Thrashers

Summary: The Southwest has 1,2,3,4 or more thrashers! Join Cheryl and Kiersten as they talk about the four thrashers found most commonly in Arizona.

 

For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.

 

Show Notes:

www.allaboutbirds.org

Our email address, please reach out with comments, questions, or suggestions:  thefeathereddesert@gmail.com

 

Transcript

Cheryl: Intro

Arizona sits in the middle of thrasher territory.  Our corner of the southwest has four different thrashers that call our deserts home.  All four of these thrashers are non-migratory, territorial, mate for life, and eat insects and spiders. Their territories might overlap only if they are not of the same species, such as the Curve-billed Thrasher would share territory with a Crissal Thrasher pair but not with another Curve-billed Thrasher pair.  They are similar, yet not.  As the saying goes so close yet so far…

Our first one is the Curve-billed Thrasher which is the most widely dispersed and most adapted to living with humans.

Kiersten: Curve-billed Thrasher

Strong legs and a long, decurved bill give the Curve-billed thrashers the perfect tool for hunting insects in the punishing deserts, canyons, and brush lands that are its home.  That long bill also keeps that  insect prey at a safe distance and comes in handy for foraging and nesting among spiny plants, especially, cacti.  This species is so typical of the deserts of the American southwest and northern Mexico that its whistled “whit-wheet” call is often the first vocalization that visiting bird watchers learn.

The Curve-billed thrasher, actually has two different looks. The Curve-billed thrasher of the Chihuahuan desert of Texas/central Mexico has a lighter breast, more contrasting spots, pale wing bars, and white tail corners.

The Arizona (western) bird of the Sonoran Desert has grayer breast with less obvious spots and inconspicuous wing bars, and smaller, more grayish tail corners.  It’s up for debate whether they are two separate species.

The Curve-billed thrasher of Arizona-Sonoran Desert population favors creosote bushes, Saguaro and cholla cacti, and Paloverde trees.  These birds forage on the ground for a variety of insects, spiders and snails along with fruit and seeds.  They use their bills to sweep back and forth through leaf litter and soil, tossing large pieces of vegetation to one side to uncover insect prey including “flipping cow chips”.   Curve-billed thrashers do not use their strong legs for scratching in leaves, instead the legs provide leverage, and the tail provides support.  Not cavity nesters, these birds build stick nests in cactus such as ocotillo, cholla or in creosote bushes.   These birds’ mate for life, and maintain a territory all year-round of about 5-11 acres.

Cheryl: Crissal Thrasher

A lanky, gray-brown bird of desert washes, the Crissal Thrasher generally stays hidden and close to the ground as it probes for insects and seeds with its long, curved-bill.  It may be easily mistaken for a curve-billed thrasher with its long tail and light orange eyes, except for a subtle black and white mustache, rich cinnamon patch under the tail, and pale, unspotted belly.  Its mellow, musical song makes it one of the finest desert songsters.

Crissal thrashers are sedentary creatures.  They almost never venture more than a mile or so from their home point.  The Crissal thrasher walks and runs around its territory more than it flies.  Even when disturbed by a predator, this thrasher is most likely to run away to cover.

Crissal thrashers live in desert and dry scrubby or brushy habitats, especially along dry creek beds, or in canyons and foothills.  Also, brushy riparian corridors and mesquite thickets.   Crissal thrasher habitats overlap Curve-billed thrasher habitats, but truly stays very much in the southwest corner of Texas, New Mexico, Arizona and Southeastern corner of California.

  Crissal thrashers are an insect and spider eater, like the curve-billed thrasher the Crissal uses its legs as leverage when foraging for insects. 

Crissal thrasher pairs usually defend nesting territories year-round, and males sing anytime of the  year to mark their territory.  Crissal thrashers have nests that are set in very dense shrubs or trees about 4ft off the ground.  These thrashers will not be attracted to bird feeding stations.

Kiersten: Bendire’s Thrasher

Bendire’s thrasher is a secretive bird of open desert habitats; it is a lanky, dusty brown songster with a curved bill that is somewhat shorter than the other thrashers on our list today.

Bendire’s thrasher spends most of its time on the ground, catching insects or digging them out of crevices in the ground.  Bendire’s thrasher’s range overlaps with the curved-billed thrasher’s but they are more comfortable in open areas with shorter vegetation while curve-billed thrashers use cactus forests and stream corridors.  Bendire’s has a bill almost like a woodpecker and they use it to extract insects lodged in the ground. It will hammer away until it frees its prey.  Bendire’s thrasher builds bowl shaped nests lined neatly with grasses, animal hair and feathers.  Crissal thrashers are non-migratory and their population is on the decline due to habitat loss.

Cheryl: Le Conte’s Thrasher

A pale, sandy gray colored bird with unmarked wings, a dark eye, and a cured-bill,  Le conte’s thrasher is a ghost of a bird that often runs on the ground with its tail held up across the desert flats.  Le conte’s thrasher when alarmed chooses to flee on foot, like a miniature roadrunner.  This thrasher lives in low sandy, open deserts that are home to few bird species.  Over most of their range are plants like cholla, cactus, creosote, yucca and mesquite spread very thinly over open flats or sand dunes.   These birds thrive in desert habitats with very little rain fall and air temperatures that are among the highest recorded on earth, such as Death Valley.

Le conte’s thrashers eat insects and spiders along with lizards, snakes, and an occasional bird’s egg.

Le Conte’s thrasher breeding season begins in December.  The female builds a twiggy cup nest in a thorny bush.  This bird lives in remote, forbidding habitats making it difficult to track their population trends.  It is on conservationist’s watch list due to destruction of its desert habitat by development, cattle grazing, off-road vehicles and fire.  The Le Conte’s has the smallest range of all four thrashers occupying just a sliver of SE California, a southern corner of Nevada, the very SW corner of Arizona and a slip of Mexico.

Closing: As I said at the beginning, so close yet so far… two of the four southwest thrashers’ bird populations are in decline, so hopefully putting this information out will help draw some attention their way so that they have a chance of adapting and overcoming man’s intrusion into their landscapes.