White-rumped Monjita

Belongs to the family Tyrannidae and is characterized by its elegant, slender silhouette and contrasting plumage. This medium-sized passerine measures approximately 19 to 20 centimeters (7.5 to 8 inches) in length and exhibits a predominantly white and grey coloration. Its head features a pale grey crown that extends toward the nape, contrasting with a pure white forehead and lores. The mantle and upperwing coverts show greyish tones that darken toward the primary flight feathers, which are almost black and feature a conspicuous whitish wing bar. The most distinctive diagnostic feature of Xolmis velatus is its bright white rump, which stands out dramatically in flight against a dark tail with pale outer margins. Its underparts are entirely pure white, devoid of any streaks or spots. The bill is black, short, straight, and strong, adapted for an insectivorous diet, while the tarsi and feet are black and the iris is dark brown.

Geographical distribution: Is widely distributed across the central and eastern regions of South America. It is highly common throughout most of Brazil, ranging from the states of Maranhão, Ceará, and Bahia, extending southward through Minas Gerais, São Paulo, and Paraná, down to Rio Grande do Sul. Its range also extends westward into eastern Bolivia, particularly within the department of Santa Cruz, and southward encompassing the eastern region of Paraguay. Occasional and historical records document its presence in the extreme north of Argentina, mainly in the provinces of Misiones and Corrientes, where it is considered a vagrant or locally rare visitor.

Habitat: Primarily inhabits open and semi-open ecosystems, showing a strong preference and specialization for the Cerrado biome. It is frequently found in shrubby savannas, natural grasslands, pastures, active agricultural fields, forest clearings, and ecological transition zones or ecotones. It strictly avoids dense forest canopies, continuous humid rainforests, and steep mountainous regions. The species adapts exceptionally well to human-modified landscapes, utilizing power lines, fence posts of cattle ranches, and scattered trees in pastures as hunting perches and observation platforms.

Feeding: Possesses a strictly insectivorous diet, relying on a wide variety of terrestrial and flying arthropods. Its typical prey includes beetles, orthopterans such as grasshoppers and crickets, hymenopterans, lepidopterans in both larval and adult stages, and dipterans. To capture its prey, it employs a passive hunting technique known as "sit-and-wait" foraging. It perches on high, exposed branches or wires from which it scans the ground; once a prey item is detected, it performs a rapid downward sally to snatch the insect from the soil surface, immediately returning to its perch or a nearby one to consume it. It is also capable of performing short aerial maneuvers to capture insects in mid-air.

Behavior: Is an eminently diurnal and solitary species, although it is frequently observed in monogamous pairs during the breeding season. It does not typically form single-species flocks or routinely join mixed-species feeding flocks. It has a territorial and conspicuous temperament, spending much of the day perched upright in highly visible locations such as the tops of shrubs or telephone wires. Its flight is direct, agile, and slightly undulating. Its vocalizations are discrete and infrequent, consisting of soft whistles and short melodic notes emitted mainly at dawn or during territorial disputes with conspecifics.

Nesting: Builds an open, deep cup-shaped nest using dry twigs, rootlets, fine grasses, and bark fibers woven together. The interior of the structure is lined with much softer materials such as feathers, wool, mammal hair, and cottony plant fibers to ensure the thermal insulation of the clutch. The nest is generally placed at a low to medium height, located in the fork of a dense shrub, in low-stature trees typical of the Cerrado, or even on wooden fence posts. The female usually lays a clutch of 2 to 3 eggs, which are creamy white in color, decorated with reddish-brown spots and speckles concentrated at the larger end. Both parents actively participate in defending the surrounding territory against potential predators and cooperate in feeding the altricial chicks.

Conservation status: Is classified under the category of Least Concern (LC) on the International Union for Conservation of Nature (IUCN) Red List. Despite the habitat fragmentation suffered by the Cerrado ecosystems due to agricultural and livestock expansion, this species does not experience alarming population declines. On the contrary, being an open-country bird, it has benefited in certain regions from deforestation and the creation of new artificial pastures, which has allowed it to colonize previously inaccessible areas within its geographic range.