AMERICAN MUSEUM Novitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET NEW YORK, N.Y. 10024 U.S.A. NUMBER 2597 JUNE 8, 1976

LESTER L. SHORT Notes on a Collection of From the Paraguayan Chaco :;It0~ ~ ~fft ~ 1~ 6 #aSs 02:n[ AMERICAN MUSEUM Novitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 2597, pp. 1-16 June 8, 1976

Notes on a Collection of Birds From the Paraguayan Chaco

LESTER L. SHORT'

ABSTRACT Systematic, distributional, molt, and breeding nor panamensis i neotropicalis, and certainly data are- provided for 723 specimens obtained represents a Middle American or Colombian pop- from the collection of Jacob Unger, mainly in ulation. The first western Paraguayan hybrid the vicinity of Lichtenau in the Paraguayan flickers (Colaptes campestris campestris X cam- chaco. The specimens represent 180 , in- pestroides) are described. Data are presented on cluding four (Coccyzus erythrophthalmus, Lep- the features and polymorphism of the wood- tasthenura platensis, Pseudocolopteryx acutipen- pecker Dryocopus schulzi. Agriornis microptera nis, and Aimophila strigiceps) reported for the microptera winters northward from Patagonia to first time from Paraguay based on this collection. the Paraguayan chaco and Cochabamba, . The status of the "chacoensis" Anthus chacoensis is noted as a valid species, is discussed, and warrants treatment as a subspe- with a breeding range indicated for the first time cies of N. maculosa. A problematical nighthawk (Cordoba, ). The status of many sub- specimen is assigned tentatively to Chordeiles mi- species is discussed. INTRODUCTION Several recent shipments of birds from the . Its features and birds were re- collection of Jacob Unger have come to the ported by Short (1975). Other relatively recent American Museum of Natural History and are the important works involving Paraguayan chaco subject of the present report. A total of 723 birds are those of Steinbacher (1962, 1968). The specimens were taken at diverse seasons during Lichtenau area is in the central chaco of Para- 1960 to 1974 in the Paraguayan chaco, mainly in guay, well west of the pantanal (wet palm sa- the vicinity of Lichtenau (approximately lat. vanna) that borders the Paraguay River, and just 22049' S, long. 59039' W) at about 180 km. east of the driest portion of the Paraguayan west of the Paraguay River, almost due west of chaco (which is less xeric than is the very dry Puerto Pinasco. central Argentine chaco). Maps indicating the lo- The chaco, a low, flat, xeric woodland area, is cation of Lichtenau were provided by Stein- situated inland from the sea in south-central bacher(1962,p. 12) and by Short(1972a, p. 32).

'Curator, Department of Ornithology, the American Museum of Natural History; Adjunct Professor, City Univer- sity of New York.

Copyright O The American Museum of Natural History 1976 ISSN 0003-0082 / Price $1.15 2 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597

Measurements of wing length that are men- and more grayish, less rusty breast. Nothura bo- tioned are those of the chord of the wing. raquira differs from N. cinerascens in its smaller All birds in the collection obtained from Mr. size (no overlap) and buffier, less gray coloration. Unger are treated herein (a few also have been The October and March males are in breeding reported elsewhere, as cited below). The follow- condition, implying a long breeding season. The ing systematic list is in the of that in Short immature male differs from adults in its browner (1975). Authorities for the scientific names em- back color, less barred flanks, and especially, its ployed here can be found in Meyer de Schauen- black-spotted neck and breast. I have compared see (1966), and in the various volumes of the it with two similarly spot-breasted, undoubted Catalogue of Birds of the Americas by Hellmayr, immatures of N. b. boraquira. As pointed out in by Hellmayr and Conover, or by Cory. Only new Short (1975), the rather weak differentiation of data are presented, hence some species merely chaco marmorata implies a recent contact with are listed for the sake of completeness. caatinga boraquira. I am grateful to Drs. Dean Amadon, Eugene Nothura maculosa chacoensis. Spotted Nothu- Eisenmann, John Farrand, Wesley E. Lanyon, ra. Males, October 16, and November 12; fe- and the late Charles Vaurie for assistance in iden- males, May 11, August 11, September 28, Octo- tifying specimens of species of groups in which ber 15, and November 12. This chaco form has they specialize, or for other assistance in the been treated as a species, but indications are that course of this investigation. it interbreeds with adjacent pantanal N. m. palu- divaga in the narrow zone west of the Paraguay SYSTEMATIC LIST River where the palm or pantanal meets the dry chaco woodland. The seven specimens FAMILY TINAMIDAE show considerable variation in the tone of the tataupa tataupa. Tataupa Tina- underparts, the amount of barring on the flanks, mou. Females, May 28, October 30. The latter and especially the spotted and streaked upper was noted as breeding. breast, and the barring of the upperparts. Gen- Nothura () cinerascens ciner- erally, chacoensis is vermiculated, with deep bars ascens. . One male, July 1, sparse dorsally, but two of the seven specimens three males, November 10 to 28; females, No- are moderately barred and one female is barred vember 10 and 22. November birds with gonads as heavily as in other races of maculosa. One fe- in breeding condition. male (May 11, fresh plumage, and in fact molt- Nothura boraquira marmorata. White-breasted ing), sparsely barred dorsally, has strong tan ven- Tinamou. Males, March 27, April 30, October 17; tral coloring, and its upper breast is entirely female, July 8; immature male, May 28. This spe- streaked, the usual dark spots being assimilated cies, and especially the chaco form, closely re- into streaks such that there is no apparent spot- sembles N. cinerascens and almost can be con- ting. These specimens are easily separable from sidered a sibling species with the latter. Olrog paludivaga by their upperpart color and pattern, (1963, p. 425) noted that the behavior of bora- with a rufescent tone (little or no gray cast), and quira is more like that of cinerascens than that of much lighter color than in the heavily barred, Nothura darwinii and N. maculosa. It resembles blacker paludivaga. Ventrally, they tend to be cinerascens in its general pattern and shape of paler, and the spot-streaks of the upper breast are bill, color tone, pattern of wing markings (no smaller and finer. Although chacoensis is smaller barring on inner vanes), barring of the sides and in size than paludivaga and other races of macu- flanks, and pale (whitish) underparts. Indeed, the losa, except cearensis, the difference among weakly defined chaco race marmorata tends forms of N. maculosa is not great. There is over- away from caatinga (zone of and scrub woods of lap, especially between adjacent races paludivaga northeastern ) N. b. boraquira and toward and chacoensis (12 specimens of the former, 22 N. cinerascens in its subspecific characters, of the latter available for comparison), and only namely, less rusty, browner nape; darker brown very small chacoensis can be separated men- and grayer, less rusty back; blacker wing coverts; surally. The difference between chacoensis and 1976 SHORT: PARAGUAYAN CHACO BIRDS 3 paludivaga in length of middle toe given earlier and the background is decidedly grayer and less (Short, 1975, p. 190) does not hold, for I now buff. The dorsal pattern of formosa is brown have measurements of chacoensis falling within with fine vermiculations, some bars, and large the range of measurements of paludivaga, even to buff spots; elegans is grayer with smaller, more their upper extreme (30.5) mm.). Using wing numerous spots. The tail of elegans is barred length, bill length, tarsal length, and length of buffy white and brownish black, and that offor- middle toe, it can be seen that about one-quarter mosa has vermiculations (much finer barring) and of chacoensis specimens are separable from palu- dark marks about the shaft, but the pattern is divaga on the basis of lesser measurements. The very much browner and less contrasting. Finally, sparse material I have seen of little known N. m. the outer primaries of formosa are unbarred on pallida (northwestern Argentina north to Formo- the inner vane, or bear vague traces of barring sa and extreme southwestern Paraguay) indicates basally, whereas elegans has strongly barred pri- that pallida is small, closely approaching chaco- maries (both vanes). formosa may be a ensis in size. Conover (1950) mentioned speci- trifle smaller than E. elegans magnistriata, but mens possibly intermediate between chacoensis more specimens must be measured to acquire and paludivaga from northern Paraguay. A fe- data to substantiate or nullify this point. male specimen (AMNH 802523) from 60 km. east of Orloff, in the eastem Paraguayan chaco, FAMILY PODICIPEDIDAE taken in November, 1956, shows a gray-brown mixture dorsally with heavy dorsal barring, Podiceps dominicus speciosus. Least Grebe. rather buffy underparts, strong breast streaking, Males, February 12, November 19; female, No- and is within the size overlap between paludivaga vember 19; downy young male and female, Feb- and chacoensis; it appears to be an intermediate ruary 12. The three adults show enlarged gonads. (intergrade) specimen. The birds taken from Sep- The adults measure 90 to 98 mm. in wing length, tember to November were noted as having en- agreeing with the 92 to 98 mm. reported for six larged gonads. birds from Orloff in the Paraguayan chaco by Eudromia formosa mira. Quebracho Crested Steinbacher (1962), and with measurements of Tinamou. Males, February 25, June 30; partly the wide ranging speciosus (Hellmayr and Con- grown immature female, December 19. This little over, 1948). known form differs hardly at all from the nomi- Podiceps rolland chilensis. White-tufted nate Argentine , being a bit browner, Grebe. Female, February 15. Ovary not enlarged less gray above (including the neck). The Febru- (breeds in the area, see Steinbacher, 1962). ary male had enlarged testes. The half-sized im- Podilymbus podiceps antarcticus. Pied-billed mature bird closely resembles the adults, but is a Grebe. Female, December 13. Ovary enlarged. bit duller, with a darker neck, and the inner Steinbacher (1962) reported young birds from vanes of its outer primaries are barred basally, nearby Orloff during March. showing a tendency toward the barred feathers of E. elegans. It might prove useful to compare E. FAMILY ARDEIDAE formosa (see also Olrog, 1959) with the nearest Butorides striatus striatus. Striated Heron. Fe- form of E. elegans,, namely E. e. magnistriata of males, November 26, December 24; immature fe- Santiago del Estero and adjacent Cordoba. Ven- male, December 24. The November bird had a trally E. formosa is whiter, although varying con- large ovary, and, with the immature bird above siderably; its breast and side bars bear strong and Steinbacher's (1962) November birds with shaft streaks, forming inverted T-bars that are large gonads from the Paraguayan chaco, this in- only hinted at in elegans. The upper breast is dicates breeding in September to November. The patterned with a combination of dark shaft adults and one other female from eastem Para- streaks and several connected bars on a brown guay are exceptionally rufescent on the sides and and buff background; in elegans the barring is back of the neck, and few South American speci- weakly developed, the bars are not connected mens match them. I can find no clear indication with the shaft streaks, and, if present, are finer, of the traits of "fuscicollis" given by Hellmayr 4 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597 and Conover (1948) for southern South Ameri- FAMILY FALCONIDAE can birds, and prefer to treat this as a synonym Bat Falcon. Fe- ofB. s. striatus. Falco rufigularis rufigularis. Egretta thula thula. Snowy Egret. Female, male, May 25, ovary enlarged. I follow Brown and Amadon (1968) in treating all South Ameri- April 29. can and Middle American birds, except those of western Mexico, as representing this subspecies. FAMILY ANATIDAE Falco femoralis femoralis. Aplomado Falcon. Callonetta leucophrys. Ringed Teal. Male and Male, February 21. female, November 14, both with enlarged go- nads. FAMILY CRACIDAE Oxyura dominica. Masked Duck. Two males, December 27; females, July 14, December 14, Ortalis canicollis canicollis. Chaco Chachalaca. and two on December 27. One December male Two males, June 8, female, February 1. The and two December females had enlarged gonads. males measure 218 and 232 mm., and the female One male shows a 14 by 10 mm. patch of im- 212 mm. in wing length. Both males have rufous maculate white on the forethroat, just inside the only in the outer two tail feathers, and the fe- black "mask" area, with scattered white spots male has some rufous at the tip of the third pair around it. Only one of 14 other adult males in from the outside. Vaurie (1964) has pointed out the American Museum of Natural History collec- that variation is too great to admit Steinbacher's tion shows a hint of this patch, and the patch is 0. c. ungeri as a subspecies from the Paraguayan much smaller. The July female, like other worn chaco. These three birds are assignable to the birds I have seen, has the tail worn to a "frazzle" wide-ranging, small, and pale nominate canicollis. tip, the bare shafts with some barbs extending 32 The female was commencing to molt (inner pri- mm. beyond the unworn part of the feathers. maries), and had an enlarged ovary. The males are in fresh plumage, one of them just terminat- ing the annual molt (central rectrices almost fully FAMILY ACCIPITRIDAE grown). Chondrohierax uncinatus uncinatus. Hook- billed Kite. Male adult, January 1, testes en- larged. FAMILY ARAMIDAE Gampsonyx swainsonii swainsonii. Pearl Kite. Aramus guarauna guarauna. Limpkin. Female, Female, January 5. Ovary enlarged. Sides im- February 13. With a wing length of 353 mm., maculate white. this may be a mis-sexed bird. It is clear from Ictinia misisippiensis. Mississippi Kite. Female, measurements given by Hellmayr and Conover February 19. (1942) that southern South American Limpkins Accipiter bicolor guttifer. Bicolored Hawk. are larger (longer winged) than are those from Immature "male," February 8. The bird is large, the northern part of the continent. One can state and is heavily streaked with a strong rusty buff that there is a cline, without treating the matter background color ventrally, hence represents an nomenclaturally. The specimen reported here is immature female of this race. very long-winged, but at best the increase in wing Accipiter striatus erythrocnemius. Sharp- length southwardly would seem to involve only a shinned Hawk. Females, May 15, June 20. These 5 to 7 percent increase, not enough to warrant have the shallow streaks and bars of this subspe- racial treatment (as "carau") of southern birds cies. Breeds (Steinbacher, 1962). apart from guarauna. Buteogallus urubitinga urubitinga. Great Black Hawk. Adult male, August 12. FAMILY RALLIDAE Buteo albicaudatus albicaudatus. White-tailed Hawk. Adult male, August 22, immature female, Rallus maculatus maculatus. Spotted Rail. April 16. Male, October 27, enlarged testes. 1976 SHORT: PARAGUAYAN CHACO BIRDS 5

Neocrex erythrops olivascens. Paint-billed FAMILY COLUMBIDAE Crake.-Male, February 18, female, April 12, both with enlarged gonads. Columba picazuro picazuro. Picazuro Pigeon. Porphyriops melanops melanops. Spot-flanked Three females, January 9 and April 22. The two Gallinule. Males, January 25, February 21, April April birds are completing the molt, and the 22, November 19, December 20; female, Febru- January bird had a much enlarged ovary. Chaco ary 21. All have enlarged gonads except the April birds assigned to this subspecies are noticeably bird, and the two February specimens had much paler, grayer, less violaceous pink than are speci- enlarged gonads. The January and February birds mens from east, northwest and west of there. were molting. Columba cayennensis sylvestris. Pale-vented Gallinula chloropus galeata. Common Gal- Pigeon. Two females, March 15. linule. Female, February 12. Zenaida auriculata chrysauchenia. Eared Porphyrula martinica. Purple Gallinule. Two Dove. Males, January 9, July 4, and (two) Octo- males, April 3; female, January 2, all with en- ber 27. Testes enlarged in October males, very larged gonads. much enlarged in January bird. Races of this spe- Fulica leucoptera. White-winged Coot. Males, cies need to be worked out carefully, with abun- November 10, January 2; two females, January 2 dant material. all with enlarged gonads. Columbina squammata squammata. Scaly Ground Dove. Females, January 7, and (two) May 6. The January bird was in breeding con- FAMILY JACANIDAE dition. Jacana jacana jacana. Wattled Jacana. Male, Columbina talpacoti talpacoti. Ruddy Ground January 25; female, same date, both with much Dove. Six males from December and January, enlarged gonads. one April male (mislabeled female); two females, February 20, one immature female, February 9. FAMILY ROSTRATULIDAE The December and January males all have en- larged testes, but gonads are not enlarged in the Nycticryphes semicollaris. South American others. Painted Snipe. Two males, February 12; two fe- Columbina picui picui. Picui Dove. Males, males, same date, all with enlarged gonads, one October 12 and February 20, and female (labeled female with much enlarged ovary. male), July 4. Both males with enlarged testes. Leptotila verreauxi decipiens. White-tipped FAMILY CHARADRIIDAE Dove. Males, July 7, October 31; females, July 12, November 27. Gonads enlarged in October Charadrius collaris. Collared Plover. Males, and November birds, which are very worn. November 26, December 14.

FAMILY SCOLOPACIDAE FAMILY PSITTACIDAE Calidris fuscicollis. White-rumped Sandpiper. Aratinga acuticauda acuticauda. Blue-crowned Male, November 6. Parakeet. Male, October 19; females, May 30, Oc- Calidris melanotos. Pectoral Sandpiper. Male, tober 19. The October birds had enlarged gonads. November 26. Myiopsitta monachus cotorra. Monk Parakeet. Tringa solitaria cinnamomea. Solitary Sand- Females, May 8, September 2. I find essentially piper. Three males, November 6 to 21. no differences separating northern chaco (cotor- ra) from southem and southwestern birds (calita, often "corrected" to catita after the Spanish FAMILY RECURVIROSTRIDAE name of the bird, but see Naumburg, 1930, p. Himantopus melanurus. White-backed Stilt. 129) and treat calita as a synonym of cotorra. Male, female, July 19. This small form differs in size and color from 6 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597 more eastern and southeastern monachus, and FAMILY TYTONIDAE from Bolivian luchsi. Amazona aestiva xanthopteryx. Turquoise- Tyto alba tuidara. Bam Owl. Male, December fronted Parrot. Males, April 25, November 7; fe- 10. A very white bird, almost unspotted below, male, April 25. The November male had enlarged approaching in color Amazonian specimens. testes; the other male is completing its annual molt. These birds all have the bend of the wing FAMILY STRIGIDAE red proximally, but almost entirely yellow distal- Otus choliba choliba. Tropical Screech Owl. ly, as do many xanthopteryx from farther south Four February males; a February female, an im- and west. Intermediates between xanthopteryx mature female from March 5; and an immature and nominate aestiva come from northwestern questionably a male, February 8. All February Paraguay and southern Mato Grosso (specimens, adults are in middle or late stages of wing molt. AMNH). These birds are a rather uniform grayish, but two adults are grayer, the other three being a paler, FAMILY CUCULIDAE browner gray. Coccyzus cinereus. Ash-colored Cuckoo. Male, Bubo virginianus nacurutu. Great Horned December 27; females, January 3 and June 15. Owl. Male and female in fresh plumage taken 90 The first two of these have enlarged gonads; the km. southwest of Lichtenau on August 14. third has not yet completed its wing molt. Glaucidium brasilianum tucumanum. Ferru- Coccyzus melacoryphus. Dark-billed Cuckoo. ginous Pygmy-owl. Males, taken March, August, Males, February 25, July 5, November 29; fe- October, November. The last two birds had en- male, December 22; immature male, November larged testes. Two of these are in gray phase, two 29; immature females, February 2 and 20, May are in rufous phase. The chaco race pallens Brod- 30. The November and December adults had en- korb may be recognizable, although resembling larged gonads. tucumanum of northwestem Argentina, because Coccyzus americanus. Yellow-billed Cuckoo. of its smaller size; but one can simply state that Four males, August 12 to November 30; two fe- tucumanum tends to be smaller and paler north- males, May 1 and September 12. The extreme wardly. Compared with Santiago del Estero tucu- dates for this migrant from North America, Au- manum the four males from Lichtenau are small- gust 12 and May 1, leave but three months when er (shorter winged); the gray phase birds are less this species is not in the chaco. Extreme measure- spotted, and the rufous phase birds are nearly ments for these birds are 137 and 149 mm., both identical. Mato Grosso specimens, even from the males. I am unable to separate the weakly de- far south of that state, are larger and represent fined races of this species with the material at brasilianum. Eastem Paraguayan specimens are hand. very dark, and represent ferox, if that form is Coccyzus erythrophthalmus. Black-billed distinct from brasilianum. Cuckoo. Female, December 11. Previously re- Athene cunicularia cunicularia. Burrowing ported (Short, 1972b) as the first Paraguayan Owl. Two males, April 24. See racial discussion specimen of this cuckoo. by Short (1975). Crotophaga ani. Smooth-billed Ani. Two Strix rufipes chacoensis. Rufous-legged Owl. males and a female, all in breeding condition, Males, February 8 and 13, and October 22, last between November 29 and December 18. with enlarged testes. Guira guira. Guira Cuckoo. Male, October 18 Asio flammeus suinda. Short-eared Owl. Fe- and female, October 11, both with enlarged go- male, October 12 (gonads not enlarged). nads. Tapera naevia chochi. Striped Cuckoo. Males, October 15, November 27; females, May 2, Octo- FAMILY NYCTIBIIDAE ber 12 and 15, and November 27; immature Nyctibius griseus comutus. Common Potoo. male, March 3. All adults except the May bird Males, October 27, December 4; female, Febru- had enlarged gonads. ary 8. Both males had enlarged testes. 1976 SHORT: PARAGUAYAN CHACO BIRDS 7

FAMILY CAPRIMULGIDAE so little difference (only in size, about 7 percent, hence overlap is great) between striatipectus and Caprimulgus parvulus parvulus. Little Night- pallidigula of Mato Grosso that the latter ought jar. Females, January 5, December 9; immature to be merged into striatipectus. These birds are female, January 3. Birds from the chaco and nearer Argentine than Mato Grosso birds in size. northeast to the caatinga tend to be smaller than those from farther south (Argentina), the varia- tion probably being clinal. FAMILY PICIDAE Podager nacunda nacunda. Nacunda Night- Picumnus cirratus pilcomayensis. White-barred hawk. Male and female, May 5, fresh plumaged. Piculet. Male, August 26; female, March 30. Chordeiles minor panamensis > neotropicalis? Sparse ventral barring is found in these as in most Common Nighthawk. Male, February 5. This specimens of this variable form. specimen was examined by Eisenmann after I Picoides mixtus malleator. Checkered Wood- found that it strongly resembled panamensis pecker. Two February males, eight females from (see Eisenmann, 1962), the winter range ofwhich January, February (three), May, September is unknown. It is small in size (wing length 176 (two), and December. Only one bird, a female mm.) and rather rusty in color, approaching taken September 22, had enlarged gonads. panamensis, but, according to Eisenmann (in Melanerpes candidus. White Woodpecker. lett.) "it is not typical of that form, which tends Seven males from March (two, one immature), to be even darker and more rufescent with a nar- May, August, October, and December (two); and rower wing-band. Probably it belongs to the Cen- females taken February 7 and August 1. The tral American population intermediate between February and March birds are in early to middle neotropicalis (described from Chiapas) and pan- molt stages, the May bird is completing its molt, amensis." Its features suggest that it represents and the October and December males had much such an intergradient population, but Eisenmann enlarged testes. points out that it possibly could represent an Melanerpes cactorum. White-fronted Wood- undescribed Colombian form related to pan- pecker. Males, March 2, July 26, August 11, Oc- amensis, known from a June specimen from tober 13; and females, February 15, July 26 in the Academy of Natural Sciences of (two), December 18, and December 19. The Feb- Philadelphia, and identified (by Meyer de Schau- ruary and March birds are in molt, and only the ensee) as C. m. henryi prior to the description of October male and one December female have en- panamensis. larged gonads. Of these specimens, eight have a yellow throat and one lacks yellow there, show- FAMILY TROCHILIDAE ing polymorphism as noted previously (Short, Chlorostilbon aureoventris aureoventris. Glit- 1975). tering-bellied Emerald. Male, January 11. Testes Piculus chrysochloros chrysochloros. Golden- This specimen is very green, with little green Woodpecker. Males, January 4, February enlarged. October November of the bronzy orange tinge of aureoventris, but 22, 8, 13; females, February does not match lucidus in throat color. 22, October 8; immature male, February 3; im- Hylocharis chrysura. Gilded Hummingbird. mature female, February 8. All February birds Three males, August 18 to 26, all with enlarged are in molt. The October to January specimens so in those taken or much enlarged testes. had enlarged gonads, especially Heliomaster furcifer. Blue-tufted Starthroat. in October. Male, January 3; female, August 26. Colaptes melanochloros nigroviridis. Green- barred Flicker. Ten adult males taken February FAMILY BUCCONIDAE to December; 10 adult females taken in most months; and two juvenile males and two such Nystalus maculatus striatipectus. Spot-backed females taken January 29 to February 20. Breed- Puffbird. Males, March 15, December 27; fe- ing birds represent late September to late Novem- males, June 15, October 22, December 29. Only ber. Specimens in molt date from December 9 the October female had enlarged gonads. There is through February, the February adults being al- 8 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597 most through the molt. There is great variation in race major averages only very slightly larger than the size of spots ventrally. Paraguayan birds, with overlap virtually complete Colaptes campestris campestroides Z campes- in all measurements (e.g., in wing length 18 tris. Campo Flicker. Four specimens were ob- Argentine birds range from 176 to 190 mm., and tained on July 10 somewhere along the Rio 20 Paraguayan and Bolivian specimens range Negro of western Paraguay. These include two from 173 to 193 mm.). males and two females. The males are near campestroides, one scoring "0.5," and the other FAMILY DENDROCOLAPTIDAE "1" in throat color (Short, 1972). The females both scoring "2," Sittasomus griseicapillus griseicapillus. Oliva- tend more toward campestris, ceous Woodcreeper. Male, February 21; female, the intermediate score. Occurrence of these vari- July 14. able hybrids in the Paraguayan chaco is of inter- Drymornis bridgesi. Scimitar-billed Wood- est, since the hybrid zone in eastern Paraguay fe- centers about Rosario just east of the Rio Negro creeper. Males, February 13, October 13; (Short, 1972, p. 75). males, February 14 and 21, June 13 (two). The February birds are in mid-molt, and the October Dryocopus schulzi. Black-bodied Woodpecker. male had enlarged testes. Males, June 9 and 10, July 22, and October 28; Xiphocolaptes major major. Great Rufous females, February 10, March 25, May 24 (two), Woodcreeper. Males, June 3, October 1 and 13; June 9, October 7. The October birds have en- females, February 11, June 28. The February larged gonads; the February and March speci- specimen is in late molt. The October males had mens are in molt. I have seen 20 adults from the enlarged (one much enlarged) testes. These birds Paraguayan chaco, of which six males and four are much paler, and more barred ventrally than females have a fully white scapular stripe (ship- the more northern subspecies castaneus (Mato toni morph), three males and six females have Grosso specimens). the "normal" black scapular area, and one male Lepidocolaptes angustirostris angustirostris. shows a partial, white scapular. Thus, both Narrow-billed Woodcreeper. Males, January 3, morphs occur here, and throughout the range of October 12; females, three, all February. The the species (Short, 1975). The Lichtenau birds are males had enlarges testes, the females are in molt. variable. One female is markedly barred on the This subspecies is rather unsatisfactory, being abdomen, and another female and a male show between some barring. The wing coverts under the "wrist" somewhat intermediate small, rufous, vary from having slight black traces in one bird ventrally unmarked bivittatus of Mato Grosso to strongly black, although most specimens show and large, deeper brown, ventrally strongly much more black than in D. lineatus. Throat marked praedatus of eastern and central Argen- color varies from white to gray-black, several tina and Uruguay. birds having strong black streaking there. The Campylorhamphus trochilirostris lafresnaya- auricular area is gray in some birds, black in nus. Red-billed Scythebill. Males, October 7, No- others. The bill is almost completely white (ex- vember 13; females, January 19, October 13; im- cept base) in two birds, is mixed in most, but is mature male, January 21. The adults all have en- mainly gray-black in three. larged gonads, those of the males being very Campephilus leucopogon. Cream-backed much enlarged. The immature bird has a short, Woodpecker. Males, February 7, March 15, May dark bill. These birds are shorter billed (the bill is 5, May 30, August 8; and females, March 15, less massive, as well), and more buffy brown, less May 5, December 8. The December female had rufous than Argentine hellmayri, matching north- an enlarged ovary, but already is commencing ern Paraguayan and Mato Grosso lafresnayanus. molt. The annual molt appears to last a long time, from early December until at least early FAMILY FURNARIIDAE May. I now find this species to be monotypic; Upucerthia certhioides estebani. Chaco Earth- the supposedly larger, southwestern (Argentine) creeper. Male and female, February 22, perhaps 1976 SHORT: PARAGUAYAN CHACO BIRDS 9 both immature. Both specimens are missing most November male had enlarged gonads. This is a rectrices. This species is very variable in size, even variable series, two birds (February male, female in comparably pluriaged birds from a single lo- of February 15) being very pale, another (No- cality. This race seems clinally variable in size, vember male) intermediate, and the others very northern (Paraguayan) birds being smaller. dark in ventral streaking. Furnarius rufus paraguayae. Rufous Hornero. Pseudoseisura lophotes argentina. Brown Males, January 31, February 9, November 13; Cacholote. Male, January 18; females, January female, January 19. The November bird had en- 19, February 22, June 15; immature male, Janu- larged testes, and the female is in molt. ary 12. These birds, if anything, are darker than Furniarius cristatus. Crested Hornero. Six Argentine specimens of this race, thus differing males, January 13, February 22, and four from strongly from pale Bolivian P. 1. lophotes. The November, last four in breeding condition gonad- January adults had enlarged gonads. ally. Leptasthenura platensis. Tufted Tit-spinetail. A questionable female taken August 28. The FAMILY FORMICARIIDAE specimen, in fresh plumage, appears to represent the first record of this species for Paraguay (see Taraba major major. Great Antshrike. Males, Meyer de Schauensee, 1966). January 14 and 19, February 25, October 12; Schoeniophylax phryganophila phrygano- females, January 21, February 25. All but the phila. Chotoy Spinetail. A male and a female, February birds had enlarged gonads. June 15, and an immature male, December 29. Thamnophilus doliatus radiatus. Barred Ant- Synallaxis albescens australis. Pale-breasted shrike. Males, February 22, March 6; females, Spinetail. Males, January 18 and 26; females, Au- February 22, March 6. The March male is in gust 28, February 21 and 22. One of the Febru- molt. Both males are weakly marked below; the ary birds is molting. Only the males have en- abdomen is nearly unmarked and the throat is larged gonads. finely streaked. The females are exceptionally Certhiaxis pyrrhophia pyrrhophia. Stripe- barred dorsally, the dark bars being weak but crowned Spinetail. Males, January 13, November visible throughout; none of our other specimens 15; female, February 13; questionable male, Feb- match these in back barring. Possibly they repre- ruary 3. Both males have much enlarged testes. sent immature individuals. The January male is in an early stage of (wing) Thamnophilus caerulescens paraguayensis. molt; the February specimens are completing Variable Antshrike. Males, January 19 to Febru- molt. ary 19 (three); female, February 13. All of these Thripophaga baeri chacoensis. Short-billed are in worn plumage with gonads indicated as Canastero. Male, February 13. This form is found enlarged, or much enlarged. This suggests later only in the Paraguayan chaco, but I find that breeding in caerulescens than in doliatus. All Argentine birds from the chaco, and from Tucu- three males are very pale (white with gray cast; man and Salta are intermediate between chaco- slight tinge of buff on lower breast of one and on ensis and the eastem and southern Argentine flanks of another) below and blackish gray subspecies baeri, tending to be smaller than the above, hence clearly represent this subspecies. latter, with a finer, smaller bill. Myrmorchilus strigilatus. Stripe-backed Ant- Phacellodomus sibilatrix. Little Thornbird. bird. Males, January 9, February 20 and 25, Oc- Males, January 12, June 13; female, January 12. tober 5; females, January 20, February 22 and These birds are somewhat smaller than Argentine 25, October 5, November 10. Only the Novem- specimens, suggesting a size cline (increasing size) ber and January females have enlarged gonads. southward from Paraguay. The February specimens are in molt, as is the Coryphistera alaudina. Larklike Brushrunner. January female. The population inhabiting Mato Males, February 15, November 29; females, Feb- Grosso to Argentina appears inseparable (as ruary 15 and 21, and (two) June 13. Only the "suspicax") from eastern Brazilian birds, individ- 10 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597 ual variation being very great (see Naumburg, sent microptera, and indeed someone has written 1939). "near microptera" on the label. Thus, Patagonian A. m. nicroptera appears to winter far north and FAMILY RHINOCRYPTIDAE northeast of the range shown by Smith and Vuilleumier (1971, p. 212). Melanopareia maximiliani argentina. Olive- Agriomis murina. Mouse-brown Shrike-tyrant. crowned Crescentchest. Males, January 18, Feb- Male, May 16; female, September 2. Wintering ruary 15; females, February 15 and 20, Novem- birds, presumably from Argentina. This species is ber 27. The January male and November female removed from Xolmis and placed in Agriomis had enlarged gonads. The female of February 20 following Smith and Vuilleumier (1971). is in molt. Xolmis cinerea. Gray Monjita. Immature fe- male, December 28. No adults were obtained. FAMILY COTINGIDAE Xolmis irupero irupero. White Monjita. Males, Casiornis rufa. Rufous Casiornis. Males, Jan- January 31, February 21; sex unknown, June 30. uary 31 to February 22 (four); females, February Both males are in full molt. 21, October 7. All but the October specimen are Xolmis coronata. Black-crowned Monjita. in molt (mid-molt to nearly completed molt). Male, May 4; females, May 30, June 13. Another Xenopsaris albinucha albinucha. White-naped species that winters in the chaco from farther Xenopsaris. Males, December 29 and January 2, south. but the latter may be a female (wing 60.5 mm.), Knipolegus striaticeps. Cinereous Tyrant. although both noted as having enlarged gonads. Males, four in January, two in June; females, Jan- Pachyramphus viridis viridis. Green-backed uary 2, May 16 (two). One of the May females is Becard. Males, November 19, December 13; fe- labeled as a male, but is in full female plumage. male, November 19. All are in breeding condi- The January female and two of the January tion. males had enlarged gonads, indicating that this Pachyramphus polychopterus spixii. White- species breeds in the area (see Short, 1975). winged Becard. Males, December 9 to February Older male specimens in AMNH are browner, less 13 (six); females, January 7, March 30. All but blackish gray than are these more recently col- the March bird had enlarged gonads. One male is lected birds. labeled as a female, but is in full male plumage. Knipolegus (Phaeotriccus) hudsoni. Hudson's The males vary greatly in color of underparts Black-tyrant. Male, October 1. This bird had from gray with faint white spots to grayish black. moderately enlarged testes. Steinbacher (1962) The two blackish birds closely resemble P. p. reported a female of this rare species from Es- niger, found from Bolivia northward, and may calante in southwestern Paraguay, taken Septem- tend toward that form. ber 30, with ovary not enlarged. The male re- ported here has the label indicating enlarged testes, and the late dates of these supposed mi- FAMILY TYRANNIDAE grants (breeding known only in Patagonia) are Agriornis microptera microptera. Gray-bellied puzzling. Shrike-tyrant. Male, August 23; females, August Hymenops perspicillata andina and H. p. 23 (two), September 2. A migrant from the perspicillata. Spectacled Tyrant. Males, July 20 southwest, reported in the chaco only in the (two); females, June 3, July 20. The species "winter" (July to September, see Steinbacher, appears not to breed in Paraguay. Steinbacher 1962). Among specimens in the American Mu- (1962) noted a female with enlarged ovary taken seum of Natural History are three June birds at Orloff, Paraguay, on October 18, a rather late from Cuchacancha, at 11,000 feet, in Cocha- date, but since breeding is known to occur so bamba, Bolivia. Two of these represent Andean near Paraguay (adjacent Formosa, Argentina), andicola, but the third (AMNH 137415) is a very this could represent a very late southward mi- large contrastingly streak-throated bird lacking grant. On the other hand, some of the specimens the buff tone of andicola. This seems to repre- reported here, contrary to those of Steinbacher, 1 976 SHORT: PARAGUAYAN CHACO BIRDS I1I appear to represent the Andean race andina that and brownish above, matching it rather than may linger for a longer time on the wintering paler northeastern Brazilian pallidiventris. ground. The four specimens measure 77 to 92 Megarhynchus pitangua pitangua. Boat-billed mm. in wing length, the females agreeing well Flycatcher. Male, March 9; females, January 28, with perspicillata. The males appear small for March 9; immature male, March 9; immature andina, measuring only 91 and 92 mm. in wing females, January 28, March 9. The March adults length, but both are very black-winged, showing are in initial stages of molt. the restriction of white there that is typical of Myiodynastes maculatus solitarius. Streaked andina. Possibly these males represent intermedi- Flycatcher. Males, January 18, October 27; fe- ates between the two races. males, January 3 and 5, December 11. All but Fluvicola pica albiventer. Pied Water-tyrant. one of these, a January female, had enlarged go- Males, January 3, December 1; female, December nads and the ovary of the December female was 1; immature males, January 13, February 21. All much enlarged. In Short (1975, p. 273) I mis- adults had enlarged gonads. The immature birds takenly referred to this form as M. m. maculatus, are brownish black above, with buffy edgings on although solitarius is indeed the subspecies dis- the wing feathers. These indications of breeding cussed and described. activity serve as the northernmost breeding re- Pitangus sulphuratus bolivianus. Great Kiska- port for this race in the western part of its range, dee. Males, January 20, May 6, October 31; fe- although November adults are known from Mato males, June 13, October 31, December 9. En- Grosso, suggesting breeding. larged gonads were noted for all but the May Pyrocephalus rubinus rubinus. Vermilion specimen, the December female having a much Flycatcher. Males, April 28, June 30, September enlarged ovary. The inner primaries are incoming 21. The April and June birds still have a mainly in the January male. These birds are paler above brown crown and some breast streaking, indi- but brighter yellow below than eastern maxi- cating immaturity. miliani and match Bolivian specimens, so must be Satrapa icterophrys. Yellow-browed Tyrant. assigned to this race rather than to maximiliani Males, January 20, April 23; female, February 9. (see Steinbacher, 1962, p. 76), or argentina, al- The February bird is in molt, that from April is though showing tendencies toward those races. completing the molt. Myiarchus tyrannulus tyrannulus. Brown- Machetornis rixosus rixosus. Cattle Tyrant. crested Flycatcher. Males, January 5, February 9 Male, October 15; female, November 15. Both of and 25, May 11 and 16, December 31; females, these had enlarged gonads. January 5 and 11, December 31; immature male, Tyrannus savanna savanna. Fork-tailed Fly- January 11. Enlarged gonads were noted in all catcher. Males, January 13 (two), October 27; but one female from January; much-enlarged go- females, February 10, October 27. All but the nads were found in the December flycatchers and February specimen had enlarged gonads. one February flycatcher. The May birds had Tyrannus melancholicus melancholicus. Tropi- molted. The breeding male taken in early Febru- cal Kingbird. Male, October 31; females, January ary is in the initial stages of molt, whereas the 3, April 23, October 31, December 23. The Octo- late February male is over halfway through the ber and January kingbirds had enlarged gonads wing (primary) molt. (but the December female did not). Myiarchus swainsoni ferocior § swainsoni. Empidonomus aurantioatricristatus aurantio- Swainson's Flycatcher. Males, five from early atricristatus. Crowned Slaty-flycatcher. Males, January, November 27, December 31; female, January 2, February 23, October 12, December December 22. Much-enlarged testes were noted 31; females, January 2 and 3. Much-enlarged in all males except one January bird with testes gonads were noted for all December and January only "enlarged," another January male showing birds except a female (ovary moderately en- no testicular growth, and the November speci- larged), and the October male had enlarged men, also without enlarged testes. The female testes. These specimens tend to be rather small was not in breeding condition. None of these ap- for this subspecies, but they are deep gray below pear to be in molt. They were identified by 12 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597

Wesley E. Lanyon, who will report on this com- December 23 to 31 (four); females, September 9, plex elsewhere. The other common Myiarchus, December 9 and 23. The gonads were much en- ferox, of the eastern edge of the chaco, was not larged in all males except that from November obtained by Unger; specimens of "ferox" re- (testes moderately enlarged), and in one Decem- ported by Steinbacher (1962, 1968) from the ber female; the other females had the ovary en- Paraguayan chaco appear, by the measurements larged slightly (December) or not at all (Sep- given, to represent M. swainsoni, not M. ferox tember). Apparently no specimens of the Small- (fide Lanyon). billed Elaenia (Elaeniaparvirostris) were obtained. Empidonax euleri argentinus. Euler's Fly- Suiriri suiriri. Suiriri Flycatcher. Males, Jan- catcher. Female, October 11 (no indication of uary 4, February 22, December 29. Only the Jan- enlarged ovary). uary bird had enlarged testes. Molt had com- Cnemotriccus fuscatus bimaculatus. Fuscous menced in the January male, and the February Flycatcher. Female, February 13; unsexed bird specimen is in mid-molt. with much enlarged gonads (sex symbol lacking Sublegatus modestus modestus. Scrub Fly- on label!), October 2. The February bird is molt- catcher. Males, February 15, December 31; fe- ing. The unsexed specimen is considerably larger males, January 2, December 31; immature males, than the other, and may represent a male. Re- January 12, December 19. The December and cently taken specimens tend to be grayer brown, January specimens had gonads enlarged or much less deeply brown than older specimens. enlarged, and the February bird is in molt. I am Todirostrum margaritaceiventer margaritacei- unable to separate the race brevirostris from venter. Pearly-vented Tody-tyrant. Female, Jan- modestus (see Pinto, 1944). uary 3. Euscarthmus meloryphus meloryphus. FAMILY HIRUNDINIDAE Tawny-crowned Pygmy-tyrant. Female, June 18. John Fitzpatrick has pointed out to me that this Tachycineta leucorrhoa. White-rumped Swal- actually is comprised of two species (see low. Male, May 30; female, May 30. Both are in Mees, 1968, pp. 105-106, contra Short, 1975), final stages of molt. apparently widespread Amazonian rufomargina- tus, and meloryphus, generally south of the FAMILY CORVIDAE former, but with seemingly extensive overlap be- tween them. Cyanocorax chrysops chrysops. Plush-crested Pseudocolopteryx acutipennis. Subtropical Jay. Male, December 28; female, June 3. The Doradito. Male, April 27; female, December 9. male is molting heavily. These represent the first and second Paraguayan records of this presumed migrant from the FAMILY TROGLODYTIDAE Andean foothills of Argentina and Bolivia Troglodytes aedon rex. House Wren. Male, (Short, 1972b, 1975). March 15; female, February 3. The female had an Habrura pectoralis pectoralis. Bearded enlarged ovary. The male is in heavy molt. East- Tachuri. Males, February 21, August 10; females, ern Paraguayan birds seem separable readily from October 13. chaco specimens, as browner T. a. musculus. Stigmatura budytoides inzonata. Greater Wag- tail-tyrant. Males, January 10, February 21. The FAMILY MIMIDAE February specimen is in molt. Serpophaga subcristata subcristata. White- Mimus saturninus modulator. Chalk-browed crested Tyrannulet. Males, January 13, August Mockingbird. Male, April 25; females, April 25 27; female, August 27. All three birds are of the (two), November 29. The April specimens are in yellow-bellied, subscristata morph, not of the late stages of molt, and the November female had morph "munda" (Short, 1975). a large ovary. Worn birds are very much browner, Elaenia spectabilis spectabilis. Large Elaenia. less gray than freshly molted specimens. Males, January 5 (two), November 29, and Mimus triurus. White-banded Mockingbird. 1976 SHORT: PARAGUAYAN CHACO BIRDS 13

Male, June 13; female, August 27. There is a February males are in worn plumage, not yet strong difference in size between the sexes, molting. exemplified by these rather comparably plum- aged birds; the male measures 112 mm., the FAMILY ICTERIDAE female, 96 mm., in wing length. Dolichonyx oryzivorus. Bobolink. Males, Jan- uary 14, November 30 (two); female, January FAMILY MUSCICAPIDAE 14. All are in full winter plumage. The resem- Turdus amaurochalinus. Dusky Thrush. Males, blance of this plumage, particularly the head February 10, December 11 (two); females, No- pattern and pattern of the hindneck, as well as vember 6, December 11. All but the February bill structure, to that of females of Sturnella specimen had enlarged gonads. Bill color varies in superciliaris is noteworthy. these specimens from fully yellow to horn- Molothrus bonariensis bonariensis. Shiny brown. Cowbird. Males, May 5, October 11; females, Polioptila dumicola dumicola. Masked Gnat- May 16, October 19. The October birds had en- catcher. Males, May 16, June 18, November 29. larged gonads; the May male is in molt. The November bird has enlarged testes. Molothrus rufoaxillaris. Screaming Cowbird. Males, November 1 and 7; females, May 16, Oc- tober 31, November 1; immature male, May 16. FAMILY MOTACILLIDAE The October and November birds all had en- Anthus lutescens lutescens. Yellowish Pipit. larged gonads. The May specimens are in molt, Male, February 16. In the course of the adult being farther along than the young identifying bird, which shows the rusty-edged outer several this specimen I found a number of previously primaries misidentified specimens ofAnthus chacoensis, in- and four secondaries. Western (western cluding specimens taken in the breeding season Argentina, chaco) birds, including these Para- (five birds, January 1 to 10) near Leones, Cor- guayan specimens, are somewhat smaller billed doba, Argentina, in with A. lutescens. than are specimens from farther east, but the dif- sympatry ference is not great and no other features seem to Thus, A. chacoensis appears to be a valid species. show The specimen of A. 1. lutescens reported here is variation with this orientation. in the final stage of molt. Molothrus badius badius. Bay-winged Cow- bird. Males, January 9, October 18, November 11 and 30. All have enlarged testes, the January FAMILY PLOCEIDAE specimen having much enlarged testes. These specimens are easily distinguished from Bolivian Passer domesticus domesticus. House Spar- bolivianus because they are at the small, gray ex- row. Male, May 1; females, January 12 and 28. tremes of M. b. badius. Noteworthy is the All three sparrows have enlarged gonads, one of marked blackish face mask that extends behind the females having the ovary much enlarged. the eye in these specimens, whereas it usually terminates at the eye. FAMILY VIREONIDAE Stumella superciliaris. Southern Marsh Mead- owlark. Females, April 25 and 30. Both are in Cyclarhis gujanensis viridis. Rufous-browed fresh plumage. Peppershrike. Males, January 3 and 18, June 15, Agelaius ruficapillus ruficapillus. Chestnut- November 13; female, August 27. Enlarged or capped Marsh Blackbird. Subadult male, Decem- much enlarged testes were noted in the January ber 27; females, December 5 (two). All had en- and November males. larged gonads. The male has some brown feather- Vireo olivaceus chivi. Red-eyed Vireo. Males, ing on the breast, abdomen, and scapular areas, January 9, February 21 (two), November 7; fe- and its crown patch is incompletely developed, male, January 9. Much enlarged gonads were but otherwise it is colored as adult males. found in all November and January vireos. The Gnorimopsar chopi chopi Chopi Blackbird. 14 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597

Males, January 4 (two), January 9 (two), August is large, not small as in chlorotica), and it shows 26, October 26; female, January 4. Three Janu- no signs of whitish that would indicate a ten- ary males had large testes, and the October bird dency toward serrirostris. It resembles the most had them much enlarged. yellow-green of Mato Grosso specimens that vari- Icterus icterus strictifrons. Troupial. Male, De- ously are treated as amazonica or amazonica Z cember 1; females, January 20, October 7; sex serrirostris (latter fide K. C. Parkes). The males unknown, October 7. Gonads were enlarged in are variable, one being especially blue above, as the January female and much enlarged in the De- in serrirostris, the others showing much purplish cember male. Three of the specimens have a nar- as well (the July male is not fully adult, showing row black band across the back; this is discon- some greenish feathering dorsally). Thus, in con- tinuous in the other bird. Since strictifrons trast to the situation farther south in the Para- barely is distinguishable from croconotus (paler guayan chaco, and in eastern Paraguay, where than latter, more often with black on back), it is populations ascribable to serrirostris are found, not possible to define a third form ("para- these birds seem to represent a population inter- guayae"). gradient between amazonica and serrirostris. Icterus cayanensis pyrrhopterus. Epaulet Ori- Thraupis sayaca sayaca. Sayaca Tanager. ole. Males, January 20, February 13 and 21, July Males, August 1, October 6 and 31, November 6 11, October 14; females, January 18, May 16. and 10; female (labeled "male"), August 1. Two The October male had much enlarged testes, as males, one from late October and one from No- did the January male; one February (13) bird vember, are in breeding condition. These resem- had enlarged testes. The January male is in mid- ble sayaca very closely, as I previously have molt. noted (1975), but several specimens show pale, Cacicus chrysopterus. Golden-winged Cacique. grayish indications of influence of Bolivian Male, female, July 26. obscura. Cacicus solitarius. Solitary Black Cacique. Piranga flava flava. Hepatic Tanager. Males, Males, January 20, October 5, December 8 and February 13, October 17; females, February 13, 23. The December and January males showed en- November 10 and 17; subadult male, January 4. larged testes. Steinbacher (1962) provided an ac- The subadult male and the October male had en- count of the nests of this and the preceding larged testes, and the November females each had species. an enlarged ovary. February specimens are in early stages of molt. FAMILY PARULIDAE Saltator coerulescens coerulescens. Grayish Saltator. Two males, December 11, both with en- Parula americana pitiayumi. Parula Warbler. larged testes. Males, February 13, June 8 and 18; female, Oc- Saltator aurantiirostris aurantiirostris. Golden- tober 12. billed Saltator. Males, four in January, February Geothlypis aequinoctialis velata. Masked Yel- 2, November 13. All but the February specimen lowthroat. Female, October 17, enlarged ovary. had enlarged testes. Bill color ranges to golden orange from yellowish in these skins. FAMILY EMBERIZIDAE Paroaria coronata. Red-crested Cardinal. Males, November 2, 3; females, April 24, Novem- Tersina viridis viridis. Swallow-tanager. Fe- ber 2. The November birds had enlarged or much males, May 2 (two). First chaco records, reported enlarged gonads; the April specimen is in fresh earlier (Short, 1972). plumage. See Short, 1975, p. 309, for reason Euphonia chlorotica amazonica Z serrirostris. why this species is treated as monotypic. Purple-throated Euphonia. Males, January 4, July Pheucticus aureoventris aureoventris. Black- 12, September 4; female, July 8. The January backed Grosbeak. Males, January 5 and 9, June male had much enlarged testes. The female, in 15, October 15 and 27. Gonads much enlarged in fresh plumage, is completely yellow with an olive January 9 and October 27 males, moderately so cast ventrally, matching E. c. amazonica (its bill in other October and January birds. Although 1976 SHORT: PARAGUAYAN CHACO BIRDS 15 black-rumped, several of these specimens show Sicalis luteola luteiventris. Grassland Yellow- yellowish at the base of the black rump feathers, . Female, April 27. In fresh plumage. and one has feathers slightly yellow-tipped. Lophospingus pusillus. Black-crested Finch. Passerina brissonii sterea ; argentina. Ultra- Male, October 15; females, June 15 (two, one marine Grosbeak. Adult male, May 20, subadult missexed), 18, 20, and 28. The male had enlarged males, January 5, February 15. Both subadults testes, but is peculiarly colored, being brownish show some black about the head or back; the backed (resembling female coloring) and having a February bird had enlarged gonads, the testes of mainly brown crown with blackish feathering on the January specimen were much enlarged. The its sides. specimens approach smaller, finer billed, sterea Coryphospingus cucullatus fargo4 Red-crested more than they resemble western argentina, but Finch. Males, February 25, October 12; females, they show tendencies toward the latter (in pale January 11, July 1. Both males had enlarged color of subadults). testes. The females are rather pale in comparison Volatinia jacarina jacarina. Blue-black Grass- with other specimens of this race at my disposal. quit. Adult males, January 18, 26, February 8, Ammodramus humeralis xanthornus. Grass- December 26; subadult male, November 27; fe- land Sparrow. Males, January 18, February 15 males, January 18, 26, February 21. All but the and 20, November 12. All had enlarged testes; February female had enlarged gonads (much en- those of both the bird from January and the one larged in January 18, February 8 males, and fe- from February being much enlarged. male, January 18). The subadult male has brown- Aimophila strigiceps strigiceps. Stripe-capped edged, black feathers, but mainly is black. Sparrow. Male, January 31; female, March 29. Sporophila lineola lineola. Lined Seedeater. These were reported elsewhere (Short, In press). Adult males, January 12, February 15 (two), No- Junco capensis hypoleuca (includes mellea). vember 30, December 18; females, January 13, Rufous-collared Sparrow. Males, February 20, February 15 (two), November 30, December 13; August 27; females, August 27, September 25. subadult male, December 23. All adults have en- The February and September birds had enlarged larged gonads. The subadult male is in full "fe- gonads. Examination of these and four other male" plumage. Paraguayan chaco specimens, in comparison with Sporophila caerulescens caerulescens. Double J. c. hypoleuca indicates that traits of chaco collared Seedeater. Males, February 15, March 4 mellea noted by Wetmore (1922) do not hold, or and 5, November 30; females, January 13, represent slight tendencies. Of the characters March 3, December 11; subadult males, January Wetmore mentioned, I note that only the pale- 9, December 8 and 18; immature male, April 27. ness of color of "mellea" is worthy of considera- The adults and subadults all were in breeding tion, and this represents a tendency matched in condition (gonads enlarged; very large in male of various Tucuman and Salta, Argentina, hypo- March 4, females of March 3 and December 11, leuca. Thus, I treat mallea as a synonym of and subadult male of January 9). hypoleuca. Sporophila hypoxantha. Tawny-bellied Seed- Embemagra platensis olivascens. Great Pampa- eater. Female, May 16. Elsewhere (Short, 1975, finch. Immature female, May 16. This specimen pp. 313-314) I stated my reasons for considering is molting into adult plumage, but still shows the S. ruficollis a "morph" of S. hypoxantha. The yellowish about the throat found in juvenal female reported here cannot be assigned defi- birds, and its crown is brown-striped. Its back is nitely to either ruficollis or hypoxantha if those unstreaked, and it matches the western race were to be treated as separate species, for their olivascens. Meyer de Schauensee (1966) did not females are indistinguishable. Males differ only in list western Paraguay in the range of this species. having or in lacking a black throat patch. Poospiza torquata pectoralis. Ringed War- Sicalis fiaveola pelzelni. Saffron Finch. Males, bling-finch. Male, June 15; female, June 20. Pre- February 12, September 7, November 8; mis- sumably these represent wintering birds from sexed female, December 9. Enlarged gonads were farther south. This species bears a striking simi- noted in the November to February birds. larity to Lophospingus pusillus in overall pattern 16 AMERICAN MUSEUM OF NATURAL HISTORY NO. 2597 and bill shape (e.g., compare with grayer females Mees, G. F. ofL. pusillus). 1968. Enige voor de Avifauna van Suriname Poospiza melanoleuca. Black-capped Warbling- Nieuwe Vogelsoorten. Gerfaut, vol. 58, finch. Males, February 3 and 21, April 8, June pp. 101-107. Meyer de Schauensee, R. 13; females, January 12, February 3, June 13. 1966. The species of birds of South America The male of February 3 had much-enlarged with their distribution. Philadelphia, testes, and the ovary was enlarged in the January Acad. Nat. Sci., xvii + 577 pp. and February females. The late February male is Naumburg, E. M. B. in molt. 1930. The birds of Matto Grosso, Brazil. Bull. Saltatricula multicolor. Many-colored Chaco- Amer. Mus. Nat. Hist., vol. 60, vii + finch. Males, January 5 and 26, February 15, 432 pp. March 4, November 18, December 22; females, 1939. Studies of birds from eastern Brazil and February 15, August 1 1. November through Feb- Paraguay, based on a collection made ruary specimens had enlarged gonads. I have by Emil Kaempfer. Ibid., vol. 76, pp. 231-276. noted that bill color has undergone fading in the Olrog, C. C. course of the two or three years that the speci- 1959. Eudromia formosa (Lillo) y Eudromia mens have been in the collection, the orange-gold elegans Is. Geoffroy (Aves, Tinami- or golden orange giving way to yellow or golden formes). Neotropica, vol. 5, pp. 13-21. yellow in most of the specimens. 1963. Notas sobre aves bolivianas. Acta Zool. Lilloana, vol. 19, pp. 407478. Short, L. L. FAMILY CARDUELIDAE 1972a. Systematics and behavior of South Carduelis magellanica alleni. Hooded Siskin. American flickers (Aves, Colaptes). Males, August 18, September 12, November 16; Bull. Amer. Mus. Nat Hist., vol. 149, females, September 4 (two); subadult male, No- pp. 1-110. 1972b. Two avian species new to Paraguay. vember 6. No breeding activity indicated. Auk,89:895. 1975. A zoogeographic analysis of the South LITERATURE CITED American chaco avifauna. Bull. Amer. Mus. Nat. Hist., vol. 154, pp. 163-352. Brown, L., and D. Amadon [In press.] Aimophila strigiceps new to Para- 1968. Eagles, hawks and falcons of the world. guay. New York, McGraw-Hill Book Co., pp. Smith, W. J., and F. Vuilleumier 1-945 (2 vols.). 1971. Evolutionary relationships of some Conover, B. South American ground tyrants. Bull. 1950. A study of the spotted , genus Mus. Comp. Zool., vol. 141, pp. 18-232. Nothura. Fieldiana (Zool.), vol. 31, pp. Steinbacher, J. 339-362. 1962. Beitrage zur Kenntnis der V6gel von Eisenmann, E. Paraguay. Abhandl. Senckenbergischen 1962. Notes on highthawks of the genus Naturf. Gesell., no. 502, pp. 1-106. Chordeiles in southern Middle America, 1968. Weitere Beitrage iuber V6gel von Para- with a description of a new race of guay. Senckenbergiana Biol., vol. 49, Chordeiles minor breeding in Panama. pp. 317-365. Amer. Mus. Novitates, no. 2094, pp. Vaurie, C. 1-21. 1964. Systematic notes on the bird family Hellmayr, C. E., and B. Conover Cracidae. No. 1. Geographical variation 1942. Catalogue of birds of the Americas and of Ortalis canicollis and Penelope the adjacent islands. Part 1, No. 1. marail. Amer. Mus. Novitates, no. Field Mus. Nat. Hist., publ. 514, zool. 2197, pp. 1-8. ser., vol. XIII, vi + 636 pp. Wetmore, A. 1948. Catalogue of birds of the Americas and 1922. Description of a Brachyspiza from the the adjacent islands. Part 1, No. 2. chaco of Argentina and Paraguay. Proc. Ibid., publ. 615, zool. ser., vol. XIII, vii Biol. Soc. Washington, vol. 35, pp. + 434 pp. 3940. :;It0~ ~ ~fft ~ 1~ 6 #aSs 02:n[ :;It0~ ~ ~fft ~ 1~ 6 #aSs 02:n[