Tuesday, November 29, 2011

Desert Queen

If you look carefully, even in the depths of what we call winter here in Phoenix, you can find several stages of the Queen Butterfly, and maybe all four! The best place to search is on a milkweed plant, which is where eggs are laid, caterpillars munch, and chrysalises are formed.

Queen butterflies usually lay their eggs on milkweeds so that when the caterpillar hatches out, its favorite food is right beneath its feet. Desert milkweed is commonly planted in suburban gardens and commercial landscaping, although it is native to areas further south and west. Twining milkweed grows wild along washes or in irrigated areas where it climbs trees, shrubs and fences. Finding butterfly eggs on a milkweed takes a lot of patience, but if you look carefully under the leaves or on the stems, you may find what looks like tiny round pale green or white beads. This is where the magic of metamorphosis begins.

When the eggs hatch, the caterpillar gets to work doing what it does best: eating. Like the Queen’s better-known look-alike, the Monarch butterfly, milkweed sap that is eaten by the caterpillars renders both the larval and adult butterfly poisonous to any bird or other critter that might try to eat them. Potential predators quickly learn to avoid eating black-and-white striped larvae with yellow spots or the equally toxic orange and black butterflies.

Both Monarchs and Queens have orange wings with black edges and white spots, but the Monarch has darker black and brighter orange, and is a bit larger. Queens are more of a rusty orange and much more common in the Phoenix area. Queens also stay in the area year round, unlike Monarchs, which are famous for annual migrations to and from warmer winter climates where they form huge colonies resting in trees. You can easily tell a male from a female in both species by the small black patches on the inside edge of the males’ wings that release a scent to attract females. (This makes me wonder: Should a male Queen be called a “King” butterfly?)

Of all the butterfly stages, the jewel like chrysalis is the most magical to me. The smooth porcelain white shell is gilded with gold spots, and hangs by a thin stalk from the milkweed plant where the caterpillar came to rest. My son and I found a chrysalis gleaming in the sun on our morning walk to school one day last spring. Looking more closely, we found a caterpillar quietly resting, and then a butterfly landed to sip nectar from the milkweed flowers. We didn't find any eggs, but seeing the other three stages all on one plant intrigued Orion so much that he sat down on the sidewalk and watched for a long time. After a while, he got up and exclaimed, "Nature sure is amazing! Wait till I tell the kids at school about this!"

You can invite Queens and other butterflies into your home garden. The key is to grow wildflowers and shrubs that are the host plant, or species that the butterflies will lay their eggs on and caterpillars need to eat. This also means that when you see a caterpillar chowing down on your plants, you need to let it be so that it will mature and transform into a chrysalis. For Queens and Monarchs, you’ll definitely need milkweeds, which are available at many local nurseries.

If you find a caterpillar, and want to watch it grow and turn into a butterfly, be sure to gather and feed it leaves and stems of the plant you found it on. When the butterfly emerges from a chrysalis, be sure to give it plenty of time and room to spread its wings, then let it go free!

To learn more about our local butterflies, butterfly gardening and information about butterfly hikes with experts, check out the Central Arizona Butterfly Association (CAZBA) website at www.cazba.org.

Monday, October 31, 2011

Ringtails: Arizona's State Mammal

Nimble and clever, with a striped tail the length of its body, the ringtail was declared Arizona’s state mammal in 1986, heralded along with the cactus wren (the state bird), giant saguaro (the state flower) and ridge-nosed rattlesnake (the state reptile) as a distinctive member of our natural landscape. Because they are nocturnal, few people ever see these creatures in the wild, although you may hear them rummaging around for food or catch their eyeshine in a flashlight if you happen to be camping out in ringtail territory.

A long, lithe body and banded tail must be very useful traits, since several other species with these features have evolved in other parts of the world. The ringtail is sometimes confused with the band-tailed lemur, a native to the island of Madagascar off the southeastern coast of Africa. Lemurs are primates and thus more closely related to humans than to ringtails. Another look-alike is the civet, a southeast Asian animal popularly known for its musk, which has been used in formulas for expensive perfumes, including Chanel No. 5.

Although not closely related to either lemurs or civets, ringtails are close cousins to two other critters with black-and-white tails that live in Arizona, raccoons and coatimundis. How to tell the difference? Raccoons and coatis are both much larger than a ringtail; a large raccoon or coati can be up to 15 pounds, whereas an adult ringtail is rarely more than 3 pounds. Coatis have a long pointed snout, and usually travel in small groups during the day; both raccoons and ringtails are nocturnal and mostly solitary. Raccoons have a black mask, whereas ringtails have big, dark eyes rimmed with white eyebrows. Ringtails are slender, like a ferret or weasel, and about one and a half feet long; half of that length is their magnificent bushy tail. Fortunately for them, their fur is not luxurious enough to be highly valued, nor are they considered pests, so ringtails are rarely trapped or hunted intentionally.

Their Latin name, Bassariscus astutus, means “clever little fox.” Sometimes they are called miner’s cats, harkening back to the days when miners kept them as pets to keep camps pest free, since ringtails feed on mice, insects and lizards. Ringtails are neither fox nor cat, which adds to the confusion about these seldom seen animals. They are common throughout the desert southwest of the United States and Mexico, as well as agricultural areas and scrub forests of higher elevations. They have adapted well to urban life also: the resident ringtail at Adobe Mountain Wildlife Center in north Phoenix, named Ringo, was captured in the attic of a nearby shopping center, where he slept during the day, and scavenged for food in the store during the night!

You can learn more about ringtails and other native wildlife at the Adobe Mountain Wildlife Center. For information about volunteer opportunities, events, education and wildlife sponsorship, visit their website: www.azwildlifecenter.net

Saturday, June 4, 2011

Black Widow Refuge

Our back yard is a refuge for black widow spiders. Perhaps it was the famous storybook character, Charlotte, who convinced me that spiders deserve to be allowed their quiet livelihood in our yard. Or maybe it’s my over-developed ecological sensibilities that respect the necessary role that spiders play in nature, even in the suburbs. Rather than spraying our home regularly with pesticides, we've chosen to let these eight-legged, venomous predators live in our yard, where they weave webs, lay eggs and provide food for the numerous lizards and birds that also visit. Whenever I see a gleaming black widow with slender legs and red violin tattoo on her belly, I am fascinated rather than repulsed.

This may seem reckless or foolish to most people, but so far, these quiet, nocturnal creatures have obliged by keeping out of sight during the day, and sinking their tiny fangs only into edible prey, such as crickets and grasshoppers that also enjoy refuge here. Once in awhile I'll see one resting on its tangled web in a potted plant on the patio at night, but as soon as she senses my presence, the spider scurries out of sight, knowing rightly that I am far more dangerous to her than she is to me.

Out in the log pile, I reach in with gloved hands to gather wood for a new moon fire, setting aside the marble sized egg sacs full of soon-to-be spiderlings. Each of those little sacs may contain more than 750 eggs; one black widow can build half a dozen sacs in a summer. The idea that nearly 5000 spiders will soon be crawling around in my back yard is a bit daunting, but in reality, only a dozen might survive to become adults. The rest are eaten by each other or by the birds and lizards that abound in our refuge.

Sticky masses of black widow cobweb are a minor nuisance to me, but not to the hummingbirds that buzz in to gather this critical nest-building material. Without an abundant supply of ultra-strong and resilient spider web, a hummingbird nest cannot be bound to a branch or hold together well enough to protect the jellybean-sized eggs that will be laid in the down-lined cup. After the eggs hatch, baby spiders are excellent food for the young hummers. This is where the web-of-life becomes quite literal! For two years we have enjoyed watching baby hummingbirds grow and fledge from nests in our back yard refuge.

So far, we have not experienced any grotesque infestations of roaches, ants, crickets, spiders or scorpions, some of the "pests" that support a thriving chemical industry in Arizona. (However, I will admit that when the termites start drilling into our walls, I call the exterminators.) Yes, all of these creatures are here in our refuge, but as long as they stay outside in the back yard, we coexist peacefully. I like it that way.

Monday, April 11, 2011

That Tropical Feeling: Palms in the Desert

Living in the Sonoran desert can get a little dry at times, so one way we delude ourselves into feeling like we actually live in a tropical paradise or on the shores of a Caribbean beach is to plant palm trees. Our need for desert denial is so great that, next to the faux saguaro, one of the most common tech art designs for cell towers is a palm. But did you know that there is actually one species of palm that is native to Arizona and the Sonoran Desert?

The Desert Fan Palm (Washingtonia filifera) is a relict of more temperate days in these parts dating to as long as over six million years ago. Today, small wild groves are still tucked up in secluded canyons and near springs in the southwest where they have a reliable source of water. Just north of Phoenix, the privately owned Castle Hot Springs Resort includes natural springs that nurture a palm forest, as well as developed springs and carefully manicured groves. West of Phoenix at the KOFA National Wildlife Refuge, a small wild grove persists high up in a narrow shady canyon. Over in California, you can relax in the shade of native palm oases at Joshua Tree National Park.

Closer to home, all around us in the suburbs of Phoenix, our native palm is one of about two dozen species that have been introduced from all over the world for landscaping. One of the best places to view what most resembles a natural Desert Fan Palm grove is at the Phoenix Zoo, where the palms have developed massive “skirts” of dead fronds that surround the stout trunks. Groves in their natural, unpruned form are habitat for abundant wildlife, including a rare bat species, desert rats, lizards, snakes, many type of insects and birds, bighorn sheep and coyotes. Hooded Orioles use palm fibers to weave beautiful nests that hang in the protective shade of the leaves. For indigenous people, palm groves were a source of fiber that was woven into cloth and twined for cordage, leaves for making thatched roofs, walls and baskets, plus fruit and seeds for food.

Unfortunately, the benefits of palms for wildlife are not so endearing to many contemporary homeowners, who prefer not to welcome so many critters into their yards. Palm skirts are also regarded as a fire hazard, although in wild areas, occasional fire actually rejuvenates the groves by clearing out dense brush and creating fertile ground for new trees. Healthy mature palms are fire resistant, and will usually survive a wildfire.

Other notable palms in the suburbs are the majestic date palms, whose Latin name, Phoenix dactylifera, happens to include the name of our fair city. Date palms differ from fan palms in having long feather-shaped leaves, and also produce sweet succulent fruit. A relict of the commercial groves that were once abundant in the area is ASU’s Polytechnic Campus Date Palm Grove, which boasts over fifty different cultivars and is reputed to be the largest date palm collection of any public garden in the country. These palms represent a rich history of human civilization centered in the Middle East, where palms were critical to the development of early agricultural societies and highly valued for trade. The importance of date palms is recorded in drawings and temples of ancient peoples dating back to 7000 years ago. According to Islamic tradition, the original tree of life in the Garden of Eden is said to have been a date palm.

Wednesday, January 26, 2011

Bougainvillea: Tropical beauty in the Desert

From a naturalist’s perspective, one of the most striking things about the Phoenix suburbs is the lush green diversity of plants that thrive in our neighborhoods and parks. Compared with the surrounding desert, where plants depend on scanty seasonal precipitation, the suburban climate is subtropical, enhanced by irrigation and elevated humidity. Added to this, we have introduced hundreds of plant species from all over the world for our personal pleasure and agriculture: citrus fruits and roses from China, olives and rosemary from the Middle East, eucalyptus from Australia and aloes from Africa.

Perhaps one of the most dramatic flowering plants that grace the corridors of the Phoenix metro area is Bougainvillea, a tropical shrub introduced from rain forests of South America. In their native habitats, these sun-loving vines sprawl and climb over other shrubs and trees. Here they are usually planted and pruned to behave as shrubs or grown on walls and trellises. Enterprising horticulturalists have hybridized the fourteen native species in every possible combination to create over three hundred varieties that are now dispersed all over the planet. There is even a website called bougainvillea.com where you can order any color of the sunrise to grace your personal garden space. Beware, however, the flesh-ripping thorns that hide beneath the evergreen foliage! Fortunately, there are thornless options, but the most brilliant magenta Bougainvillea’s are inevitably the most fiercely armed.

These plants were named after Admiral Louis Antoine de Bougainville, who is well regarded in his homeland as the first Frenchman to lead a sailing expedition around the world between 1766 and 1769. In addition to having a spectacular tropical plant named in his honor, the admiral’s legacy includes several south Pacific islands, ports and straights, plus thirteen ships in the French navy that have celebrated his prestige on their transom. The circumnavigation was also historic for being the first to include professional naturalists, as well as the first woman known to sail around the world, as members of the ships’ crew. Historians still question the strange liaison between the expedition’s botanist, Philibert Commercon, and his valet, Jeanne Bare. The petite valet’s true identity as a woman was supposedly not known until the ships landed in Tahiti, where perceptive natives instantly recognized him as a her. Bougainville’s travelogue, Voyage Autour du Monde (Journey Around the World), was influential to philosophers and artists of the time who transformed his descriptions of Tahitian society into iconic images of the Noble Savage.