aggressive towards humans, and will only sting if threatened, such as when they get stuck between your shoe and your foot. They hide in rock crevices or burrows in the soil during the day, when humans are more likely to be outside. At night when they are active, it is not uncommon to see one cruising down the sidewalk or crawling on a tree trunk. If you shine a black light around your yard or in the desert on a moonless night, you will be able to easily find them glowing greenish white in the dark. Other than humans, the main predators of scorpions are nocturnal animals including snakes, mice, shrews, elf owls and other scorpions.

Although it is true that the sting of some species of scorpion can be fatal to even a very strong man, this is extremely rare. According to current medical records, there have only been two deaths in Arizona due to scorpion stings since 1968. Compared to other risks we face each day, these creatures are relatively benign. If you can overlook their venomous capability, they are fascinating to see and watch.

However, if you do not feel comfortable sharing your space with scorpions, be sure to keep your yard tidy and free of debris where they like to hide. Look carefully before you put your hands or feet under rocks, in woodpiles, or even when moving outdoor potted plants. Don’t leave close-toed shoes outdoors and avoid going outside barefoot at night. You can also have an exterminator treat your property with a special arachnid poison. Scorpions are not insects, so insecticides will not affect them. However, insecticides are useful if you want to eliminate prey that would attract scorpions to your home.

Suburban Century

#12 What is the land use history by humans in your bioregion during the past century?

I have delayed writing about this 12th question in the "Where You At?" series (begun on April 10th in my blog) because I thought I would find the time to dredge up more real numbers on the subject. Acres, decades, populations, etc. However, for the purposes of this blog, my personal observations and a few basic statistics will suffice. As a starting point, the Phoenix metropolitan region comprises ~2500 square miles of land.

Anyone who lives in the Phoenix area could make a reasonable generalization that about 50% of the current land use is dedicated to transportation needs. Or desires, if you prefer. That is to say, parking lots, roads, highways, train tracks and airports take up a staggering amount of land. This is a primary characteristic of Phoenix, other than the fact that it is in a desert. Of all the cities I have lived in (Seattle, Chicago, Fort Collins, Boulder, Colorado Springs, San Francisco), Phoenix is by far the most vehicle intensive and pedestrian/bicycle unfriendly.

But it wasn't always that way. Phoenix's humble beginnings were as an agricultural community, with citrus and cotton being the main crops and economic base, although transportation did play an important role since the beginning because large scale agriculture also requires large scale distribution. Agriculture requires prodigious amounts of water, however, so the economy of the area has changed dramatically from growing food and fiber to developing corporate headquarters, malls and housing, which supposedly require far less water to sustain. Which begs the question: So where do we now get our food? But, I digress.

The city was established in 1868. Arizona was inducted into the union in 1912. In the last 100 years, the population of the Phoenix area has swollen like a cancer from ~11,000 people to over 4 million people. We were rated as the 2nd fastest growing metro area in the U.S., after Las Vegas, over the past decade. The growth has slowed somewhat since the economic recession. A shocking 24% of the growth has occurred in the past 10 years. I have personally contributed 3 people to that statistic.

The stunning vastness of this metro area is most easily comprehended from the air or a mountain top at night. Electric lights spread to the horizon in every direction if you climb to the top of Squaw Peak, for instance. This photo was taken one early morning from the top of our more humble neighborhood high point, Thunderbird Mountain.

But, lest I forget, Phoenix and the other two dozen or so cities that comprise the Valley of the Sun's contiguous suburban landscape, have dedicated a reasonable amount of land to open space, including one of the nation's largest city parks, the 16,500 acre South Mountain Park, which you could just about go backpacking in, except I don't think they allow overnight camping.

This is a view from the mountain preserve in my "backyard," a 5 minute hike up the road.

And we also have the standard urban delights of universities/colleges, museums, ballparks, theatres and zoos. Plus a few military bases. To support all of this, I would bet that you could put at least a single digit percentage on the land use dedicated to our energy needs, including a nuclear power plant (see my December 1, 2008 entry). And our water needs (reservoirs and canals plus treatment plants).

However, the majority of land use here now is lots and lots of malls, massive corporate offices, lots and lots of tract housing (much of which is seasonally vacant or for sale now), and huge acres of asphalt. There are also a few remaining citrus groves and cotton fields on the fringes.

Oding

Common Baskettail Dragonfly, photo by Karolyn Darrow

Every so often we discover an unexpected gem in the Phoenix megalopolis. Last weekend, believe it or not, we found the most amazing wetland, right in the middle of the suburbs! The Gilbert Riparian Preserve, southeast of the crossroads at Guadalupe Road and Greenfield Avenue, is a 110-acre park with eight huge manmade ponds that were created and vegetated with native species as part of a water reclamation program for the city of Gilbert.

We got up very early on Saturday morning to go oding at the preserve. Arriving at 7:00 am after an hour long drive, we joined about a dozen other folks, ranging from ages 5 to 85, to learn about dragonflies. Since these fascinating bugs are in the taxonomic order Odonata, the sport of dragonfly (and damselfly) watching is called oding! Ya learn something new every day. (The excellent photo above of a newly emerged dragonfly was actually taken near Washington D.C. by my sister. That species is native to the Eastern U.S., so is not fund at the preserve.)


Mexican Amberwing at the Preserve

With the help of our knowledgeable guide, Bob Witzeman , we spotted and identified eight species of Odonata, including the Mexican Amberwing, Blue Dasher, Flame Skimmer and Wandering Glider. They have the coolest names! Interestingly, dragonflies and their more slender relatives, damselflies, did not have official common names until 1996. Since then, there has been a proliferation of dragonfly field guides, of which we now own two. Hey, in our house, you can never have enough field guides!

As a bonus, we were also treated to a flotilla of fuzzy ducklings, a turtle, a flock of black-necked stilts, avocets, egrets, great blue herons, geese, and black-crowned night herons. But best of all, I was so happy to see lots of families and children enjoying the outdoors early on a Saturday morning. There were probably at least a hundred people out bird-watching, photographing, fishing, hanging out, walking, running, dog-walking and, of course, oding.

Orion was certainly the spiffiest oder in his new dragonfly vest!

Zoom and Bloom

One of the most extravagant botanical happenings in the southwest deserts is when agaves have mustered the energy to send up their flowering stalk. Their reproductive strategy is known colloquially as "boom and bust" reproduction, because the plant will live for many years as a leafy rosette, (anywhere between 3 and 100, depending on the species) and then shoot up a stalk bearing hundreds or thousands of flowers in one season. Then the entire plant dies. The academic term for this is "monocarpic perennial," which translates to "plant that lives for many years but only produces seeds once." I call it "zoom and bloom."

For the past few weeks we have been measuring a few agaves near our house every day or two to see how fast they zoom. When we started measuring the first one on April 24th, it grew three or four inches a day until a thoughtless vandal snapped the flowering stalk and put an end to the zooming. But in that week it went from 38" tall to 65" tall. The broken stalk is still alive but could not grow any taller since these plants grow from the tips of their stems (the apical meristem, if you want to speak botanese). Today we noticed that, despite the damage, the remaining buds on the lower part of the stalk are beginning to open.

We started measuring two other agaves after the sad day when the first plant was brutalized, one of the same species and one of a different species. (I confess that I haven't taken the time to identify either of them yet. There are over 300 species, and in landscaping it could be any of those, not necessarily a native to the area.) The slim stalked species like the one that got broken has topped out at 115" tall, nearly 10 feet, and is now beginning to bloom. The other is growing even faster, zooming up to 9" per day, with no sign of flower buds yet. Eyeing old stalks of the same species, I'm going to predict that it will zoom up to 15 feet tall before it blooms.

So this is what we do to amuse ourselves during the hottest May on record in Phoenix-14 consecutive days of 100+F highs.
Tune in for the next exciting installment of the Agave Chronicles next week when we begin counting flowers and recording pollinators!