WINTERING SANDHILL CRANES IN SOUTHERN ARIZONA |
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by Jon Friedman
Historical Locations - Southern Arizona, and particularly Southeastern Arizona, has in recent years become one of the best regions to observe Sandhill Cranes in their winter territories. In prehistoric times, ancient native peoples placed images of Sandhill Cranes on rock/boulder surfaces in the lower Colorado and Gila River valleys. Today, we know these images as pictographs and petroglyphs. These images show the cranes in their mating courtship of exaggerated strutting display, their breeding season ritual "dancing", or mutual calling. Historically, Southwestern Arizona was the best place to visit to observe wintering Sandhill Cranes. An 1862 account called the species "abundant" south of Yuma to the Colorado River Delta. In modern times the delta doesn't really exist anymore as there is rarely any river flow from around Yuma south to where the dry river "empties" into the Sea of Cortez (Gulf of California). This is due to the fact that almost 100% of the Colorado River water is diverted with canals and aqueducts to bring water to irrigated agricultural fields on both sides of the river, and to major cities throughout the region as drinking water (Tucson, Phoenix, Las Vegas, Los Angeles, etc.). In the years prior to the advent of big agribusiness, the entire lower Colorado River watershed was filled with thousands of wintering birds, including many of the crane species. But, by 1953, the annual winter count found only a handful, and in years since that date virtually no cranes were found in that region. Only very small numbers of cranes can be found there in recent times. The disappearance of water in the lower Colorado to the delta and the legal (and illegal) hunting of these birds were the major causes of their disappearance in the southwestern region of the state. Ever increasing loss to the groundwater table is another factor for decreased sightings of cranes as small natural water flows and ponds have dried up and disappeared, causing loss of habitat.
In Modern Times - In recent years Southern Arizona, and particularly Southeastern Arizona, has become one of the best regions to observe Sandhill Cranes in their winter territories. The Sulphur Springs Valley in Southeastern Arizona (from Douglas to north of Willcox) sees a steady annual increase in the number of wintering cranes. Recordkeeping for cranes in this area began in 1970 when nearly a thousand cranes were observed in the entire valley. The number of cranes seen there each winter there has increased dramatically. Last year it was estimated that as many as 50,000 to 60,000 cranes were present on their wintering grounds. Most census numbers are arrived at by aerial methods. It's much more difficult to actually get an accurate count by trying to count each and every bird. For these reasons population counts are not exact and vary. Cranes begin appearing in the Sulphur Springs valley as early as October 1st. By mid-November their numbers are in the tens of thousands and by the end of the calendar year they are at their peak. The birds remain until the end of February or into early March, when they begin their spring migration to northern portions of the U.S., throughout Canada, into Alaska, and across the Bering Strait into Siberia - where they join up with many thousands of other cranes from Russia, China, and elsewhere in Asia. The highest concentration of cranes numbers in Southeastern Arizona are found in the Whitewater Draw (near Bisbee) and secondarily in the Willcox Playa. There are a number of other locations in the valley that also may have wintering cranes but their numbers are minimal compared to Whitewater Draw. Whitewater Draw draws the lion share of the valley's cranes for two basic reasons. First, the area has year round water and, second, the farmers in the valley are encouraged (paid) by the state to set aside a significant percentage of their cultivated acres as winter feed for these birds. Corn is the major grain in their diet but milo (maize), wheat, barley, and oats are also foraged. Alfalfa farmers consider the cranes pest birds and some use sound cannons to keep these federally protected birds at bay. Prior to the advent of big agribusinesses, it is thought that cranes fed primarily on the seedheads of wild native grasses. Cranes observed in cottonfields and other row crops are thought to be in the process of regrouping after being disturbed rather than feeding. They prefer open landscapes where their views are unobstructed for foraging. For this reason, they prefer harvested, trampled and disc-harrowed fields to taller standing crops. They prefer shallow water and avoid deeper watering holes with lush thick vegetation along the banks. Cranes are wary of human disturbance and always watchful for predators. Long distance viewing ability is essential to their survival and flocks understand strength in numbers. Diet - While their winter diets consist mainly of grains and other farmed crops, their diet in their breeding territories changes. Spring and summer diets are more varied in the ponds and marshes they occupy. They continue to eat seeds and grains whenever available but supplement this diet with a great variety of foods such as roots and tubers, berries, mice, lemmings, small birds, lizards, snakes, frogs, and grayfishes, which they break into small pieces by threshing them on the ground, then swallowing bit by bit. When foraging in open fields, tundra, grasslands and pastures they consume large quantities of earthworms, crickets, grasshoppers and beetles. On dry land they might wander as far as a mile, on foot, in search of these foods.
Traveling - The distance between their roosting sites and feeding sites is another important factor as cranes rarely fly more than ten miles to their feeding sites. Any particular foraging field is used by the flock up to several months or as long as the food supply holds up. Cranes are attracted to fields that already have others of their kind present and usually pass up similar fields without cranes. Most cranes roost considerably closer than ten miles. The cranes follow the exact same flight path each day. They forms lines or V-shaped formations in flight and usually fly at 25-35 mph speed. These birds communicate incessantly as they fly, and their unique, primitive-sounding creaks and grates are unmistakable. When seen, the callers are easily identified as they give directions and commands to the birds following them. No other birds fly in such ragged, extended formations with outstretched necks, spindly legs trailing behind a stubby tail, propelled by steady beats of large wings. Migratory cranes often fly thousands of miles between their breeding and wintering grounds. They may spend considerable time at staging areas socializing and fattening up before beginning the grueling migration. They usually begin migration several hours after sunrise, when the thermals begin to develop with the warming of the day. Most Sandhill Cranes fly at altitudes of 500-2,500 feet in migration, but have been noted to fly as high as 12,000 to 15,000 feet. Flying high in the thermals enables them to conserve energy by gliding, not flapping their wings. It also puts them high above the range of their major predator, the eagles. Once they've reached "cruising" elevation, they usually assume the familiar V formation and can glide about 500 miles in less than 10 hours. Young cranes need only accompany their parents once on a migration route before they know it well and use it the rest of their lives. Different Races - The majority of the cranes in Southeastern Arizona fall into three distinct races - the Lesser Sandhill cranes, the Rocky Mountain Greater sandhills, and the Canadian sandhills. Aerial surveys are the common method of counting populations. It is estimated that the Lesser Sandhills comprise as much as 60-80 % of the overall population. Greater Sandhills account for only 20-35% of the population, with the Canadian Sandhills accounting for only a few percentages of the overall totals. Once in a great while, a young Whooping Crane or two may be present among all the others as a result of inexperience in migration or strong winds blowing them off course. Family and Age - Sandhill Cranes do not normally form pair bonds until three years of age or older. It is thought that cranes are monogamous and mate for life. Both adults share in the nest-building and parenting of the young. Usually two eggs are laid but occasionally only a single egg or possibly three eggs are laid. Parent birds keep the babies apart much of the time as the first chick to hatch is usually more aggressive toward siblings. However, for a variety of reasons, an adult pair often ends up raising only one baby. Both adults and chicks can swim well. Young can fly well by the time they reach 3 months of age. Average age of cranes in the wild is hard to determine until further research is accomplished. One banded crane was found dead and the band information indicated it was at least six years old. It's thought that cranes in the wild can live to 12-15 years old. Cranes in captivity can live considerably longer when provided with a quality diet and ideal living conditions. At the National Zoo, in Washington, D.C., a Sandhill Crane lived 24 years, 2 months and 18 days.
Appearance - Males and females look alike, except females are smaller. These large, gray-brown have such long necks and legs that they stand chest-high. They have wingspans of 6 to 7.3 feet. Their bills are dark green. Their irises are yellow. The red cap that they wear is actually a patch of naked, red skin on their heads. In the spring, the cranes paint themselves with mud during preening. Mud coats their bills as they dig into the ground foraging, then is transferred to their feathers during preening. The mud contains iron oxide and stains their feathers a reddish-brown until their first molt in the summer. The juveniles are the same reddish-brown color as the painted adults, but lack the red cap. Instead, the heads of the young are covered with brown feathers. Cranes do bear a resemblance to herons, but there are a few pointers to help tell them apart in the field. In flight, cranes hold their necks straight out in front of them, with feet extending back beyond their short tail. Herons fold their necks and hold their heads close to their bodies. The calls of the two are distinctly different. Herons usually are silent in flight, but if they do call, it is with a honking note, or a low-pitched croak. Cranes are much more musically inclined. Their long, rolling hollow sounding call (garooooooooo ooooooooooooooooooooo) can be heard for well over a mile away. While flying, the cranes keep in constant communication by means of primitive-sounding creaks and grates. On the ground, cranes are usually found in flocks, quite often large flocks. Usually, herons are solitary creatures. The cranes overall grayish or grayish-brown coloration and their upright posture also serve to differentiate them from other wading birds. In Arizona, they are the only such bird to be seen feeding in open, cultivated fields.
Displays - In the spring breeding season, cranes perform a ritual mating dance. This is the most important visible component of courtship displays. Sub-adults and adult birds engage in this complex and dynamic dancing. Older adults that have long established relationships with their mates may only do a simplified version of this ritual or perhaps not at all. The dance consists of synchronized dips, bows, head swings, wing spreads, leaps, and flapping of wings. The birds occasionally pick up items off the ground and toss them into the air. This ritualistic behavior is an important component of courtship and is especially common among sub-adult birds that have yet to breed. It often occurs in the early morning hours and during spring migration. This dancing activity can spread contagiously through a flock, creating a spectacular show. Older, more mature birds, typically have an established relationship with their existing mates and dance less frequently as a result. Cranes also display a variety of aggressive behaviors that are used to defend breeding territories or feeding areas. Sometimes these aggressive displays are present in their dancing.
Habitats - Our wintering Sandhills need habitats for three purposes - for roosting, for loafing, and for feeding. They awaken from roosting before dawn. Around sunrise, or slightly before, they begin vocalizing. When the height of a long crescendo is reached, flocks of from 5 to 500 or more cranes take flight from their nighttime roosting site. They head directly out to cultivated fields, where they feed for 2 to 6 hours. Once satiated, they seek out a loafing site. At about 3-4:00 o'clock in the afternoon, they return to the fields for more feeding. Close to sunset, they start returning to the roosting site, although some late feeders may not straggle back until long after dark. Open shallow water or wet ground are the most desired roosting sites. Dry ground is rarely used, and they hardly ever stand in water more than 10 inches deep. Almost all the roosting sites in Arizona are on wet or damp ground, usually with no more than 3" of standing water. If you are observing a standing water roost, look for an adjacent landing platform. Cranes do not land directly on water, and they need a mud flat, or other suitable place, to touch down. Cranes also view low dunes and sandy banks as enhancements to a roosting site. When the cranes are loafing, people assume that they are feeding. This is not true. They just seem to be on an extended break. For loafing they usually prefer wet, grassy meadows with lots of marsh plants. If this is not available, they use fields of alfalfa and Bermuda grass, or even fallow or abandoned fields. Don't be tempted to approach cranes in daylight. They are likely to feel threatened and may abandon that area not to return. Cranes do not tolerate much human interruption in their daily lives. USE CAUTION WHEN APPROACHING A ROOSTING SITE!! - PLEASE! Never disturb roosting cranes! Roosting sites must offer unlimited visibility for the cranes and removed from human contact. This is of critical importance if you go to see them. Be sure to arrive well before sun-up. Position yourself, be quiet, and keep your movement to a minimum. They are extremely wary and have been known to abandon a site if they are harassed or disturbed. Best Location for Viewing - Whitewater Draw, between Bisbee and McNeal, is this month's newsletter birding destination. It is the single best location to observe these cranes close-up. Some folks still go to Willcox Playa (further north in the Sulphur Springs Valley) as it is a little closer to Tucson. The Willcox location rarely has water in winter months, fewer cranes are seen there each year, and one must have a spotting scope to observe them. At that site they usually flush at the first glimpse of a human, so longer distance viewing is the norm there. Years ago, when observing cranes at the playa, we found we could get much closer to the flock if we crawled closer, losing our upright human profile. It's difficult getting closer than a quarter of a mile to the cranes, so stronger optics than binoculars are required at that site. Whitewater Draw is more easily accessed, has year-round water of varying depths, has tens of thousands of cranes by December and January, and humans can get to within yards of the birds without disturbing them. So, naked vision, or binoculars, is all that's needed for satisfactory viewing. In addition, Whitewater Draw has a variety of habitat that the Willcox Playa doesn't have. Consequently, a much greater number of wintering species can easily be observed there. Experienced birders may be able to list as many as 50-60 species in a single morning without hiking or walking great distances. The Sulphur Springs Valley (from the Mexican border to north of Willcox) is one of best locations in the United States to observe winter raptors, including exotic species rarely otherwise seen in Arizona. The valley hosts many Golden Eagles (the major predator of cranes), merlins, harriers, falcons, buteos, accipiters, and several species of owls. A day trip to Whitewater Draw and the valley will be one of the best birding experiences one can have. It's important to arrive at Whitewater Draw BEFORE sunrise to have the most memorable experience of seeing Sandhill Cranes awaken, get noisy, and get into flying formations. When they take off in flight they will be just feet over your head. You'll never have a more intimate experience with cranes than what Whitewater offers. There are few experiences more humbling and awe inspiring than watching wave after wave of these large "prehistoric" birds pass closely overhead. If you plan to visit these wetlands, you can visit me at the store before your trip and I'll gladly provide some helpful hints to make your Whitewater visit as successful as possible. You may want to stay overnight in Bisbee (a delightful little historic mining town with ample overnight accommodations). Bisbee is only a short 15-20 minute drive to Whitewater Draw. Remember, birders from all over the country (and elsewhere) travel here to see the wonderful variety of common and exotic species that make Southeastern Arizona such a great hotspot. For further information, we freely make our reference library available to all our customers. All the following books, and more, are housed at The Wild Bird Store:
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Wintering Sandhill Cranes in Southern Arizona
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