Friday, December 7, 2012

Snowbirds


Hermit Warbler                      photo by Richard Halliburton

Every year, the human population of the valley dramatically increases with the annual migration of "snowbirds" to southern Arizona, flocks of retirees who winter down here where it is warm and sunny and head back north between May and October to escape the insanely hot summer. Or is it that they are residents in the north during the balmy summers, and flee south to escape the blistering cold winters? Either way you look at it, they are in plenty of good company, because dozens of bird species use the same strategy of seasonal migration to up their chances of finding abundant food year round and good nesting sites when the urge to mate urge arises.
As opposed to the northern or high-altitude bioregions, where avian life is much more diverse during the summers, the Sonoran desert region hosts more winter residents. We are the south that many birds migrate to during the winter, but there are also some heat-loving summer residents that hang around here during the searing hot summer months and migrate further south during our ever so slightly chilly winters.
Some of the most common snowbirds, those that migrate to the desert for the winter, are American goldfinch, Western bluebird, and white-crowned sparrow. Waterfowl are the most abundant migratory species, seeking open water to feed in and be safe from predators, bringing us cormorants, egrets, ibis’s, and all kinds of ducks.
Quail Eggs      photo R. Halliburton
Although the best places to see birds are natural areas and open water, you need not go further than your own backyard to see dozens of species, both migratory and year-round residents. Over the years I’ve logged over thirty species that have stopped by for a visit. Local resident Richard Halliburton has been backyard birding in Stetson Hill for ten years, and has logged over 50 species, including a green heron and a hermit warbler that were migrating through. Quails love his yard so much that they laid a dozen eggs in his hedge. Richard’s secret? Homemade suet, made from a combination of lard, peanut butter, corn meal, flour and fruit.
What visits your backyard is of great interest to scientists who monitor the abundance and distribution of bird species. The 16th annual Great Backyard Bird Count will be collecting data from citizens all over North America between February 15-18th, and will be expanding to the entire globe for the first time this year. Like the Audubon Society’s annual Christmas Bird Count, which has been going on for over 100 years, the GBBC is an important tool to help understand what is going on with bird populations, both urban and wild. All you need to do is pay attention to the birds in your yard, or anywhere else you like, for fifteen minutes and log in your results to the GBBC website at http://www.birdsource.org/gbbc/howto.html.
You might be surprised what you see!

Green Heron                        photo by R. Halliburton


Make your own suet
In a large bowl, blend together 2 cups flour, 2 cups corn meal, 2 cups quick oats and 2 cups wild bird seed mix. In a medium pot, melt together 1 pound of lard and half cup chunky peanut butter over medium heat. Stir in 2 heaping tablespoons of berry preserves and a cup of raisens or dried cranberries. Remove from stove and blend with the dry ingredients. Press the mixture into a greased 9x9 pan and let it cool. Cut the suet into blocks and store in the frig until use.

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Wednesday, October 17, 2012

Owl Calls


Photo by Ken Simms

Anyone who walks at dawn or dusk near Phoenix suburbs will sooner or later be rewarded with the soft, low hoot of a great horned owl. Whether the resonating call of an owl evokes feelings of wild beauty or primeval dread, the sound is always a reminder of something greater than the human world to anyone who pauses to listen. If you're lucky, you may spot the striking silhouette of an owl perched on a saguaro, or see one glide overhead on silent wings. 

Among the six species of owl native to the Sonoran Desert (barn, western screech, pygmy, elf and burrowing owls are the others), the hoot of the great horned owl, along with its impressive size, make them easy to identify. Some call them the "5-hooter," since their most common call has five parts, with the second and third hoot more rapid than the rest. With a little imagination, you can hear them say, "Who's awake? Me too!" The female hoots are shorter and higher than the males.

But if you're listening for any of the other desert dwelling owls, don't expect a hoot or even a "who." Listen instead for the "raspy, hissing shriek" of a barn owl, or the "nasal trumpeting" of a burrowing owl. The Western screech owl is reputed for a "spooky wavering tremolo" or "bouncing ball song." An elf owl belts outa duck-like squawk or high barking call. If you hear "monotonous toots, a high rattle or trill," it could be a nearby pygmy owl. Even the great horned owl's repertoire includes a "low, nasal bark," the common response of a female to an amorous male, plus the "high, wheezy bark" of young owlets. (Sibley's Field Guide to Birds of North America, 2000)

At this time of year, the tiny elf owls, smaller than a common house sparrow, have fled to warmer climates south of here for the winter. If they are still hanging around though, you may spot one resting in a cavity in a saguaro or perched in a palo verde tree. 

Screech owls and pygmy's are also cavity nesters, using saguaros as well as sycamores, cottonwoods, or any other tree that a woodpecker has excavated and abandoned. 



It is true that barn owls like barns and attics of buildings, but they will gladly occupy a box of just the right size if you build them one, as has been done by many and Eagle Scout for their wildlife conservation project.


All of these birds are primarily nocturnal, but it is not uncommon to spot a burrowing owl in broad daylight on golf courses, railroad cuts or anywhere else that there are prairie dog or ground squirrel dens. burrowing owls will dig their own burrows, but also take up residence in those of their prey. their long legs and terrestreial habits are unique among owls.


You can listen to calls of all 200 of the world's owls at: www.owlpages.com/sounds.php

Photos of the screech owl, barn owl and burrowing owl were taken at the Adobe Mountain Wildlife Center in Phoenix, Arizona.




Sunday, September 23, 2012

Desert Willows



At the same time most native desert plants are shutting down in preparation for the searing heat of summer, Desert Willows, aka Chilopsis linearis, are emerging from a cool winter season of dormancy. Named for their long, slender willow-like leaves, Desert Willows are one of the only Sonoran desert natives that bloom throughout the summer. They are also one of our only winter deciduous natives, dropping their leaves in late October, and not renewing them until late spring. 
Flamboyant pink flowers burst forth in May, scenting the air with sweet perfume to attract pollinators, mostly large bees and the occasional hummingbird. The ruffled blossoms and luxurious leaves seem extravagant in the arid climate where water conservation is the primary adaptation of desert plants. Desert willows grow naturally along arroyos and streams, insuring that moisture is plentiful. They do especially well in well-watered suburban landscapes.
Known as chimov by the Hualapai people and aan by the Pima tribe, Desert Willow is not a true willow in the botanical sense, but a member of a family of tropical plants called the Bignonias, named after Jean-Paul Bignon, a Frenchman who served in the royal court of King Louis XIV of France. The family of over 650 species includes several domesticated trees, shrubs and vines that have been imported to the Phoenix area from all over the world, including Jacaranda from Brazil, Cat-claw Vine from Mexico, plus Catalpa, Calabash and Trumpet Vine from southeastern North America. Horticulturists in Uzbekistan developed a popular hybrid between catalpa and desert willow known as “Chitalpa.”  The “Rio Salado” variety of desert willow is a cultivar with deep purple and magenta flowers. 
Indigenous people used the leaves for medicinal purposes as an anti-fungal, a good treatment for athlete’s foot and candida. Teas made of leaves, bark and flowers have been used to treat coughs; poultices can help heal cuts and abrasions. The flexible limbs are excellent for making bows and baskets. Although humans have not used Desert Willow for food, birds and insects thrive on the nectar and other wildlife feast on the leaves.
At summers end, long skinny seedpods dangle from the tips of desert willow branches where flowers once were, soon to dry and split open to release hundreds of feathery seeds that are carried by the wind to chance landing in a sunny spot next to a desert stream. 

Monday, June 4, 2012

Mockingbirds



“Teach all the children to venerate it as a superior being
 which will haunt them if any harm is done to itself or its eggs.”  –Thomas Jefferson

Thomas Jefferson’s reverence and admiration for mockingbirds was shared by many others during the early 19th century, when keeping them as caged birds became popular. Pet mockingbirds were so valued for musical entertainment that an especially ardent male was worth up to $50.  Thus, for mama to buy a mockingbird to sing her baby to sleep was once a valuable offer, on par with at least a small diamond ring!  The mockingbird trade on the East Coast was robust enough in the early 1800’s to cause a severe local decline of the species. Fortunately the practice waned, and mockingbirds are now well established throughout North America and the Caribbean Islands.
Named for their impressive vocal repertoire, Mimus polyglottos, or the “many-tongued mimic,” is capable of learning over 200 different songs throughout its lifetime. Songs imitate not only other birds, but may also include sounds of sirens, trains, cats and frogs.  Jefferson, who was a polyglot (he was able to speak five languages fluently) and a musician himself, reputedly had a favorite pet mockingbird named Dick that he doted on.
The mockingbird has had a recent revival in popularity as the female half of the sci-fi icon, the mockingjay. A symbol of hope, justice and rebellion in the Hunger Games trilogy, the mockingjay is a cross between genetically engineered “jabberjays” and wild mockingbirds.  Jabberjays hark back to the subversive 1950’s CIA scheme to influence the national media, known as Operation Mockingbird. At that time, a network of influential journalists was hired to assist with a vigorous anti-communist agenda. When mated with the mockingbird, a symbol of innocence and beauty, the hybrid offspring became allies in communication for the trilogy’s protagonists through their ability to repeat human songs.
But the symbol of the mockingbird in literature is best known from the Pulitzer Prize winning novel by Harper Lee, in which Miss Maudie explains to the children: “Mockingbirds don’t do one thing but . . . sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.”  
Bachelor males are especially well known for their habit of crooning through moonlit nights, and are often fooled by city lights into singing constantly throughout the summer if they are not successful in finding a mate. Once the birds pair up though, things quiet down during nesting season, when the monogamous birds get busy building a nest and later caring for their young. Male birds are devoted dads, taking over care and feeding of the first brood while the female incubates a second.
In the Phoenix Region, you are more likely to hear a mockingbird in the suburbs than in the wild desert. Like many other creatures, mockingbirds are well adapted to human altered environments, which often provide more abundant food and water, especially in desert regions. They are omnivores, feasting on berries and fruit, as well as insects and lizards. Light posts are favorite perches, and sometimes used as nesting sites.
Local mockingbirds will imitate other avians common in the desert suburbs, like the cactus wren, grackles, finches, verdin and quail. Their song might be confused with that of their cousin, the curve-billed thrasher, who can also carry a decent tune, but not nearly as varied. The flash of white outer tail feathers and white wing patches can help to easily identify the otherwise drab gray mockingbird when it flies.



Photos by Richard Halliburton

Wednesday, April 18, 2012

Agaves


Of all the strange spiky botanical forms thriving in the Sonoran desert, some of the most spectacular and extravagant are the agaves. Flowering stalks of agaves begin to emerge as the weather warms in spring, and depending on the species, may grow to over twenty feet tall!   Their reproductive strategy is known colloquially as "boom and bust" reproduction, because the plant will live for many years as a leafy rosette, and then shoot up a stalk bearing hundreds or thousands of flowers in one season. The plant uses so much energy in the process that it dies after the seeds have ripened. The academic term for this is "monocarpic perennial," which translates to "a plant that lives for many years but only produces seeds once." Although agaves are sometimes called “century plants,” most species only live between 20-30 years.

Several years ago, I measured the daily growth of a few specimens in our neighborhood. My records show that agave flowering stalks will grow anywhere between 3 and 9 inches per day for one species I was tracking, Murphey’s Agave.  Murphey’s is one of several dozen types of agave found growing in the Phoenix area, thanks to a bustling import and cultivation business for use in ornamental landscaping. There are actually no wild agave populations within the metropolitan region, although several species grow naturally at higher elevations in surrounding mountains. However, there are a few small populations of Murphey’s, also known as Hohokam Agave, that appear to be remnants of pre-Columbian agricultural settlements. Agave has been, and continues to be, one of the most important utilitarian and food plants for indigenous cultures throughout the Sonoran desert.

Trade between ancient cultures played a large role in distributing agave to new areas far beyond their natural range. Many populations now known between central Arizona and Grand Canyon appear to be what is left of small plantations that were created to harvest for food, medicine and fiber. Both the piña and stalk of some species were roasted and eaten; the large stone-lined roasting pits remain as some of the most visible archaeological features of some pre-historic settlements.  The pulp and juice were also considered to be excellent tonics and healing medicine. Stalks were used as tools, building material and musical instruments. Fiber from the leaves was used to make sandals, fabric and nets. Be forewarned: the sap of some species is so toxic that it could be used as fish poison or arrow poison for hunting.  As noted by historian William H. Prescott in 1843: “The agave, in short, was meat, drink, clothing, and writing materials for the Aztec. Surely, never did Nature enclose in so compact a form so many of the elements of human comfort and civilization!”

Today, huge agave plantations are an important part of the North American economy. Tequila, mescal, agave syrup, and sisal are some of the major products exported from Mexico all around the world. Harvesting agaves is highly regarded as a technical skill, requiring strength and knowledge to recognize and properly cut the mature plants.  Harvesters, called jimadores, use specially designed cutting tools, called coas, to expertly remove the spine-tipped leaves and extract the piña, or core of the plant. Certain species are raised specifically for the fiber in leaves, which is used to produce everything from rope to place mats. Other species are best for the sweet sap that can either be pressed out and fermented to brew tequila, or reduced to make honey-like syrup. Industrial researchers are currently investigating the use of agave to produce bio-fuels. 

Despite the stunning effort put into seed production, very few of the tens of thousands of seeds made by a single agave actually germinate and grow into mature plants. For many species, most reproduction is from plantlets that emerge either on the stalk, called bulbils, or from the roots of the parent plant, called “pups” or hijos (Spanish for “sons”).  These smaller plants are the form that has been most easily traded for thousands of years, and allows us to now enjoy so many kinds of agaves in the suburbs of Phoenix.  Part of the job of an jimadore on an agave plantation is to extract the parent plant without destroying the hijos. Likewise, if you have the privilege of witnessing the flowering and passing of an agave in your home landscape, be sure to collect the hijos and find a good home for them to carry on their line of noble plants.