Nombre en español: Trepatroncos Listado

Nombre en inglés: Striped Woodcreeper

Nombre científico: Xiphorhynchus obsoletus

Familia: Furnariidae

El trepatroncos loco​ (Xiphorhynchus obsoletus), también denominado trepatroncos listado (en Colombia y Ecuador), trepador listado (en Perú) o trepador loco (en Venezuela),​ es una especie de ave paseriforme de la familia Furnariidae, subfamilia Dendrocolaptinae, perteneciente al género Xiphorhynchus. Es nativa de la cuenca amazónica y del escudo guayanés en Sudamérica.

Distribución y hábitat

Se distribuye por el sur y este de Colombia, hacia el este por el sur y este de Venezuela, Guyana, Surinam y Guayana francesa, hacia el sur por el este de Ecuador, este de Perú, por toda la extensión de la Amazonia brasileña, hasta el norte de Bolivia.​

Esta especie es considerada generalmente poco común en sus hábitats naturales:​ el sotobosque de las selvas húmedas de regiones bajas, los pantanos y las zonas de matorral tropicales. Vive en las riberas de la Amazonia, hasta los 500 m de altitud.​

Descripción

En promedio el trepatroncos loco mide 20,3 cm de longitud y pesa 31 g.​ Su pico mide 2 cm.​ El dorso y la cabeza presentan rayas color ante sobre fondo de color castaño, más oscuro en la cresta que tiene un borde negro; alas, grupa y cola castaño rojizo o rufo; garganta ante a rosada; pecho castaño oscuro con rayas blacuzcas a anteadas; vientre castaño oscuro.​

Sistemática

Descripción original

La especie X. obsoletus fue descrita por primera vez por el naturalista alemán Martin Lichtenstein en 1820 bajo el nombre científico Dendrocolaptes obsoletus; la localidad tipo es: «sin localidad = estado de Pará, Brasil».​

Etimología

El nombre genérico masculino «Xiphorhynchus» se compone de las palabras del griego «ξιφος xiphos»: espada, y «ῥυγχος rhunkhos»: pico; significando «con pico en forma de espada»;​ y el nombre de la especie «obsoletus», del latín: liso, desgastado, olvidado.​

Taxonomía

Las relaciones de esta especie son inciertas; con base en los datos moleculares, la primera idea es que sería ancestral a un clado morfológicamente variable integrado por Xiphorhynchus susurrans, X. guttatus, X. flavigaster y X. lachrymosus, y posiblemente también X. erythropygius y X. triangularis. La calificación de la subespecie notatus es complicada debido a la marcante variación individual de la coloración, y a la intergradación a lo ancho de un área aparentemente amplia, con la nominal y palliatus; aves de la cuenca del río Purus en el oeste de Brasil, algunas veces son reconocidas como la subespecie multiguttatus, pero es intermediaria entre la nominal y palliatus. La subespecie caicarae se diferencia pobremente de la nominal y es de dudosa validad.​

Subespecies

Según las clasificaciones del Congreso Ornitológico Internacional (IOC) y Clements Checklist v.2019​ se reconocen cuatro subespecies, con su correspondiente distribución geográfica:​

• Xiphorhynchus obsoletus notatus (Eyton, 1852) – cuencas de los ríos Apure, alto Orinoco, bajo Caura y alto Negro en el este de Colombia (Arauca, Vichada), oeste y sur de Venezuela y adyacencias del noroeste de Brasil; aves del bajo río Negro son intermediarias con la nominal.
• Xiphorhynchus obsoletus caicarae J.T. Zimmer & Phelps, Sr, 1955 – medio valle del Orinoco en el centro de Venezuela (noroeste de Bolívar).
• Xiphorhynchus obsoletus palliatus (Des Murs, 1856) – oeste de la Amazonia, tanto al norte como al sur del río Amazonas, en el sureste de Colombia (Meta, Caquetá), este de Ecuador, este de Perú, oeste de la Amazonia btasileña (hacia el este hasta los ríos Negro y Juruá) y norte de Bolivia (al sur hasta el norte de La Paz y noroeste de Beni); aves del río Purus son intermediarias con la nominal.
• Xiphorhynchus obsoletus obsoletus (M.H.C. Lichtenstein, 1820) – este de la Amazonia en el este de Venezuela (Delta Amacuro), las Guayanas y norte de Brasil (bajo río Negro al este hasta Amapá y, al sur del río Amazonas, desde el río Madeira hacia el este hasta el río Tocantins y al sur hasta el oeste y norte de Mato Grosso); las poblaciones del noreste de Bolivia (noreste de Santa Cruz) y noreste de Venezuela (este de Monagas) probablemente representen esta subespecie.

Striped woodcreeper

The striped woodcreeper (Xiphorhynchus obsoletus) is a species of bird in the woodcreeper subfamily (Dendrocolaptinae). It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical swamps, and subtropical or tropical dry shrubland.

The Striped Woodcreeper is widely distributed virtually throughout the Amazon Basin, where it prefers evergreen forests in close proximity to water, especially on large river islands, or near to rivers and lakes, although it also ranges marginally into the Cerrado region. The species is practically confined to lowland areas below 500 m. Like many woodcreepers, comparatively little is known of its breeding biology, but feeding behaviour has been well studied. The Striped Woodcreeper feeds mainly on insects, and usually selects small-sized prey items. It regularly joins mixed-species flocks, from the understory to the canopy, and the species appears to prefer to inspect slimmer-trunked trees. The Striped Woodcreeper is generally fairly common, expect in areas where flooded forest habitats are rare, or at the edge of its range, where competition with Elegant Woodcreeper (Xiphorhynchus elegans) occurs.

Habitat

Evergreen forest, especially near water. Principally floodplain-forest and seasonally (and tidally) flooded forests, frequenting both várzea and igapó, large river islands, wooded swamps, and edges of rivers and lakes, locally also forest on sandy soils and terra firme forest; along S fringe of Amazonia, ranges in gallery forest a short way into cerrado region. Largely restricted to low-lying fig (Ficus) swamps in SE Peru, but one radio-tracked bird repeatedly attempted to expand territory into adjacent terra firme and late-successional forest defended by X. elegans and X. chunchotambo; this bird spent 35% of its time outside swamp, making long circuits through territories of X. elegans, before returning to swamp upon expulsion by territory-owners. May prefer interior of mature forest at upland sites; away from flooded forest found mostly in second growth, at forest edge, or even in scattered trees near clearings. Exclusively Amazonian lowlands below 500 m.

Movement

Resident.

Diet and Foraging

Chiefly insectivorous. Stomach contents mostly beetles and various species of ant, with lesser quantities of hemipteran bugs, cicadas and lanternflies (Homoptera), cockroaches (Blattodea), caterpillars, and spiders. Observed prey in one study were remarkably small, generally less than 0·5 cm, only occasionally longer than 1 cm. Forages singly, less frequently in pairs. Usually apart from mixed-species flocks, but associates transitorily with those that pass through its habitat; one radio-tracked bird spent only c. 25% of its time with flocks. Joins both understorey and canopy flocks, but seems to prefer those with Thamnomanes antshrikes over those without. Radio-tracking revealed that one bird in swamp-forest switched between a canopy flock (with which spent 14% of its time) and an understorey flock (8%); defence of flock minimal, unlike X. chunchotambo and, especially, X. elegans. Forages primarily while hitching up trunks and branches from understorey to subcanopy; in one study, preferred slim trunks 2–7 m up, with mean height 5·5 m; regularly creeps along undersides of horizontal branches. Most prey obtained by gleaning, pecking or probing (roughly 70% in one study), but sallies recorded significantly more frequently (30% of attempts) than for all others of genus at same site; items taken mostly from surface of trunks, limbs or palm stubs (c. 70%), with remaining 30% split evenly between foliage (including palm fronds, and both flowers and leaves of cacao) and mid-air sallies. Has been suggested that sallying may be adaptation for living in flooded forest with open understorey, which not easily exploited by gleaning woodcreepers; also that increased percentage of sallying may correspond to more alert behaviour, and thus reduced need to travel with flocks for protection from predators. Single birds and pairs only occasionally encountered among birds foraging over army ants (Eciton burchelli) that move through várzea. Subordinate to X. elegans (at least within latter’s territories in upland forest), but dominant over Sittasomus griseicapillus; interactions with X. chunchotambo in high-ground forest were equivocal. High degree of overlap in diet and substrate use with both X. elegans and X. chunchotambo results in intolerance (aggression at almost every encounter within flocks) and interspecific territoriality; also significant overlap in these parameters with Lepidocolaptes albolineatus, a canopy species separated spatially at most sites, but limited data suggest both interspecific territoriality and reciprocal turnover of territories where the two do meet.

Sounds and Vocal Behavior

Song, among first heard in flooded forests at dawn and last heard at dusk (also intermittently during day), a trill 1·5–3 seconds long, 20–35 sharp notes, first stuttering, then speeding up slightly, rises conspicuously at end, “che-e-e-e-e-e-ee-ie-ie-iek!”; at some sites in E Colombia, song said to be instead a sharp “peep” followed by trill; similar but slightly descending trill sometimes given when agitated. Calls include “sip” note like that of hummingbird (Trochilidae), also “ti-dik” and dry twittering “tit-it-it” or “si-si-sip”.

Breeding

Specimens in breeding condition in Nov and Feb–May in S Venezuela, E Colombia and adjacent Brazil, but nests with eggs in both mid-Feb and early Aug in Surinam. Nest in cavity in palm stump, also recorded in arboreal nest of termites (Isoptera); territory at site in SE Peru suggested as 14 ha, but only loosely territorial, seems not to defend an exclusive area. Clutch 2 eggs, white, average 25 × 19 mm.

Conservation Status

Conservation status on Birdlife LC Least ConcernNot globally threatened. Generally uncommon to fairly common in C Amazonia, especially where bottomland and seasonally flooded forests are extensive; rare and somewhat local at periphery of range in regions where occupies other habitats. Estimated densities in early-successional forest and mature floodplain-forest in SE Peru 0·5–2·5 pairs/100 ha (after correcting for small percentage of plot occupied). A radio-tracked bird at site in SE Peru ranged over area of 78 ha but occurred exclusively in only 2·4 ha; home range was therefore quite large compared with congeners occupying same site, with daily movements almost double those of territorial X. elegans. Populations at some sites near edge of range apparently depressed by competition with dominant X. elegans, which restricts present species to habitats that may be marginal or of limited extent, as evidenced by constant attempts by one bird to expand territory, and rapid turnover of territories in swamps at SE Peru site. Believed to be at least moderately sensitive to loss and fragmentation of forest; successional nature of its habitat, however, suggests greater tolerance of modification than is shown by most terra firme species. An indicator of flooded tropical evergreen forest in N & S Amazonia, and more specifically of flooded swamp-forest in SE Peru.

Fuentes: Wikipedia/eBird/xeno-canto/Birds of the world