Curve-billed Scythebill
Campylorhamphus procurvoides
A brown, tree-climbing bird with a strongly curved bill. Appears small-headed; plumage is mostly rufous-brown with buffy streaking on head and neck. Found in tall rainforest, where it is uncommon and locally distributed; often occurs in areas with extensive bamboo thickets. Generally shy and rather difficult to observe. Forages at middle and upper levels, using extraordinary bill to probe into deep bark crevices, bromeliads, and broken bamboo stems. Regularly follows mixed-species flocks. Song is variable, usually an accelerating series of strident whistles. Curved bill should immediately distinguish this species from most other woodcreepers in range. In western and central Amazonia, may overlap with Red-billed Scythebill, from which it may not be safely separable unless singing.
Identification
The curve-billed scythebill is 22.5 to 25 cm (8.9 to 9.8 in) long and weighs 30 to 38 g (1.1 to 1.3 oz). It is a slim, medium-sized woodcreeper with a very long, slim, dramatically decurved bill. The sexes have the same plumage. Adults of the nominate subspecies C. p. procurvoides have a dark brown head and neck with thin whitish to buffy streaks on them and the face. Their back and wing coverts are olive-brown to reddish brown. Their flight feathers, rump, and tail ares rufous-chestnut that contrasts with the back. Their throat is buffy-white with a fine scaly appearance. Their underparts are dull brown with buffy-white arrow-shaped marks that become narrow streaks on the belly but don't continue onto the undertail coverts. Their underwing coverts are cinnamon-rufous. Their iris is dark brown to chestnut, their bill dark red to reddish brown (often with a dusky brown base and a paler mandible), and their legs and feet dusky green, brown, or dark gray. <p>Subspecies C. p. gyldenstolpei is very similar to the nominate. C. p. sanus is smaller than the nominate. It is more warmly colored with a whiter throat that is streaked instead of scaly. Its bill is shorter and more strongly decurved.
Taxonomy
Taxonomists have not reached agreement on the curve-billed scythebill. The International Ornithological Committee (IOC), BirdLife International's Handbook of the Birds of the World (HBW), and the Clements taxonomy assign it these three subspecies:<p>The South American Classification Committee of the American Ornithological Society adds three others, C. p. probatus, C. p. cardosoi, and C. p. multostriatus. Until 2023 the IOC and Clements also included them. In July the IOC split off probatus and carsosoi to create the Tapajos scythebill and multostriatus to create the Xingu scythebill. Clements followed suit in October 2023. HBW had previously made those splits.<p>Subspecies C. p. gyldenstolpei was originally proposed as a full species.<p>This article follows the three-subspecies model.
- Scientific name
- Campylorhamphus procurvoides
- Authority
- (Lafresnaye, 1850)
- Order
- Passeriformes
- Family
- Furnariidae
- Genus
- Campylorhamphus
Range and habitat
The subspecies of the curve-billed scythebill are found thus:<p>The curve-billed scythebill inhabits humid evergreen forest. It greatly favors terra firme but occasionally occurs in floodplain forest. In southern Amazonia it often occurs in bamboo thickets. Subspecies C. p. gyldenstolpei tends to be in forest on sandy soils. In all forest types the species favors the interior though it does visit the forest edges. In elevation it mostly occurs below 500 m (1,600 ft) but reaches 700 m (2,300 ft) in Suriname. There is also a sight record in Venezuela at 900 m (3,000 ft).
- Migration
- Resident species
Behavior
The curve-billed scythebill is assumed to be a year-round resident throughout its range.<p>The curve-billed scythebill's diet is mostly if not entirely arthropods. Single birds and pairs usually forage as part of mixed-species feeding flocks in the forest understory to its mid-level, though it will feed up to the subcanopy. It forages by gleaning and probing while hitching up and along trunks, branches, vines, and bamboo.<p>The curve-billed scythebill's breeding season has not been fully defined but appears to include at least February to April. It nests in cavities in trees, either natural or made by a woodpecker. The clutch size is two eggs. The incubation period, time to fledging, and details of parental care are not known.<p>The curve-billed scythebill sings mostly at dawn and only in short bursts. The subspecies' songs differ. That of the nominate is "an accelerating series...of 7–9 somewhat melancholy whistles on even pitch or falling slightly...'weeee, weé, wee, we, we, wew' or 'kuweee, kuwee, kwee, wee-wee-we-we-we. ". That of C. p. sanus "begins as series of drawn-out whistles, rapidly accelerates into fast and relatively harsh rattle, 'tweee, weee, weee, weee, weee, twe-we-we-wi-wi-i-i-i-i-wik!' ". That of C. p. gyldenstolpei has not been put into words, but "differs from that of other members in the complex in the shape and syntax of the notes, it being the only taxon to possess notes characterized by an abrupt frequency peak before their end". All subspecies give "an explosive, relatively harsh 'chit-di-dit' " call.
Conservation
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
Gray-breasted Sabrewing
Campylopterus largipennis
Large hummingbird of humid forests and semi-open habitats in Amazonia. Plain gray below and iridescent green above. Note large dark tail with white tips; also look for fairly heavy, slightly dropped bill and white spot behind eye. Occurs mostly in forest clearings or other semi-open habitats such as edges, tree fall gaps, and gardens. Forages at low- to mid-levels.
Nahan's Partridge
Ptilopachus nahani
Unusual francolin that is small and very dark, with a thick tail that is usually cocked up. A good view reveals red legs, red bare skin around the eye, and bright white markings on the breast and neck. Found very locally on the ground in rainforest. Usually in pairs or small groups. The distinctive vocalization is a series of loud “chu-wheet” notes that rises and becomes more emphatic, usually given as a duet by a pair. Similar to Latham’s Francolin, but separated by the partly red bill, red bare facial skin, and red rather than yellow legs. Somewhat similar to Scaly Francolin, but smaller, with red bare facial skin and bright white markings below.
Winding Cisticola
Cisticola marginatus
Relatively colorful, mid-sized, long-tailed cisticola of wetlands. Note the brown back with thick black streaks, rufous on the wing and cap, and whitish underparts. Shows geographical variation in overall richness of color, including rufous cap and wing patch. Found in wetland habitats, especially reedbeds, and locally in wet scrub. Song varies across the range. Most populations give a high, rising trill. Some sing with rough “chyup” notes. Similar to Levaillant’s Cisticola, but Winding has a gray or brown tail and an unstreaked rump. Relatively bold colors separate the two from other cisticolas.
Start Your Bird Watching Journey
Identify a bird outdoors and keep the field guide close for your next observation.