Distribution and taxonomy of Pyrgophorus platyrachis (Caenogastropoda: Hydrobiidae) in the Sistema de Maracaibo, Venezuela

The presence of a microgastropod identified as Potamopyrgus sp. was detected previously in the Maracaibo System; nevertheless, a detailed morphological analysis identified this snail in other genera. The objective of this work is to update the distribution and taxonomy of Pyrgophorus platyrachis in the Maracaibo System, Venezuela in samples obtained between 2001 and 2009. The presence of hundreds of individuals of P. platyrachis were observed in the estuary, indeed in the localities of the Gran Eneal lagoon (4 111 snails), Peonías lagoon (229 snails), Punta Capitán Chico (758 snails), San Francisco (2 517 snails), Curarire (240 snails), Apon River mouth (173 snails), Ojeda City (240 snails), Bachaquero (128 snails) and Tomoporo de Agua (385 snails). We performed a taxonomical analysis, and emphasized in ecological aspects, such as the distribution of the species and habitat features, as near vegetation and type of associated sediment. We found three morphotypes of the species, one smooth, another with spiral striations and the other with spines. Smooth morphotype was exclusive of the Gran Eneal lagoon, Peonías lagoon, Punta Capitan Chico and Apon River mouth localities, whereas the other two morphotypes were found together in the remaining localities. According to our detailed anatomical and taxonomical analysis we propose a synonymy between P. platyrachis and the other species described like Pyrgophorus parvulus and Pyrgophorus spinosus.     

Isospora toxostomai n. sp. (Apicomplexa: Eimeriidae) from the curved-billed thrasher Toxostoma curvirostre (Swainson) (Passeriformes: Mimidae) at the Central highlands of Mexico

Systematic Parasitology - Isospora toxostomai n. sp. (Apicomplexa: Eimeriidae) is described based on material from the curved-billed thrasher Toxostoma curvirostre (Swainson) in the Central...     

Phylogenetic relationships of the mockingbirds and thrashers (Aves: Mimidae)

The mockingbirds, thrashers and allied birds in the family Mimidae are broadly distributed across the Americas. Many aspects of their phylogenetic history are well established, but there has been no previous phylogenetic study that included all species in this radiation. Our reconstructions based on mitochondrial and nuclear DNA sequence markers show that an early bifurcation separated the Mimidae into two clades, the first of which includes North and Middle American taxa (Melanotis, Melanoptila, Dumetella) plus a small radiation that likely occurred largely within the West Indies (Ramphocinclus, Allenia, Margarops, Cinclocerthia). The second and larger radiation includes the Toxostoma thrasher clade, along with the monotypic Sage Thrasher (Oreoscoptes) and the phenotypically diverse and broadly distributed Mimus mockingbirds. This mockingbird group is biogeographically notable for including several lineages that colonized and diverged on isolated islands, including the Socorro Mockingbird (Mimus graysoni, formerly Mimodes) and the diverse and historically important Galapagos mockingbirds (formerly Nesomimus). Our reconstructions support a sister relationship between the Galapagos mockingbird lineage and the Bahama Mockingbird (M. gundlachi) of the West Indies, rather than the Long-tailed Mockingbird (M. longicaudatus) or other species presently found on the South American mainland. Relationships within the genus Toxostoma conflict with traditional arrangements but support a tree based on a preivous mtDNA study. For instance, the southern Mexican endemic Ocellated Thrasher (T. ocellatum) is not an isolated sister species of the Curve-billed thrasher (T. curvirostre).     

Isolation of Histoplasma capsulatum from an oil bird (steatornis caripensis) cave in Venezuela

Summary 1.Histoplasma capsulatum was recovered from two of fifteen soil specimens collected in a Venezuelan cave. This cave, located near Caripe in the state of Monagas, harbors a large colony of the oil bird,Steatornis caripensis.2. This finding confirms the previous discovery in Tingo Maria, Peru, of the association ofH. capsulatum with oil birds.3. The relationship ofH. capsulatum with animal habitats is discussed along with the public health importance of this association.

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Zusammenfassung 1.Histoplasma capsulatum ist in zwei Bodenproben aus fünfzehn, die einer Höhle in Venezuela entnommen wurden, gefunden worden. Diese Höhle, die sich in der Nähe von Caripe, im Staate Monagas befindet, herbergt eine grosse Kolonie von Fettvögeln,Steatornis caripensis.2. Dieser Befund bestätigt die Vergesellschaftung vonH. capsulatum mit den Fettvögeln, wie es vorher bereits in Tingo Maria, Peru, entdeckt worden ist.3. Die Beziehung vonH. capsulatum zum tierischen Habitat wird diskutiert unter Betonung der Wichtigkeit dieser Vergesellschaftung vom Standpunkte des öffentlichen Gesundheitswesens.

     

Description of Pythonella scleruri n. sp. (Apicomplexa: Eimeriidae) from a brazilian bird rufous-breasted-leaftosser Sclerurus scansor, 1835 (Passeriformes: Furnariidae)

Coccidian oocysts containing 16 sporocysts with 4 sporozoites in each were observed in a faecal sample from Sclerurus scansor collected in the Itatiaia National Park, southeastern region of Brazil. The oocysts are characterized by ellipsoidal shape measuring 42.5 x 32.8 mm, with smooth, thick double-layered wall of a greenish-orange colour. An oocyst residuum of numerous scattered granules among the sporocysts in sporulated ones; 16 round sporocysts, averaging 10.5 x 10 mm each containing four elongated sporozoites; presence of residuum; absence of Stieda body. The presently described coccidian, recorded for the first time in birds, is a new species named P. scleruri.     

Cooperative breeding in corvids (Passeriformes,Corvidae)

The family of corvids differs from most other passerines by the significant number of species (at least 33) in which the feeding of nestlings and fledglings involves not only parents, but also individuals from their already grown broods (one-year-old and older). A review of the currently known data on cooperative breeding (or helping behavior) in corvids is given. This paper discusses factors that can contribute to the manifestation of delayed dispersion of young birds and the appearance of their helping behavior. It emphasizes the importance of long-term social bonds between parent birds and their offspring in delayed dispersion. At the heart of such social relationships is the tolerance of adult birds to their offspring and prolonged care for the young birds. The appearance of irregular helpers near the nests may be a prerequisite for the emergence of the helping behavior in certain family groups and populations.     

A distinctive new subspecies of Scytalopus griseicollis (Aves,Passeriformes, Rhinocryptidae) from the northern Eastern Cordillera of Colombia and Venezuela

We describe a new subspecies of Pale-bellied Tapaculo Scytalopus griseicollis from the northern Eastern Cordillera of Colombia and Venezuela. This form differs diagnosably in plumage from described subspecies Scytalopus griseicollis griseicollis and Scytalopus griseicollis gilesi and from the latter in tail length. It is also differentiated non-diagnosably in voice from both these populations. Ecological niche modelling analysis suggests that the new subspecies is restricted to the Andean montane forest and páramo north of both the arid Chicamocha valley and the Sierra Nevada del Cocuy.     

Physical and chemical characteristics of ephemeral pond habitats in the Maracaibo basin and Llanos region of Venezuela

Physical and chemical variables of ephemeral rainwaterpond habitats in the Maracaibo basin and Llanos regionof Venezuela were investigated to assess environmentalfeatures important for future studies of thephysiological ecology and bioenergetics of annualkillifish. Dissolved oxygen, temperature, pH, Eh, andconductivity measurements were made in the field ateach collection site. Water and filter samples werecollected and analyzed for trace metals, cations,anions, and osmolality. Physical and chemicalcharacteristics of rainwater ponds are highly variableboth temporally and spatially. Large diurnalfluctuations occur in temperature and dissolvedoxygen. Dissolved oxygen content, temperature, pH andconductivity values exhibit a high degree of interpoolvariation. All pools sampled have a high amount ofsuspended solids consistent with high turbidity. Poolsediments appear to be anoxic as indicated bymeasurement of Eh. Llanos region pools are dominatedby calcium as the major cation, while Maracaibo basinpools are dominated by sodium as the major cation. Maracaibo pools can be further separated into twodistinct regions, inland savanna and coastal desert,based on ionic composition. Annual killifishinhabiting ephemeral ponds may be exposed to extremesin dissolved oxygen concentration, temperature and pHvalues during adult, juvenile, and embryonic stages. This revised version was published online in July 2006 with corrections to the Cover Date.     

Regulation of numbers in the Great tit (Aves: Passeriformes)

The census data of the Great tit collected by Perrins (1965) and others in Marley Wood near Oxford are analysed for density-dependence. Clutch size and hatching success are density-dependent and sufficiently so to regulate the population at the observed level (assuming that there is in addition a fairly large density-independent mortality). There may also be some weak density-dependent mortality outside the breeding season. The density-dependent variations in clutch size are probably in the main due to shortage of available food and density-dependent hatching failure is caused by predation. Territorial behaviour has been shown experimentally to determine breeding density, and may produce a density-dependent effect outside the breeding season. These three factors are responsible for regulation of the Great tit population in Marley Wood.     

Natural and man-induced changes in a tidal channel mangrove system under tropical semiarid climate at the entrance of the Maracaibo lake (Western Venezuela)

Caño Paijana is a tidal channel that connected, until recently, theUruba bay at the mouth of the Limón river, to the Gulf of Venezuelanorth of Maracaibo, Venezuela. It separated the Island of San Carlos fromthe mainland. In the last 50 years the channel has been drying out rapidly,to the extent that presently there is no water flow into or from the seathrough its mouth opening on the Gulf of Venezuela. This mouth wascovered by healthy mangroves (mainly Avicennia germinans) until atleast 1952. The two extremes of the Paijana water channel differ radicallytoday. At Uruba bay end the channel is fringed by dense mangrovevegetation dominated by Rhizophora mangle, while at the Gulf ofVenezuela mouth the vegetation cover is mostly constituted by scrubby,scattered trees of Avicennia germinans, xerophytic shrubs acting asdune fixers, and halophytic strand vegetation. The process is the result ofcomplex interaction between: a) high frequency of low-rainfall years; b)high dune activity during dry years c) dam construction on tributaries ofthe Limón river that reduced discharge of fresh water into Uruba bay.     

Phylogeny, biogeography and taxonomy of the African wattle-eyes (Aves: Passeriformes: Platysteiridae)

The African wattle-eyes (genera Platysteira and Dyaphorophyia) comprise 10 species endemic to Africa. We analyzed both mitochondrial and nuclear DNA sequence data to test the monophyly of this group and its two genera, provide a preliminary assessment of species limits, and gain insight into the phylogeographic history of the wattle-eye radiation. Analyses based on mitochondrial ND2 sequences failed to recover wattle-eye monophyly, but the alternatives were not well-supported. In contrast, analyses of two nuclear introns (myoglobin intron-2 and beta-fibrinogen intron-5) recovered wattle-eye monophyly, as did combined analyses of mitochondrial and nuclear data. These analyses, however, did not support reciprocal monophyly of the two wattle-eye genera typically recognized, suggesting instead that Platysteira is nested within a paraphyletic Dyaphorophyia. The diversification of most wattle-eye species and many subspecies occurred through the divergence of allopatric populations well before the Pleistocene. Species and subspecies with disjunct distributions are typically characterized by deep genetic divergences, suggesting that many of these populations are evolutionary independent and could be recognized as additional phylogenetic species. In D. castanea and D. chalybea, for example, divergent haplotypes from geographically disjunct populations were paraphyletic with respect to those of D. tonsa and D. jamesoni, respectively. Similarly, Platysteira laticincta is highly divergent from its sister taxon P. peltata ( approximately 9.5% ND2 sequence divergence), consistent with species level recognition of this endangered species. In contrast, more broadly distributed taxa inhabiting a greater diversity of habitats (e.g., P. peltata and P. cyannea) show evidence of gene flow and connectivity among regions, suggesting that previously isolated populations expanded and fused into one another. Our study provides a framework for additional analyses of intraspecific phylogeography and species limits in these colorful birds.     

New species of mites of the genus Ptilonyssus (Gamasina: Rhinonyssidae) isolated from Passeriformes (Aves: Passeriformes) from Russia and neighboring countries

Eight new species of the genus Ptilonyssus (Berl. et Troues.) (Gamasina: Rhinonyssidae) from nasal cavities of the passeriformes from territory of the former USSR are described: P. ammomani sp. n. from Ammomanus deserti (Alaudidae) collected in Turkmenistan; P. spini sp. n. from Spinus spinus (Fringillidae) of Kaliningrad district (Russia); P. ripariae sp. n. from Riparia riparia (Hirundinidae) and P. acanthopneustes sp. n. from Phylloscopus borealis (Sylviidae) collected in Tjumen district (Russia); P. pyrrhulinus sp. n. from Pyrrhula pyrrhula (Fringillidae) and P. anthi sp. n. from Anthus trivialis (Motacillidae) of Rjazan district; P. sylviicola sp. n. from Sylviae communis (Sylviidae) collected in Tatarstan; P. cyanosylviae sp. n. from Cyanosylvia svecica (Turdidae) collected from Novosibirsk district.     

Phylogeny and evolution of the Australo-Papuan honeyeaters (Passeriformes, Meliphagidae)

We analyzed nucleotide variation at four loci for 75 species to produce a phylogenetic hypothesis for the Meliphagidae, and to examine the evolution and biogeographic history of the Meliphagidae. Both maximum parsimony and Bayesian methods of phylogenetic analysis were employed. The family was found to be monophyletic, though the genera Certhionyx, Anthochaera, and Phylidonyris were not. Four major clades were recovered and the spinebills (Acanthorhynchus) formed the sister clade to the remainder of the family in most analyses. The Australian endemic arid-adapted chats (Epthianura, Ashbyia) were found to be nested deeply within the family Meliphagidae. No evidence was found to support the hypothesis of separate New Guinean and Australian endemic radiations, nor of a close phylogenetic relationship between taxa from the New Guinea highlands and those from Australian northern rainforests.     

Molecular taxonomy of Brazilian tyrant-flycatchers (Passeriformes: Tyrannidae)

The tyrannids are one of the most diverse groups of birds in the world, and the most numerous suboscine family in the Neotropics. Reflecting such diversity, many taxonomic issues arise in this group, mainly due to morphological similarities, even among phylogenetically distant species. Other issues appear at higher taxonomic levels, mostly brought up by genetic studies, making systematics a rather inconclusive issue. This study looks into the use of DNA barcodes method to discriminate and identify Tyrannidae species occurring in the Atlantic Forest and Cerrado biomes of Brazil. We analysed 266 individuals of 71 tyrant‐flycatcher species from different geographical locations by sequencing 542 bp of the mtDNA COI gene. The great majority of the analysed species showed exclusive haplotypes, usually displaying low intraspecific diversity and high interspecific divergence. Only Casiornis fuscus and Casiornis rufus, suggested in some studies to belong to a single species, could not be phylogenetically separated. High intraspecific diversity was observed among Elaenia obscura individuals, which can suggest the existence of cryptic species in this taxon. The same was also observed for Suiriri suiriri, considered by some authors to comprise at least two species, and by others to be divided into three subspecies. Additionally, the use of sequences from voucher specimens allowed us to correct four misidentifications that had happened in the field. Our findings suggest a great power of the COI barcodes to discriminate species of the Tyrannidae family that are found in Brazil.     

Phylogeny and biogeography of Oriolidae (Aves: Passeriformes)

Understanding oscine passerine dispersal patterns out of their Australian area of origin is hampered by a paucity of robust phylogenies. We constructed a molecular phylogeny of the oscine family, Oriolidae, which is distributed from Australia through to the Old World. We used the phylogeny to assess direction and timing of dispersal and whether dispersal can be linked with the well‐documented movements of geological terranes in the Indonesian Archipelago. We sampled 29 of 33 species of Oriolidae from fresh tissue and from toe pads from museum specimens, and examined two nuclear introns and two mitochondrial genes. Model‐based phylogenetic analyses yielded strong support for clades that generally mirrored classical systematics. Biogeographical analyses and divergence time estimates demonstrated that the family originated in the Australo‐Papuan region from where it dispersed first to Asia and then onwards to Africa and the Philippines before back‐colonising Asia and the Indonesian archipelago. Thus, contrary to several other avian families in the region, Oriolidae represents a sequential dispersal pattern from Australia to Africa via Asia. However, it is noteworthy that the Pacific islands and archipelagos remain uncolonised and that members inhabiting Wallacea are recent colonisers suggesting that Oriolidae are poorly adapted to island life.     

Extreme Endemic Radiation of the Malagasy Vangas (Aves: Passeriformes)

Phylogenetic relationships of the family Vangidae and representatives of several other passeriform families were inferred from 882 base positions of mitochondrial DNA sequences of 12S and 16S rRNA genes. Results indicated the monophyly of the Vangidae, which includes the genus Tylas, hitherto often placed in the family Pycnonotidae. Our results also revealed the Malagasy endemic Newtonia, a genus never previously assigned to the Vangidae, to be a member of this family. These results suggest the occurrence of an extensive in situ radiation of this family within Madagascar, and that the extant high diversity of this family is not the result of multiple colonizations from outside. The extremely high morphological and ecological diversification of the family seems to have been enhanced through the use and ultimate occupancy of vacant niches in this island. Received: 8 September 2000 / Accepted: 13 February 2001     

Photoreceptor-like outer segments in the pineal organ of the lovebird,Uroloncha domestica (Aves: Passeriformes)

Summary In the pineal organ of the lovebird, Uroloncha domestica, bulbous, cup-shaped and elongated outer segments of photoreceptor-like pinealocytes are demonstrated by scanning electron microscopy. These scarce outer segments, 4–11 m in length, extend into the pineal lumen. The present structural observations speak in favor of photosensitive pinealocytes in the pineal organ of Uroloncha domestica. The relation of the photoreceptor-like pinealocytes to acetylcholinesterase-positive nerve cells and a nervous connection between the pineal and the brain indicate that the pineal organ of this passeriform species may be the site of neuroendocrine and photoreceptive functions.Supported by a fellowship from the Japan Society for the Promotion of Science to M. UeckSupported by a grant from the Ministry of Education of Japan to K. Wake and by a grant of the Deutsche Forschungsgemeinschaft to M. Ueck