The two Marbled Murrelets (Figures 1 and 2) remained close to one another the entire time we observed them, diving and foraging over the sandy bottom. They appeared healthy; their alert posture, with heads and tails up, contrasted with that of the Ancient Murrelet seen later. They called several times as we slowly approached them by boat, giving soft quack-like notes (eh-eh; S. B.C. Dechesne, unpubl. data) typical of the species. Presumably the same birds were seen again on 11 January by R. E. Webster (in litt.), but they were not found later in the month, despite considerable searching by K. Radamaker, A.M. Sada, L. Santaella, and T. E. Wurster (pers. comm.).
The lowlands of the Isthmus of Tehuantepec separate the range of the Guatemalan Pygmy-Owl (Glaucidium cobanense), recognized as a species in modern owl taxonomy and resident in the highlands of southeastern Mexico, Guatemala, and Honduras, from the range of Mountain Pygmy-Owl (Glaucidium gnoma) in the Mexican highlands northwest of the isthmus. Here we document hitherto undescribed vocalizations of Guatemalan Pygmy-Owls in the Guatemala-Chiapas highlands. We recorded four different vocalization types of adults: (1) territorial toot calls, (2) whiwhiwhi calls given by the female during nest-site establishment, (3) soft toot calls of the male near the nest, and (4) copulation calls. The territorial toot calls of Guatemalan Pygmy-Owls differed from those of Mountain Pygmy-Owls in Mexico. The mean individual call rate of Guatemalan Pygmy-Owls was 3.4 ± 0.5 notes/sec (n = 49 call series of six individuals), significantly higher than in Mountain Pygmy-Owls (1.9 ± 0.3 notes/sec, n = 34 call series of eight individuals). This new evidence of vocal differences supports modern taxonomic separation of both taxa.Las tierras bajas del istmo de Tehuantepec aíslan el área de distribución de Glaucidium cobanense, reconocida como especie según la taxonomía moderna de búhos y residente en las tierras altas de Chiapas, México, Guatemala y Honduras, del área de distribución de Glaucidium gnoma en las tierras altas de México al norte del istmo. Aquí documentamos vocalizaciones de Glaucidium cobanense de las tierras altas de Guatemala y Chiapas que aún no habían sido descritas. Cuatro diferentes vocalizaciones de adultos fueron registradas: (1) llamado territorial, (2) serie de llamado vivivi de la hembra durante la fase de establecimiento del sitio de anidación, (3) llamado suave del macho cerca del nido, y (4) llamados de copulación. El llamado territorial de G. cobanense fue distinto del de G. gnoma del norte de México. El promedio individual del tiempo de llamadas fue significativamente más rápido en G. cobanense (3.4 notas/seg ± 0.5, n = 49 series de notas de seis individuos) que en G. gnoma (1.9 notas/seg ± 0.3, n = 34 series de notas de ocho individuos). Esta nueva evidencia de diferencias vocales apoya la separación taxonómica de ambos taxones.
In this issue, Jenni and Winkler, Piersma, Thompson, and Willoughby offer commentaries on our modifications (Howell et al. 2003) to the Humphrey-Parkes system for naming molts and plumages (Humphrey and Parkes 1959; the H-P system). Piersma generally accepts our revision and outlines how its use could improve our ability to understand other cyclic life-history phenomena. Both Jenni and Winkler and Willoughby disagree with the philosophy of the H-P system, particularly its ability to reveal homologies. Thompson accepts the H-P system but argues that our elaboration on the system is faulty. However, we believe that despite a diversity of opinion concerning our proposal there is much common ground, including agreement regarding the homology of juvenal and basic plumages across species and the utility of the new term "formative." The main points we review here are the potential dichotomy between homologies of molt and homologies of plumage coloration; the caution that should be applied when using plumage coloration to identify presumed homologous molts; and a clarification of definitions of plumage, molt, and the first plumage cycle. We remain convinced that our modified version of the H-P system represents a significant improvement in terminology, and will better reflect the homologies of molts.
Recent seabird identification guides (e.g., Tuck and Heinzel 1978, Harrison 1983, 1987) and articles on the Manx Shearwater (Puffinus puffinus) complex (e.g., Jehl 1982, Bourne et al. 1988), do not satisfactorily address the problem of separating the Manx Shearwater (P. puffinus) from Newell's (P. auricularis newelli) and Townsend's (P. a. auricularis) shearwaters, presumably because Townsend's and Newell's are Pacific Ocean species while Manx is essentially a bird of the Atlantic Ocean. The Manx, however, is a long-distance migrant that has occurred in the Pacific off Australia and New Zealand (Kinsky and Fowler 1973, Lindsey 1986, Tennyson 1986) and off Washington state, in September-October 1990 and September-October 1992 (Tweit and Gilligan 1993). In addition, five California records of the Manx from July to October 1993 have been submitted to the California Bird Records Committee (M. A. Patten pers. comm.). Here, on the basis of museum and literature research, combined with extensive field experience of this complex, we summarize identification characters of the Manx, Townsend's, and Newell's shearwaters.
Abstract In this issue, Jenni and Winkler, Piersma, Thompson, and Willoughby offer commentaries on our modifications (Howell et al. 2003) to the Humphrey-Parkes system for naming molts and plumages (Humphrey and Parkes 1959; the H-P system). Piersma generally accepts our revision and outlines how its use could improve our ability to understand other cyclic life-history phenomena. Both Jenni and Winkler and Willoughby disagree with the philosophy of the H-P system, particularly its ability to reveal homologies. Thompson accepts the H-P system but argues that our elaboration on the system is faulty. However, we believe that despite a diversity of opinion concerning our proposal there is much common ground, including agreement regarding the homology of juvenal and basic plumages across species and the utility of the new term “formative.” The main points we review here are the potential dichotomy between homologies of molt and homologies of plumage coloration; the caution that should be applied when using plumage coloration to identify presumed homologous molts; and a clarification of definitions of plumage, molt, and the first plumage cycle. We remain convinced that our modified version of the H-P system represents a significant improvement in terminology, and will better reflect the homologies of molts. El Problema del Primer Plumaje Básico: Respuesta a los Comentarios sobre Howell et al. (2003) Resumen. En este número, Jenni y Winkler, Piersma, Thompson y Willoughby ofrecen comentarios sobre nuestras modificaciones (Howell et al. 2003) al sistema Humphrey-Parkes para nombrar las mudas y los plumajes (el sistema H-P; Humphrey and Parkes 1959). Piersma en general acepta nuestra revisión y esboza cómo su uso podría mejorar nuestra habilidad para entender otros fenómenos cíclicos de las historias de vida. Tanto Jenni y Winkler como Willoughby están en desacuerdo con la filosofía del sistema H-P, particularmente en cuanto a su habilidad para revelar homologías. Thompson acepta el sistema H-P, pero aduce que nuestra elaboración sobre éste es errónea. Sin embargo, creemos que a pesar de la diversidad de opiniones en torno a nuestra propuesta existen muchos puntos en los que convenimos, incluyendo la homología de los plumajes juveniles y básicos a través de las especies y la utilidad del nuevo término formativo. Los puntos principales que aquí revisamos son la dicotomía potencial entre las homologías de la muda y las homologías de la coloración del plumaje, la cautela que debe tenerse al usar la coloración del plumaje para identificar mudas presuntamente homólogas y una clarificación de nuestras definiciones de plumaje, muda y el primer ciclo del plumage. Seguimos convencidos de que nuestra versión modificada del sistema H-P representa un mejoramiento significativo en la terminología, que reflejará mejor las homologías de las mudas.
117 First Chilean record of Yellow-crowned Night Heron Nyctanassa violacea On 11 November 2009 we found a first-cycle Yellow-crowned Night Heron Nyctanassa violacea roosting on a fishing boat in the harbour at Arica, Region I, in northernmost Chile. The bird was spotted by SNGH as we returned from a pelagic trip. We approached the bird closely and observed it in good light, in direct comparison with Black-crowned Night Herons Nycticorax nycticorax. RH took video of the bird (posted at http://www.youtube.com/ watch?v=HNVixuA3ye0) and numerous photographs were also taken to document the record (Fig. 1). On the Pacific coast of South America, Yellow-crowned Night Herons occur regularly south only to northernmost Peru, c.1,000 km north of the Chilean border. Vagrants occur south very rarely to Lima, Peru, but the species was not recorded in 16 years (1953–67) of field work in southern Peru. There appear to be no previous records of this species in Chile. The relatively dark plumage of the Arica individual (compared to birds in North and Middle America) suggests the race calignis, which is also most likely on geographic grounds.
