Great Rufous Woodcreeper

Characterized as one of the largest members of its subfamily, this robust bird measures between 11 and 13.5 inches (28 to 34 cm) in length and weighs approximately 120 to 150 grams. Its plumage is overwhelmingly a rich rufous-chestnut color, showing slightly paler tones on the underparts. The head displays fine, pale buffy streaks on the crown and throat. One of its most diagnostic features is the massive, slightly decurved bill, which has a pale horn or pinkish-grey coloration. The tail is composed of stiff, spiny-tipped feathers that act as a crucial support prop when clinging to vertical tree trunks, facilitating its typical spiraling climbing movement.

Geographical distribution: This species is endemic to the south-central regions of South America. Its range encompasses northern and central Argentina (extending south to Córdoba and Santa Fe), western and southern Paraguay, southeastern Bolivia, and southwestern Brazil, including the states of Mato Grosso, Mato Grosso do Sul, and western Rio Grande do Sul.

Habitat: It primarily occupies semi-open, arid to semi-humid woodlands, with a distinct preference for the dry Chaco forest, gallery forests, deciduous woodlands, and the woody savannas of the Cerrado and the Pantanal regions. Unlike many of its relatives in the Dendrocolaptidae family, it strictly avoids dense, continuous humid rainforests, favoring instead open canopy structures and edge habitats with mature trees.

Feeding: It is an opportunistic carnivore and insectivore. Its diet consists of large invertebrates such as beetles, grubs, spiders, and orthopterans extracted from deep bark crevices using its powerful bill. Because of its large size, it also regularly preys upon small vertebrates, including lizards, tree frogs, and small snakes, and has been documented raiding nests to consume eggs and small nestlings.

Behavior: Typically encountered singly or in pairs, this bird is highly territorial and maintains large home ranges. It moves methodically up trunks and large branches, tapping and probing the bark. Its vocalization is a loud, ringing sequence of clear whistles that can carry over long distances through the dry forest. Although generally solitary, it occasionally joins mixed-species foraging flocks or associates with army ant swarms to capture fleeing prey.

Nesting: Breeding occurs in natural tree cavities or old cavities excavated by large woodpeckers. The interior of the nest chamber is sparsely lined with dry bark flakes and small wood chips. The female typically lays 2 to 3 pristine white eggs. Both sexes participate equally in incubation duties and in provisioning the nestlings with highly nutritious insect prey until they fledge.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List due to its extensive range and stable overall population. Nevertheless, local declines have been documented due to severe habitat loss and fragmentation within the Gran Chaco biome, primarily driven by agricultural expansion and charcoal production, which deprives the species of the mature, cavity-bearing trees essential for its survival.