North American Bird Migrants in Paraguay ’

Home , Chaco (Paraguay), Filadelfia, Fuerte Olimpo, Villa Hayes

The Condor92~947-960 8 The cooper onlithologid society1990

NORTH AMERICAN BIRD MIGRANTS IN PARAGUAY ’

MuseoNational de Historia Natural de1Paraguay, SucursaIl9, Ciudad Universitaria, San Lorenzo, Paraguay

STEVEN M. GOODMAN~ Mu.wumof Zoology, The Universityof Michigan, Ann Arbor, MI 48109

JENNIFERA. Fox4 AND TARSICIO GRANIZO TAMAYO~ Centro de Dates para la Conservacibn,Casilla de Correo 3303, Asunci6n.Paraguay

NANCY E. ~PEZ Muse0 National de Historia Natural de1Paraguay, SucursalI9, Ciudad Universitaria, San Lorenzo, Paraguay

Abstract. The status of North American bird migrants in Paraguay is reviewed and summarized. Observations (from 1987-1989) are reported for 29 of the 32 speciesdocumented from Paraguay.New extreme migration dates, maximum counts,and distributional records are reported for many species,including six speciesof North American migrants documented from Paraguayfor the first time: Peregrine Falcon (Falco peregrinus),Black- bellied Plover (Pluvialis squatarola), Red Knot (Calidris canutus), Sanderling (C. alba), Arctic Tern (Sterna paradisaea), and Purple Martin (Progne subis). Paraguay’s Nearctic migrant fauna is dominated by aquatic nonpasserines,especially shorebirds; terrestrial non- passerinesand passerinesare poorly represented.Paraguay ’sfauna is depauperatecompared with other Neotropical areasto the north, presumablydue to its southernand inland location. Most migrant speciesfeed primarily on invertebrates. More speciesinhabit wetlands than dry areas. Key words: Bird migration; distribution;food use;habitat use;North America; Paraguay: seasonality.

Resumen. Se resume el estado de las aves migrantes norteamericanasen el Paraguay. Se informa en relaci6n alas observaciones(desde 1987 hasta 1989) para 29 de las 32 especies documentadaspara el Paraguay.Se presentandatos referentesa nuevas fechas extremas de migracibn, censosmaximos y registrosdistribucionales para muchas especies,incluyendo seisespecies de migrainesnorteamericanas documentadas para el Paraguaypor primera vez: el Hal&n Peregrino (Falco peregrinus),Chorlo Artico (Pluviahssquatarola), Player0 Rojizo (Calidris canutus), Playerito Blanco (C. alba), Gaviotln Artico (Sterna paradisaea) y Go- londrina Purpurea (Prognesubis). La fauna m&ante neartica de1Paraguay esta dominada por las aves acuaticasno-paserinas, especialmente10s playeros; las aves terrestres no-pa- serinasy las paserinase&n pobremente representadas.La fauna paraguayaes pequefia en comparacidn con otras areas neotropicales m&s al norte, presumablemente debido a su ubicacion meridional y lejos de1mar. La mayoria de las especiesmigratorias se alimentan principalmente de invertebrados. Se encuentran mls especiesen humedales que en areas secas.

INTRODUCTION ’ Received 12 February 1990. Final acceptance 15 Although more than half of the Nearctic breeding July 1990. bird speciesspend at least part of their lives as *Present address: Department of Biology, Loma Linda University, Loma Linda, CA 92350. migrants in Neotropical areas (Rappole et al. 3 Presentaddress: Department ofZoology, Field Mu- 1983), much remains to be learned of their dis- seumof Natural History, RooseveltRoad at Lake Shore tribution, abundance, and seasonality in many Drive, Chicago, IL 60605. areas of the Neotropics. In the Republic of Par- 4 Present address:11 Orrantia Circle, Danvers, MA aguay, where previous ornithological researchfo- 01923. 5Present address:Avenida Venezuela 2225, Quito, cused primarily on the distribution and taxon- Ecuador. omy of local breeding species, a paucity of

19471 948 FLOYD E. HAYES ET AL. published information exists on the occurrence by undulating or precipitous hills, none exceed- of North American migrants. In this paper we ing 800 m in elevation. report our observations, from 1987-1989, of 29 Precipitation in Paraguay is lowest in the west- speciesof North American bird migrants in Par- em Chaco, averaging lessthan 500 mm annually aguay, and review the status of all species re- in some areas, and highest in southeastern Par- ported from the country. New extreme migration aguay where an average of over 1,700 mm of dates, maximum counts, and distributional rec- rain falls annually. The distribution of precipi- ords are reported for many species,including six tation is highly seasonalin the Chaco, where rain speciesdocumented from Paraguay for the first seldom falls during the dry season,from June to time. We also compare the migrant fauna of Par- October, yet causesextensive flooding during the aguay with several other Neotropical areas and wet season, from November to May. The same discussfood and habitat use of migrants. seasonal pattern holds true for the Oriental region, although rainfall is more evenly distributed ECOLOGICAL ZONES AND CLIMATE during the year and more frequent than in the Situated in the interior of south-central South Chaco. Temperatures in Paraguay often exceed America, the land-locked Republic of Paraguay 40°C during the austral summer, and occasion- comprises an area of 406,752 km*. The country ally dip below freezing during winter, thus subis divided by the southward-flowing Paraguay jecting large portions of the country to occasional River into two distinctive regions (Fig. 1). To frost. Mean annual temperatures range from less the west, the Chaco region is essentially a vast, than 2 1°C in southeasternParaguay to over 25°C relatively flat alluvial plain gradually sloping in the northeastern Chaco. downward toward the Paraguay River from the Andean foothills. The northwestern portion of SPECIES ACCOUNTS the Chaco is arid and characterizedby xerophytic In the following accounts, species enclosed by vegetation. Further east, toward the Paraguay brackets are presently regarded as hypothetical River, the scrub forests gradually become taller in Paraguay. Figure 1 showsthe location of each and more scatteredas the terrain becomesdom- of the 19 departments (Dept.) of Paraguay; de- inated by seasonally inundated palm savannas. partments are identified only at the first mention The northeastern comer of the Paraguayan Cha- of a specific locality. Geographical coordinates co is more heavily forestedthan the lower Chaco are given for localities not listed in Paynter (1989). and is ecologically similar to the Pantanal of ad- Seasonal references pertain to the boreal cycle jacent Bolivia and Brazil. becauseNorth American bird migrants winter in East of the Paraguay River, the more topo- the southern hemisphere even though locally it graphically diverse Oriental region comprises a is summer. “Migrant” refers to birds passing mosaic of habitats. Xerophytic Chaco forma- through during fall and spring; “visitor” refers tions persist along the east bank of the river in to birds remaining during winter or summer. some areas, gradually yielding to taller and more Abundance terms are defined as follows: com- humid deciduous foreststo the east. The north- mon, observed daily in appropriate habitat; fair- eastern comer of the Oriental region is domi- ly common, observed every other day on aver- nated by a peculiar scrub forest formation re- age;uncommon, observed once every 2- 10 days; ferred to as camposcerrados. The upper Parand rare, observed at intervals of 10 or more days. River basin of the southeasternpart of the Ori- Nomenclature and sequenceof speciesfollow the ental region was once dominated by tall humid AOU (1983). forests,but as in many areas of the region, much Acronyms in addition to the authors’ initials of the forest has been cleared during the last few include: AFARP = Archive Fotografico de Aves decadesby developing agricultural communities. Raras de1Paraguay, San Lorenzo; FMNH = Field Toward the confluence of the Parana and Para- Museum of Natural History, Chicago; IML = guay Rivers, in the southwestern comer of the Instituto Miguel Lillo, Tucuman, Argentina; MAS Oriental region, the terrain is characterized by = Museo A. Schulz, Resistencia, Argentina; extensive prairies and wetlands dotted by scat- MNHNP = Museo National de Historia Natural tered patchesof scrub forests,and is ecologically de1Paraguay, San Lorenzo; MVZ = Museum of similar to the eastern Chaco. The topography of Vertebrate Zoology, University of California, the Oriental region is punctuated in many areas Berkeley; UMMZ = University of Michigan Mu- NEARCTIC MIGRANTS IN PARAGUAY 949

PARAGUAY

FIGURE 1. Map of Paraguayshowing location of 19 departmentsand major rivers. Departments: 1 = Chaco; 2 = Nueva Asuncion; 3 = Alto Paraguay;4 = Boqueron; 5 = PresidenteHayes; 6 = Conception; 7 = Amambay; 8 = San Pedro; 9 = Canindeyu; 10 =-Central; 11 = Cordillera; 12 = Caaguazk 13 = Alto Parank 14 = Paraguari, 15 = Guairl; 16 = Caazapl; 17 = Neembucti, 18 = Misiones; 19 = Itapua. seum of Zoology, Ann Arbor; and VIREO = records include single birds seen by FEH along Visual Resourcesfor Ornithology, Philadelphia, the Tebicuary River at Villa Florida, border of Pennsylvania. Depts. Paraguari and Misiones (26”25’S, 57%5’W), on 12 June 1988, and along the Par- OSPREY (PANDION HALIAETUS) aguay River near Puerto Maria, Dept. Alto Par- In Paraguay, this specieshas been recorded only aguay, on 16 June 1988. SMG noted a single bird a few times along the Paraguay River at LambarC 16 km N of Antequera, Dept. San Pedro, on 15 and Asunci6n, Dept. Central (Berlepsch 1887, September 1988. A Madrofio (pers. comm.) ob- Bertoni 1914), and at Rio Negro, Dept. Presi- served four Ospreys on 22, 24, and 26 August dente Hayes (Bent 1937). A specimen in UMMZ 1989 along the Paraguay River north of Con- wascollected 40 km WSW of Capital Bado, Dept. cepci6n. The Osprey appears to be a common Amambay, on 15 November 1938. At Bahia de migrant and winter visitor and rare summer vis- Asuncmn, we observed this speciesduring eight itor of the larger rivers in Paraguay. of 37 visits between the dates of 20 October and 29 March. Shipboardcensuses conducted by FEH MISSISSIPPI RITE along the Paraguay River between Asunci6n and (ICTINIA MISSISSIPPIENSIIS) Bahia Negra, Dept. Alto Paraguay (853 km of Specimens have been collected at (Colonia) river), revealed linear densities of 0.07 birds/ 10 Nueva Italia, Dept. Central (Blake 1949; undated km from 14-17 June 1988 (138.2 km surveyed), specimenin MAS), and at Lichtenau, Dept. Pres- 0 birds/l0 km from 9-11 August 1988 (159.8 idente Hayes (Short 1976) between the dates of km), 1.13 birds/l0 km from 25-28 October 1988 14 December and 26 February. Sightingsby FEH (195.0 km), and 0.86 birds/l0 km from 24-27 include five birds at Chore, Dept. San Pedro January 1989 (185.6 km). During these censuses (24”1O’S, 56”35’W), on 1 October 1987 (listed by Ospreys were noted at least once in each dept. Hayes and A. de Medina 1988); one with three bordering the river (Fig. 1). Noteworthy summer Plumbeous Rites (I. plumbeu) along the Ruta 950 FLOYD E. HAYES ET AL.

Tram Chaco at Rio Negro, Dept. Presidente and 25 March 1988 (adult), 30 October 1988,17 Hayes (24”12’S, 58”19’m on 16 October 1987; December 1988 (adult), and 21 October 1989; five at Cerro Acahay, Dept. Paraguari (25”53’S, on cliffs at Puerto Valle Ml, Dept. Conception, 57”15’W), on 24 March 1988; three at Puerto on 29 October 1988 (adult); flying along both Marla Auxiliadora, Dept. Alto Paraguay(21 ”43’S, sides of the river 1 km S of Conception, Dept. 57O55’W), on 27 October 1988; three at Bahia Concepcibn, on 25 January 1989 (immature); Negra on 28 October 1988; and 14 at Ayolas, and perched on a large communications tower Dept. Misiones, on 11 March 1989. This species at Bahia Negra, seen daily between 27 January appears to be an uncommon migrant and rare and 7 February 1989 (adult). On 18 September winter visitor in Paraguay. 1988, SMG noted an immature flying along the Paraguay River 10 km N of Puerto Max, Dept. SWAINSON’S HAWK (BUTEO SWAINSONI) Conception. On 30 October 1989, FEH and TGT Steinbacher (1962) reported a male collected at saw an adult female perched on a tall building Orloff, Dept. Boqueron, on 13 December 1955. in downtown Asuncion. The origin of the Par- On 3 December 1987, TGT observed a light- aguay River birds is uncertain. The timing of phased adult perched on a post in a marsh 40 these sightings suggeststhat the birds may have km SE of Bella Vista, Dept. Amambay (22”17’S, been migrating or wintering birds of North 56”21’W). On 25 February 1989, FEH noted a American origin; none was seen along the river light-phased bird (adult?) soaring over fields at during ship surveys in June and August 1988. Parque National Ybycui, Dept. Paraguari Peregrine Falcons of North American origin may (26%7’S, 56’49’W). This speciesappears to be a be uncommon migrants and winter visitors in rare winter visitor in Paraguay. Paraguay. The falcons apparently benefit from the installation of high man-made structures,of- PEREGRINE FALCON (FALCO PEREGRINUS) ten utilized as perchesand roosts, along the Par- Bertoni (19 14) reported a juvenile specimenfrom aguay River. Puerto Bertoni, Dept. Alto ParanB; the Bertoni collection apparently has been lost. Steinbacher BLACK-BELLIED PLOVER (1962) and Storer (1989) reported five specimens (PLUVIALIS SQUATAROLA) of Peregrine Falcons from the central Paraguayan This speciesis a rare migrant in the interior of Chaco, Depts. Boqueron and Presidente Hayes, South America, where it has been recorded at between the dates of 27 December and 1 June. Cordoba, Argentina (Nores and Yzurieta 1979), Four of these specimens were identified as the the Napo River region of Ecuador and the Mato Neotropical race F. p. cassini;the fifth specimen Gross0 region of Brazil (Meyer de Schauensee was unavailable for examination. In late Novem- and Mack 1982), and at Santa Cruz, Bolivia ber or early December 1987, an adult Peregrine (Schmitt et al. 1986). At Bahia de Asuncion, FEH Falcon was found dead in Asuncion (USFWS photographedsingle birds on 11 December 1987 band 576-87545; photographs in Anonymous (AFARP, VIREO x08/6/002) and on 2 Decem- 1987). The bird was banded by J. Weaver on ber 1988 (AFARP, VIREO x08/6/003); identi- 13 October 1979, as a male less than one year fications were confirmed by M. Robbins. Both old, at Loggerhead Key, Dry Tortugas, Florida birds were foraging with Lesser Golden-Plovers (G. M. Jonkel, pers. comm.). The subspecificsta- (Pluvialis dominica). A third individual was ob- tus and whereabouts of the specimen are un- served at Bahia de Asuncion by FEH and F. A. known. This is the only documented occurrence de Medina on 5 January 1989 as it foraged with of a North American Peregrine Falcon in Para- Southern Lapwings (Vanellus chilensis)and Pec- guay. Along the Paraguay River, FEH observed toral Sandpipers(Calidris melanotos).The Black- single Peregrine Falcons flying over Bahia de bellied Plovers were in nonbreeding plumage, Asuncibn on 20 October 1987 (adult), 16 De- and were observed both at rest and in flight. cember 1987, and 5 and 23 January 1989 (adult); These birds probably representsouthward-bound perched below the bridge at Puente Remanso, migrants. These are the first records of this spe- border of Depts. Presidente Hayes and Central cies in Paraguay, where it appears to be a rare (25”l I’S, 57”3 l’w), on 17 March (observed cap- but regular migrant, passing through rather late turing a Wattled Jacana [Jacanajacana] in flight) in the season. NEARCTIC MIGRANTS IN PARAGUAY 951

LESSER GOLDEN-PLOVER Bado and 40 km SW, taken as early as 3 1 August, (PLUVIALIS DOMINICA) and one from Rosario, Dept. San Pedro. At Ba- In Paraguay, this specieshas been recorded from hia de Asuncion, Greater Yellowlegs were usu- Depts. Boqueron (Steinbacher 1968) and Presi- ally present between 20 October and 23 January, dente Hayes (Bertoni 1930, Wetmore 1926, with a maximum of eight birds on 10 November Steinbacher 1962, 1968; specimens in FMNH), and 2 December 1988. FEH noted two birds near and southeastern Paraguay (Bertoni 19 14), be- Carayao, Dept. Caaguazti,on 14 September 1989, tween 6 September (Wetmore 1926) and 19 No- and one bird 5 km N of Curuguaty, Dept. Canin- vember (Steinbacher 1968). The UMMZ has deytt, on 16 September 1989. During spring mi- three specimensfrom 170 km W of Puerto Cas- gration, FEH observed one bird at Laguna Cap- ado, Dept. Boquer6n or Alto Paraguay, two from it& Dept. Presidente Hayes, on 1 April 1988; 120 km W of Puerto Pinasco, Dept. Presidente one bird on the Tebicuary River N of Villa Flor- Hayes, and a male collected on 20 November ida, in Dept. Paraguari, on 15 and 16 April 1988; 1938 from 40 km WSW of Capitan Bado. At nine birds 10 km W of San Cosme y Damian, Bahia de Asuncion, FEH and JAF regularly ob- Dept. Itapua (27”19’S, 56”25’W), on 23 March served this speciesbetween 22 October and 16 1989; and two birds at Yabebyry, Dept. Misiones December, with a maximum of 100 birds on 17 (27”23’S, 57”08’W), on 25 March 1989. The November 1988; later recordsinclude singlebirds Greater Yellowlegs appears to be a fairly com- on 8 March 1988 and 11 January 1989, and three mon fall migrant and an uncommon winter vis- birds on 17 January 1989. SMG collected three itor and spring migrant. birds (UMMZ) from a flock of 30 on 2 1 Septem- ber 1988 at Colonia Carmelo Peralta, Dept. Alto LESSER YELLOWLEGS (TRINGA FLA VIPES) Paraguay. On 31 August 1989, NEL and R. Behrstockobserved six birds at Conception. FEH In Paraguay, this specieshas been recorded from has observed small numbers on several occasions Depts. Alto Paraguay (Lopez 1985; specimensin in the central Chaco; in September most of the MNHNP and UMMZ), Boqueron (Steinbacher birds retained traces of their breeding plumage, 1962), Presidente Hayes (Wetmore 1926, Stein- whereas birds observed later were in nonbreed- bather 1962, Peris and Sukez 1985, Peris et al. ing plumage. This speciesappears to be a fairly 1987; specimensin UMMZ), Conception (Laub- common fall migrant in Paraguay through mid- mann 1939) and Central (Grant 191 l), between December, and a rare winter visitor and spring 8 August and 7 May (Steinbacher 1962, 1968). migrant. Its primary winter range appears to be The UMMZ has eight specimens from Capitin further south in Argentina (Myers and Myers Bado and one from 20 km E of Rosario. We have 1979). observed Lesser Yellowlegs at several localities in the Chaco, with maximum counts (by FEH) [SEMIPALMATED PLOVER of 266 birds at Laguna Capital on 1 April 1988, (CHARADRIUS SEMIPALMATUS)] and 140 at Bahia Negra on 18 August 1988. At Myers and Myers (1979) observed three indi- Bahia de Asuncibn, LesserYellowlegs were usu- viduals 320 km “west” (undoubtedly northwest, ally present between the dates of 20 October and in Dept. Presidente Hayes) of Asuncion, on 5 15 February, with a maximum count of 48 birds September 1973. Becauseno description of the on 17 January 1989. Elsewhere,FEH saw a single birds was given, we consider this sight record bird at Yabebyry on 25 March 1989; 20 near hypothetical. Carayao on 14 September 1989; and 35 near Curuguaty on 16 September 1989. This species GREATER YELLOWLEGS appearsto be a common migrant and winter vis- (TRINGA MELANOLEUCA) itor in Paraguay. This specieshas been recorded from Depts. Bo- quer6n (Steinbacher 1962; specimen in MVZ) SOLITARY SANDPIPER and Presidente Hayes (Wetmore 1926, Stein- (TRINGA SOLITARIA) bather 1968), from late August (Myers and My- This species is a common migrant and winter ers 1979) until 23 November (Steinbacher 1962). visitor throughout Paraguay, where it has been The UMMZ has six specimens from Capitan recorded from Depts. Alto Paraguay (Lopez 952 FLOYD E. HAYES ET AL.

1985), Boqueron (Brodkorb 1938, Steinbacher UPLAND SANDPIPER 1962, 1968; specimens in MVZ), Presidente (BARTRAMZA LONGZCAUDA) Hayes (Grant 19 11, Bertoni 1930, Wetmore 1926, In Paraguay, this specieshas been recorded from Short 1976, Pet-is and Suarez 1985, Peris et al. Depts. Presidente Hayes (Wetmore 1926, Stein- 1987), Conception (Salvadori 1895, Brodkorb bather 1968) and Conception (Wetmore 1926), 1938, Laubmann 1939), San Pedro (Brodkorb and southeastern Paraguay (Bertoni 19 14), be- 1938), Central (Contreras and Gonzalez Romero tween 29 Septemberand 12 January. The UMMZ 1988), Paraguari (Chubb 1910; specimen in has two specimensfrom 265 km W and one from MNHNP), Guaira (Dabbene 1912, Laubmann 195 km W of Puerto Casado, Dept(s). Nueva 1939, Partridge 1954) and Itaptia (Partridge Asuncion, Alto Paraguay or Boqueron, and two 1954), between 25 August (Grant 1911) and 29 specimensfrom Capitan Bado, collectedbetween March (Steinbacher 1968). A specimenin UMMZ 25 September and 11 April. At Bahia de Asun- was taken on 7 November 1938 from 40 km ci6n, Upland Sandpipers were usually present WSW of Capitan Bado. The MNHNP has a male between 25 November and 28 February, with a collected by M. R. Rolon at Parque National maximum of 12 birds on 2 December 1988. Else- Defensoresde1 Chaco, Dept. Chaco (ca. 20”2O’S, where, FEH observed single birds at Estancia La 60”3O’W), on 3 1 October 1980. We observedthis Golondrina on 14 November 1988, and at Loma speciesat many localities in Paraguay, with max- Plata, Dept. Boquer6n (22”21’S, 59”48’W), on 8 imum counts (by FEH) of 105 birds at Bahia December 1989. This speciesis an uncommon Negra on 18 August 1988, and 5 1 at Guaram- migrant and winter visitor in Paraguay. bare, Dept. Central (25”3O’S, 57”26’W), on 25 December 1987. Our maximum count at Bahia ESKIMO CURLEW (NUMENZUS BOREALIS) de Asuncion was nine birds on 9 November 1988. Sharpe (1896) reported two adults, taken from TGT frequently saw up to five birds 20 km SE Paraguay, in the British Museum (Natural His- of San Ignacio, Dept. Misiones, in 1987 and 1988. tory); one was dated 9 October. Bertoni (1899) Noteworthy recordsof FEH include one bird near stated that this speciesinhabited both dry and Tobati, Dept. Cordillera, on 24 February 1987; wet fields in Paraguay, arriving in flocks of 15 to 16 birds at Laguna Capit&i on 1 April 1988; four 20 birds in September. This nearly extinct spe- at Estancia La Golondrina, Dept. Presidente cies appearsto have been a regular winter visitor Hayes, on 30 July 1989; one near Caraya6 on 14 to Paraguay. September 1989; and one near Curuguaty on 16 September 1989. [WHIMBREL (NUMENZUS PHAEOPUS)] Peris and Sukez (1985) reported Whimbrels to SPOTTED SANDPIPER be “muy abundante” (very abundant) in the low- (ACTZTZS MACULARZA) er Paraguayan Chaco, Dept. Presidente Hayes, This species has been recorded from Paraguay in December 1983. Because there are only two in Depts. Boqueron and Presidente Hayes, be- records of this species in the interior of South tween December (Peris and Sulrez 1985) and 28 America, both from the Andes (Fjeldsa and March (Steinbacher 1962). A specimen in Krabbe 1986), we consider this species hypo- MNHNP was taken by M. R. Rolon at Parque thetical in Paraguay. National Ybycui on 22 January 198 1. On 19 February 1987, FEH observed two birds beside HUDSONIAN GODWIT (LZMOSA HAEMASTZCA) the Ruta Trans Chaco at Rio Confuso, Dept. Steinbacher (1962) reported a male collected at Presidente Hayes. In Dept. Alto Paraguay, SMG Escalante, Dept. Presidente Hayes, on 19 Sep- noted single birds near Puerto Esperanza on 19 tember 1960. On 2 October 1939, two males and September 1988, at Estancia Dofia Julia on 26 a female were collected 240 km W of Puerto and 27 September 1988, and one collected Casado, Dept. Nueva Asuncion or Boqueron (UMMZ) at Puerto Ramos on 30 September (UMMZ). At Bahia de Asunci6n, FEH and JAF 1988. JAF saw a single bird at Bahia de Asuncion observed 25 birds on 9 November 1988, 37 the on 31 January 1989. This speciesappears to be following day (photograph in AFARP), and an uncommon migrant and winter visitor along smaller numbers thereafter until a single bird the upper Paraguay River, and rare elsewherein remained on 21 December 1988. NEL and R. Paraguay. Behrstock observed six birds at Conception on NEARCTIC MIGRANTS IN PARAGUAY 953

31 August 1989. On 21 October 1989, FEH not- [SEMIPALMATED SANDPIPER ed single birds at Laguna Capit&i and along the (CALZDRZSPUSZLLA)] Ruta Trans Chaco 1 km S of Riacho San Carlos, Wetmore (1927) saw a single bird at Puerto Pi- Dept. Presidente Hayes (23%3’S, 59”l SW). The nasco, Dept. Presidente Hayes, on 1 September Hudsonian Godwit appearsto be an uncommon 1920, and a flock of 12 in the same region on 20 fall migrant in Paraguay. September 1920; no descriptionswere given. Be- cause of the possibility of confusing this species REDKNOT (CALZDRZSCANUTUS) with other Calidris spp., we consider this sight The only published records of this speciesin the record hypothetical. interior of South America are sightings of single LEASTSANDPIPER (CALZDRZSMZNUTZLLA) birds at Cordoba, Argentina, in November 1976 Steinbacher (1962) reported a female collected (Nores and Yzurieta 1979) and at La Cumbre, at Lichtenau, Dept. Presidente Hayes, on 20 Oc- Dept. La Paz, Bolivia, on 2 October 1983 (Don- tober 1960. On 5 January 1989, FEH and F. A. ahue 1986). Unpublished records include a ju- de Medina observed a Least Sandpiper from a venile, banded in Massachusettson 7 September distance of 15 m for about 8 min at Bahia de 1973 (USFWS band 722-19049), that was re- Asuncion. The bird accompanied a flock of Col- covered in November 1973, at UniSlo de Vitoria, lared Plovers (Charadrius collaris); it was slightly Brazil, and several sight records from the Bra- smaller than the plovers, and its legs were yel- zilian Pantanal in March (B. Harrington, pers. lowish in contrast to its darker bill, thus distin- comm.). On 29 October 1987, FEH and F. A. guishing it from other possible Calidris spp. The de Medina photographeda winter-plumaged Red Least Sandpiper appearsto be a rare fall migrant Knot foraging beside a Lesser Golden-Plover at and winter visitor in Paraguay, where it ap- Bahia de Asunci6n (AFARP, VIREO x08/6/004); proaches the southern extent of its wintering the identification was confirmed by B. Harring- range. ton. FEH observed a second bird, also in winter plumage and foraging with Lesser Golden-Plo- WHITE-RUMPED SANDPIPER vers, at Bahia de Asuncion on 10 November (CALZDRZSFUSCZCOLLZS) 1988. These records, presumably of southward- In Paraguay, this specieshas been reported from bound migrants, are the first of the Red Knot for Depts. Boqueron (Steinbacher 1962; specimens Paraguay, where it is probably a rare but regular in MVZ), PresidenteHayes (Wetmore 1926, Stein- fall migrant. bather 1962, Short 1976) Conception (Laub- mann 1939) and Central (Contreras and Gon- SANDERLING (CALZDRZSALBA) zalez Romero 1988; specimens in FMNH), and Sanderlings are rare in the interior of South southeastern Paraguay (Bertoni 19 14) between America; the most noteworthy records are from 30 August (Myers and Myers 1979) and 6 No- Mendoza and Cordoba Provinces, Argentina vember (Short 1976). The UMMZ has five spec- (Pereyra 1927, Nores and Yzurieta 1979), and imens from Capital Bado and 40 km WSW, col- the Manu River, southeasternPeru (Bolster and lected between 7 September and 17 November. Robinson 1990). Although Rappole et al. (1983) FEH and JAF frequently observedWhite-rumped listed this speciesfor Paraguay, there is no pre- Sandpipers at Bahia de Asuncion between 20 vious documentation of its occurrence in the October and 29 March, with a maximum of 243 country. On 17 November 1988, M. Angel, FEH birds on 17 November 1988. Their numbers ta- and JAF photographedan adult Sanderling as it pered off in December, and increased somewhat foragedwith a large flock of White-rumpcd Sand- from January to March; our highest count after pipers (C. fuscicollis) at Bahia de Asuncion December was 50 birds on 23 January 1989. (AFARP, VIREO x08/2/002); the identification Noteworthy records by FEH include three birds was confirmed by M. Robbins. This is the first at Bahia Negra on 18 August 1988; one near documented record of this speciesin Paraguay. Capiibary, Dept. San Pedro (24”49’S, 56%3’W), On 25 November 1988, FEH saw a Sanderling on 14 September 1989; and approximately 250 resting in a field with Lesser Golden-Plovers at birds 5 km N of Curuguaty on 16 September Bahia de Asuncion. These birds were probably 1989. This speciesappears to be a common fall southward-bound migrants. The Sanderling ap- migrant and an uncommon winter visitor and parently is a rare fall migrant in Paraguay. spring migrant in Paraguay. 954 FLOYD E. HAYES FT AL.

[BAIRDS’ SANDPIPER BUFF-BREASTED SANDPIPER (CALZDRZS BAZRDZZ)] (TRYNGZTES SUBRUFZCOLLZS) Although listed for Paraguay by Meyer de This species has been reported only in Dept. Schauensee(1966), we are unable to locate any Presidente Hayes, between late August (Myers documentation of this species for the country. and Myers 1979) and 21 September (Wetmore Lopez (1985) reported 15 birds from Dept. Alto 1926), and in southeastern Paraguay (Bertoni Paraguay, but the identification is suspectas nei- 19 14). The MVZ has two specimenstaken from ther Pectoral Sandpiper nor Buff-breasted Sand- 320 km NW of Villa Hayes, in Dept. Boqueron, piper (Tryngitessubruficollis), both similar to on 3 September 1973. NEL collected a female Baird’s Sandpiper and much more common in (MNHNP) at Estancia Dofia Julia on 26 Septem- Paraguay, was listed. ber 1984. At Bahia de Asuncion, Buff-breasted Sandpipers were usually present between 20 Oc- PECTORAL SANDPIPER tober and 25 November, with a maximum count (CALZDRZS MELANOTOS) of 35 birds on 25 October 1987; later records This specieshas been recorded from Depts. Alto include single birds on 16 December 1987 and Paraguay (Grant 19 1 l), Boqueron (Steinbacher 8 March 1988, and eight on 17 January 1989. 1962; specimens in MVZ), Presidente Hayes This speciesappears to be a fairly common fall (Wetmore 1926, Bertoni 1930, Steinbacher 1962, migrant and a rare winter visitor and spring mi- Short 1976), Conception (Laubmann 1939) and grant in Paraguay. Its primary winter range ap- Central (Myers and Myers 1979; specimens in pears to be further south in Argentina (Myers PMNH), and southeastern Paraguay (Bertoni 1980). 19 14), between 3 August (Myers and Myers 1979) and 7 March (Steinbacher 1962). The UMMZ WILSONS’ PHALAROPE has five specimensfrom 40 km WSW of Capit&r (PHALAROPUS TRICOLOR) Bado, and five more from 195-265 km W of This specieshas been reported from Depts. Bo- Puerto Casado. We commonly observed fair querbn and Presidente Hayes, between 3 and 27 numbers of this speciesin the Chaco and along September (Steinbacher 1962, 1968; Myers and the Paraguay River. At Bahia de Asuncion, FEH Myers 1979), and from Dept. Guairb (Laubmann and JAF observed this speciesas late as 7 April 1939). The UMMZ has a male taken from 235 1988, with a maximum of 200 birds recorded on km W of Riacho Negro (presumably at its con- 5 January 1989. New dept. records by FEH in- fluence with the Paraguay River), Dept. Presi- clude five birds near Carayao on 14 September dente Hayes, on 1 September 1939; two birds 1989 and 250 birds near Curuguaty on 16 Sep- obtained from 265 km W of Puerto Casado, on tember 1989. The Pectoral Sandpiper is a com- 3 October 1936; and two specimenscollected at mon migrant and winter visitor in Paraguay. Campo Esperanza, Dept. Presidente Hayes, on 15 October 1940. A specimen in MVZ was col- STILT SANDPIPER lected 320 km NW of Villa Hayes, in Dept. Bo- (CALZDRZS HZMANTOPUS) queron, on 4 September 1973. On 20 and 21 In Paraguay, this specieshas been reported only October 1989, FBH saw a single bird along the from Dept. Presidente Hayes, where flocks of up Ruta Trans Chaco 1 km S of Riacho San Carlos. to 40 birds have been recorded (Wetmore 1926), This speciesis apparently a rare fall migrant in between 25 August (Myers and Myers 1979) and Paraguay, occurring most frequently in ponds 30 September (Steinbacher 1962, 1968). PEH west of the Paraguay River. observed seven birds at Bahia Negra on 18 Au- gust 1988, and a single bird at Mariscal Estigar- RED PHALAROPE tibia, Dept. Boqueron, on 3 September 1988. (PHALAROPUS FULZCARZA) SMG noted a single bird along Riacho San Al- Brodkorb (1938) reported a female collected 170 berto, Dept. Alto Paraguay, on 19 September km W of Puerto Casado, Dept. Alto Paraguay or 1988. At Bahia de Asuncion, three birds were Boqueron, on 5 March 1938. observed on 9 November 1988, 34 on 17 No- vember 1988, 22 on 22 November 1988, and ARCTIC TERN (STERNA PARADZSAEA) three on 5 January 1989. This speciesappears Although the Common Tern (Sternahimdo) has to be an uncommon fall migrant and a rare win- been recorded from several inland localities in ter visitor in Paraguay. South America, including Bolivia (Di Costanzo NEARCTIC MIGRANTS IN PARAGUAY 955

1978, Remsen and Traylor 1989) there appear found this speciesto be common in Depts. Bo- to be no previous inland records for the Arctic queron and Concepci6n during the months of Tern in South America. On May 1989, FEH and January and February. Noteworthy records in- TGT found an adult Arctic Tern, in breeding clude eight seen by FEH and TGT on 16 Feb- plumage, fishing alone at Bahia de Asuncion; it ruary 1988 near Ygatimi, Dept. Canindeytt, and was photographed later that day (AFARP, VIR- singlebirds seenby FEH at Fuerte Olimpo, Dept. EO X08/ 17/00 1) and was seen the following day Alto Paraguay, on 27 October 1988, and at Cap- by FEH and JAF. The identification was con- it&r Miranda, Dept. Itapua (27”14’S, 55”49’W), firmed by K. Garrett and J. Dunn. The bird was on 14 December 1988. presumably a northward-bound migrant. [ALDER/WILLOW FLYCATCHER (EMPIDONAX ALNOR UM/TRAILLII)] BLACK-BILLED CUCKOO (COCCYZUS ERYTHROPTHALMUS) Although Fitzpatrick (1980) listed this species complex from Paraguay, there appears to be no Short (1972) reported a female collected at Lich- published documentation of its occurrencein the tenau, Dept. Presidente Hayes, on 11 December country. 1970. FEH failed to find this bird in the central Paraguayan Chaco during 3 weeks of fieldwork EASTERN KINGBIRD in January, February, and December 1988. This (TRYANNUS TYRANNUS) speciesappears to be a rare winter visitor in Par- Single specimens have been taken in Dept. Bo- aguay, where it reachesthe southern limit of its queron from 50 km S of Orloff on 17 October winter distribution. 1956 (Steinbacher 1962) and at Teniente Ochoa (21”42’S, 61“02’W) on 26 October 1972 (Schmitt YELLOW-BILLED CUCKOO and Hubbard 1974). Contreras and Gonzalez (COCCYZUS AMERICANUS) Romero (1988) reported this speciesfrom Asun- This specieshas been recorded from Depts. Bo- ci6n, but gave no details. The UMMZ has a spec- queron (Steinbacher 1962; specimensin FMNH), imen collected at Fortin Isla PO-~, Dept. Presi- Presidente Hayes (Kerr 190 1, Short 1976), Con- dente Hayes, on 26 September 1936. Near Bahia cepcion (Laubmann 1939) Amambay (Lopez, Negra, FEH saw one or two birds on 28,30 (pho- undated) and Paraguari (Chubb 19 lo), between tograph in AFARP), 31 January 1989, and 2 12 August and 1 May (Short 1976). The UMMZ February 1989; thesebirds associatedwith Fork- has a male collected from 265 km W of Puerto tailed Flycatchers (T. savanna) and Tropical Casado on 14 October 1936; a female taken at Kingbirds (T. melancholicus),foraging along the Puerto Gibaja, Dept. Alto Parana, on 3 Septem- edge of the Paraguay River and in the canopy of ber 1940; and a female obtained from 15 km E nearby scrub forests.The Eastern Kingbird may of Rosario on 8 February 1939. In January and be an uncommon migrant and winter visitor in February 1988, FEH observedthis speciesnearly the northern Paraguayan Chaco; further south it every day at Fortln Toledo (22”21’S, 60“2O’W) is rare, having been recorded as far as Misiones, and Filadelfia, Dept. Boqueron, where it appears Argentina (Kiinig 1979) and the Falkland Is- to be a fairly common migrant and winter visitor. lands (L&&que 1978). Elsewhere in Paraguay it is apparently rare. PURPLE MARTIN (PROGNE SUBIS) COMMON NIGHTHAWK On 26 September 1988, SMG collected a female (CHORDEILES MINOR) (UMMZ 226503) from a flock of lOO+ Brown- This specieshas been reported from Depts. Bo- chestedMartins (Phueoprognetuperu) at Estan- queron (Steinbacher 1962), Presidente Hayes cia Dofia Julia, Dept. Alto Paraguay; the iden- (Kerr 1901, Short 1976; specimens in FMNH), tification was confirmed by R. W. Storer. This Conception (Laubmann 1940; specimens in is the first documented record of this speciesfor UMMZ), San Pedro (Brodkorb 1938, Laubmann Paraguay. From 28 January to 7 February 1989, 1940) and Central (Berlepsch 1887) between 20 five entirely dark male martins were seen daily January and 9 March. It is a common winter by FEH at Bahia Negra; thesebirds were accom- visitor in Dept. Central, where FEH has seen panied by approximately 50 females and young flocks of up to 25 birds between 5 December males, each of which possesseda dark chest in 1987 and 12 March 1988, at Guarambart. We contrast to their whitish underparts. The birds 956 FLOYD E. HAYES ET AL. were probably Purple Martins rather than BARN SWALLOW (HIRUNDO RUSTICA) Southern Martins (Progne modesta), which have In Paraguay, this specieshas been recorded from more uniformly dusky underparts and have not Depts. Alto Paraguay (L6pez 1985), Boqueron been recorded from Paraguay. The Purple Mar- (specimen in FMNH), Presidente Hayes (Wet- tin may be a regular winter resident along the more 1926, Peris et al. 1987), San Pedro (Laub- upper Paraguay River; it has been recorded in mann 1940), Central (Bertoni 1914, 1930), and adjacent Bolivia (Remsen and Traylor 1989) and Itapua (Bertoni 19 14), between 24 September Mato Grosso, Brazil (Antas et al. 1986). (Wetmore 1926) and 28 February (Laubmann BANK SWALLOW (RIPARIA RIPARIA) 1940). The Barn Swallow is a common migrant and winter visitor in Paraguay,occurring in flocks Brodkorb (1938) reported two males collected of up to several hundred birds. FEH has observed 120 km W of Puerto Pinasco, Dept. Presidente it as early as 3 September 1988 at Mariscal Es- Hayes, on 4 January 1938. Contreras and Gon- tigarribia (three birds), and as late as 17 April zalez Romero (1988) listed this specieswithout 1988 at Villa Florida (one bird). Barn Swallows details from Asuncion. In October 1988 and Jan- are ubiquitous along the Paraguay River, where uary 1989, FEH observed flocks of up to 20 birds we have observed them in each bordering dept., at several localities in all Depts. bordering the and in fields and marshes throughout Depts. Paraguay River north of Asunci6n. Elsewhere, Chaco, Presidente Hayes, Caaguazti, Canindeyi, FEH observed about 70 birds at Laguna Salada, Cordillera, Central Paraguari, Misiones, and Dept. Presidente Hayes (22”32’S, 59”18’W), on Itapua. 1 April 1988; two at Villa Florida, Dept. Mi- siones, on 17 April 1988; two birds at Estancia [SWAINSON’S THRUSH La Golondrina on 6 November 1988 (with TGT); (CATHARUS USTULATUS)] and one near Carayao on 14 September 1989. Bertoni (19 14) listed this species from Puerto From 11-17 September 1989, TGT observednine Bertoni.I but Igave no details. birds, three of which were banded, at Parque BOBOLINK (DOLICHONYX ORYZIVORUS) National Defensoresde1 Chaco. The Bank Swal- low appears to be an uncommon migrant and This specieshas been recorded from Depts. Bo- winter visitor in Paraguay. queron (Steinbacher 1968; specimens in MAS), Presidente Hayes (Bertoni 1930, Steinbacher CLIFF SWALLOW (HIRUNDO PYRRHONOTA) 1962; specimensin MAS and IML), Concepci6n Schadeand Pallerts (197 1) reported a specimen (Laubmann 1940), Caaguazu (Salvadori 1895), from Paraguay, but did not provide any details. and Alto Parani (Bertoni 1914, 1926), between On 4 January 1938, an adult female was taken 20 September (Laubmann 1940) and 25 March from 120 km W of Puerto Pinasco (UMMZ). On (Steinbacher 1968). The UMMZ has two speci- 9 November 1980, M. R. Rolon collected an mens from 3 km E of Horqueta, taken on 12 adult male at Parque National Defensores de1 November 1937; two from 170 km W of Puerto Chaco (MNHNP). Observations by FEH include Casado, taken on 12 and 19 February 1938; and flocks of up to 80 birds in Depts. Central and one from 265 km W of Puerto Casado, taken on Misiones on many occasions; 15 at Villa Florida 31 January 1938. At Bahia de Asuncion, FEH on 17 April 1988; one at Estancia La Golondrina and JAF observed 12 Bobolinks on 22 Novem- on 6 November 1988 (with TGT); one at Coronel ber 1988,80 on 25 November 1988, and 40 on Bogado, Dept. Itapua (27”12’W, 56”l l’w), on 15 2 December 1988; all were in winter plumage. December 1988; 20+ at Emboscada, Dept. Cor- The Bobolink appears to be an uncommon mi- dillera (25”09’S, 57”2O’W), on 1 January 1989; grant and winter visitor in Paraguay. two at Puerto Esperanza on 27 January 1989; three at Bahia Negra on 29 January 1989; 50+ FAUNAL COMPOSITION AND at Parque National Ybycui on 27 February 1989; REGIONAL COMPARISONS three near San Cosme y Damian on 23 March Thus far 32 speciesof North American bird mi- 1989; and 15 near Carayao on 14 September grants have been documented from Paraguay. 1989. This speciesappears to be a fairly common Although other speciesundoubtedly will be add- migrant and winter visitor in Paraguay. ed, the present list is complete enough to warrant NEARCTIC MIGRANTS IN PARAGUAY 957

TABLE 1. Comparison of North American bird migrant species by family and ecological groups (percent composition in parentheses)in five selectedNeotropical regions.

RiioGFuTde Family S”“~::tem VtTKZUL?l~ Bolivia Paraguay Ardeidae - 2 - - - Anatidae : 1 - Accipitridae 2 2 4 3 Falconidae 1 2 1 1 1 Rallidae 1 - Charadriidae 3 5 ; 3 z Scolopacidae 26 21 20 15 16 Laridae 14 9 4 2 1 Cuculidae 1 2 1 2 2 Caprimulgidae - 2 1 - 1 Apodidae 1 1 - - - Alcedinidae 1 - - - Tyrannidae z 5 - 6 1 Hirundinidae 3 4 3 4 4 Muscicapidae 1 3 - 2 - Bombycillidae - 1 - - - Vireonidae 3: - - - Emberizidae z 1 7 1 Total families 12 18 10 11 10 Total species :: 104 :; 4: 32 Aquatic nonpasserines (79) 49 (47) (78) (46) 20 (63) Terrestrial nonpasserines 4 (7) g (8) 4 (11) 6 (13) 6 (19) Passerines g (14) 47 (45) 4 (11) 19 (41) 6 (19) comparison with other Neotropical areas. To fa- of the Amazon River, and only one as far as cilitate such a comparison, we compiled lists of Paraguay. There is also a paucity of aquatic non- Nearctic bird migrants (excluding pelagic spe- passerinesin the inland localities of Bolivia and cies) recorded from the following four regions: Paraguay, although this group neverthelesscom- southwest Peru (based on Hughes 1988); Vene- prises nearly half of the Nearctic migrant fauna zuela (Meyer de Schauenseeand Phelps 1978); in Bolivia and nearly two-thirds in Paraguay. Rio Grande do Sul, Brazil (Belton 1985); and Scolopacidsalone account for half of Paraguay’s Bolivia (Remsen and Traylor 1989). A compar- migrant fauna. The number of terrestrial non- ison of Nearctic migrants by family and ecolog- passerine migrants varies little between these ical groups for Paraguay and each of these four regions, never constituting more than a fifth of geographicregions is presented in Table 1. the total migrant fauna. The most striking pattern in this comparison is the reduction of migrant species, especially FOOD AND HABITAT USE passerines,at the more southerly localities. Ven- Terrestrial and aquatic invertebrates constitute ezuela boasts a fauna of 104 Nearctic migrant the most significant items in the diets of North species,whereas Rio Grande do Sul, Bolivia and American bird migrants in Paraguay; terrestrial Paraguay each have lessthan 50. Paraguay is the invertebrates are consumed to some extent by most depauperate of these regions. Passerines all 32 species,whereas aquatic invertebrates are comprise nearly half of the migrant bird species used by 18 (Table 2). Less frequently used food in Venezuela, but only 11% of the migrant fauna items include fruits (used by seven species),seeds of Rio Grande do Sul, the southernmost locality. (five species), terrestrial vertebrates (five spe- Like Rio Grande do Sul, Paraguay has only a cies), aquatic vertebrates (five species),terrestrial few long-distance passerine migrants, consisting plants (one species),and aquatic plants (one spe- chiefly of hirundinids. Although ember&ids make cies). Habitats most frequently utilized for for- up more than a quarter of Venezuela’s migrant aging by Nearctic migrants in Paraguay (Table fauna, few speciespenetrate the continent south 2) include beaches(used by 19 species),marshes 958 FLOYD E. HAYES ET AL.

TABLE 2. Summary of food items (based mostly on Rappole et al. 1983) and foraging habitats used by North American bird migrants in Paraguay.For food items, small caseletters refer to items constitutinga small portion of the normal diet. For habitats, upper caseX refers to more frequently used habitats; lower casex refers to less frequently used habitats. Beachesinclude water shallow enough for wading; water refers to deeperopen water.

Habitats Fooditems ’ Forests Fields Marshes Beaches Water

Mississippi Kite TI, tv X X X - - Swainson’s Hawk TI, tv - X - - Osprey AV, ti, tv - - - X X Peregrine Falcon TV, ti - - X x - Black-bellied Plover AI, TI, tp - - - x - Lesser Golden-Plover AI, TI, f - X x - Solitary Sandpiper AI, ti - - k x - Lesser Yellowlegs AI, ti - - X x - Greater Yellowlegs AI, av, ti - - X x - Spotted Sandpiper AI, TI, av - - x - Red Knot AI, TI - - x - Sanderling AI, TI - - x - Least Sandpiper AI, TI - - x - White-rumped Sandpiper AI, TI - x - Pectoral Sandpiper AI, TI - ii X - Stilt Sandpiper AI, ap, av, s, ti, tv - - x - Buff-breastedSandpiper TI, ai - X x - Upland Sandpiper TI, ai, s - - - Eskimo Curlew ai, f, TI - - - - Hudsonian Godwit AI, ti - X x - Red Phalarope AI, ti - ? ? Wilson’s Phalarope AI, TI - X ? Arctic Tern AV, ai, ti - - X Black-billed Cuckoo F, S, ti - - - - Yellow-billed Cuckoo F, S, ti - Common Nighthawk TI X - - Eastern Kingbird F, TI X - - Purple Martin TI X - X Bank Swallow TI X X X Barn Swallow TI, f X X X Cliff Swallow TI, f X - X Bobolink S, TI - - - ’ AI = aquaticinvertebrates; AP = aquaticplants; AV = aquaticvertebrates; F = fruits;S = seeds;TI = terrestrialinvertebrates; Tp = terrestrial plants;TV = terrestrialvertebrates.

(17 species), fields (13 species),forests (eight spe- Perrin, A. Robinson, P. Scharf, G. Sequera,D. Snider, cies), and open water (six species). The Nature Conservancy, United States Peace Corps and University of Michigan Museum of Zoology. ACKNOWLEDGMENTS We thank J. R. Contreras, M. S. Foster, N. K. Johnson, R. W. Storer, and two anonymous reviewers for com- LITERATURE CITED menting on earlier versionsof this manuscript;S. Soret AMERICAN ORNITHOLOGISTS UNION. 1983. Check- critiqued the Spanishabstract. Specimen recordsfrom list of North American birds. 6th ed. American various institutions were provided by J. R. Contreras, Ornithologists’ Union, Washington, DC. N. K. Johnson, and R. W. Storer. J. R. Contreras, B. ANONUMOUS.1987. Ram especiede ave lleg6 hasta Harrington, N. K. Johnson,G. M. Jonkel, A. Madrofio, Paraguay.El Diario, Asuncion, Dec. 11:15. and J. Weaver kindly allowed us to cite unpublished ANTAS, P. DE T. Z., C. YAMA~HITA, AND M. DE P. information. Funds for various trips in Paraguaywere VALLE. 1986. First record of Purple Martin provided in part by the Asociaci6n de Apoyo a las (Progne subis) in Mato Gross0 State, Brazil. J. ComunidadesIndigenas, Center for Human Potential, Field Omithol. 57:171-172. J. EscobarArgafia, Evany, German Technical Mission, BELTON, W. 1985. Birds of Rio Grande do Sul, Brazil. JapaneseInternational CooperationAgency, New York Part 2. Formicariidae throughCorvidae. Bull. Am. Zoological Society, Ministerio de Agricultura y Gana- Mus. Nat. Hist. 180:1-241. deria, Ministerio de Defensa National, Sigma Xi, R. BENT,A. C. 1937. Life histories of North American NEARCTIC MIGRANTS IN PARAGUAY 959

birds of prey. Part 1. Bull. U.S. Natl. Mus. 167: LAUBMANN,A. 1939. Wissenschaftliche ergebnisse 1409. der DeutschenGran Chaco-Expedition. Die Vogel BERLEPSCH,H. 1887. Systematischesverzeichniss der von Paraguay.Vol 1. Streckerund Schriider, Stutt- von Herm Ricardo Rohde in Paraguay gesam- gart. melten Vogel. J. Omithol. 35: l-37, 113-134. LAUBMANN,A. 1940. Wissenschaftliche ergebnisse BERTONI,A. DEW. 1899. Cat&logodescriptive de las der DeutschenGran Chaco-Expedition. Die Vogel aves utiles de1Paraguay. Rev. Agr. Cs. Apl., Asun- von Paraguay. Vol. 2. Strecker und Schriider, cibn 1:377-410. Stuttgart. BERTONI,A. DEW. 1914. Fauna paraguaya.Catalogos L~&QuE, R. 1978. Premiere observation du Tyran sistematicosde 10svertebrados de1 Paraguay. Grl- tritri Tyrannustyrannus aux iles Falkland. Alauda fico M. Brossa,Asuncion. 46:362. BERTONI,A. DEW. 1926. Apuntesomitologicos. Hor- ti~nz, N. 1985. Avifauna de1Departamento de Alto tier0 3:39wOl. Paraguay.Volante Migrato&4:9-13. BERTONI,A. DEW. 1930. Sobreomitologia de1Chaco MP)PEZ.N. Undated. Paraue National Cerro Cora. Paraguayo:Aves colectadaspor Felix Posner en Lista de aves. ServicioForestal National de Par- la Colonia “Monte Sociedad”, hoy Benjamin Ace- aguay,Amambay, Paraguay. val (Villa Hayes). Rev. Sot. Cient. Parag. 2:241- MEYERDE SCHAUENSEE.R. 1966. The soeciesof birds 257. of South America and their distribution. The BLAKE,E. R. 1949. Ictinia mississippiensiscollected Academy of Natural Sciences of Philadelphia, in Paraguay.Auk 6682. Philadelphia, PA. BOLSTER,D. C., AM) S. K. ROBINSON.1990. Habitat MEYERDE SCHAUENSEE,R., AND A. L. MACK. 1982. useand relative abundanceof shorebirdsin a west- Addenda to “A guide to the birds of South Amer- em Amazonian site. Condor 92~239-242. ica,” p. 429-463. In R. Meyer de Schauensee,A BRODKORB,P. 1938. Further additions to the avifau- guideto the birds of SouthAmerica. The Academy na ofparaguay.Gccas. Pap. Mus. Zool. Univ. Mich. of Natural Sciencesof Philadelphia, Philadelphia, 394: l-5. PA. (Reprinted by The Pan American Section,The CHUBB,C. 1910. On the birds of Paraguay.Ibis, series International Council for Bird Protection). 9,4:53-78, 263-285, 517-534, 5il-b47. MEYER DE SCHAUENSEE,R., AND W. H. PHELPS,JR. CONTRERAS.J. R.. ANDN. GONZALEZROMERO. 1988. 1978. A guide to the birds of Venezuela. Prince- Una avifauna intraurbana en la ciudad de Asun- ton Univ. Press, Princeton, NJ. cion, Departamento Central, Republica de1 Par- MYERS,J. P. 1980. Territoriality and flockingby Buff- aauav. D. 30-34. In J. R. Contreras Ied.1. Omi- breasted Sandpipers: variations in non-breeding tolo&-Argentina-Paraguay, 1988. C&i&es. dispersion. Condor 82:241-250. DABBENE,R. 1912. Contribution a la omitologia de1 MYERS,J. P., AND L. P. MYERS. 1979. Shorebirdsof Paraguay;notas sobre las aves colectadasen Villa coastal Buenos Aires Province, Argentina. Ibis Rica por el sefior Felix Posner. An. Mus. Nat., 1212:186-200. BuenosAires 23:283-390. Noans, M., AND D. Yzuamr~. 1979. Aves de costas DI COSTANZO,J. 1978. Occurrencesof the Common marinas y de ambientescontinentales, nuevas para Tern in the interior of South America. Bird-Band- la Provincia de C6rdoba. Homer0 12:45-52. ing 49~248-251. PARTRIDGE,W. H. 1954. Estudio preliminar de una DONAHUE,P. K. 1986. Sight record of Red Knot for coleccionde aves de Misiones. Rev. Mus. Arg. Cs. Bolivia. Am. Birds 40:224. Nat. B. Rivadaria, Cs. Zool. 3:87-153. FIT~PATIUCK,J. W. 1980. Wintering of North Amer- PAYNTER,R. A., JR. 1989. Ornithological gazetteer ican tyrant flycatchers in the Neotropics, p. 67- of Paraguay.2nd ed. Museum of Comparative Zo- 78. In A. Keast and E. S. Morton [eds.], Migrant ology, Cambridge, MA. birds in the Neotropics: ecology, behavior, distri- PERFYRA,J. A. 1927. Segundalista de avescolectadas bution, and conservation.Smithsonian Institution en la regidn ribereiia de la Provincia de Buenos Press, Washington, DC. Aires. Homer0 4:23-34. FJELDSA,J., AND N. KRABBE. 1986. Some range ex- PERIS, S., L. A. CABELLO,F. Sub, AM) B. Pnco. tensionsand other unusualrecords ofAndean birds. 1987. Las aves de1baio Chaco: evaluaci6n ore- Bull. Br. Omithol. Club 106:115-124. liminar. Inf. Cient. 5327-33. GRANT,C.H.B. 1911. List of birds collected in Ar- PERIS,S. J., AND F. SuAw. 1985. Algunas aves in- gentina, Paraguay, Bolivia, and southern Brazil, vemantes en el bajo Chaco Paraguayo. Volante with field-notes. Ibis, series9,5:80-137,317-350, Migratorio 5:20. 459-478. RAPPOLE,J. H., E. S. MORTON,T. E. L~WOY, III, AND HAYES,F. E., ANDF.E.A. DE MEDINA. 1988. Notes on J. L. Ruos. 1983. Nearctic avian migrants in the the ecologyof the avifauna of Chore, Department Neotropics. Fish and Wildlife Service, U.S. De- of San Pedro, Paraguay.Homer0 13:59-70. partment of the Interior, and World Wildlife HUGHES,R. A. 1988. Nearctic migrants in southwest Fund-U.S., Washington, DC. Peru. Bull. Br. Omithol. Club-108:29-43. REMSEN,J. V., JR., AND M. A. TRAYLOR,JR. 1989. KERR. J. G. 1901. On the birds observed durina a An annotated list of the birds of Bolivia. Buteo second zoological expedition to the Gran Chaco. Books, Vermillion, SD. Ibis, series 8, 1:215-236. SALVAWIU,T. 1895. Viaggio de1dott. Alfred0 Borelli K&JIG, C. 1979, Presenciade Tyrannus tyrannusen nella Republica Argentina e nel Paraguay.Ucelli Misiones. Homer0 12:55-56. raccolti nel Paraguay,nel Matto Grosso, nel Tu- 960 FLOYD E. HAYES ET AL.

cuman e nella Provincia de Salta. Boll. Mus. Zool. SHORT,L. L. 1976. Notes on a collection of birds Anat. Comp. Torino 15(378):1-19. from the Paraguayan Chaco. Am. Mus. Novit. SCHADE,F., ANDR. M. PAL~RES. 1971. Lasaves de1 2597:1-106. ParanuavY un indice. Rev. Paraa. Microbial. 6: STEINBACHER,J. 1962. Beitragezur Kenntnis der V6- 103--l2i. _ gel von Paraguay. Abh. Senckenb. Nat. Gesell. SCHMITT, G., AND J. P. HUBBARD. 1974. Eastern 502:1-106. Kingbird in Paraguay.Wilson Bull. 86:466. STEINBACHER,J. 1968. Weitere Beitriige tiber Vogel SCHMITT,C. G., D. C. SCHMITT,J. V. REMSEN,JR., AND von Paraguay.Senckenb. Biol. 49:317-365. B. D. GLICK. 1986. New bird records for De- STORER,R. W. 1989. Notes on Paraguayan birds. partamento SantaCruz, Bolivia. Homer0 12:307- Occas. Pap. Mus. Zool. Univ. Mich. 7 19:1-21. 311. WETMORE,A.- 1926. Observations on the birds of SHARPE,R. B. 1896. Catalogue of the Limicolae in Argentina,Paraguay, Uruguay and Chile. Bull. U.S. the collection of the British Museum. British Mu- Natl. Mus. 133:l-448. seum (Natural History), London. WETMORE,A. 1927. Our migrant shorebirdsin south- SHORT,L. L. 1972. Two avian speciesnew to Para- em South America. U.S. Dep. Agric. Tech. Bull. guay. Auk 89:895. 26: l-24.