Pájaro Gato/Gray Catbird/Dumetella carolinensis

Nombre en español: Pájaro Gato

Nombre en inglés: Gray Catbird

Nombre científico: Dumetella carolinensis

Familia: Mimidae

Canto: Paul Marvin

El pájaro gato gris (Dumetella carolinensis) es una especie de ave paseriforme de la familia Mimidae propia de América del Norte y el Caribe. Es el único miembro del género Dumetella. Debe su nombre común a su llamada similar al maullido de un gato.

Bastante sencillo pero con mucha personalidad, el maullador gris suele ocultarse en los matorrales, emitiendo una extraña variedad de sonidos musicales y discordantes, incluido un maullido similar al de un gato que es responsable por su nombre. En otras ocasiones, se traslada con audacia a campos abiertos, agitando su cola larga expresivamente. La mayoría de los maulladores inverna al sur de los Estados Unidos o en los trópicos, pero unos pocos se quedan en el norte si tienen acceso a fuentes confiables de bayas o a comederos de pájaros bien abastecidos.

Estado de conservación

Al menos en el este, parece ser que las poblaciones han estado aumentando en las últimas décadas.

Habitat

Matorrales, arbustos, malezas espinosas y jardines suburbanos. En todas las estaciones, prefiere la vegetación baja y densa. Es más común en matorrales frondosos a orillas de bosques y arroyos, en pantanos llenos de arbustos, en campos tapados de matorrales y en setos de jardines. Evita los bosques intactos y los bosques de coníferas.

Alimentación

Principalmente insectos y bayas. En especial a principios del verano, se alimenta de varios tipos de escarabajos, hormigas, orugas, saltamontes, grillos, chinches y otros insectos, así como también de arañas y milpiés. Alimenta a sus crías casi completamente con insectos. Más de la mitad de la dieta anual de los adultos puede consistir en materia vegetal, en especial en otoño e invierno, cuando se alimentan de muchas clases de bayas silvestres y de algunas frutas cultivadas. Rara vez atrapa peces pequeños. En los comederos, consume surtidos inusuales que incluyen rosquillas, queso, patatas hervidas y copos de maíz.

Suele buscar gran parte de su alimento en el suelo, revolviendo las hojas con el pico en busca de insectos. Se alimenta de bayas en la parte superior de los arbustos y árboles.

Reproducción

4, a veces de 3 a 5 y rara vez 2 o 6. De color azul verdoso, a veces con manchas rojas. La incubación la realiza solo la hembra y dura alrededor de 12 o 13 días.

Ambos padres alimentan a las crías. Las crías abandonan el nido 10 u 11 días después de la eclosión. 2 nidadas por año.

Al principio de la época de reproducción, el macho canta constantemente por la mañana, al atardecer y, a veces, por la noche. El cortejo puede implicar que el macho persiga a la hembra, adoptando poses y haciendo reverencias con las alas caídas y la cola levantada; el macho puede mirar en dirección contraria a la hembra para lucir el parche de color castaño debajo de su cola. Cuando los tordos cabecicafé ponen huevos en los nidos de estas especies, los maulladores adultos generalmente picotean estos huevos y los sacan del nido. Nido: Se coloca en arbustos densos, matorrales, marañas de brezos o árboles bajos, por lo general, a una distancia de entre 1 y 3 metros del suelo. El nido (construido principalmente por la hembra) es un cuenco voluminoso hecho de ramas pequeñas, malezas, hierba, hojas y, a veces, algo de basura, y está revestido con raíces pequeñas y otros materiales finos.

Gray catbird

The gray catbird (Dumetella carolinensis), also spelled grey catbird, is a medium-sized North American and Central American perching bird of the mimid family. It is the only member of the «catbird» genus Dumetella. Like the black catbird (Melanoptila glabrirostris), it is among the basal lineages of the Mimidae, probably a closer relative of the Caribbean thrasher and trembler assemblage than of the mockingbirds and Toxostoma thrashers. In some areas it is known as the slate-colored mockingbird.

Nomenclature and taxonomy

On the road from Stanley to Boise, Idaho

The name Dumetella is based upon the Latin term dūmus («thorny thicket»; it thus means approximately «small thornbush-dweller» or «small bird of the thornbushes». It refers to the species’ habit of singing when hidden in undergrowth. The specific name carolinensis is New Latin for «from the Carolinas».

The species was first described by Carl Linnaeus in his 1766 edition of Systema naturae. His original name Muscicapa carolinensis reflected the belief, widespread at that time, that the gray catbird was some sort of Old World flycatcher (presumably due to its remarkably plain coloration, not similar to other mimids).

The genus name has a convoluted nomenclatorial history. The monotypic genus Galeoscoptes, proposed by Jean Cabanis in 1850, was widely used up to 1907. This name roughly means «capped mockingbird», from Latin galea «helmet» and Ancient Greek skóptein (σκώπτειν, «to scold» or «to mock»). But as it turned out, Dumetella was a technically acceptable senior synonym, even though the peculiar circumstances of its publishing left the identity of its author unsolved until 1989. As it turned out, the genus name was published by C.T. Wood in 1837. His description is somewhat eccentric, and was published under his pseudonym «S.D.W.». Wood misquotes his source—John Latham’s 1783 General Synopsis of Birds—as calling the bird «cat thrush», probably because he knew the species under that name from George Shaw’s General Zoology. Latham’s name was «cat flycatcher», analogous to the scientific name of Linné.

Shaw (and subsequently C.T. Wood) used L.J.P. Vieillot’s specific name felivox. This means «cat voice», a contraction of Latin felis («cat») and vox («voice»). Vieillot, differing from the earlier authors, believed the bird to be a true thrush (Turdus).

Though mimids were widely considered Turdidae until the 1850s, this was not any more correct than treating them as Old World flycatchers, as these three families are distinct lineages of the Muscicapoidea superfamily. In the mid-20th century, the Turdidae and even most of the Sylvioidea were lumped in the Muscicapidae—but the Mimidae were not.

Lastly, the smaller gray catbirds from Bermuda, which have proportionally narrow and shorter rectrices and primary remiges, were described as subspecies bermudianus («from Bermuda») by Outram Bangs in 1901. But this taxon was never widely accepted, and today the gray catbird is generally considered monotypic as a species, too.

Description

Adults weigh from 23.2 to 56.5 g (0.8 to 2.0 oz), with an average of 35–40 g (1.2–1.4 oz) They range in length from 20.5 to 24 cm (8.1 to 9.4 in) and span 22 to 30 cm (8.7 to 11.8 in) across the wings. Among standard measurements, the wing chord is 8.4 to 9.8 cm (3.3 to 3.9 in), the tail is 7.2 to 10.3 cm (2.8 to 4.1 in), the culmen is 1.5 to 1.8 cm (0.6 to 0.7 in) and the tarsus is 2.7 to 2.9 cm (1.1 to 1.1 in). Gray catbirds are plain lead gray almost all over. The top of the head is darker. The undertail coverts are rust-colored, and the remiges and rectrices are black, some with white borders. The slim bill, the eyes, and the legs and feet are also blackish. Males and females cannot be distinguished by their looks; different behaviours in the breeding season is usually the only clue to the observer. Juveniles are even plainer in coloration, with buffy undertail coverts.

Diet

Approximately 50% of the gray catbird’s diet is fruit and berries. They also eat mealworms, earthworms, beetles, and other bugs. In summer, gray catbirds will eat mostly ants, beetles, grasshoppers, caterpillars, and moths. They also eat holly berries, cherries, elderberries, poison ivy, bay, and blackberries.

Vocalizations

This species is named for its cat-like call. Like many members of the Mimidae (most famously mockingbirds), it also mimics the songs of other birds, as well as those of Hylidae (tree frogs), and even mechanical sounds. Because of its well-developed songbird syrinx, it is able to make two sounds at the same time. The alarm call resembles the quiet calls of a male mallard.

A gray catbird’s song is easily distinguished from that of the northern mockingbird (Mimus polyglottos) or brown thrasher (Toxostoma rufum) because the mockingbird repeats its phrases or «strophes» three to four times, the thrasher usually twice, but the catbird sings most phrases only once. The catbird’s song is usually described as more raspy and less musical than that of a mockingbird.

In contrast to the many songbirds that choose a prominent perch from which to sing, the catbird often elects to sing from inside a bush or small tree, where it is obscured from view by the foliage.

Ecology and behavior

Geographical range and habitat

Native to most of temperate North America east of the Rocky Mountains, gray catbirds migrate to the southeastern United States, Mexico, Central America, and the Caribbean in winter; except for the occasional vagrant they always stay east of the American Cordillera. They are extremely rare vagrants to western Europe. Normally present on the breeding grounds by May, most leave for winter quarters in September/October; as it seems, this species is increasingly extending its stay in the summer range, with some nowadays remaining until mid-winter as far north as Ohio. The gray catbird is a migratory species. Spring migration ranges from March to May, and in the fall ranges from late August to November.

The catbird tends to avoid dense, unbroken woodlands, and does not inhabit coniferous, pine woodland. Catbirds prefer a dense vegetative substrate, especially if thorny vegetation is present. Scrublands, woodland edges, overgrown farmland and abandoned orchards are generally among the preferred locations of the catbird. In Bermuda, its preferred habitats are scrub and myrtle swamp. During the winter season, the catbird has an affinity for berry-rich thickets, especially within proximity of water sources.

Breeding

Nest and egg in a cedar shrub four feet above the ground

Their breeding habitat is semi-open areas with dense, low growth; they are also found in urban, suburban, and rural habitats. In the winter months they seem to associate with humans even more. These birds mainly forage on the ground in leaf litter, but also in shrubs and trees. They mainly eat arthropods and berries. In the winter months, Cymbopetalum mayanum (Annonaceae) and Trophis racemosa (Moraceae) bear fruit well liked by this species, and such trees can be planted to attract the gray catbird into parks and gardens.

They build a bulky cup nest in a shrub or tree, close to the ground. Eggs are light blue in color, and clutch size ranges from 1–5, with 2–3 eggs most common. Both parents take turns feeding the young birds.

Predation and threats

The gray catbird can be attracted by «pishing» sounds. Gray catbirds are not afraid of predators and respond to them aggressively by flashing their wings and tails and by making their signature mew sounds. They are also known to even attack and peck predators that come too near their nests. They also will destroy eggs of the brood parasitic brown-headed cowbird (Molothrus ater) laid in their nests by pecking them.

This species is widespread and generally plentiful, though its reclusive habits often make it seem less common than it is. It is not considered threatened by the IUCN due to its large range and numbers.

On Bermuda however, gray catbirds were once very common, but their numbers have been greatly reduced in recent years by deforestation and nest predation by introduced species (including the great kiskadee Pitangus sulphuratus and the European starling Sturnus vulgaris). In the United States, this species receives special legal protections under the Migratory Bird Treaty Act of 1918.

BNA Account Authors: Smith, Robert J., and Margret I. Hatch, Cimprich, David A., and Frank R. Moore

The Gray Catbird was named for its mewing call, although few people would mistake the sound of this bird for that of an actual cat. Like other species in the family Mimidae, this bird displays considerable vocal versatility. Part of this ability stems from the structure of its syrinx. Because both sides of this vocal organ are able to operate independently, the Gray Catbird can sing with two voices at the same time.

The song of this species is a long series of short syllables delivered in rapid sequence. Its repertoire may include syllables of more than 100 different types varying from whistles to harsh chatters, squeaks, and even mimicry. These are sung in seemingly random order at an uneven tempo, resulting in what often sounds like an improvised babble of notes occasionally spiced with the familiar mew.

The genus name, Dumetella, meaning «small thicket,» accurately reflects the Gray Catbird’s habitat: dense, shrubby vegetation. In this setting, it builds a bulky, open nest, usually within two meters of the ground. Although Brown-headed Cowbirds (Molothrus ater) parasitize the Gray Catbird, they rarely are successful. This catbird is one of only about a dozen species known to recognize cowbird eggs and eject them from its nest¿an ability that is learned, not innate. On both breeding and wintering grounds this catbird eats much fruit, sometimes becoming a pest for farmers and gardeners.

This is a bird with a broad wintering range, from the southern New England coast south to Panama, with concentrations on the US Gulf coast and the Yucatan Peninsula. Yucatan winterers, and those to the south, are trans-Gulf migrants, with individuals tending to lay on significant stores of fat to complete that crossing.