Strange-tailed Tyrant

This is an extraordinary and highly dimorphic passerine bird belonging to the tyrant flycatcher family. The breeding male is unmistakable, reaching up to 30 centimeters in total length, with its most striking feature being the pair of immensely elongated, broad, and fan-shaped outer tail feathers that can measure more than twice the length of the bird´s body. These streamers are predominantly deep black and have bare, wire-like shafts near the base, widening into paddle-like webs at the tips. The male´s upperparts are glossy black, contrasting sharply with a pure white belly and throat, which is bordered by a distinct black chest band. During the breeding season, the male undergoes a unique physiological change, losing the feathers on its throat to expose a patch of bright, bare orange-pink skin. Females are considerably smaller, measuring around 20 centimeters, and lack the bare throat skin. They possess a much shorter, narrower, and less dramatic tail, with overall cryptic mottled brown and buff upperparts.

Geographical distribution: Endemic to the open grasslands of southern South America. Its historical range once extended across southern Brazil, western Uruguay, eastern and northern Argentina, and southern Paraguay. However, the modern distribution has suffered a severe contraction, leaving highly fragmented populations. Currently, its key strongholds are located in northeastern Argentina, specifically within the provinces of Corrientes and Formosa, and southern Paraguay, while it is considered critically endangered or possibly extirpated in its former Uruguayan and Brazilian strongholds, such as Rio Grande do Sul.

Habitat: Strictly associated with pristine, tall, wet grasslands and natural savannahs. It shows a strong ecological preference for native pastures and damp depressions near marshes or wetlands that feature tall, herbaceous vegetation reaching over one meter in height. The species is highly sensitive to habitat alteration, completely avoiding areas subjected to intensive cattle grazing, frequent burning, or monoculture agriculture.

Feeding: It is an obligate insectivore, feeding primarily on a diverse range of terrestrial invertebrates. Its diet consists largely of orthopterans like grasshoppers and crickets, coleopterans including beetles, and lepidopteran larvae. It hunts using active sallying techniques, perching prominently on tall grass stems to scan the surroundings before launching short, acrobatic flights to snap up insects in mid-air or glean them directly from the upper stems of native grasses.

Behavior: Outside the breeding season, it displays semi-gregarious tendencies, often forming small, loose flocks. During the spring and summer breeding months, males establish territories and perform spectacular, undulating aerial displays. To attract mates, they fly upward with heavy, noisy wingbeats, showing off their oversized, fluttering tail feathers and inflating their colorful, bare throat skin while uttering soft, buzzing vocalizations. It is a highly conspicuous bird when perching, using the highest available grass seedheads as sentry posts.

Nesting: The breeding period spans from September to January. The nest is a delicate, open cup constructed entirely from fine grass fibers, rootlets, and cobwebs, typically built very close to the ground, concealed within the thickest clumps of tall native grasses. The female lays a clutch of two to three creamy-white eggs marked with fine reddish-brown spots. Although incubation is performed solely by the female, both parents actively participate in territorial defense and provisioning the nestlings.

Conservation status: Classified as Vulnerable (VU) on the IUCN Red List. Its survival is severely threatened by the rapid conversion of native grasslands into intensive agricultural fields, commercial exotic forestry plantations such as pine and eucalyptus, overgrazing, and untimely seasonal fires, which destroy the essential nesting cover.