Curve-billed Thrasher (Toxostoma curvirostre)

[order] PASSERIFORMES | [family] Mimidae | [latin] Toxostoma curvirostre | [UK] Curve-billed Thrasher | [FR] Moqueur a bec courbe | [DE] Krummschnabel-Spottdrossel | [ES] Cuitlacoche piquicurvo | [NL] Krombekspotlijster

Subspecies

Physical charateristics

This, the commonest desert thrasher, can be told from the others that have well-curved bills by the mottled breast (indistinct in the westernmost form, palmeri )
i . Some individuals have narrow white wing bars. Eyes pale orange. Juvenile has yellow eyes, straighter bill.

Listen to the sound of Curve-billed Thrasher

[audio:http://www.aviflevoland.nl/sounddb/C/Curve-billed Thrasher.mp3]

Copyright remark: Most sounds derived from xeno-canto

Range

North America, Middle America : Southwest USA, Mexico

Habitat

Deserts, arid brush. Lives in Sonoran desert (with its varied vegetation) or in dry brushy country, mainly in lowlands. Avoids extreme deser
t situations with sparse plant life. Often in suburban neighborhoods, especially where cholla cactus grows. In southern Texas, lives in chaparral with prickly-pear cactus. Sometimes on open grassland around stands of cholla.

Reproduction

Pair may remain together all year on permanent territory. Especially in spring, male defends territory by singing.
Nest: Most commonly placed in fork of cholla cactus, 3-5′ above the ground. Sometimes in yucca, prickly-pear, or thorny
shrub, or on top of mistletoe clump in shrub or low tree. May build on top of old Cactus Wren nest. May sometimes reuse same nest sites. Nest (probably built by both sexes) is bulky cup of thorny twigs, lined with fine grasses, rootlets, feathers, hair.

Eggs: 3, sometimes 2-4. Pale blue-green with tiny brown dots. Incubation is by both parents during the day, apparently only by female at night; incubation period 12-15 days.
Young: Both parents feed young. If nest is in situation exposed to sun, female may spend much time shading the nestlings. Young leave nest about 14-18 days after hatching. 2 broods per year, sometimes 3.

Feeding habits

Mostly insects and berries.
Feeds on many insects and their larvae, including beetles, ants, grasshoppers, wasps, others; also spiders, centipedes, snails, and sowbugs. Also eats many berries, and feeds on the fruits and seeds of cactus, including those of prickly-pear and saguaro.

Behavior:
Forages mostly on ground, using its heavy curved bill to dig in soil, to flip leaf litter aside, and to turn over small rocks. When digging in hard dirt, braces its tail against the ground and pounds straight downward with heavy blows of bill.

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Migration

Resident, southwestern United States to southern Mexico. Migration: Permanent resident. Rarely wanders out of range, mainly in fall and winter.

Distribution map