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Acoustic signals show immense variation among passerines, and several hypotheses have been proposed to explain this diversity. In this study, we tested, for the first time, the relationships of song structure to phylogeny, habitat type, and morphology in the vireos and allies (Vireonidae). Every measure of song structure considered in this study had moderate and significant phylogenetic signal. Furthermore, two song-constraining morphological traits, bill shape and body mass, also exhibited significant phylogenetic signal. Song length showed the largest within-clade similarity; longer songs were highly conserved in part of the greenlet (Hylophilus) clade, whereas shorter songs characterized the remaining seven genera. We found no differences in song structure among vireonids living in different habitat types. However, vireonids with shorter, stouter bills and larger bodies sang songs with lower minimum and maximum peak frequency, compared with species with longer, thinner bills and smaller bodies. We conclude that Vireonidae song evolution is driven partially by phylogenetically conserved morphological traits. Our findings support the phylogenetic signal and morphological constraints hypotheses explaining structural diversity in avian acoustic signals.

A new coccidian species, Isospora gilvusin. sp. (Apicomplexa: Eimeriidae) collected from the warbling vireo Vireo gilvus, is reported from Morelia, Michoacán State, Mexico. Sporulated oöcysts of the new species are spherical to subspherical, 27−31 × 27−29 (30.1 × 28.4) μm, with a length/width (L/W) ratio of 1.1; one or two polar granules are present, but micropyle and oöcyst residuum are absent. Sporocyts are ovoid to drop-shaped, 16−17 × 11−12 (17.0 × 11.5) μm, with a L/W ratio of 1.7; Stieda and sub-Stieda bodies are both present, but para-Stieda body is absent; sporocyst residuum diffuse. At the histological study, endogenous stages were observed in the epithelial cells of the duodenum. This is the second species of Isospora recorded infecting a bird of the family Vireonidae in the New World.

For signal divergence to drive speciation, receivers should perceive structural differences in divergent signals; similar-structured signals from closer relatives are expected to elicit stronger responses than dissimilar signals from distant relatives. Two mechanisms can affect receiver responses to passerine song: (1) sympatric song familiarity and (2) an innate auditory template used to assess acoustic similarity. We examined the role of acoustic similarity by comparing behavioral responses of male Bermuda White-eyed Vireos (Vireo griseus bermudianus) to playback of the songs of allopatric species from across the family Vireonidae. Phylogenetic distance between the focal and stimulus species predicted response strength. Males uttered fewer vocalizations, had fewer speaker flyovers, and remained farther from the speaker during playback of the songs of more distantly related vireos. We then tested whether structural similarity of playback songs, as defined by three phylogenetically conserved song traits, explained these relationships. As predicted, males uttered fewer vocalizations, had fewer speaker flyovers, and remained farther from the speaker in response to more dissimilar songs. Collectively, our results suggest that male Bermuda Vireos perceive and respond to interspecies variation in the phylogenetically conserved song traits of allopatric species of vireos. This suggests that song divergence, and the ability to distinguish divergent songs, reinforces reproductive isolation and competitor exclusion. Para que la divergencia de señales conduzca a la especiación, los receptores deben percibir las diferencias estructurales de señales divergentes. Se espera que las señales de estructuras similares de parientes más cercanos provoquen respuestas más fuertes que las señales disimilares de parientes distantes. Dos mecanismos pueden afectar las respuestas de los receptores al canto de paserinas: (1) familiaridad de canto simpátrico y (2) una plantilla auditiva innata que se usa para determinar la similitud acústica. Examinamos el papel de la similitud acústica por medio de comparaciones de respuestas de comportamiento en machos del vireo Vireo griseus bermudianus a grabaciones de cantos de especies alopátricas de la familia Vireonidae. La distancia filogenética entre las especies focal y estímulo predicen la fuerza de la respuesta. Los machos completaron menos vocalizaciones, tuvieron menos sobrevuelos a la bocina y permanecieron más lejos durante el tiempo en que se tocó la grabación de los vireos más distantemente emparentados. Cuando sometimos a prueba la similitud estructural de los cantos grabados, tal y como lo definen tres características filogenéticamente conservadas de los cantos, éstas explicaron esas relaciones. Como lo predecimos, los machos completaron menos vocalizaciones, tuvieron menos sobrevuelos a la bocina y permanecieron más lejos en respuesta a los cantos más disímiles. En conjunto, nuestros resultados sugieren que los machos de este vireo perciben y responden a variación interespecífica en las características del canto filogenéticamente conservadas de las especies de vireos alopátricos. Esto sugiere que la divergencia del canto, y la capacidad de distinguir cantos divergentes, refuerza el aislamiento reproductivo y la exclusión competitiva.

We review 147 incidents of the capture of small birds by mantids (order Mantodea, family Mantidae). This has been documented in 13 different countries, on all continents except Antarctica. We found records of predation on birds by 12 mantid species (in the genera Coptopteryx, Hierodula, Mantis, Miomantis, Polyspilota, Sphodromantis, Stagmatoptera, Stagmomantis, and Tenodera). Small birds in the orders Apodiformes and Passeriformes, representing 24 identified species from 14 families (Acanthizidae, Acrocephalidae, Certhiidae, Estrildidae, Maluridae, Meliphagidae, Muscicapidae, Nectariniidae, Parulidae, Phylloscopidae, Scotocercidae, Trochilidae, Tyrannidae, and Vireonidae), were found as prey. Most reports (>70% of observed incidents) are from the USA, where mantids have often been seen capturing hummingbirds attracted to food sources in gardens, i.e., hummingbird feeders or hummingbird-pollinated plants. The Ruby-throated Hummingbird (Archilochus colubris) was the species most frequently reported to be captured by mantids. Captures were reported also from Canada, Central America, and South America. In Africa, Asia, Australia, and Europe, we found 29 records of small passerine birds captured by mantids. Of the birds captured, 78% were killed and eaten by the mantids, 2% succeeded in escaping on their own, and 18% were freed by humans. In North America, native and non-native mantids were engaged in bird predation. Our compilation suggests that praying mantises frequently prey on hummingbirds in gardens in North America; therefore, we suggest caution in use of large-sized mantids, particularly non-native mantids, in gardens for insect pest control.

Cyclarhis gujanensis is a little bird which feeds on high number of large preys, such frogs, lizards, snakes, bats and birds. As there are few studies on the cranial anatomy of this species, the authors aimed to describe the cranial myology to contribute to the anatomical knowledge of this species and to make some assumptions about functional anatomy. Thus, they described the muscles from the jaw apparatus (external and internal adductor muscles, the muscles of the pterygoid system and the depressor muscles of the mandible). The adductor system is the greatest and multipinulated, particularly in its origin in the caudal portion of the temporal fossa. The depressor jaw muscles systems are enlarged with many components in complexity. The most of jaw apparatus muscles are short, but the strength (biting or crushing forces) from short feeding apparatus fibers probably is increased by high number of components and pinnulation. These anatomical aspects of the muscles indicate a considerable force in the jaws, without which C. gujanensis probably could not cut their prey into smaller pieces. However, functional approaches to analysis of forces of the muscle fibers are needed to corroborate/refute the hypotheses mentioned above.

Most species of songbirds exhibit biparental care, but, for many taxa and species, little is known about the relative contributions of males and females in brooding and provisioning nestlings. Additional studies of the contributions of males and females in brooding and feeding nestlings are needed to better understand the respective roles of males and females as well as the factors that might contribute to interspecific variation in those roles. We examined the roles of adult male and female White-eyed Vireos (Vireo griseus) in brooding and provisioning nestlings in east-central Kentucky during the 1996 breeding season. Nests were located by monitoring adult behavior and checking likely nest sites. Once eggs hatched, nests were video-recorded to monitor the behavior of adults. Subsequent review of videos revealed that both male and female White-eyed Vireos brooded young and that males provisioned nestlings at higher rates than females. In contrast to males in many other species of songbirds, male White-eyed Vireos assisted in brooding young and provisioned nestlings at higher rates than their mates. One possible explanation for this is that low rates of extra-pair paternity might increase male confidence of their paternity status. Parental care provided by male White-eyed Vireos may also limit energy expenditure by their mates and increase the likelihood of females re-nesting if nests are predated or initiating second nesting attempts if initial attempts are successful.

The genus Hylophilus sensu lato was recently recognized as polyphyletic and split in to several genera, including the monotypic genus Tunchiornis. We describe in detail the nesting features of T. ochraceiceps that could provide additional evidence to support the split of the genus. Nests were found at two stations in southwestern Perú, Manu National Park. We found three cup-nests covered externally with green moss and internally with thin and light straw fibers, with inner and outer major and minor axes of 48.6 × 49.2 mm and 66.6 × 61 mm, respectively, a wall thickness of 9.8 mm, and an inner depth of 38.7 mm. The eggs were creamy-white with dark-brown spots concentrated at the base and measured 18.3 ± 0.4 × 13.1 ± 0.3 mm with a mass of 1.73 ± 0.12 g. Overall nest attentiveness was 64% and the egg were incubated at 32.35 ± 3.11 °C. The incubation and nestling period lasted 15 and 11 days, respectively. The nest materials used by Tunchiornis are similar to Hylophilus but differ from Pachysylvia, which use dried leaves and bark. These results advance our understanding of the reproductive biology of this phylogenetically divergent group.

Data are presented on the status of the vireos (Vireonidae) that occur in Louisiana. Based primarily on year-round surveys at coastal sites in southwestern Louisiana and censuses at an inland site in central Louisiana, data on timing of migration are presented for White-eyed (Vireo griseus), Solitary (V. solitarius), Yellow-throated (V. flavifrons), Philadelphia (V. philadelphicus), and Red-eyed (V. olivaceus) vireos. In general, migrant vireos in spring are much more common on the coast than inland, whereas the reverse is true in fall. Bell's Vireo (V. bellii) has been recorded 12 times in southern Louisiana between 4 November and 22 January; this represents a substantial portion of all late fall/early winter records from eastern North America. No documented records exist of Yellow-throated Vireo from early November to early March for Louisiana, or probably elsewhere in the Gulf Coast region, despite numerous published sight records. Warbling Vireo (V. gilvus) has declined dramatically as a breeding species in Louisiana for unknown reasons; there have been almost no reports of breeding birds for three decades. Two specimens of the subspecies V. g. swainsonii from western North America have been collected in Louisiana, one of which is the first winter specimen of the species for eastern North America. One specimen of White-eyed Vireo from Louisiana is V. griseus micrus, this represents the first record of this taxon north of southern Texas. One of the three Louisiana specimen records for Bell's Vireo is of a subspecies (V. b. medius) from the southwestern USA and north-central Mexico. One specimen record of solitary Vireo from Louisiana is a distinctive subspecies (V. s. plumbeus) from western North America. A specimen of Yellow-green Vireo (V. flavoviridis) from Lousiana evidently is just the second documented record for the eastern United States. Two of 12 Louisiana specimens of Black-whiskered Vireos (V. altiloquus) are of the nominate subspecies (from the Greater Antilles), for which there was only one previous record for the United States.

An unprecedented influx of vagrant vireos and wood-warblers into California occurred in the spring and summer of 1992. The seven species involved (White-eyed Vireo [Vireo griseus], Yellow-throated Vireo [V. flavifrons], Northern Parula [Parula americana], Yellow-throated Warbler [Dendroica dominica], Worm-eating Warbler [Helmitheros vermivorus], Kentucky Warbler [Oporornis formosus], and Hooded Warbler [Wilsonia citrina]) all breed primarily in the southeastern United States, suggesting a common factor for the influx. Furthermore, all seven species have been recorded in California with increasing frequency over the past two decades, suggesting a common trend in the populations of these species. We examined five hypotheses that could explain the increasing number of California records of these species: (1) observer bias, (2) pesticide-caused misorientation, (3) shifts in winter range, (4) anomalous weather conditions (including global warming and El Niño-Southern Oscillation), and (5) range expansions into the western United States and/or dramatic population increases in the southeastern United States. We found little or no support for the first three hypotheses. Anomalous weather conditions probably accounted for the magnitude of the 1992 influx, but the final hypothesis is needed to explain the overall trend. Although available data are not sufficient to distinguish between summer distributional shifts and population increases within the \"normal\" breeding ranges of these species, the possibility of westward range expansion is intriguing.

Pilherodius pileatus (Boddaert) / Euxenura galeata (Molina) / Accipiter superciliosus supereciliosus (Linne) / Laterallus exilis (Temminck) / Touit stictoptera (Selater) / Amazona festiva festiva (Linne) / Deroptyus accipitrinus accipitrinus (Linné) / Tyto alba guatemalae (Ridgway) / Bubo virginianus elutus Todd / Nyctibius grandis (Gmelin) / Chordeiles minor sennetti Coues / Notharchus macrorhynchos hyperrhynchus (Sclater) / Nystactes tamatia pulmentum (Sclater) / Nasica longirostris (Vieillot) / Turdus grayi incomptus (Bangs) / Vireo philadelphicus (Cassin) / Pitylus grossus grossus (Linné).