Rufous-throated Dipper Cinclus schulzii Scientific name definitions

The Rufous-throated Dipper is a distinctive and very range restricted species of dipper, it is only found in the subtropical zone on the east slopes of the Andes in southernmost Bolivia and Northwestern Argentina. As is typical of all dippers it is restricted to streams, preferring those with ample flow and cool and clean water. The Rufous-throated Dipper is gray throughout with a blue tint to the plumage, and shows a noticeable rufous patch on the throat and upperbreast. The wings have a white wing stripe which they make prominent through flicking of the outer wing when the dipper is perched on a streamside rock. Unlike the northern American Dipper (Cinclus mexicanus), the two South American species, one of which is the Rufous-throated, they do not dive beneath the water to feed. Rufous-throated Dippers swim and peck at food on rocks, and will dip into the water to forage, but they do not remain submerged and swim under water as does the northern species. The Rufous-throated Dipper needs shaded, cold water streams, disturbance of the areas upstream and increases in water turbidity, or removal of the vegetation adjacent to the watercourses they use negatively affects the dippers, making them quite vulnerable to habitat change.

14–15·5 cm; 39·5 g. Plumage is dull dark brownish-grey above , wings and tail slightly darker; white on bases of inner webs of primaries  (visible when wing open  ); chin greyish, throat to uppermost breast  contrastingly orange-rufous, rest of underparts  grey-brown, greyer on breast, darker on belly; underwing grey, broad white band at bases of primaries; iris dark brown to blackish; bill  black to dark grey; legs lead-grey. Sexes similar, female slightly smaller than male. Juvenile resembles adult, but paler, bill more pinkish.

E Andes in S Bolivia (S Chuquisaca, W Tarija) and NW Argentina (Jujuy, Salta, Catamarca, Tucumán).

Fast-flowing rocky mountain streams and rivers, 5–15 m wide, with cascades, waterfalls, and rocky cliffs or banks. Breeds mainly in the Andean alder (Alnus acuminata) zone, at 1500–2500 m; reported also at higher levels, and in Bolivia possibly breeds on streams in pastureland at lower elevations (1200 m). In frosty conditions often descends to lower levels, down to c. 800 m, and then sometimes found on larger rivers. Rarely occurs on narrow forest streams (1–2 m wide) favoured by Sharp-tailed Streamcreeper (Lochmias nematura).

Resident; some altitudinal movement in cold weather.

Food aquatic insects and larvae; one stomach contained mostly beetle imagos (Coleoptera). Forages by wading in shallow water or standing on wet rocks  and on lips of waterfalls, and picking invertebrates; also probes in wet moss on rocks and in other vegetation on river margin. Occasionally jumps up or makes short flights to take aerial insects. Often feeds with head and most of body immersed, with wings flapping to maintain balance, but, despite some published statements, no definite records of plunging beneath surface. Noted as being more active on overcast days or during light rain; on clear sunny days, remains motionless for long periods in shade beneath rock overhangs. Usually makes only short flights between foraging sites.

Song  a loud melodious warbling or trilling, resembles that of C. cinclus; call  a loud “zzit” or “dzchit” or “schenk”, usually in series, faster when in flight.

Nests and eggs Sept–Jan. Monogamous, so far as is known; solitary nester. Large globular nest 24 cm high, 22 cm wide and 14 cm deep, side entrance hole 7 × 5 cm, outer shell made of moss and grass  , inner bowl of grass stems, algae, Alnus leaves, sometimes few feathers, once paper and plastic, nest cup 8 cm in diameter and 4 cm deep; placed in rock crevice, on cliff ledge, in niche of rocky wall, under overhang in earth bank, on tree roots or in brickwork of bridge, 0·5–1·25 m above rushing water; linear territory of 500–1000 m on suitable stretches of river, sometimes 2 km in less favourable places. Clutch 2 eggs; no information on incubation and fledging periods; nestlings fed by both parents.

VULNERABLE. Restrictedrange species: present in Argentine and South Bolivian Yungas EBA. Uncommon to locally common. Range covers approximately 600 km × 100 km, but many distributional gaps within this; area occupied probably c. 19,000 km². Has small, highly fragmented population estimated at 3000–4000 individuals, and thought to be declining. Bolivian population currently estimated as numbering variously up to 500 pairs to probably over 1000 pairs; Argentine population put at maximum of 1000 pairs. Widespread and not uncommon on rivers on E-facing slopes of two ridges of Andean foothills in S Bolivia; on one of these possibly up to 200 pairs, at low density of 1 pair/1–2 km, on several tributaries of R Guadalquivir and R Camacho; more numerous on better-forested rivers on the other ridge (farther E), where estimated 250–500 pairs on rivers between Entre Ríos and Argentina border; occurs also, less commonly, N of Narváez, as on R Villa into Chuquisaca. In Argentina, recorded in Salta in the Orán and Baritú areas as well as near San Lorenzo, on R Pulares, R Blanco and R Mazano, all on forested W slopes of Valle de Lerma, also reported at higher elevations on a tributary of R Santa Victoria and on R Sacha Runa; known from only a few sites in Jujuy, Catamarca and Tucumán . Main threats arise from changes in river management, water pollution, perhaps also deforestation; quality of rivers adversely affected by mining effluent, nutrient enrichment, siltation, water abstraction for irrigation of crops (tobacco, sugar cane and others), also dam construction and hydro-electric schemes. Logging, grazing and erosion have adverse effects in breeding areas where streams flow through forest. Food competition with introduced trout (Salmo) also a potential problem. Impact of these threats most marked in Argentina, and pollution, reduced flows and river-channel modifications most prevalent at lower altitudes. Nevertheless, much of this species’ habitat is currently fairly inaccessible, and thus effectively protected. Occurs in Tariquía National Reserve, in Bolivia, and in Baritú, Calilegua and Campo de los Alisos National Parks and Portrero de Yala Provincial Park, in Argentina.