Rufous-sided pygmy-tyrant  (Euscarthmus rufomarginatus)

The small rufous-sided pygmy tyrant is a member of the family Tyrannidae, a name taken from the Greek word tyrannas, meaning ‘lord' or ‘ruler', and refers to their aggressive behaviour (3). The plumage is mostly a drab brown, slightly darker on the wings, and, as the name suggest, the sides are a warm orange. The long, brown tail feathers are edged in yellowy-orange. The underparts are pale yellow, the throat is white, and the light brown face has a short, whitish ‘eyebrow', or supercilium. The upper part of the beak is black, whilst the lower part is flesh-coloured, and the eyes are dark brown (2).

The rufous-sided pygmy tyrant occurs in east and central Brazil, north-eastern Bolivia, north-eastern Paraguay and southern Suriname. It was probably once widespread, but now occurs at scattered localities across this range (2) (4).

Inhabits pristine, shrubby grasslands and open savanna, up to an elevation of 1,000 meters. It may also occur in bamboo-dominated scrub (2).

The rufous-sided pygmy tyrant spends its time searching for food in pairs, usually in grass or low shrubs, and occasionally down on the ground, where it feeds on arthropods and small fruits (2). There has been nothing recorded about the breeding behaviour of this species, but other tyrant flycatchers lay two or three eggs, which are incubated by the female for 14 to 20 days, and the nestlings fledge after 14 to 23 days (5).

It is thought that the loss of habitat is responsible for the rufous-sided pygmy tyrant's decline and present rarity. The savanna region, or Cerrado, it inhabits has been greatly affected by human developments, such as pastures, plantations and highways. In 1998 it was estimated that around 67 percent of the Cerrado had been completely converted or modified in a major way. Further agricultural developments and human colonization continues to put pressure on the remaining natural vegetation (6). However, its absence in apparently suitable habitat suggests that there may also be other reasons for its rarity, which as yet remain unknown (2).

The rufous-sided pygmy tyrant occurs in a number of protected areas within the Cerrado, such as the Noel Kempff Mercado National Park and the Emas National Park, but even these face some level of threat, such as fire and pesticide pollution from surrounding agricultural land (7) (8). Surveys have been undertaken in Brazil, which uncovered no additional populations (2), but there have been no other conservation measures targeted at this small bird.

For further information on this species see Birdlife International:
http://www.birdlife.org/datazone/sites/index.html?action=SpcHTMDetails.asp&sid=4188&m=0

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk