I report specimens and sight records of 15 species new to Honduras: Mesembrinibis cayennensis, Falco femoralis, Anous minutus, Ara ambigua, Chalybura urochrysia, Baryphthengus martii, Myrmeciza exsul, Hylopezus perspicillatus, Conopias parva, Lophotriccus pileatus, Dacnis cayana, Vermivora ruficapilla, Tachyphonus delatrii, Pitylus grossus, and Sporophila schistacea. Twelve additional range extensions within Honduras are reported for species that reach their northern limit of distribution in the lowland forests of the Mosquitia region: Tigrisoma lineatum, Leucopternis semiplumbea, Ortalis cinereiceps, Ramphastos swainsonii, Myrmotherula fulviventris, Myrmotherula axillaris, Hylophylax naevioides, Phaenostictus mcleannani, Colonia colonus, Myiozetetes granadensis, Cyporhinus phaeocephalus, and Cacicus uropygialis. With the exception of Anous minutus, Falco femoralis, and Vermivora ruficapilla, all records are range extensions from the south. Some of the northward range extensions into the forests of eastern Honduras from the contiguous forests of Nicaragua were expected, but other records indicate notable range extensions. A list is provided of those species that currently reach their northernmost distribution in Nicaragua and whose presence may be expected in adjacent regions of Honduras. The extensive humid forests in the departments of Olancho and Gracias a Dios are the northernmost limits of numerous species, which may be prevented from further northward dispersal by biogeographic barriers. Received 12 April 1982, accepted 26 January 1983.

Direccion General de Recursos Naturales Renovables, Departmento de Vida Silvestre y Recursos Ambientales, Tegucigalpa, Honduras, and Department of Zoology, University of Maine, Orono, Maine 04469 USA  FROM December 1978 to March 1981 I record- ed range extensions of 25 species during the course of my fieldwork assessing National Park wildlife as a Peace-Corps volunteer assigned to work for the Honduran Department of Wild- life and Ecology (RENARE). Two additional species new to Honduras observed by R. S. Ridgely are here reported. Specimens were col- lected, photographed, or tape recorded when possible and subsequently deposited in the Louisiana State University Museum of Zoology (LSUMZ); tape recordings are deposited at the Cornell University Library of Natural Sounds. The majority of records here reported are from the recently established Platano River Bio- sphere Reserve (Reserva de la Biosfera Rio Pla- tano), in an isolated region of the Mosquitia. The interior forests of the Mosquitia are vir- tually inaccessible except by canoe and foot, and the Miskito Amerindian inhabitants of this region continue to be dependent on wildlife for a large percentage of their food and cloth- ing (Marcus 1981). No ornithologist had pre- viously collected along the Rio Platano. Prior to the 1960's, the ornithological knowl- Present address. edge of Honduras was fragmentary, with most records published in a few works (Bangs 1903, Peters 1929, Stone 1932). After extensive field- work and collecting in the 1960's, Monroe (1968) published the first and only distribu- tional survey for the whole country. Monroe acknowledged, however, that several regions were poorly explored and that, based on rec- ords from adjacent countries, numerous addi- tional species were likely to be added. Virtually every visiting researcher in recent years has recorded new species (Brown and Monroe 1974, Sibley et al. 1980, Udvardy et al. 1973, Avedillo 1977) and range extensions for the country (Udvardy 1976; Marcus 1980a, b; Hanson 1982). There are likely to be further new records, par- ticularly in poorly explored regions such as the Montafias de la Esperanza in the north, the in- terior forests of Gracias a Dios and Olancho, the pine savannas of the Mosquitia, and the Mon- tafia de Celaque in western Honduras. Localities frequently mentioned in the species accounts of this paper (see Fig. 1) are: (1) Re- serva de la Biosfera Rio Platano (Dept. Gracias a Dios = La Mosquitia), a 350,000-ha region of lowland wet evergreen forest, moist montane evergreen forest, and coastal pine savanna en- compassing the Platano River watershed; (2) IO0 KM '16 HON PACIFIC OCEAN 9, == : ol 0 " OLANCHO DUR:AS ,8  "CARIBBEAN SEA *'" ". :GRACIAS : DI OS NICARAGUA Fig. 1. Map of Honduras showing locations discussion in the text. (1) Platano River Biosphere Reserve; (2) Kuri; (3) Bulebar; (4) Las Mafias; (5) Tuskruhuas River; (6) Mairin Tighni; (7) Lancetilia; (8) Parque Nacional La Tigra; (9) Southwest Cay; (10) Catacamas; (11) Arenal; (12) Cordillera Nombre de Dios; (13) Danto; (14) La Ceiba; (15) Tela; (16) San Pedro Sula; (17) Trujillo; (18) Segovia River. Kuri = Zapote (Gracias a Dios), a savanna vil- lage near the mouth of the Platano River and the location of the Biosphere Reserve head- quarters (15ø55 ', 84ø32'; sea level); (3) Bulebar (Gracias a Dios), a small Miskito settlement along the banks of the Platano River in old second-growth forest and used as a base camp- site (15ø45 ', 84ø43'; 25 m); (4) Las Marias (Gra- ciasa Dios), the last Miskito and Paya Amer- indian settlement inland on the Platano River in old second-growth wet evergreen forest (15ø44 ', 84ø47'; 30 m); (5) Tuskruhuas River (Gracias a Dios), a base campsite in primary wet evergreen forest about 25 km southeast of Las Marias (ca. 15ø25 ', 84ø45'; 35 m); (6) Mairin Tighni (Gracias a Dios), a base campsite in old second-growth wet evergreen forest inter- spersed with patches of primary forest about 9 km southwest of Las Marias (15ø30 ', 84ø58'; 40 m); (7) Lancetilia (Dept. Atlantida), a botanical garden and forestry research station with an 800-ha forest reserve 7 km south of Tela (15ø42 ', 87ø27'; 30 m); (8) Parque Nacional La Tigra (Dept. Morazan), a 7,500-ha cloud forest re- serve 15 km northeast of Tegucigalpa (14ø13 ', 87ø04'; 1,400-2,700 m); (9) Southwest Cay (Dept. Bahia), a small island off the southwest coast of Utila (16005 ', 87ø00'); (10) Catacamas (Dept. Olancho); (11) Arenal (Dept. E1 Paraiso), an old lumber camp at the southwest edge of Olancho and used by Townsend in 1887 as a collecting site (13ø48 ', 85ø49'; 370 m); (12) Cordillera Nombre de Dios (Dept. Atlantida); a mountain range parallel to the Caribbean coast extending from Trujillo to the Sula Valley; and (13) Danto (Atlantida), A base campsite in the Cordillera Nombre de Dios about 7 km south of Danto (15ø39 ', 86ø50'; 160 m). SPECIES ACCOUNTS Tigrisoma lineatum.--Rufescent Tiger Heron. An immature visited the Mairin Tighni camp during the first three days in February 1981 and was photographed at close range (LSUMZ photo file). Other than one doubtful record from Chiapas, Mexico (Peterson and Chalif 1973), this record represents the northern limit of their distribution. The only previous Hon- duran record is a specimen taken at the Segovia River in 1887 (Monroe 1968). Falco femoralis.--Aplomado Falcon. Although the species ranges in distribution from the southwest United States to Tierra del Fuego, there are no previous records of it in Honduras, and, indeed, there are few records for Central America. Land (1970) reports no Guatemalan records during this century, and Ridgely (1976) notes them as uncommon in Panama and cur- rently (1982) decreasing (pers. comm.). Howell (1971) reports this species as scarce but regular in the Mosquitia of Nicaragua, and Koford et al. (1980) report its occurrence in Costa Rica. In the coastal pine savanna of the Honduran Mos- quitia, I found this species present and con- spicuous between October 1980 and February 1981. These birds were identified by the striped facial pattern, gray back, and the black band across the belly. One pair was frequently ob- served perched on the tops of small palm clumps growing in the open savanna sur- rounding the Platano River Biosphere Reserve headquarters in Kuri. Ortalis cinereiceps.--Gray-headed Chachalaca. This species was found to be a common resi- dent throughout eastern Olancho and the Mos- quitia. On 30 March 1979 R. S. Ridgely ob- served one pair at Aguas Calientes, southeast Catacamas (pers. comm.). ! found them to be fairly common in disturbed habitats in the Mosquitia. In the Platano River Biosphere Re- serve, groups of a dozen or more individuals were frequently seen feeding on the fruits of riverside Cecropia trees and in second-growth or disturbed forest habitats. They are very shy in this region due to heavy hunting pressure. Howell (1971) reported this species as common in the broad-leaved forests in the Nicaraguan Mosquitia and suggested that they would also be found in Honduras. O. cinereiceps is the only chachalaca encountered in eastern Honduras, but it probably overlaps with the Plain Cha- chalaca (O. vetula) in the vicinity of Trujillo, Dept. Co16n. A photograph of a specimen of O. cinereiceps (LSUMZ photo file) shot by a local hunter was taken in Las Marias. These records are the northernmost to date, and there is only one previous published record from Honduras, a specimen from Arenal. Anous minutus.--Black Noddy Tern. On 9 Au- gust 1980 at Southwest Cay, S. Eldred, A. Boerstoa, and ! observed an individual perched on dead coral protruding above the water's sur- face. It allowed close approach by boat so that its distinguishing characteristics (dark body, white crown, long thin bill, and gray tail) were clearly observed. A. minutus is reported to nest off the coast of Belize (Bond 1971), and its presence in Honduras is expected. Udvardy (1976) observed A. stolidus on nearby Sandy Cay, and it is quite possible that cays in the vicinity of Utila support nesting colonies of both species. This is the first report from Honduras. Ara ambigua.--Great Green Macaw. The oc- currence of a large green macaw in Honduras has long been known (Wells 1857 in Monroe 1968); yet, the positive identification of this species has remained a mystery. Monroe (1968) and others have assumed this macaw to be A. ambigua, although the Honduran Ministry of Renewable Natural Resources in a campaign to protect threatened species has mistakenly de- clared full protection to the Military Maca,w (A. militaris), a primarily South American species with an isolated population in western and central Mexico. Ridgely (1981) records a spec- imen of this species (AMNH 812649), reported to have come from the Honduran Mosquitia, that was collected by a Miskito hunter. From October 1980 to March 1981 A. ambigua was en- countered daily in the Platano River Biosphere Reserve. On 30 October a female (LSUMZ 99936) was collected while perched in the can- opy of a 30 m-tree located in an overgrown rice field bordered by humid forest 3 km north of Bulebar. Its crop was found to contain numer- ous seeds and orange arils of fruits tentatively identified by R. Foster as Sloanea sp. (Elaeocar- paceae). Although frequently observed along the Platano River, A. ambigua is decidedly more numerous in mountainous terrain and areas of undisturbed forest away from human settle- ment. They are generally observed flying in pairs at low altitudes above the forest canopy and in flocks of up to six individuals. A. ambi- gua is known to range as far north as northern Nicaragua, and thus it is not surprising that it occurs in the adjacent Honduran forests as well. Although once reported to occur in the now deforested Juticalpa and Catacamas region of Olancho [Carr in Monroe (1968)], A. ambigua now appears to be restricted to the more re- mote regions of eastern Olancho and the Mos- quitia. Chalybura urochrysia.--Bronze-tailed Plume- leteer. On 24 October and 2 November 1980, two specimens (LSUMZ 99902 and 99903 alch., respectively) were netted in the low strata of old second-growth wet evergreen forest about 1 km north of Bulebar. These are the first rec- ords from Honduras. Baryphthengus martii.--Rufous Motmot. This species was found to be fairly common to un- common in the Platano River Biosphere Re- serve. On 10 November 1980 an individual was briefly observed at the Tuskruhuas campsite, and on 24 January 1981 a recently killed female (LSUMZ 99937) was found in excellent condi- tion by J. W. Froehlich along a trail on Cerro I1 Bila 15 km southwest of Las Marias (eleva- tion ca. 200 m). On 30 January a female (LSUMZ 99938) was netted in dense forest at Mairin Tighni. At the Mairin Tighni campsite individ- uals and pairs commonly sang from a low perch throughout most of the day. These are the first Honduran records of another species that reaches its northern limits of distribution in the wet evergreen forests of Gracias a Dios in northeast Honduras. There are no previous Honduran records. Ramphastos swainsonii.--Chestnut-mandibled Toucan. Although Monroe (1968) lists this tou- can as extending only to the forests of Olancho, R. swainsonii was found to be a common resi- dent of the forested areas of the Mosquitia in northeast Honduras. Previous records in Hon- duras are from Arenal, the Patuca River, the Segovia River, Nueva Choluteca, and Aguas Calientes. In the Platano River Biosphere Re- serve R. swainsonii is a common resident. It oc- curs sympatrically with the Keel-billed Toucan (R. sulfuratus) in disturbed second-growth for- est and in primary forest, where it dominates the smaller R. sulfuratus at feeding areas. Be- tween feeding bouts in the early morning and again shortly before sunset, individuals were often observed singing in monotonous high- pitched yelps from the exposed branches of riverside Cecropia trees. On 20 October 1980 a tape recording was made of their song at Bu- lebar. This record is the northernmost for the species. Hylophylax naevioides.--Spotted Antbird. This is another species that reaches its northern lim- it of distribution in the forests of northern Honduras. H. naevioides were commonly en- countered in the forested regions of northeast- ern Honduras and as far west as La Ceiba, where they were observed in close association with swarms of army ants (Eciton sp.). On 27 Feb- ruary 1980 a female (LSUMZ 95041) was col- lected in the Cordillera Nombre de Dios (8 km south of Danto, 160 m). On 11 September a specimen with female plumage (LSUMZ 99917 alch.) was collected in the same vicinity. In the Platano River Biosphere Reserve a male (LSUMZ 99945) was collected on 12 November at Tuskruhuas, and another male (LSUMZ 99918 alch.) was nettled on 30 January 1981 at Mairin Tighni. The Danto records are the northern- most distribution locality of this species and the only known location north of the Cordille- ra Nombre de Dios. Monroe (1968: 393) mistak- enly lists this species as occurring as far west as the Sula Valley; the four Honduran localities that he cites, however, are either south or east of the Cordillera. Phaenostictus mcleannani.--Ocellated Antbird. Monroe (1968) remarked that he was surprised to find this species at a collecting site in Olan- cho (5 mi south of San Esteban) and noted that it is a rare bird even as far north as Nicaragua. I found P. mcleannani to be a fairly common resident throughout forested parts of Olancho and Gracias a Dios. During the course of field- work in the Platano River Biosphere Reserve I collected five specimens (LSUMZ 99920 alch., 27 October 1980, Bulebar; LSUMZ 99944 fe- male, 9 November, Tuskruhuas; LSUMZ 99953 male skel., LSUMZ 99919 alch., and LSUMZ 99943 female, 30 January 1981, Mairin Tighni). P. mcleannani was frequently observed in close attendance at swarms of army ants, along with the Spotted Antbird and the Bicolored Antbird (Gymnopithys leucaspis), as has also been ob- served for Panamanian birds (Willis 1973). P. mcleannani reaches its northern limit in the hu- mid forests of northeast Honduras. Myrmotherula axillaris.--White-flanked Ant- wren. There is only one previous record for this species in Honduras, a female collected in 1887 along the Segovia River in extreme south- ern Honduras by C. H. Townsend (Monroe 1968). On 30 January 1981 a female (LSUMZ 99942) was collected at the Mairin Tighni camp in the Platano River Biosphere Reserve. On 3 and 8 February M. axillaris was observed for- aging in mixed-species flocks, where it searched epiphytes and vines growing on large trees. Its voice is a soft and plaintive piah. On one oc- casion it was associated with the same foraging flock as M. fulviventris. This record is the north- ern limit of their known distribution. Hylopezus perspicillatus.--Streak-chested Ant- pitta. On 11 November 1980 a female (LSUMZ 99946) was netted in the low strata of primary wet evergreen forest near the Tuskruhuas Riv- er campsite. During the month of January 1981 H. perspicillatus was infrequently observed yet often heard singing a loud plaintive song from near the forest floor in the vicinity of Mairin Tighni in old second-growth wet evergreen forest. There are no previous Honduran rec- ords. Colonia colonus.--Long-tailed Tyrant. In northeast Honduras this species is so common and conspicuous that it is surprising that there are only two previously published records: the Segovia River and Arehal, both in extreme southern Honduras. In the Platano River Bio- sphere Reserve C. colonus was frequently en- countered in open and semi-open situations. In the coasta! savanna near Kuri they nest in tree cavities excavated by Go!den-fronted Wood- peckers (Melanerpes aurifrons) in coconut pa!ms growing throughout areas of human sett!e- ment. One individua! was photographed at a nest hole in October 1980. They were often seen in the vicinity of Kuri, Bu!ebar, Las Marias, Tuskruhuas, and Mairin Tighni. Ridgely (pers. comm.) found them to be widespread near Aguas Ca!ientes in O!ancho. Northeast Hon- duras is the northern limit of their distribution. Conopias parva.--White-ringed F!ycatcher. This species was found to be a breeding resi- dent a!ong the P!atano, Tuskruhuas, and Mair- in Tighni rivers. They were common!y ob- served perching in the canopy or on high exposed dead limbs near river and stream bor- ders and in the forest interiors; they were more often observed in open situations. This species was distinguished from the sympatric Socia! F!ycatcher (Myiozetetes similis) by the broad white superciliary extending comp!ete!y around the nape, the !onger bi!l, and song type. A re- cording of their song was made at Bu!ebar. On 29 March 1979 a pair was observed southeast of Catacamas, Dept. O!ancho, by R. S. Ridgely (pers. comm.). These observations suggest that this species, formal!y known to range on!y as far north as Costa Rica, is probab!y widespread in the forests of O!ancho, Gracias a Dios, and in eastern Nicaragua. These are the first Hon- duran reports. Cyporhinus phaeocephalus.--Song Wren. I ob- served a group of as many as five Song Wrens dai!y from 28 January to 9 February whi!e I wa!ked a dai!y census route a!ong a trai! at the Mairin Tighni camp. The wrens wou!d become very disturbed by my approach and sco!d with a noisy and continuous wree, wree, wree, wree from a brush pile in old second-growth forest. These sightings and a tape recording are the northernmost record of their distribution. There is on!y one previous record for this species in Honduras, a female co!lected in 1887 at the Se- govia River in southern Honduras by C. H. Townsend. Dacnis cayana.--B!ue Dacnis. While foraging at the fringes of a mixed-species flock in the canopy of primary forest, a ma!e was observed at !ength on 12 November 1980 a!ong the Tus- kruhuas River. In January 1981 pairs were in- frequent!y seen in the vicinity of Bu!ebar, and Ridgely (pers. comm.) observed one pair on 28 March 1979 southeast of Catacamas, Olancho. This is another species former!y known to range as far north as Nicaragua that is apparent!y widespread, though uncommon, in the forests of Olancho and Gracias a Dios. These are the first reports from Honduras. Vermivora ruficapilla.--Nashvi!!e Warbler. On 28 November 1979 an individua! was netted in open wood!and at Rosario, Dept. Morazn, 1,500 m, Parque Naciona! La Tigra. The bird was photographed and re!eased. V. ruficapilla has been recorded in the high!ands of Guatema!a (Land 1970) and has been sighted in Panama (Ridge!y pers. comm.). This is the first Hon- duran record. Cacicus uropygialis.--Scar!et-rumped Cacique. At the Mairin Tighni campsite C. uropygialis was first encountered on 28 January 1981, when a stoa!! group was observed in a mixed-species flock moving through the mid-strata of second- growth wet evergreen forest. Whi!e foraging, they sang a !oud didee dum. On 3 February at the same !ocation, a so!itary ma!e was seen dis- p!aying in a manner very simi!ar to that of the Montezuma Oropendola (Gymnostinops monte- zuma). Whi!e perching on an exposed !imb 20 m above the ground and not far from the can- opy, it gave a quick squeaky two-note descend- ing eeoow eeoow ca!! fo!!owed by a soft crack- !ing noise simi!ar to the second of gurg!ing water or the crump!ing of ce!!ophane. With wings he!d s!ight!y away from the body and thus exposing the bright scar!et rump, it !eaned forward over the edge of the perch singing an oodle oodle song virtua!ly identica! to that of G. montezuma yet shorter in duration. This species is known from only one previous !ocation in Honduras: a ma!e co!!ected at Arena! in 1953 by Howell (Monroe 1968). This is another of the humid forest inhabitants that reach the northern !imit of their distribution in north- east Honduras. The fo!!owing is a !ist of those species for which on!y sight records exist and whose doc- umentation needs to be substantiated further. Mesembrinibis cayennensis.--Green Ibis. Two individua!s were observed foraging together on an exposed muddy bank of the P!atano River 10 km east (downstream) of Las Marias on 17 October 1980. These were observed in good lighting and were identified as M. cayennensis rather than the similar but larger immature White-faced Ibis (Plegadis chihi) or the Glossy Ibis (P. falcinellus), two species with which I am familiar. An effort was made to collect the birds, but upon my approach they flew into an im- penetrable swampy grove and could not be pursued. In July 1980 Harry L. Bell (pers. comm.) identified a green ibis as M. cayennensis along the Platano River east of Las Marias. These sightings are the northernmost reports for this species. M. cayennensis is rare from the Panama Canal north and has been collected but twice in southern Costa Rica (Slud 1964), al- though there have been many sight records in recent years (Ridgely pers. comm.). Future workers will undoubtedly find this species lo- cally through the Caribbean lowlands of Hon- duras and Nicaragua. This is the first report from Honduras. Leucopternis semiplumbea.-- Semiplumbeous Hawk. On February 7 1981 L. Benshoof, T. Lo- gan, and I observed one individual at length while it perched within 2 m of the forest floor near the Mairin Tighni camp. It was identified as L. semiplumbea rather than the similar Mi- crastur mirandoIlei, both being species with which I am familiar, by the presence of orange cere and legs. This is the northernmost report for this species. The specimen collected by C. H. Townsend along the Segovia River in 1887 is the only previous Honduran record (Monroe 1968). MyrmotheruIa fulviventris.--Checker-throated Antwren. This species was uncommonly en- countered in the Platano River Biosphere Re- serve at Mairin Tighni. Monroe (1968) listed this species as reaching the northern limit of distribution in the Olancho forests of eastern Honduras based on the specimen collected at the Segovia River in 1887 and the specimen from Arenal in 1953, both locations being in extreme southern Honduras along the Nicara- guan border. On 5 February 1981 M. fulviventris was encountered on two separate occasions for- aging in a mixed-species flock in old second- growth wet evergreen forest. It foraged in dense vine thickets and probed curled dead leaves for insects, which is their foraging technique in Costa Rica (Skutch 1969) and Panama (Grad- wohl and Greenberg 1982, pers. obs.). While foraging, they gave a high-pitched, two-note call and an ascending churr. On 8 February they were again encountered in a mixed-species flock foraging in dense vine thickets. These reports are the northernmost for the species. Myrmeciza exsul.--Chestnut-backed Antbird. On 29 March 1979 Ridgely observed one sing- ing male in the vicinity of Cerro Las Perlas southeast of Catacamas, Dept. Olancho. There are no previous Honduran reports for this species, formerly known to range as far north as Nicaragua. Myiozetetes granadensis.--Gray-capped Fly- catcher. On 19 January 1981 an individual was observed at close range as it perched in an Aca- cia tree along the Platano River at Bulebar. This represents the northernmost report. It is known previously in Honduras from two specimens collected at Arenal in 1955 by Howell, a single specimen from the Guampu River collected by R. R. Graber in 1963 (Monroe 1968), and several pairs observed by Ridgely on 30 March 1979 at Aguas Calientes, Dept. Olancho. Lophotriccus pileatus.--Scale-crested Pygmy- Tyrant. On 29 March 1979 Ridgely observed one individual and heard others in the vicinity of Cerro Las Perlas southeast of Catacamas, Dept. Olancho. This is the first report from Honduras. They were previously known to range as far north as Costa Rica. Tachyphonus delatrii.--Tawny-crested Tana- ger. A foraging flock of 10-15 individuals was observed in the middle and upper strata of pri- mary wet evergreen forest near the Tuskruhuas campsite on 10 November 1980. These were identified by the uniform black plumage and the orange crest of the male. While foraging, they uttered sharp metallic chink call notes. One bird was observed eating a large green imma- ture grasshopper (Orthoptera) on a horizontal leaf; the insect was first dismembered with the bird's bill and then swallowed in individual pieces. This species has not previously been re- ported from Honduras. PityIus grossus.--Slate-colored Grosbeak. One individual was observed on 9 November 1980 in primary wet evergreen forest near the Tus- kruhuas campsite. It foraged in dense foliage 5-10 m above the forest floor along the fringes of a mixed-species flock. While searching the foliage, it called a loud single note: pweeah. This is the first report for Honduras of yet another species previously known to occur as far north as Nicaragua. SporophiIa schistacea.--Slate-colored Seedea- ter. Individuals carefully identified as this species were observed during every month of TABLE 1. Species which have reached their known northern distribution in Nicaragua but whose presence is expected in adjacent regions of Hon- duras. Pearl Kite Tiny Hawk Violaceous Quail Dove Crimson-fronted Para- keet Rufous-vented Ground- Cuckoo Short-tailed Nighthawk Gray-rumped Swift Bronzy Hermit Blue-chested Humming- bird Steely-vented Hum- mingbird Cinnamon Woodpecker Black-striped Wood- creeper Striped Leaf-gleaner Wing-banded Antbird Fulvous-bellied Antpitta Black-and-White Becard Tawny-chested Fly- catcher Yellow Tyrannulet Stripe-breasted Wren Bay Wren Black-throated Wren Tawny-faced Gnatwren Yellow-crowned Eu- phonia Palm Tanager Carmiol's Tanager Great-billed Seed Finch Gampsonyx swansonii Accipiter superciliosus Geotrygon violacea Aratinga finschi Neomorphus geoffroyi Lurocalis semitorquatus Chaetura cinereiventris Glaucis aenea Amazilia amabilis Amazilia saucerottei Celeus loricatus Xiphorhynchus lachrymo- sits Hyloctistes subulatus Myrmornis torquata Hylopezus fulviventris Pachyramphus albogriseus Aphanotriccus capitalis Capsiempis fiaveola Thryothorus thoracicus Thryothorus nigricapillus Thryothorus atrogularis Microbates cinereiventris Euphonia luteicapilla Thraupis palmarum Chlorothraupis carmioli Oryzoborus maximiliani the year (1979-1980) at the Lancetilia Botanical Gardens, where they roosted, sang, fed, and presumably nested in the flowering and fruit- ing clumps of bamboo (Bambuseae) along the banks of the Tela River. These birds generally perched 5-15 m above the forest floor in either bamboo or in a tree close to bamboo clumps and repeatedly sang a long high-pitched trill. On 5 March 1981 an individual singing at great length in old second-growth moist evergreen forest along the Tela River was observed by myself, J. Baird, and a natural history tour group. S. schistacea was frequently observed along the north coast of Honduras between Tela and La Ceiba during 1979-1980. It is presumed to be increasing its range in Central America due to the spread of introduced bamboo, the seeds of which appear to be an important food source; they were not present at all in Lance- tilla 15 yr ago (Monroe pers. comm.). Willis and Eisenmann (1979) suggest that S. schistacea wanders widely to areas of bamboo seed crops. This is the first Honduran report. DISCUSSION The topography of Honduras acts as a major filter barrier affecting the distribution of many neotropical species north of Panama by con- stricting and breaking up the vast expanse of lowland evergreen forests (Monroe 1968). There exist two major environmental and ortho- graphic obstacles limiting northern and west- ern distributions of the lowland forest species of Olancho and Gracias a Dios: in western Hon- duras the terrain is a semi-arid highland dom- inated by pine (Pinus oocarpa) and oak (Quercus spp.), and the north coast is flanked by the Cor- dillera Nombre de Dios running parallel to the coastline and exceeding 2,400 m in elevation. This latter mountain range effectively divides the arid interior from the humid coastal plain. There are presently at least 34 bird species (Monroe lists 21 and 13 additional species are recorded here) that range into Olancho and Gracias a Dios but have not yet been recorded north and west of this region due, perhaps, to the presence of this barrier. The constricted corridor and low elevation of the Cordillera Nombre de Dios in the vicinity of Trujillo offer the only continuous north-south corridor in Honduras for the dispersal of lowland species, which are restricted to humid evergreen for- ests. Species such as Lanio Ieucothorax and Or- talis cinereiceps reach their northern limit of dis- tribution in Olancho and are replaced by an allospecies, L. aurantius and O. vetula, respec- tively, north of the Cordillera. It appears that this mountain range is also an effective barrier filtering mammalian and floral distributions (Marcus in prep.). Monroe (1968) lists 663 bird species known to occur in Honduras. The additions of Sterna albifrons and S. dougallii (Udvardy et al. 1973), Sula dactylatra, Piuviaiis dorninica, Stercorarius parasiticus, Larus delawarensis, L. atricilIa, and Sterna sandvicensis (Brown and Monroe 1974), the spread of Passer domesticus into Honduras (Avedillo 1977), and the 16 species herein re- ported bring the total known Honduran avi- fauna to 688 species. At the present time there are at least 26 additional species known to range northward as far as Nicaragua that have not yet been recorded in Honduras (Table 1). It is like- ly that many of these also will be found to oc- cur in Honduras, particularly in the adjacent forested areas of Olancho and Gracias a Dios. The Honduran Mosquitia and the Caribbean slope are in need of further ornithological re- search; these central areas are also in need of additional parks and reserves with ample pro- tection from deforestation and poaching. At the present time three species (Mesembrinibis cay- ennensis, Conopias parva, Lophotriccus pileatus) are known from Costa Rica and Honduras but not from Nicaragua. It is expected that as many as 54 additional species now known to occur as migrants or ac- cidentals in adjacent countries and the Carib- bean may be found as winter residents or ac- cidentals in Honduras (from Peterson and Chalif 1973). The Pacific lowlands, interior highlands, islands in the Gulf of Fonseca, the Bay Islands, and the Mosquito coast should be particularly fruitful regions for investigations of migrant and transient species. Already Hon- duras is known to support a richer avifauna than any of the adjacent countries, and the above analysis suggests that many more species are likely to be found. ACKNOWLEDGMENTS I am grateful to Lic. Wilberto Aguilar, Direccion General de Recursos Naturales Renovables, for his cooperation and for providing transportation costs to the Mosquitia. I thank Peter Lara, Nicholas Metes, and other members of the Peace-Corps staff in Hon- duras for their support and encouragement through- out the duration of my fieldwork. R. S. Ridgely is gratefully acknowledged for permitting use of his unpublished field notes and for comments on this manuscript. I appreciate the laboratory space provid- ed at the Lancetilia Botanical Gardens by Donald L. Hazlett and the hospitality in Tegucigalpa of Julieta and Graciela David. Professor Sixto George is thanked for his hospitality and invaluable assistance while I was in Kuri, and I thank Alan, Ladis, and Nectaline Riven in Bulebar, without whose help fieldwork along the Platano River would have been impossible. Nan- cy Aker Chaplin, Thomas Chaplin, Donald Hanson, Brian Lee, and Jonathon Lind are thanked for their field assistance, and J. V. Remsen, LSUMZ, for sup- plying field equipment. I thank Burr L. Monroe, Jr., J. V. Remsen, and William E. Glanz for offering many helpful comments on and criticisms of the manu- script. I owe special thanks to Robert E. Engle for his continued support and encouragement. LITERATURE CITED AVEOILLO, M. 1977. Communicacion: Passer domes- ticus (Gorri6n cornfin) en Honduras. Ceiba 21: 57-62. BANGS, O. 1903. Birds and mammals from Hondu- ras. Bull. Mus. Comp. Zool. 39: 6. BOND, J. 1971. Birds of the West Indies. Boston, Massachusetts, Houghton Mifflin Co. BROWN, H. C., & B. L. MONROE, JR. 1974. Bird rec- ords from Honduras. Condor 76: 348-349. GRADWOHL, J., & R. GREENBERG. 1982. The effect of a single species of avian predator on the arthro- pods of aerial leaf litter. Ecology 63: 581-583. HANSON, D.A. 1982. Distribution of the Quetzal in Honduras. Auk 99: 385. HOWELL, T.A. 1971. An ecological study of the birds of the lowland pine savanna and adjacent rain forest in northeastern Nicaragua. Living Bird 10: 185-242. KOFORD, R. R., G. S. WILKINSON, & B. S. BOWEN. 1980. First record of an Aplomado Falcon (Falco femo- falls) in Costa Rica. Brenesia 17: 23-25. LAND, H.C. 1970. Birds of Guatemala. Wynnewood, Pennsylvania, Livingston Publ. Co. MARCUS, M.J. 1980a. Birds of Lancetilia. Tela, Hon- duras, Jardin Botanico "Wilson Popenoe" de Lancetilia, ESNACIFOR (COHDEFOR). 1980b. Aves del Parque Nacional La Tigra. Tegucigalpa, Honduras, Departmento de Vida Silvestre y Recursos Ambientales (RENARE). 1981. Aprovechamiento de fauna silvestre y avifauna: Reserva de la Biosfera Rio Platano. Tegucigalpa, Honduras, Dept. de Vida Silvestre y Recursos Ambientales (RENARE). MONROE, B. L., JR. 1968. A distributional survey of the birds of Honduras. Ornithol. Monogr. No. 7. PETERS, J. L. 1929. An ornithological survey in the Caribbean lowlands of Honduras. Bull. Mus. Comp. Zool. 69: 12. PETERSON, R. T., & E. L. CHALIF. 1973. Field guide to Mexican birds. Boston, Massachusetts, Hough- ton Mifflin Co. RIDGELY, R.S. 1976. Birds of Panama. 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The behavior of Ocellated Ant- birds. Smithsonian Contrib. Zool. No. 144. --, r E. EISENMANN. 1979. A revised list of birds of Barro Colorado Island, Panama. Smithsonian Contrib. Zool. No. 291.