Memoria de la Fundación La Salle de Ciencias Naturales 2002 (“2000”), 154: 145-151

NOTA

Notes on the thinocorids of the high Andes of Bolivia

José Cabot, Javier Castroviejo e Iñigo Fajardo

Resumen. gayi, orbignyianus y T. rumicivorus se distribuyen por los Andes Centrales, desde el sur de Perú hasta el norte de Chile y Argentina. Attagis gayi simonsi se localiza en los fondos de valles de la cresta Andina Oriental y en los cinturones pantanosos de vegetación almohadillada de la Cadena Occidental hasta el área de Arica donde intergrada con A. g. gayi que se extiende hacia el sur. Tanto Thinocorus orbignyianus como T. rumicivorus, están representadas por dos poblaciones distintas que difieren entre sí en comportamiento gregario, en hábitos migratorios y en dimensiones corporales. Ambas especies ocurren en planicies y terrenos ondulados del Altiplano. En la Reserva de Ulla-Ulla, en el extremo noroeste de la de los Andes de Bolivia las especies se segregan espacialmente. T. rumicivorus se distribuye por las áridas y pedregosas morrenas planas. La población invernante de T. orbignyianus se ubica en áreas encharcadas de vegetación almohadillada, mientras que la población local residente todo el año se distribuye por las llanuras aluviales secas. Ambas especies comparten un rango altitudinal de 4000 a 4500 m. A. gayi se sitúa por encima hasta los 5000 m de altitud, está en los bordes de los glaciares y los húmedos fondos de valle. Palabras clave. Attagis gayi. Thinocorus orbignyianus. Thinocorus rumicivorus. Sistemática. Distribución. Selección de hábitat.

Notas sobre los tinocóridos de los Andes altos de Bolivia.

Abstract. Attagis gayi, Thinocorus orbignyianus and T. rumicivorus are distributed throughout the Central Andes, from southern Peru to the northern parts of Chile and Argentina. Attagis gayi simonsi are found in the valleys of the eastern Andean crest and in the belts of marsh vegetation mats on the Western Chain as far as Arica where this taxon intergrades with A. g. gayi which extends south. Both Thinocorus orbignyianus and T. rumicivorus are represented by two distinct populations which differ in gregarious behavior, migratory habits and body dimensions. Both species ocurrs in plains and rollins terrain of the altiplano. In the Ulla-Ulla Reserve of the extreme northwestern Andes of Bolivia, the species segregate spatially. T. rumicivorus is found on the dry and rocky flat moraines. The winter population of T. orbignyianus is located on the flooded vegetation mats, while the local resident population occurs year round on the flat, dry alluvial plains. Both species share an altitudinal range of 4000 to 4500 m. A. gayi is found higher up, occurring to an altitude of 5000 m, where it is found on the borders of glaciers and along wet valley bottoms. Key words. Attagis gayi. Thinocorus orbignyianus. Thinocorus rumicivorus. Systematics. Distribution. selection.

Three Seed- species, Attagis gayi, Thinocorus orbignyianus and T. rumicivorus, can be found in Central Andes, from south Perú to northern Argentina and Chile (Blake 1977, Fjeldsa and Krabbe 1990). The information available about these species in the Central Andes basically referred to distributional data of specimens collected in a few localities (Remsen and Traylor 1989). 146 Notes on the thinocorids of the high Andes of Bolivia

In this note we analyse, for the highlands of Bolivia, the distribution of Attagis gayi subspecies; morphological variation among populations of Thinocorus orbignyianus, and migratory habits in T. rumicivorus, as well as habitat preferences for all species. This is based on field data gathered between 1981 and 1985, in the Altiplano and cordilleran localities, and data on the skins of the Estación Biológica de Doñana collection. Habitat data was recorded monthly during 1982 at Ulla-Ulla Reserve (4400 m a.s.l.), 14º50’-15º64’S and 69º15’-69º30’W 60 km N of lake Titicaca, La Paz Dpt. Bolivia. The area comprises one sector of the “Macizo de Apolobamba” in the eastern Andean cordillera, and the large morrain plains to the west. Attagis gayi Geoffroy Saint-Hillaire, I and Lesson 1831. Three subspecies have been recognised. The northernmost, A. g. latreilli, is restricted to páramos of northern Ecuador. The other two, A. g. simonsi and gayi, both southernmore, replace each other in different ecoregions although they overlap somewhat by altitude. Their respective ranges are described in Blake (1977) and Fjeldsa and Krabbe (1990). These authors agree that A. gayi ranges from the puna of northern Chile southwards to Tierra del Fuego, and in the eastern Andes from Salta southwards in Argentina, at high altitudes in the north to near sea level in the south. Johnson (1965), provides basically the same distribution, cites it also in western Bolivia. The only record for this subspecies is from the puna zone of Potosí (Cabot and Serrano 1988), in the southwestern Bolivian extreme, near to the north Chilean border. This subspecies, in its northernmost Bolivian and Chilean range in the western base foothills of the Andean massif, inhabits a specific habitat: bogs (“bofedales”) of humid evergreen cushion plant vegetation in the periphery of the lagoons of the high altitude semidesert. Rufous Seed-snipe was recorded by Fjeldsa (1987) at Sajama in humid bogs, but these authors do not mention its subspecific status. According to Blake (1977) and Fjeldsa and Krabbe (1990), Attagis gayi simonsi ranges from the humid puna zone of Central-Southern Perú (Huancavelica, Puno) and Western-Central Bolivia (La Paz, Cochabamba y Oruro Dpts.), Northwestern Argentina (Tucumán) and probably Northern Chile, in Tarapacá (Blake op. cit.). However the presence of A. g. simonsi in the north of Chile is recorded by a photographed at Salar de Surire (northern Chile), which looks like a typical subspecies simonsi (Fjeldså 1996). The occupied in northern Chile are similar to the bogs at the base of volcanoes of south Perú. Johnson (1965) conversely cites the subspecies gayi in the area of Arica (Chile). There could be an intergradation but this needs documentation. Both subspecies range apparently parallel and separately along both sides of the southern Altiplano of Bolivia. A g. gayi inhabits the desert of Potosí in the Bolivian- Chilean Andes ledge, although its presence must be fully confirmed in SW Oruro Dpt. (Bolivia). A.g.simonsi is found at the opposite side of the Altiplano, by the crests on the humid Eastern Andes, from La Paz and Cochabamba departments (Bolivia). Nevertheless the presence has not been confirmed in eastern Oruro, Tarija and Chuquisaca departments in Bolivia. Mem. Fund. La Salle de Cienc. Nat. 154 147

Tinocorus orbignyianus Geoffroy Saint-Hillaire, I and Lesson 1831. Two subspecies have been described on the basis of size difference criterion. T. o. ingae, slightly smaller than the nominate subspecies, has a northernmost distribution, ranging in the Andes from Libertad (Perú) southward to high altitudes in western and central Bolivia to Tarapacá in Chile and Catamarca in Argentina (Blake, 1977). The nominate subspecies goes from the puna zone of Chile (north to Antofagasta but also to Tacna according to Fjeldsa and Krabbe 1990) to La Rioja and Santa Cruz (Argentina) at decreasing elevations southward to Tierra de Fuego and Staten Island (Blake 1977). At Ulla-Ulla two different populations occur: a resident one and a migrant. Each shows different habitat preferences, group size structure, body size and migrant status.

Table 1. Weights and body measurements of Thinocorus orbignyanus ingae: resident-permanent and wintering in North Bolivia, and breeding in Southwestern Bolivia. Wintering Potosí Residents NW Bolivia SW Bolivia NW Bolivia

(n=7) (n=8) (n=12)

X X

SD SDX SD Weight 117,3 13,1 114,8 8,7 107,0 7,9 Total L 223,7 5,1 218,0 4,2 214,0 3,1 Culmen L 16,3 1,1 15,9 0,8 15,1 0,9 Tars L 23,1 0,7 21,7 0,7 22,1 0,9 Tars W 3,1 0,2 3,0 0,2 3,0 0,2 M. toe L 21,4 1,7 20,8 0,7 20,4 1,2 Wing L 140,3 6,1 139,1 5,2 136,0 3,8 Tail L 64,7 3,7 62,7 4,3 62,1 2,1

Resident are smaller. They live in pairs throughout the year and use rolling plains of dry, stony soils of fine sediments with scarce and short tussock grass. These habitats undergo a severe dry period from April to October, when the vegetation withers and the land becomes denuded. Birds in breeding condition are recorded throughout the year, although more frequently in spring and summer (Cabot 1988). Wintering populations stay in flocks, generally six to thirty individuals, only in the dry season (May to September). They are located in boggy and flooded flat areas, locally named “bofedales” with evergreen grass and compact cushion plant cover. No individuals in breeding condition have been detected. Up to date migratory behaviour has not been recorded for this species (Johnson 1965, Olrog 1959, Blake 1977, Fjelsa and Krabbe 1990). However the occasional autumnal presence has been previously reported in Córdoba prov., Argentina (Nores et al. 1983). No pairs or isolated birds have been seen in boggy areas during the winter. On the other hand, in summer, during the wet season, no bird was observed in the humid or very flooded habitats. Individuals from each population were collected and no difference in plumage was found. However, resident-permanent birds were lighter and 148 Notes on the thinocorids of the high Andes of Bolivia

smaller than migrants (Wilcoxon test p > 0.01; Table 1). Local seasonal shifts between bogs and puna terrain occur in the northern part of the range, in Perú (Fjeldsa 1996) Specimens from Potosí, SW Bolivia (aprox. 800 km S Ulla- Ulla), which theoretically belong to T. o. ingae, according to the distribution given by Blake (1977), Johnson (1965) and Fjeldsa and Krabbe (1990), were collected in the austral spring of 1982. They were found in semidesert and desert puna, and their measurements were intermediate (except for the minor tarsal length) between resident-permanent and migrant populations at Ulla-Ulla (Wilcoxon test, p > 0.01). That intermediate measurement suggests the existence of a gradual latitudinal increase from north to south. Each Bolivian population, including the large-sized migrant visitors to Ulla-Ulla, must refer to T. o. ingae, since tail and wing lengths fit into the values provided for the northern Chilean population of this subspecies by Johnson (1965). This confirms that there is a gradient in body size and that the migrants wintering at Ulla-Ulla have a more southern origin than Bolivia. T. o. ingae measurements given by Blake (1977) are quite similar to ours: culmen length is similar to Potosí and migrant birds at Ulla-Ulla; the wing is also similar to Ulla-Ulla and Potosí residents and the tail (60 y 61.3 mm) is slightly shorter than ours. The measurements taken by Johnson (1965) and Blake (1977) and the weights given by Crawshay (1907) for T. o. orbignyianus are higher than the average for skins of birds wintering at Ulla-Ulla. Maclean (1969) uses measurements taken by several authors, but it would not be correct to contrast them because we do not know which subspecies they belong to, how many birds were measured, how many wing measurements were taken, if chord or flat ones, etc. On the whole, the species fits into Bergman’s rule, since the size increases the higher the latitude, in response to the hardships of cold weather. Size variation found for T. o. ingae (which could be equally possible in T. o. orbignyianus) shows the existence of gradual changes on the clinal gradient of body size in relation to the latitude. The body size of birds wintering in the Bolivian northern Altiplano (also possible in the south of Peru), greater than that of the local population and even than that of those from southern Bolivia, shows that they must have more southerly breeding areas. The geographic origin of birds wintering in the northern Altiplano should be determined by the process of ringing. Systematic collecting should also be carried out, during the austral summer, in areas where the distributions of each subspecies become put together and overlap. This would help to clarify whether or not two different taxonomic forms are being dealt with. Nevertheless, both subspecies must be recognised. T. rumicivorus Eschscholz 1829. Three subspecies have been recognised. The northernmost T. r. cuneicauda has a coastal distribution from southwestern Ecuador, Perú to northern Chile (from Arica to Tarapacá); T. r. bolivianus inhabits the puna (La Paz, Oruro and Potosí Dpts.) in Bolivia, Andes from Arica to Tarapacá in northern Mem. Fund. La Salle de Cienc. Nat. 154 149

Chile and Jujuy, La Rioja and Tucumán in northwestern Argentina; T. r. rumicivorus from Atacama southward and Tierra del Fuego to Río Negro in south Argentina. Postbreeding movements are recorded for the first time in the subspecies bolivianus at Ulla-Ulla, northwestern Bolivia. Migratory behaviour is well known for the nominate subspecies which go from the southern places northward to winter in Córdoba, Santa Fé, Buenos Aires (Argentina) and Uruguay. In the northern Bolivian Altiplano T. r. bolivianus is only present in the austral winter, from May to October. This population has a southernmost origin and moves

Table 2. Weights and body measurements of Thinocorus rumicivorus bolivianus in Northern and Central Bolivia Males (8) Males (4) Females (7) Wintering Potosí Residents

NW Bolivia SW Bolivia NW Bolivia

X X

SD X SD SD Weight 58,7 2,8 61,2 6,3 59,2 2,3 Total L 191,0 3,4 ------191,2 3,2 Culmen L 12,5 0,7 12,3 0,5 12,2 0,8 Tars L 21,7 0,8 21,6 0,1 21,2 0,8 Wing L 127,2 3,5 128,7 3,1 128,4 2,7 Tail L 63,4 3,2 61,2 1,6 63,0 3,3 northward in the Andes showing a migratory behaviour like the Red-backed Hawk (Buteo polyosoma), Cinereus Harrier (Circus cinereus), Tawny-throated Dotterel (Eudromias ruficollis) and Ground-Tyrants species (Muscisaxicola capistrata, M. juninensis and M. flavinucha) all of them wintering in the highlands of northwest Bolivia (Cabot 1988, Cabot and Serrano 1986). Nine males and eight females collected at Ulla-Ulla during 1982, some with considerable fat reserves, were compared with four breeding males collected in November 1982 in Sud-Lipez Prov., Potosí Dpt. The males of both samples were similarly sized, but the Potosí ones were slightly heavier and had shorter tails (Table 2) and also a similar dorsal plumage. There were differences only in the underparts. The breeding Potosí males were greyer in front, auriculars and chest; also the lines and bands across the breast were blacker. Wintering specimens were in eclipse plumage with sandy brown in the breast and crown. There is no strong sexual dimorphism in measurements in birds from the northern Altiplano. Females were larger than males, with minor differences in length, wing and weight (1.3; 1.2 mm and 0.5 respectively). Habitat segregation by the three thinocorids species at Ulla-Ulla Reserve. The morraine plains (4100-4300 m a.s.l.) are rolling plains located at the base of the crest of mountains. These are stony and nearly denuded areas with low productivity and scanty vegetation. This habitat is occupied by the Lesser Seedsnipe, which stay in flocks only during the austral winter. 150 Notes on the thinocorids of the high Andes of Bolivia

In the flat dry alluvial lands (4000-4100 m a.s.l.) only a few Lesser Seedsnipe are recorded, preferentially in stony areas. This habitat is instead occupied by resident Gray-breasted Seedsnipes, generally in pairs. This species tends to avoid stony areas and shows preference for grassy sectors. The density of the resident Gray-breasted Seedsnipe decreases during the dry season, when Lesser Seedsnipes are present. Moors or flooded (4000 m a.s.l.) in the alluvial plains are the habitat of the wintering Gray-breasted Seedsnipe, which are recorded in flocks of variable size. In the mooors or humid bottom of valleys at the crest of mountains, above the plains (4600-4900 m a.s.l) at the base of permanent snowy peaks, Attagis gayi simonsi is found. This species lives in flocks during the austral winter and in pairs in the remaining period.

Acknowledgements. We would like to thank an anonymous referee who made comments that helped me to improve the manuscript. Armando Cardozo, Humberto Alzérreca, the deceased head-gamekeeper Juan Nogales and other people from the Instituto Nacional de Fomento Lanero, especially the staff stationed at the Ulla-Ulla Reserve for their companionship and help. Also Eliana Flores, Lilian Villalba and the staff of the Museo Nacional de Historia Natural de La Paz are thanked.

Bibliography. BLAKE, E. R. 1977. Manual of Neotropical Birds. The University of Chicago Press, Chicago and London. 651pp. CABOT, J. 1988. Dinámica anual de la avifauna en cinco habitats del Altiplano norte de Bolivia. Ph D tesis. Estación Biológica de Doñana, Sevilla. Unpublished. 267pp. CABOT, J. AND P. SERRANO. 1986. Data on the distribution of some species of raptors in Bolivia. Bull. Brit. Ornith. Club 106:170-172. CABOT, J. AND P. SERRANO. 1988. Distributional data on some non passerines species in Bolivia. Bull. Brit. Ornith. Club 108:187-193. CRAWSHAY, R. 1907. The birds of Tierra del Fuego. Bernard Quaritch, London 432 pp. FJELDSÅ, J. 1987. Birds of relict forest in the high Andes of Perú and Bolivia. Technical repport from the Polylepis expedition of the Zoological Museum, 1987, with some preliminary suggestions for habitat preservation. Copenhagen. 80pp. FJELDSÅ, J. AND N. KRABBE 1990. Birds of the high Andes. Apollo Books. Denmark. 888 pp. FJELDSÅ, J. 1996. Family Thinocoridae (Seedsnipes) In Handbook of the Birds of the world. Vol. 3. p. 538-545. J. del Hoyo, A Elliott & J. Sargatal. Lynx Edicions, Barcelona, JOHNSON, A. W. 1965. The birds of Chile and adjacent regions of Argentina, Bolivia and Perú. Vol I. Platt Establecimientos Gráficos, Buenos Aires. 398 pp. MACLEAN, G. L. 1969. A study of Seedsnipe in southern South America. Living Bird 8:33-80. NORES, M., D. YZURIETA AND R. MIATELLO. 1983. Lista y distribución de las aves de Córdoba, Argentina. Bol. Acad. Nac. Cienc. Córdoba 56:114 p. OLROG, C. 1959. Las aves argentinas, una guía de campo. Universidad Nacional de Tucumán, Instituto “Miguel Lillo”, Tucumán. 344 pp. REMSEN, J. V. AND M. A. TRAYLOR. 1989. An annotated of Bolivia. Buteo Books, Vermillion, South Dakota. 80 pp. Mem. Fund. La Salle de Cienc. Nat. 154 151

Recibido: 17 julio 2001 Aceptado: 22 octubre 2001

José Cabot1, Javier Castroviejo1 e Iñigo Fajardo2

1 Estación Biológica de Doñana, Avda Mª Luisa s/n, Pabellón de Perú, 41013 Sevilla, Spain. 2 College Marcelo Spinola, Pza Arzobispo 1, 41806 Umbrete, Sevilla, Spain.