Sandhill Cranes

The Whitewater Draw Wildlife Refuge is run by Arizona Game and Fish, and they estimate more than 25,000 Sandhill cranes are currently wintering over at the area. The cranes congregate near the marshy shoreline, a sprawling crowd of 3-foot-tall birds, each preserving its own bit of personal space. Beyond the cranes and the marsh stretch miles of grassland edged with distant blue mountains.   

The cranes spread their massive wings and rise up from their roosting area every morning at daybreak, flying to fallow agriculture fields. They probe the rubble with stout bills, gleaning leftover corn, as well as insects and any sprouts of greenery. After a morning of feeding, the cranes fly back to the marsh. 

I arrived about noon, and by then thousands of Sandhill cranes were already on the ground, some wading in the water, some standing along the banks. High overhead, incoming cranes appeared as dark specks in the endless blue, a scattering like pepper corns. Gradually small groups or pairs dropped lower, circling overhead, honing in on where they would land, calling out to announce their arrival. Wings outspread, they spiraled ever more tightly downward until their long legs reached to touch land.

There are six different migratory populations of Sandhill cranes on the continent. These gathering in Arizona are likely from a couple of different populations. The Mid-Continent population has breeding grounds in western and central Canada, western Alaska and northeastern Siberia. These cranes winter in northern Texas as well as central and northern Mexico, and southeast Arizona. A Rocky Mountain population also contributes to Arizona’s winter residents. 

In optimal situations, tail winds and thermals boost the birds on their journeys, and they cover up to 150 miles per day. The cranes can fly 50 miles an hour in good conditions, but in some cases must labor along at only 15 miles per hour. 

Sandhill crane pairs mate for life, and the youngsters often stay on with the family group for a year or two. Breeding does not start until cranes are two to eight years old. The young hatch covered in down and soon leave the nest. By early winter they appear adult-like, lacking only the red crown patch.

Sandhill cranes communicate via an extensive language of trumpets, bugles, rattles, honks, moans, purrs and hisses combined with posturing that includes bows, feather ruffled bows, stretches, stabs and kicks. The Unison Call is a duet sung by courting males and females, and accompanies elegant dance moves – leaps, head pumps and tosses of vegetation.  Guard Calls used with Tall Alert Posture defend nesting territory or warn of predators. Rattle Calls allow individuals to find each other in migration.  Chicks peep and trill.

The Sandhill cranes will stay at Whitewater Draw until early to mid-April, resting and feeding in preparation for their next migration.  

Juvenile in middle does not yet have a red crown patch
Graceful drinkers
Afternoon is rest time

Gilded Flicker

Male Gilded Flickers sport a red moustache

I once visited a church in Mexico where workers on scaffolding were hammering paper thin sheets of gold onto the interior walls, “gilding” them. Gilded Flicker have similar glory hidden away on the undersides of their wings. This is a flamboyantly colored bird, and the beautiful yellow undersides of the wings and tail are only part of the story. 

We commonly see these large woodpeckers on the ground in our yard in the warm season. They visit us because of our ants, ants being their favorite food.  That makes Gilded Flickers one of my favorite birds! These residents of the Sonoran Desert typically live near saguaro cacti, where they excavate their cavity nests. 

In April the female lays 3-4 eggs inside the cool, dim, unlined nest. The parents take turns incubating and later feeding the young. After about a month the meal train stops, forcing the young out of the nest and into the practice of finding their own food.

Last November I looked out the window and saw two Gilded Flickers on the ground in the backyard. They were dancing, stretching their necks to the sky and then bowing to each other and shuffling in circles together. I grabbed my camera and took some pictures through the glass – they are not great photos. But they captured this play time the two birds were enjoying. After the dance they took turns hiding behind a pot or a plant and then popping out to startle the other, a combination of hide-and-seek and peek-a-boo. 

In the winter when ants and other insects are not active Gilded Flickers eat winter fruits and seeds. They are closely related to the more widespread Northern Flicker. 

The dance
Aha!
Female Gilded Flicker calls

The call of the Gilded Flicker rings loud and clear across the desert. https://www.allaboutbirds.org/guide/Gilded_Flicker/sounds

Not So Bad: The Butcher Bird

Loggerhead Shrike

They call Shrike the butcher bird, but that seems a bit unfair. After all, pairs are monogamous, and every spring the male sings to his female and brings her choice tidbits to eat. They search together for a perfect nesting site and work in tandem to gather twigs, rootlets, strips of bark and grasses. Females actually build the nest, lining it with soft flowers, lichen, feathers and fur. 

These robin sized birds are fascinating and fearsome because they are meat eaters. Their menu includes other birds, even those equal in size, rodents, reptiles and insects. But unlike, raptors that have fierce talons to do the dirty work, Shrikes must kill with an ancient adaptation called a tomial tooth. This is a notched space at the end of the beak that fits rather perfectly between rodent vertebrae.

Another method Shrikes employ to get a meal is to skewer their prey on a sharp thorn or even a prong of barbed wire. The food items may be eaten immediately cached for a later meal.

When I see Shrikes in the desert near my home, they are usually perched up high, and that is how they hunt, scanning the ground below with their excellent eye sight. It is said they can make out details from 70 yards. The Shrike is strong as well as fierce, and capable of carrying its own weight in flight. 

All About Birds, the Cornell Ornithology website points out another more endearing characteristic of Shrikes. Before breeding season, Shrikes have been observed gathering together for a short meeting of sorts, perhaps sorting out territories, cementing pair bonds or helping direct new arrivals to nearby available territories. 

Nest Building 101

This Curved-billed Thrasher hopped down into the interior of the cactus, apparently working on a nest. She seemed to be using her beak to place and move materials around.  Later, I went past the cactus again to check on her progress. There was no sign of a nest!  Was she practicing? Measuring? 

Researchers in Edinburgh were the first to publish a report that indicated nest building is a learned behavior, not instinct. Their observations revealed that nests are better designed and more efficiently constructed by birds that had built previous nests.  There were also variations in the actions that individual birds used that indicated their behaviors are not automatic.

As stated in Ecology and Evolution Journal, bird nests are multifunctional structures that require considerable cognitive ability. Most basically nests are containers for eggs and a space to raise young. But they are more!

Nests must minimize predation on the young. Site selection is the primary tool here, with the local abundance of predators having an influence. Ground nests may be the safest in areas with lots of raptors. Here in the Sonoran Desert, several species place their nests in thorny cacti to deter predators. The nesting area must also offer nearby sources of food and nesting material. 

Nests are designed to reduce parasites. Fresh greenery woven into the nest cup and replaced daily has a biocidal affect on parasites. Feathers lining a nest can hold bacteria that produce antibiotic substances.  Urban house sparrows and house finches have added cigarette butts to their nest cups. How did they know that the cellulose acetate in cigarettes repel parasites?

Every nest is a microclimate designed to protect the young from the elements. The outer nest material provides structural support for eggs and parents, but also thermoregulatory effects. The inner nest cup is all about providing a dry warm microclimate. Feathers keep nestlings warm, but birds use less of this insulation as the spring temperatures warm. Overhead shade is important, as is positioning in relation to prevailing wind.

In some cases nests attract mates. Since nest building burns energy, those that can build the largest nests, or the most nests, appear superior. Nests can serve as signals to potential mates and potential competitors….see how great I am!

Curve-billed Thrasher nest in Teddy Bear Cholla

Hummingbirds At Home

Female Costa’s Hummingbird on Desert Spoon in January

When we added a small patch of native plants to our front yard, we not only enhanced a previously bare space, we invited in hummingbirds. Now when we step outside the front door, we often notice Costa’s hummingbirds, colorful and entertaining neighbors.

Experts say a male Costa’s only pairs with a female long enough to ensure his legacy.  After courtship and breeding, the male goes his own way. The female sets to work, building a nest, laying eggs, incubating and feeding the youngsters. A female hangs out in our front yard year around, feeding on Chuparosa nectar in the winter, and Orange Bells (Tecoma hybrid) around the corner in the summer. When not hovering near a blossom or zooming away from our interruptions, the Costa’s perches in what seem to be customary places.  

The Chuparosa’s twining stems embrace an adolescent saguaro, fifteen years old but just four feet tall. A Cassia’s dense growth provides shelter and presumably an insect buffet, but it is on the spiky blades of the Desert Spoon that the hummingbird perches, overseeing her Chuparosa and drawing warmth and shelter from the east-facing wall. 

The Ironwood tree, just across the driveway, provides more perfect hummingbird domain.  I often see the female perched on a low branch, blending perfectly into the grey-green palette of leaves. In this tree she finds shelter, nesting space, an insect population for snacks and baby food, and a good view of that Chuparosa plant, covered now with deep red blooms, juicy with nectar. 

When she turns her eye to this winter food source, she can’t help but watch for the glistening purple cap of the Costa’s male. It seems soon she will begin to construct a nest, bringing tiny twigs and bits of leaf, and binding them with spider webs into a walnut sized cup to hold her precious eggs. 

Female Costa’s fluffed up for warmth in Ironwood Tree
Chuparosa, Saguaro, Cassia, Desert Spoon and Brittlebush are all plants to attract wildlife
Costa’s male

Winter Flowers Feed Bees

Early blooming Paloverde tree

About 1000 different species of bees live in the Sonoran Desert.  Most are solitary and nest in underground burrows or the hollow stems of pithy plants.  The majority of these bees are herbivores, subsisting on pollen and nectar. 

Upwards of 80% of native flowering plants in the Sonoran region are pollinated by bees, as are 30% of agricultural crops.  Bees are vital partners in the production of many of our foods, fabrics (cotton), beverages and medicines.

The introduced honey bees shown in these pictures live in social colonies of 30,000 or more.  They nest in manmade hives, hollow trees or rock outcrops.  Close examination of these bees reveals hairy eyes!  

Baja Fairy Duster, Chuparosa, Lantana, Valentine Emu Bush and Arugula provide winter nectar for bees, butterflies, moths, hummingbirds, and Verdins.

The Very Small Verdin

A thief has been at work in the chuparosa patch! Verdin does not have a beak long enough to access the sweet nectar at the throat of the bloom, so makes a slit at the base of the flower and sips straight from the source. Feeding avidly at the chuparosa, Verdin does not contribute to pollination. 

In addition to pilfering nectar, busy Verdins eat 400-500 insects every day. They also feast on seasonal fruits of desert plants, and seed pods of trees such as ironwood, paloverde and mesquite. All of this nutrition supports an active metabolism that is on display as the tiny birds flit about constantly, chittering, gleaning insects and sipping nectar, often hanging upside down from plant stems to do so.    

Verdins are also energetic nest builders. Recently I watched a Verdin bring a long chain of fluffy plant material to an existing nest, apparently adding insulation for upcoming cold weather. Verdins build different types of nests for different situations. In spring, the solitary birds pair up and the male builds an outer shell of a breeding nest for his female. She completes the interior and lays her eggs. The male also constructs smaller roosting nests for nighttime use. Some of these are for the fledglings once they leave their natal nest.

Verdin nests are easy to see when you walk in a desert wash, built as they are within the outer branches of the trees. These enclosed, ball shaped nests have an opening facing out and downward. Breeding nests include an interior lip to prevent eggs and nestlings from rolling out. Clever Verdins build summertime nests with less insulation, and they position the opening facing towards prevailing breezes to provide cooling. 

Nectar awaits at the base of the tubular flowers

   

More Than a Common Songbird

Northern Mockingbird in Palo Verde branches

Northern Mockingbird is a fancy, flamboyant song bird. With a sleek silhouette, and elegant grey plumage, Mockingbird has an outsized attitude, and you’ll know if you’ve wandered into a mocker’s nesting territory. Mockingbirds defend their nest aggressively, dive- bombing people, dogs, other birds, snakes, you name it. 

But Mockingbird is also impressive for his song. Clear liquid notes are combined in an amazing range of compositions. Mockingbirds mimic other birds and other sounds they hear, and mix these with their own melodies, making them into songs. The male keeps composing songs and adding them to his repertoire over his whole lifetime.  He may end up with 200 songs.  He sings tirelessly, all day and into the night when the moon is out.  Females sing too, but more quietly, using their songs to establish winter territories rather than during breeding season. 

Mockingbirds hop and run on the ground to catch insects, as well as nabbing them in the air. They also eat a wide range of fruits from native plants such as cacti, wolfberry, hackberry and mistletoe to fruits from cultivated plants in suburban yards. 

Northern Mockingbird fledglings leave the nest about a week before they are able to fly, running on the ground and climbing into nearby bushes for safety. Mom and Dad keep a close eye on them, bringing them food and warding off intruders. 

The male takes a break from this extended care and builds the outer shell of a new nest while the female continues with feeding duty. Then he returns to caring for the fledglings while she finishes the interior of the nest, lays 2-6 new eggs and incubates them. The pair may raise up to four broods between March and August in the desert.

Mockingbirds enjoy the water fountain
Mockingbird fledgling in Creosote bush in on a hot day in May