展品:沙漠环形步道

On the 沙漠环形步道 you will have a rugged outdoor hiking experience. 这个环线有半英里长, downhill and back up where you will encounter javelinas, coyotes and 蜥蜴 in very naturalistic enclosures. Also along the way you will learn about the marvels of the agave plant and identify various legume trees native to the region.

Currently on exhibit around the 沙漠环形步道:

• 土狼
• 一种野猪)
• 蜥蜴
• 蓝色帕洛维德
• 仙人掌

土狼

The coyote is without a doubt the most famous desert animal, the very symbol of the west. He is prominently figured as the Trickster as well as the Wise One in Native American myths and legends. The coyote fascinates us with its intelligence and adapability. It can survive eating anything from saguaro fruit to roadkills, and is able to live in any habitat from cactus forest to the city. The coyote has expanded its range throughout the United States despite human attempts to eradicate it. 土狼不仅聪明, 好奇又好玩, it has very keen senses that adapt it for survival-acute hearing, 优秀的视觉, and an extremely sensitive sense of smell.

土狼 are mostly social animals, living in small family groups. Within the larger hunting area of a coyote family is a central core area where the den sites are located. This area is scent-marked and defended, particularly during the spring and summer months. 土狼 urinate on bushes or other plants, 然后用爪子刨地, 它们有气味腺体. This leaves both olfactory and visual markers for other coyotes. 粪便也被用来标记领土.

土狼 typically sing a "good morning" wake up song around dusk as they prepare for the night's hunt. They also sing to communicate with neighbors, 保持家庭成员的联系, 夏雨过后, 满月时, 看起来, 只是为了好玩.

一种野猪)

一种野猪) meander in loose groups, feeding as they move through an area. They dig up roots and bulbs with their sharp hooves or with their snouts. They eat prickly pear cacti, spines and all, by tearing off bites with their large canines. Because they don't have sharp cutting teeth, much fibrous material is left on the prickly pear. 贾维琳娜边走边嚼, so bits and pieces fall from their mouths, 有时会留下一条小路.

一种野猪) live in groups of 2 to 20 animals, the average being about 8 to 12. Each group defends a territory of about 700 to 800 acres, the size and boundaries varying in different seasons and different years; the territories include bed grounds and feeding areas, but they may overlap at critical resources, 尤其是水坑. An older, experienced sow leads the herd, determining when to bed down, feed, or go to water. 一种野猪) have no defined breeding season; the babies, usually twins, can be born in any month. Not many predators other than a mountain lion will attack an adult javelina, 但幼崽也是土狼的猎物, 山猫, 还有其他动物.

一种野猪) have poor vision, relying instead on their sense of smell.

蓝色帕洛维德

The green bark color of palo verdes is due to chlorophyll-bearing tissue. 许多其他物种也是如此, these trees conserve water by dropping their leaves during dry seasons, but palo verdes can still carry on some photosynthesis. Blue palo verde also drops its leaves in response to cool autumn temperatures.

The flowers are pollinated by numerous species of solitary bees that gather pollen and cache it in burrows for their grubs to feed on. The main palo verde bee is Centris pallida, but there are 6 other species of Centris that visit palo verdes, 除了汗水蜜蜂, 几只切叶蜜蜂, 大黄蜂, 还有木蜂. Bee specialist Bob Schmalzel casually identified about 20 different species of bees foraging in a single palo verde tree at the same time.

仙人掌

The huge green columns of saguaros have captivated the attention of nearly every tourist who has set eyes on one, 更不用说整片“森林”了. The United States has even devoted a national park to this plant. 仙人掌s are even more important to the O'odham peoples who have lived in their habitat for centuries. The high esteem O'odham have for saguaros is reflected in their many creation stories for this plant, which tend to share the common theme of people being turned into saguaros. These giant cacti are not plants to the Tohono O'odham; they're another form of humanity.

The saguaro is the largest cactus in the United States, commonly reaching 40 feet (12 m) tall; a few have attained 60 feet (18 m) and one was measured at 78 feet (23.8 m). The cylindrical stems are accordion-pleated; the ridges (outer "ribs") are lined with clusters of hard spines along the lower 8 feet (2.4 m) and flexible bristles above this height. White flowers are about 3 inches (8 cm) in diameter; they bloom mainly in May and June and are followed 一个月后由多汁的红色果实.

The saguaro's range is almost completely restricted to southern Arizona and western Sonora. A few plants grow just across the political borders in California and Sinaloa. 仙人掌s reach their greatest abundance in Arizona Upland. Plants grow from sea level to about 4000 feet (1200 m). In the northern part of their range they are most numerous on warmer south-facing slopes.

Water comprises most of the weight of the saguaro. A fully hydrated large stem is more than 90 percent water and weighs 80 pounds per foot (120 kg per meter).

The great, mostly aqueous bulk of larger plants protects them from temperature extremes. Heat absorbed through the surface during the day is stored in the mass of interior tissue, resulting in a fairly small temperature rise that doesn't reach a lethal level. The heat is slowly radiated and conducted back into the air during the cooler night. The same thermal inertia usually keeps the tissues above freezing on cold winter nights.

仙人掌s flower mostly near the stem tips during the dry foresummer; peak production is from mid-May to mid-June. The sturdy white flowers open late at night and remain open until midafternoon of the next day. They are about 3 inches (8 cm) in diameter and emit an aroma like that of overripe melon. The flowers are self-sterile; cross-pollination is necessary for fruit set.

The fruit ripens in tremendous abundance during the peak of the foresummer drought, and is nearly the only moist food available during this hottest, 一年中最干燥的时候. It becomes a staple for many birds, mammals, and insects during late June and early July. The primary effective seed dispersers are several species of fruit-eating birds, 比如白翅鸽, 毒蜥啄木鸟, 和家雀. The birds digest the pulp, and the seeds pass through their guts intact. Birds also tend to defecate while perched in trees, thus depositing the seeds in favorable environments for establishment.

Seedlings grow very slowly during their first few years and are extremely vulnerable. They are tiny, heat- and frost- tender, soft-spined canteens. 啮齿动物, 兔子, 鸟类会吃掉它们能找到的幼苗, and many others succumb to desiccation or winter freezes. Nearly all survivors are located beneath the canopies of nurse plants, where they are sheltered from weather extremes and concealed from herbivores. Most desert plant species-not only saguaros-must begin life under nurse plants. 布什杂酚油, bursage, and desert zinnia are among the few perennials that can successfully establish in fully exposed sites.

在图森山脉, which averages 14 inches (355 mm) annual rainfall, a saguaro takes about 10 years to attain 1¼ inches (3.8 cm) in height and 30 years to reach 2 feet (61 cm). 仙人掌s begin to flower at about 8 feet tall (2.平均需要55年的时间. Compare this with 40 years to first flowering in the wetter eastern unit of 仙人掌 National Park (16 inches, 406 mm, average annual rainfall) and 75 years in the drier Organ Pipe Cactus National Monument (9 inches, 230 mm). No one has studied the populations near Yuma, which receive about 3¼ inches (90 mm) average annual rainfall.

仙人掌s may begin to grow arms when the plant is between 50 and 100 years of age (in the Tucson Mountains), usually just above the stem's maximum girth at about 7 to 9 feet (2.1 to 2.距地面7米. The number of arms and overall size of a plant seem to be correlated with soil and rainfall. 仙人掌s在bajadas和finer上, more water-retentive soils tend to grow larger and produce more arms than do those on steep, 岩石山坡上. A few saguaros have been observed with as many as 50 arms; many never grow arms. 天龙的手臂总是向上长. The drooping arms seen on many old saguaros is a result of wilting after frost damage. The growing tips will turn upwards in time. There is a myth that arms are produced so as to balance the plants, but research shows arm-sprouting to be random. Many saguaros can be found with several arms all on the same side of the main stem.

仙人掌s make excellent nesting places for many birds. The primary nesting associates are Gila woodpeckers and gilded flickers, both of which excavate nest holes in the fleshy stems. The plant seals the wound with scar tissue called callus, which quickly becomes very hard and impervious to microbial infection.

Woodpeckers usually excavate new nesting holes each year. Several other hole-nesting but non-excavating birds occupy abandoned woodpecker nests, 包括猫头鹰精灵, 房子雀, ash-throated霸鹟, 还有紫色的海燕. 无脊椎动物也栖息于其中.

Larger birds such as red-tailed hawks build nests in the angles between the main stems and the arms. Tall saguaros also make good hunting and resting perches for many birds. Cactus wrens sometimes nest among the arms or, less often, in a woodpecker cavity.

Fallen saguaros become homes for many small animals. 蛇, 啮齿动物, 蜥蜴, and inverteb利率 find shelter beneath and within them, until the community of reducers and decomposers completely recycle the remains.