Sonoran Desert

Pima Pineapple Cactus recovery

The Pima Pineapple cactus (Coryphantha scheeri var. robustispina) is a small (pineapple-sized) cactus that inhabits grasslands and desert scrub in Pima County and parts of Santa Cruz County, Arizona, and parts of northern Sonora, Mexico, at elevations below 4,000 feet. About 90 percent of its historic range is in Pima County.

The cactus is sparsely distributed within its range, but does have some high-density clusters. According to the U.S. Fish & Wildlife Service (FWS) this species is incapable of self-fertilization, which means pollen from another individual cactus is required.

The Pima Pineapple cactus is a low-growing hemispherical cactus that may be found as single or multi-stemmed plants. Mature plants measure 4-18 inches tall and 3-7 inches in diameter. The spines are stout and arranged in clusters with one central hooked spine and 6-15 radial straight spines. Spines are originally straw colored, but become black with age. Flowers are yellow and the fruit is a green ellipsoid. See photos here. The flowers are pollinated mainly by bees. Seeds are dispersed by rodents, rabbits, and ants.

Because the cactus is small and inconspicuous, it is subject to danger from grassland fires, livestock grazing, off-road vehicles, and housing development.

The Pima Pineapple cactus was listed as endangered by FWS on September 23, 1993. FWS never got around to establishing “critical habitat” but now is proposing a recovery plan which you can read here (76 pages). If we follow the plan, which will cost $62,910,560, FWS says they can delist the cactus by the year 2046. There have been many studies of the cactus, but FWS still doesn’t know how many there are scattered around its habitat.

The main recommendations of the recovery plan boil down to protecting existing habitat from human intervention, invasive species, and wildfires. In other words, restrict land usage. FWS also recommends acquisition of private lands to increase habitat and limit development.

The plan recommends monitoring the cactus for at least 15 years. It so happens that Buenos Aires National Wildlife Refuge (BANWR) established in 1985, comprising 117,464-acres, lies in southern Pima County within the range of the cactus. Has not the FWS been paying attention to the cactus on the Refuge during the past 25 years?

Ironically, management of BANWR may have caused the population of the cactus to plunge. When BANWR was established, they removed all cattle. The result was that the grass grew taller which promoted more damaging wildfires which damaged more cactus. Tall grass also discouraged jackrabbits which are the primary agent of seed dispersal. In tall grass, jackrabbits can’t run fast enough to escape predators.

I have an alternative suggestion. In order to preserve the cactus, delist it and farm it. Buenos Aires National Wildlife Refuge could be used as an initial farm stock source with many plots dedicated to the cactus. FWS could, if the cactus were delisted, allow commercial nurseries to grow and sell the plants to people who would like them for their yards or gardens, something that is problematical as long as the cactus is listed as “endangered.” This small cactus would make a good potted plant for porches and patios.

See also:

The Flaws in the Endangered Species Act

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The Tiny Common Ground-Dove

 

The Common Ground-Dove (Columbina passerina) is about the size of a sparrow with a body length of six to seven inches and a wingspan of 10 inches. It is the smallest dove in the U.S.

This dove occurs along the southern border of the U.S. from California to Florida. Its range includes Mexico, parts of Central America, Caribbean islands, and northern South America.

“Common Ground-Doves are sandy brown overall, with large, dark spots on the wing coverts. In flight the wings show rich rufous patches. Males have a pinkish wash on the head, neck, and chest, and bluish crowns; females are duller. Both sexes have fine, dark scaling on the neck and chest, and pinkish-red bills with a dark tip. Common Ground-Doves live in open or shrubby areas with tall grasses or groves of trees, including riparian corridors and open savannas. They also live in towns and suburbs, where they frequent yards and hedges.” (Cornell) The male is pictured above. See more photos here.

Ground-Doves eat primarily seeds from grasses and weeds. They may eat as many as 2,500 seeds every day. They also eat berries, insects, and snail shells (for the calcium to produce “crop milk” for nestlings).

Both male and female build the nest, usually a depression in the ground lined with grasses. They also nest in shrubs and trees. The male and female share incubation duty (12-14 days) and both feed the nestlings until they fledge (11-14 days). Normal clutch size is one to three eggs.

According to Cornell, “During the day Common Ground-Doves spend time on the ground searching for seeds and roosting. They may also roost in trees or shrubs at any hour of the day or night. They nod their heads as they walk, often holding their tails slightly elevated, and they usually make short, low, and direct flights. When startled they can quickly burst into nearby cover, but they are not a very anxious bird—allowing humans to get very close without appearing bothered.” Listen to their cooing sound here.

See also:

White-winged Doves

Mourning Doves

Inca Doves – small and surprising

Eurasian Collared-Doves

 

Inca Doves – small and surprising

The Inca Dove (Columbina inca) is a small dove with a body length of about 8 inches. It is smaller than a Mourning dove and the White-winged dove. The Inca Dove’s color is light brownish gray and has a scaled appearance on its back. The tail is slender and has white sides. At rest, this dove is very dull looking. That changes in flight or when the dove is displaying. Then the bright rufus-colored primaries on the underside of the wings are visible. Male doves use the display of raising one wing over their backs to defend their territory against other males.

During courtship, the male bobs its head, raises its tail high over back and spreads it widely to show off black and white markings.

Inca doves occur in the southwestern U.S. and most of Mexico. They are found around human settlements throughout much of the Sonoran Desert region. They seem to prefer open areas with sparse shrub cover and scattered trees such as palo verde and oak.

They are seed and fruit eaters. Doves grind seeds in their muscular stomachs (or gizzards) using sand or gravel much like internal teeth.

According to the Arizona-Sonora Desert Museum, “The Inca Dove has the longest breeding season of any Arizona bird: January to November. That fact, plus its preference for grass and weed seeds, have made the Inca Dove the most abundant bird in southwestern urban areas, after the house sparrow.”

According to Audubon, Nest sites vary, usually in trees or shrubs 5-20 feet above ground, sometimes as high as 50 feet. Nests (built by female, with material gathered by male) are a small platform of twigs, stems, leaves, sometimes lined with grass.

Both parents incubate the eggs for about two weeks. Upon hatching, the chicks are fed “pigeon milk” produced by both parents. “Both males and females produce this substance in their crops (the pouch just above the stomach that birds use to store food). The walls of the crop swell with fat and proteins until the cells in the crop wall begin shedding, producing a nutritious, milky-colored secretion. Despite its appearance, it’s not related to the milk produced by mammals.” – (Cornell)

The chicks fledge within two weeks of hatching and may be tended by the parents for another week or two.

Inca doves have a distinct sound. Listen here. Do you recognize it?

See also:

White-winged Doves

Mourning Doves

Eurasian Collared-Doves

Black-bellied Whistling Ducks

Black-bellied Whistling ducks (Dendrocygna autumnalis) range from southern Arizona, south Texas and Louisiana, through parts of Mexico and Central American to Brazil. Their range is expanding northward.

These large ducks (body length about 22 inches, wingspan 37 inches) are reddish brown, have a black belly, white wing patches, and a pink to orange bill. They are long-legged, long-necked, and are sociable and noisy. The Cornell Lab of Ornithology describes them as “boisterous.”

My own experience with these ducks is confined to the mixed-species aviary at the Arizona-Sonora Desert Museum. Often, a gang of these noisy ducks will follow me around, pecking at my legs and attempt to untie my shoelaces.

Whistling ducks can be found in marshes, ponds, and lakes where they feed on aquatic animals such as snails. Their main diet, however, consists of seeds and grains. Whistling ducks frequent grasslands and agricultural areas where they feed on many agricultural crops including sorghum, millet, corn, rice, and wheat. They also eat insects and spiders.

Whistling ducks are casual about nesting. According to the Cornell Lab of Ornithology: they usually nest in tree hollows where a limb has broken or the trunk has rotted away. They typically don’t build a nest; they lay their eggs directly on whatever debris has collected there. Cavity openings range from 5–12 inches across. When nesting on the ground, they make a scrape or a shallow bowl of grasses, with thick vegetation overhead, such as willow, mesquite, or cactus. They typically lay 9 to18 eggs which are incubated for 25 to 30 days. Hatchlings are nearly independent upon hatching.

About the noise. Whistling ducks do not make the “quacking” noise of other ducks. Rather they have a range of sounds. Listen here.

According to ASDM, United States populations are increasing, probably because of nest boxes. This species was rare in Arizona before 1949 but has since become a rather common nesting bird.

Stingrays in the desert

You probably don’t think of stingrays when visiting the desert. However, several species of stingrays inhabit the Gulf of California which is part of the Sonoran Desert. Last October, the Arizona Sonora Desert Museum opened a new exhibit featuring cownose stingrays. At the Museum, the stingers have been clipped. The exhibit allows the sting rays to touch you (rather than you touching the rays). They feel like wet velvet. The skin of a ray is covered by tooth-like structures (called dermal denticles) instead of scales like fish.

Rays are bottom feeders. “Besides gills, rays have an extra adaptation to help them breathe while resting on the bottom of the ocean. These special openings, which are near their eyes, are called spiracles. Instead of sucking sandy water in through their gills, they can pull clear water in through their spiracles. They then push the water out through their gill slits.” (ASDM)

Stingrays (skates and ratfishes) are close relatives of sharks and evolved from sharks about 200 million years ago during the Jurassic Period. Like sharks, rays have a cartilaginous skeleton rather than hard bones. In rays, the front fins have expanded around the head to form a pectoral disk that act like wings. Most rays are marine animals, but some have evolved to tolerate brackish and fresh water.

Differences between bony fish and rays (info from Arizona Sonora Desert Museum):

Bony fish have a bony skeleton, overlapping ganoid, cycloid or ctenoid scales, a gill opening covered by a bony plate called an operculum, flexible pectoral fins, a swim bladder and internal fertilization. The operculum allows fish to actively pump water over their gills. Having flexible pectoral fins made up of fin rays allow bony fish to be more maneuverable, navigate tight spaces, and the ability to turn around. A swim bladder is a gas filled organ that helps control the buoyancy of a bony fish.

Sharks and rays a cartilaginous skeleton, tooth-like scales called dermal denticles or placoid scales, five to seven pairs of gill slits, no swim bladder, very large liver, fixed pectoral fins, spiral valve intestine, specialized electroreceptors called the ampullae of Lorenzini, and internal fertilization. Since cartilaginous fish lack a swim bladder for buoyancy, they have a significantly enlarged liver filled with oil called squalene that helps them float.

The following photos and information, from the Arizona Desert Museum, shows the rays which inhabit the Gulf of California. Visit the museum and be touched by a ray.

 

The Cactus Mouse – another creature of the night

cactus-mouse-nps

The Cactus mouse (Peromyscus eremicus) is one of eight species in the genus Peromyscus that inhabit Arizona. All are similar-looking grayish-brown, with white bellies and feet, and large ears. They are about 3.5 inches long. The cactus mouse has a sparsely furred tail with a slight tuft at the tip. “Females weigh slightly more than males and are significantly larger in body length, ear length, length of mandible and bullar width of skull. Cactus mice can be identified by having naked soles on their hind feet, and almost naked tails which are usually the same length or longer than the animals body length.” (Source)

The Cactus mouse ranges from southern California and Nevada, through southern Arizona and New Mexico, west Texas into northern Mexico. They are common in washes and rocky hillsides, in sandy deserts and desert foothills. Depending on location, they may breed throughout the year. A female may produce 3 to 4 litters per year, each with 4 to 5 young.

cactus-mouse-range

Cactus mice are nocturnal feeders. They eat seeds, fruit, and succulent plant material. Their diet includes mesquite beans and leaves, and insects. During the day they remain in burrows in clumps of cacti, in the ground, or among rocks. Their nests are usually a ball of grasses or twigs.

According to the Arizona-Sonora Desert Museum:

“The cactus mouse often climbs around in vegetation and brush, searching for seeds and fruits to eat. It may nest in wood piles or rock piles, or use the abandoned burrows of other animals. Although this mouse needs less water than many others and is desert-adapted, it may estivate or go into a torpor in the summer when resources for food and moisture are not available.”

“These little rodents are at the bottom of the vertebrate food chain, preyed upon by everything from coyotes and snakes to hawks and bobcats. In response, they breed prolifically, with some species, like the cotton rats, able to produce eight to ten litters a year. Populations still fluctuate with drought and predation, but the mice and rats are able to respond to good conditions by rapidly rebuilding their numbers.”

“All rodents, including the mice and rats, are gnawers. Their teeth are ever-growing and must be kept trimmed down by constant gnawing. A layer of hard orange enamel covers the front surface of the teeth. The rest of the tooth is softer and wears down quicker than the enamel as the rodent gnaws, thus creating a chisel-like shape to the front teeth that is unique to the rodent family.”

Other desert rodents:

Creatures of the night – Pocket Mice

Ferocious Grasshopper mouse

Kangaroo rat

Pack Rats are Desert Archaeologists

 

 

 

 

 

 

 

Eurasian Collared-Doves

eurasian-collared-dove-6

Have you seen this bird? Collared doves have been showing up in my backyard for the past few years. They flock with other doves and I rarely seen more than one collared dove at a time.

The Eurasian Collared-Dove (Streptopelia decaocto) is about 12 inches long and has a wingspan of about 14 inches which makes it larger than a Mourning dove and about the same size as a White-winged dove.

According to the Cornell Lab of Ornithology:

“Eurasian Collared-Doves made their way to North America via the Bahamas, where several birds escaped from a pet shop during a mid-1970s burglary; the shop owner then released the rest of the flock of approximately 50 doves. Others were set free on the island of Guadeloupe when a volcano threatened eruption. From these two sites the birds likely spread to Florida, and now occur over most of North America.”

Eurasian Collared-Doves eat mainly seeds and cereal grains. They will occasionally eat berries, plant greens, and bugs. Their principal habitat appears to be urban and suburban areas, especially where people put out bird feeders. They may also occur on farms.

“Mainly ground foragers, they peck at grain and seeds scattered beneath backyard feeders and on feeding platforms, or spilled at farmyards. Flocks of 10 to several hundred doves may gather at prime spots. Although they can feed peacefully in mixed flocks, Eurasian Collared-Doves will also chase off other birds, including Mourning Doves, cardinals, and Blue Jays.” (Cornell)

Nesting (source, Cornell):

“The male dove brings the female twigs, grasses, roots and other nesting materials, which he sometimes pushes directly under her. Over 1 to 3 days she builds a simple platform nest, which may include feathers, wool, string and wire. A pair often uses the same nest for multiple broods during the year, and may renovate old nests.

“Males show females potential nest sites in trees and on buildings, giving a low- pitched, slow koo-KOO-kook call at each site (listen here). Nests are usually built 10 or more feet above the ground. In warmer regions, Eurasian Collared-Doves can nest year-round, which may help explain their success as colonizers.”

“Eurasian Collared-Doves are one of very few species that can drink “head down,” submerging their bills and sucking water as though drinking through a straw. Most birds must scoop water and tip the head back to let it run down into the throat.” (Cornell)

Eurasian Collared-Doves may be mistaken for Ringed Turtle Doves which are slightly smaller and lighter in color. According to the Sibley Guide to Birds, the Ringed Turtle Dove is a domestic variety, not a naturally occurring species, and it fares poorly in the wild.

See also:

Mourning Doves

White-winged Doves

Black-necked Stilt

black-necked-stiltThe Black-necked Stilt (Himantopus mexicanus) is a fun bird to watch as it noisily feeds along shorelines. (Listen to sounds). This Stilt occurs in the southern and western U.S. Its range includes the Great Basin, Sonoran and Chihuahuan deserts near bodies of water. The Sonoran Desert, south to the tip of Baja, California Mexico, is within its year-round range. You can see some at the Arizona-Sonora Desert Museum where I took the photograph.

black-necked-stilt-rangeThe Black-necked Stilt stands about 18 inches high and has a wingspan of 28 inches. It has a black head, neck and back over a white body. Its bill is long and black. One of its most striking features is its very long, red/orange legs. “ They have the second-longest legs in proportion to their bodies of any bird, exceeded only by flamingos.” “Five species of rather similar-looking stilts are recognized in the genus Himantopus.” (Source)

Stilts forage, often in groups, in shallow water or along shorelines for insects and other prey. Cornell Lab of Ornithology adds: “Black-necked Stilts wade in shallow waters to capture their meals of aquatic invertebrates and fish. They often consume such fare as crawfish, brine flies, brine shrimp, beetles, water boatmen, and tadpoles. They peck, snatch, and plunge their heads into the water in pursuit of their food, and will herd fish into shallow waters to trap them there.”

According to ASDM: “These are ground-nesting birds, whose eggs are well camouflaged and whose downy chicks can run about and find their own food shortly after hatching. Adults defend eggs or chicks with a repertoire of distraction displays. These birds are good runners and strong flyers.”

According to Cornell: “Male and female Black-necked Stilts trade off the job of constructing the nest. While one mate observes, the other scrapes into the dirt with breast and feet to form a depression about 2 inches deep. As they dig, they throw small bits of lining over their back into the nest. Most lining is added to the nest during incubation, and consists of whatever material is closest to the nest, including grasses, shells, mud chips, pebbles, and bones.” “ During breeding and during winter, they are strongly territorial birds, and are particularly aggressive to chicks that are not their own. When not breeding, Black-necked Stilts roost and forage in closely packed groups, often staying within a foot of each other. Black-necked Stilts are semicolonial when nesting, and they participate en masse in anti-predator displays. The displays include one in which nonincubating birds fly up to mob predators, and one in which all birds encircle a predator, hop up and down, and flap their wings.”

A more general note on shorebirds from ASDM:

Shorebirds in general do most of their foraging along the water’s edge, probing in soft mud or picking at the surface in search of tiny invertebrates. They belong to several related families. The largest shorebird group is the sandpiper family (Scolopacidae); nearly two dozen species of sandpipers migrate through the Sonoran Desert, but for the most part their presence with us is fleeting, a few days’ stopover as they travel between breeding grounds on Arctic tundra and wintering grounds on southern coasts. More relevant here are two long-legged waders and one plover that are with us for much of the year.

The avocets and stilts make up a small family, with only a few species worldwide. All are slim birds with long necks, thin bills, very long legs, and striking patterns. All forage in shallow water, feeding on small invertebrates. North America has one avocet and one stilt. Both have ranges which extend into the Sonoran Desert, where they seem to have benefited from human activity; most of their modern nesting sites are around the edges of artificial ponds.

Matilija poppy (fried egg plant)

The Matilija poppy (aka the fried egg plant), Romneya coulteri, is native to southern California and northern Mexico. The shrub, itself, can get up to 8 feet tall, and the flowers are upto 8 inches in diameter.

They are called “fried eggs plants” because the flower has an intense yellow center in a field of crinkled white petals. The plant is also known as a “fire follower” because it frequently establishes itself in recently burned areas. The California Native Plant Society claims that seeds will not germinate “unless they have experienced the flash heat of wild fire.”

Matilija poppy

The plant is a perennial that prefers sunny locations and good soil, but will grow in clay, and in dry, rocky soil. The flower has an apricot-like scent. Individual flowers last several days, then form seed pods that resemble a bird cage.

The foliage consists on blueish-gray to green, deeply lobed leaves that have a leathery texture. The base of the stems often become woody with age. The plant acts as a semi-shrub, spreading by rhizomes year by year until large clumps are formed.

The flowers bloom from late Spring through late Summer. You can see some at the Arizona-Sonora Desert Museum. (See more photos here.)

Planting the Matilija poppy in a garden is apparently hit or miss. According the an article in the Los Angeles Times: “If a Matilija poppy doesn’t like where it’s planted, it will promptly wither and die. If it does like the location, then after a modest first season, the Matilija can proceed to colonize a garden. Success can be uneven.” According to another California source, Growing Native, “This plant has idiosyncratic and unpredictable needs. It will sulk and die in what you would think would be a perfect place, and thrive gloriously in an apparently unsuitable one.”

A tincture or tea made from this plant has been used externally for skin inflamation due to allergies or sunburn. This concoction is also reputed to have antimicrobial properties. (Source).

Sphinx Moths

Sphinx moth adult

Sphinx moth caterpillar

Sphinx moths (also called hawk moths and hummingbird moths) belong to a large family, Sphingidae, with about 1450 species. These are large moths with wingspans up to six inches.

Most common in the Tucson area is the White-lined sphinx moth (Hyles lineata) which has a wingspan of up to 5 inches and a body length of up to 3.5 inches. Its range extends from Central America, throughout the U.S. and into southern Canada. These moths are often mistaken for hummingbirds at first glance because they are about the same size and behave much like hummingbirds. They are fast flyers and can hover at a flower to sip nectar with their very long tongues; and they can fly side-to-side, and backwards. These moths are mainly nocturnal but may be about during daylight hours. The first generation adults appear in mid-May, with subsequent generations appearing throughout the summer. See good close-up photos of the adult moth and caterpillar here.

Life cycle:

Adults females lay eggs generally on the underside of leaves upon which they feed. The eggs hatch into the larval stage – caterpillars. The sphinx moth caterpillar, which can be up to 5 inches long, is generally bright green with dark spots, but it can also be almost completely black or striped yellow and brownish. It has a large (harmless) hook on its back end similar to a tomato “hookworm.” According to DesertUSA, the name “sphinx moth” derives from the behavior of the caterpillar. “When alarmed, these larvae rear up their heads in a threatening sphinx-like posture and may emit a thick, green substance from their mouths.”

To complete pupation, the caterpillars dig burrows. Pupation can last from two weeks to several months depending on species and conditions. The adults moths dig themselves out from underground and may mate soon thereafter. According to DesertUSA, “In the Sonoran and Chihuahuan deserts, there may be two broods, one in the spring and another in summer. In the colder Great Basin desert, only one brood is produced.” In some species, if pupation begins in the Fall, it will last all winter with adults emerging in the Spring.

The moths feed exclusively on nectar and seek out flowers which have large supplies. This includes the evening primrose (see my ADI primrose article and a photo of the long tongue of a sphinx moth.) Some species can be harmful to crops.

According to a study at the University of Arizona, the Tohono O’odham would harvest the caterpillars, dry and braid them and use them as food. The study says that the caterpillars are not poisonous, but warns that eating too many will result in an upset stomach. (It doesn’t say how many are too many.)