White-crowned Sparrow

Lately I’ve noticed flocks of these striking birds foraging on the desert floor, and singing in trees. White-crowned Sparrows hop around, kicking at the soil, uncovering seeds to eat. During breeding season in spring and summer, they establish and defend territories, hunting insects, caterpillars, wasps, and beetles, for themselves and for their young.   

White-crowned Sparrows are famous for their dialects, common songs that vary slightly depending on where they live. Young males learn the local songs from other males in the neighborhood when they are just 2-3 months old. Females also sing, but their songs are more limited and related to defending breeding territories and feeding grounds.

A White-crowned Sparrow’s song is key to its survival, helping to attract mates and to defend nesting territories, with a particularly vigorous song warning off other males. Dialects of White-crowns are quite distinct – imagine a Southern drawl or a Yankee twang, and the boundaries between dialect areas are sharp. Sometimes a particular White-crowned sparrow dialect is only learned by males within a several mile area, and the sparrows just on the other side of this sparrow defined boundary sing a slightly different song. Birds that live in the middle usually learn both dialects.

These distinctive dialects make the sparrows prime candidates for many types of scientific studies. Using digital recordings of White-crowned Sparrows’ songs recorded over many years, scientists report that birds in urban areas are evolving to sing at higher frequencies so as to be heard over city noise.

This sparrow can be found across the North American continent, generally breeding in the far north and wintering in southern areas.  Some stay in place all year, others undertake long migrations. White-crowned Sparrows that breed in Alaska migrate 2600 miles to winter in Southern California.

To hear the song of the White-crowned Sparrow click the link below.

https://www.allaboutbirds.org/guide/White-crowned_Sparrow/sounds

Singing White-crowned Sparrow at South Mountain

Prehistoric Insect

Orange Skimmer

Dragonflies are among the most ancient creatures alive today. Fossils of dragonflies date back to 300 million years ago, 100 million years before dinosaurs appeared on the planet.

The dragonfly hunts on the wing, capturing prey in basket traps formed by dangling, haired legs. Patrolling the edges of streams and ponds, males hunt, guard their territories and look for mates. Females hunt, receive mates and lay millions of eggs.

The aquatic juveniles hatch and grow in streams, ponds and marshes. They feed on small invertebrates, small fish and even tadpoles. Dragonfly nymphs breath through internal gills.

The juveniles live underwater for a year or longer, expanding in size and developing adult features through a series of molts. There will come a day when the nymph gorges with water and climbs out of the water, onto a rock or up the stem of a plant. The exoskeleton splits open and an adult emerges, without gills and with two gigantic eyes. The dragonfly hangs in place as new legs, wings and a long slender abdomen slowly dry and harden. Then it lifts into the air, reborn as a superbly designed flying machine.

Dragonflies are among the fastest flying insects. They are highly maneuverable, able to fly forwards, backwards, hover and turn 180 degrees. Two sets of wings beat in opposite directions, enabling remarkable feats of aerodynamics. 

Enormous eyes provide exceptional vision and allows them to avoid predators. More than 80% of the dragonfly brain is used in analyzing visual data gathered by the compound eyes. Yet for all of their incredible adaptations, adult dragonflies live only a few weeks.  In late fall they all die, while underwater the nymphs eat, grow, and prepare to take to the wing.

Look for dragonflies where there is water and sunlight

A Teapot of Towhees

Abert’s Towhee is a shy but engaging bird. This member of the sparrow family has one of the smallest ranges of any bird species, making it a prize sighting for birders; and a familiar face for desert dwellers. 

Secretive Abert’s Towhees are described in field guides as residents of thick brush in Sonoran riparian corridors, usually cottonwood and willow woodlands along rivers and streams. Yet a pair of Abert’s hangs around our back yard, kicking and pecking on the ground for insects and seeds. They shelter in the creosote and chuparosa, and sip water trickling from the cement lip of our fountain. 

The native waterways that make up Abert’s Towhee’s traditional range have mostly dried up. Growing demands on ground water have brought Arizona’s desert streams to a nonexistent or strictly ephemeral status.  Water collects in these channels after rains, but lately the amount is insufficient to bring the water table up to the surface level of the stream beds.  Suburban yards, particularly those planted with native species that attract insects and produce seeds, have proven to be havens for these displaced song birds. 

Abert’s Towhee is a homebody. He keeps to a small home range and mates for life.  In a romantic ritual, the male woos the female by feeding her seeds and the two sing duets together. Throughout the year towhee pairs forage together, calling to each other often, always strengthening their bond. The female weaves a large open cup shaped nest and decorates the outside with flowers. She lays 1-4 eggs, often raising two broods. 

Did you know if you see a group of Abert’s Towhees together you can claim you’ve seen a tangle of towhees? Or if it seems appropriate, a teapot of towhees works too. 

Hosting Hummers

The desert plant Chuparosa grows in both our front and back yards, bringing in a resident population of Costa’s hummingbirds. Costa’s is the only true Sonoran Desert hummer, well adapted to the arid environment. Hummingbirds lap nectar from tubular shaped flowers using long beaks and tongues. They also eat soft bodied insects, gleaning their small prey from foliage or seizing them in midflight. 

A hummingbird beats its wings 80 times per second, flying forward, backward, up, down and sideways. The active heart rate of this tiny being is 1260 beats per minute. This racing metabolism requires the bird to feed nearly constantly to survive. 

The key to the gorgeous iridescent colors of a hummingbird is found in the cellular structure of the feathers. The light absorbing and pancake shaped “melanosomes” within the cells of feathers are filled with tiny air bubbles that create a multitude of surfaces.  When sunlight glints off these surfaces we see the shimmering colors.

Males wear the dazzling pigments to attract females of course, and these flashy guys also put on astounding flight displays in breeding season. The Costa’s male loops 75 to 120 feet up into the sky, and rockets down at 60 mph, adding a whistling call to the descent, all to impress the watching female. After he has secured her attention and after the pair have mated, he moves on. The female builds her nest, incubates the eggs and raises the young on her own.

Costa’s hummingbirds nest early in the desert to take advantage of winter blooming plants such as the Chuparosa. In February the female begins collecting spider webs and binding together her walnut shell sized nest. She weaves small stems, leaves, bits of bark, and feathers into a cozy receptacle for her two bean sized eggs. The spider webs ensure the nest is stretchy enough to accommodate two rapidly growing nestlings. 

Although the most arid adapted of all hummingbirds, the Costa’s that visit our yard drink frequently from the trickling water of our fountain.

Male leans in to access lavender bloom
Chuparosa blooms winter to spring
Male Costa’s Shows Amethyst Colors

Strange and Lovely

Photo from Allaboutbirds

In summer when I walk along the desert washes, I’ll often spook a Lesser Nighthawk. The startled bird lifts silently in strange, buoyant flight, more like a butterfly than a bird.

But then this is a most unusual bird. Nighthawks hunt at dawn and dusk, soaring low across the landscape, scooping up insects. Unfortunate bugs are inhaled from the air and trapped by small hairs that line the gaping mouth.

When not hunting Lesser Nighthawks hide in plain sight, sitting on the ground or sideways on a horizontal tree branch, completely concealed by their cryptic coloring. 

Lesser Nighthawks are among the very few birds known to hibernate. They typically migrate south in winter, but they have the ability to slow their heart rates, temperature and respiration to a near stop for days and even weeks to survive. At the other extreme, when the weather is too hot for even resting in the shade, the bird turns into the breeze and open its wide mouth, making a passive cooling system. 

Out walking in the early morning I’ve heard a low-pitched sustained trill – the mating call of the male Lesser Nighthawk. It’s eerie and beautiful. The bird also calls with a whinnying laugh. 

The female lays her two eggs on the bare ground, and conceals them with her own mottled grey and brown body. She moves the eggs as needed, rolling them to shade or a safer hiding place.  Her nestlings are born with eyes open and covered with a fine down.  They will walk in a day or two, but won’t fly or feed themselves for several weeks. 

Hear the calls of the Lesser Nighthawk:  https://www.allaboutbirds.org/guide/Lesser_Nighthawk/sounds

Photo from Allaboutbirds

A New Face

Hopping around in our backyard, with his tail held high, was a bird I had never seen before.  His cap of rust red was fluffed up in a slight topknot, creating a jaunty aspect.  On his face showed two striking white lores (mustaches) and a white throat. 

Who was this visitor?  His shape reminded me of a towhee so I started there in my bird guide.  Yes, it is a Green-tailed Towhee, a beautiful little bird.

Generally found in arid brushy habitats, this is a member of the sparrow family.  Green-tailed Towhees are said to be shy and secretive, so this was a particularly brave individual, coming right into the open.  These towhees forage for seeds and insects, scratching at the soil and leaves beneath dense shrubs. 

In courtship the Green-tailed Towhee male bows to the female, drooping his wings, with his tail pointed straight up.  He offers her a bit of nesting material.   If she accepts his proposal, she builds a carefully hidden nest in dense foliage, quite low to the ground.  She brings twigs, stems and grasses for the outer nest, and lines the inner cup with small roots and hair.  According to All About Birds, the Cornell Lab of Ornithology website, horse, cow, and even porcupine hair has been found in Green-tailed Towhee nests. 

In winter these beautiful towhees will flock with other sparrows, finding safety in the larger groups from predators such as hawks and falcons.

Coyote Calling

As it weaves through the landscape, only the movement of the coyote catches your eye.  Otherwise these intelligent wild dogs blend perfectly into the desert habitat. They also blend into cities and suburbs, where they hunt in parks and greenbelts.  Living invisibly right outside of our awareness, coyotes make a career of finding food to survive.   

One source claimed a desert coyote’s diet to be 40% plant matter – dried seed pods of mesquite or ironwood, as well as cactus pads and grasses.  Coyote hunts cottontails and jackrabbits, the entire range of rodents, snakes, quails, and is not above munching up insects and even carrion. This may sound like a desperate character, but coyote has a bold stare, and trots along with a devil may care attitude.  Coyote’s “trickster” reputation is well earned.    

I’ve looked up on several hikes to find the yellow eyes of a coyote observing me from a ridge, or a rocky shelf.  The stare is wary and at any moment the coyote will turn and vanish.  A coyote pup materialized out of the predawn darkness at the schoolground where I’d taken my shepherd for a run.  He tried to instigate play.  Some say this is a trap, the single coyote leads your beloved pet into the desert where the rest of the family waits to pounce. But it seemed to me like this pup was simply curious about my white, coyote-shaped dog. 

Coyotes mate for life and pups from a previous brood often stay on for another season, helping to hunt for the new babies before striking out on their own.  Desert coyotes are about half the size of other coyotes, at 20 pounds or so, and their coat is shorter, thinner, allowing for heat to more easily dissipate.

Coyotes yip, bark, whine, growl and howl, as well as using non-verbal cues like tail wagging, lip curling and scent marking.  Put into a range of combinations, the sophisticated language facilitates a layered social structure involving group activities from hunting and courtship to play.  Hearing coyotes howl at night is one of my favorite things about the desert.  Our dog Lexie used to raise her rounded lips to the heavens and howl right along, making sure we never missed a serenade. 

On a hot August morning this coyote lay down to wait and see what I would do

Summer Heat Relief

After enduring 50 days of 110 degree plus temperatures, it seemed like a good idea to head to higher ground.  The elevation at the North Rim of the Grand Canyon is 8,000 feet, and that makes for a whole different world.  Ponderosa pines infuse the cool air and aspens rattle shimmering leaves in occasional breezes.  During winter storms the North Rim catches enough snow to bury a house.  Over millennia, the resulting melt and erosion has crafted a fantasy land of bridges, fingers and islands of towering layers of rock.   Across all of this, and beyond the river threading so far below, sits the implacable edge of the South Rim, and above that only the sky, arching pale blue above.

Hiking paths meander through forests lush with undergrowth. Breaks in the trees open to landscapes that drop away vertically, sometimes dotted with trees, mostly showing sheer faces of rock, with airy canyons beyond.   Wilderness and solitude press in, pushing away that pervasive separation we have from nature.  The trails are ours alone, a world of leaves and stark white trunks, fanlike clusters of long Ponderosa needles top glowing cinnamon trunks.

Descending off the Kaibab Plateau we reach Marble Canyon. This tiny community, sleepy from the highway, is near the historic river crossing Lee’s Ferry.  Now outfitters and motels offer visitors access to the Colorado’s waters. Below Glen Canyon Dam, we paddled kayaks, joining the river’s drowsy journey through sinuous walls of sandstone.  The slow pulse of the river nudged us along at a leisurely pace, giving us time to contemplate groups of fish nibbling at the surface, to notice water birds dabbling at the green edge.   The icy cold water was transparent, revealing pockets of fish swimming in the shallows. 

Ravens patrolled the campground where we stayed and frolicked in canyon updrafts at the rim. Uinta chipmunks foraged busily for ponderosa and juniper seeds.  Red-backed juncos were everywhere, flitting in trees and scavenging on the ground for seeds. A Swainson’s hawk stared us down from a mountain meadow. The Desert Spiny lizard was a resident at the Marble Canyon Motel, as was a fox who peered in our window.