Blood parasites in some birds from eastern plains of Colombia.

A total of 315 birds representing 75 species (23 families) from Villavicencio and San Miguel (Meta, Colombia) were examined for haematozoa. Fifty birds (15.9%) harbored blood parasites. Microfilariae were the most common haematozoans encountered, followed by species of the genera Haemoproteus, Plasmodium and Trypanosoma. This survey included 15 new host-parasite records and 8 species of birds that were examined for haematozoa for the first time. The prevalence registered in this research was similar to others recorded in the Neotropical region, but in sharp contrast with the prevalence of blood parasites in other major land masses.     

Rampant polyphyly indicates cryptic diversity in a clade of Neotropical flycatchers (Aves: Tyrannidae)

Polyphyletic arrangements in DNA phylogenies are often indicators of cryptic species diversity masked by erroneous taxonomic treatments that are frequently based on morphological data. Although mitochondrial (mt)DNA polyphyly is detected relatively rarely in phylogenetic studies, it has recently been found in a variety of tyrant‐flycatcher (Tyrannidae) groups. In the present study, we provide a DNA phylogeny for a mitochondrial and a nuclear locus with a complete species sampling in Zimmerius flycatchers, showing that the genus is characterized by multiple mtDNA polyphyly. Based on phylogenetic and life‐history information, we suggest the elevation of a number of taxa to species status, leading to a doubling of Zimmerius species‐level diversity compared to taxonomic treatments conducted before 2001. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, ●●, ●●–●●.     

A cryptic, intergeneric cytochrome c oxidase I pseudogene in tyrant flycatchers (family: Tyrannidae)

Nuclear mitochondrial pseudogenes, or "numts", are nonfunctional copies of mitochondrial genes that have been translocated to the nuclear genome. Numts have been used to study differences in mutation rates between the nuclear and mitochondrial genomes, but have also been implicated as troublesome for phylogenetic studies and DNA-based species identification (i.e., DNA barcoding). In this study, a suspected numt discovered during a study of mitochondrial cytochrome c oxidase I (COI) diversity in North American birds was targeted and sequenced from tyrant flycatchers (family: Tyrannidae). In total, the numt was found in five taxa representing two genera. Substitution rates were compared between COI and numt sequences. None of the numt sequences harboured stop codons nor frameshift mutations, but phylogenetic analysis revealed they had accumulated more amino acid substitutions than the mitochondrial COI sequences. Mitochondrial COI appeared to be preferentially amplified in most cases, but methods for numt detection are discussed for cases like this where sequences lack obvious features for identification. Because of its persistence across a broad taxonomic lineage, this numt could form a valuable model system for studying evolution in numts. The full size of the numt and its location within the nuclear genome are yet to be determined.     

Tyrant flycatchers coming out in the open: phylogeny and ecological radiation of Tyrannidae (Aves, Passeriformes)

Tyrant flycatchers constitute a substantial component of the land bird fauna in all South American habitats. Past interpretations of the morphological and ecological evolution in the group have been hampered by the lack of a well‐resolved hypothesis of their phylogenetic interrelationships. Here, we present a well‐resolved phylogeny based on DNA sequences from three nuclear introns for 128 taxa. Our results confirm much of the overall picture of Tyrannidae relationships, and also identify several novel relationships. The genera Onychorhynchus, Myiobius and Terenotriccus are placed outside Tyrannidae and may be more closely related to Tityridae. Tyrannidae consists of two main lineages. An expanded pipromorphine clade includes flatbills, tody‐tyrants and antpipits, and also Phylloscartes and Pogonotriccus. The spadebills, Neopipo and Tachuris are their closest relatives. The remainder of the tyrant flycatchers forms a well‐supported clade, subdivided in two large subclades, which differ consistently in foraging behaviour, the perch‐gleaning elaeniines and the sallying myiarchines, tyrannines and fluvicolines. A third clade is formed by the genera Myiotriccus, Pyrrhomyias, Hirundinea and three species currently placed in Myiophobus. Ancestral habitat reconstruction and divergence date estimation suggest that early divergence events in Tyrannida took place in a humid forest environment during the Oligocene. Large‐scale diversification in open habitats is confined to the clade consisting of the elaeniines, myiarchines, tyrannines and fluvicolines. This radiation correlates in time to the expansion of semi‐open and open habitats from the mid‐Miocene (c. 15 Mya) onwards. The pipromorphine, elaeniine and myiarchine–tyrannine–fluvicoline clades each employ distinct foraging strategies (upward striking, perch‐gleaning and sallying, respectively), but the degree of diversity in morphology and microhabitat exploitation is markedly different between these clades. While the pipromorphines and elaeniines each are remarkably homogenous in morphology and exploit a restricted range of microhabitats, the myiarchine–tyrannine–fluvicoline clade is more diverse in these respects. This greater ecological diversity, especially as manifested in their success in colonizing a wider spectrum of open habitats, appears to be connected to a greater adaptive flexibility of the search‐and‐sally foraging behaviour.     

The role of ecologic diversification in sibling speciation of Empidonax flycatchers (Tyrannidae): multigene evidence from mtDNA

Avian genera characterized by sibling species with distinctive habitat preferences present an evolutionary enigma in view of the more commonplace occurrence of syntopic congeners that differ strikingly in colour and pattern. No existing theory has explained the evolutionary background that led to these differences. Here we propose that great phenotypic similarity among some groups of sibling species limits their coexistence and that clues to their radiation can be seen in patterns of geographical occurrence. To illustrate our thesis we focused on the New World flycatcher genus Empidonax, a group of 15 species notorious for their great phenotypic similarity. Using 3069 base pairs of mitochondrial DNA from four genes, we produced a complete molecular phylogeny that identified four clades, three of which represent close relatives. The fourth clade includes only E. virescens, which apparently has no close living relatives. The majority of species, including many distant relatives, are completely (58.1%) or essentially (6.7%) allopatric in breeding distribution and exhibit striking ecological segregation into distinctive climate-vegetation zones. Even where ranges overlap, occupancy of the same habitat by different species is rare. Phylogenetic and distributional patterns in Empidonax suggest a peripatric model of stepwise colonization and then range expansion of small groups of pioneers during glacial periods into initially enlarging, distinctive habitats destined to be widespread during interglacials. Vicariance is not indicated in the absence of barriers of appropriate age and geographical position. Rapoport's rule that northern species have larger ranges than southern species is strongly supported.     

Fall migration of Empidonax flycatchers in northwestern Colombia

ABSTRACT South of Mexico, little is known about the fall migration patterns of most Neotropical migrants. I studied the migration of Empidonax flycatchers using mist‐net surveys in northwestern Colombia from late September to mid‐October in 4 yr (2003–2005, 2008). Empidonax species were identified using linear measurements and color patterns. About 62% of captured individuals were reliably identified to species, with 86% identified as Willow Flycatchers (Empidonax traillii) and 14% as Alder Flycatchers (E. alnorum). No Acadian Flycatchers (E. virescens) were identified. Most birds captured were adults (84.9%) and, due to overlap in measurements, I was only able to determine the sex of 16.3% of the birds. Most Empidonax flycatchers migrated through northwestern Colombia during September and October, with individuals migrating through my study area over a period of at least 1 mo. Willow Flycatchers tended to migrate earlier than Alder Flycatchers, a pattern consistent with the fall movements of these two species at other locations. No captured flycatchers were molting either remiges or rectrices, and most (89%) had either no or slight traces of subcutaneous fat. No Empidonax flycatchers were recaptured, suggesting that stopover duration at my study site was brief. My results show that many Empidonax flycatchers can be identified as Willow and Alder flycatchers during the nonbreeding period, and such identification will enhance our knowledge of their geographical distribution and improve our understanding of possible patterns of segregation on their wintering grounds.     

Nest and nest-site reuse within and between breeding seasons by three neotropical flycatchers (Tyrannidae).

Nest and or nest site reuse within and between breeding seasons was reported by the Euler's Flycatcher (Lathrotriccus euleri), the Sepia-capped Flycatcher (Leptopogon amaurocephalus) and the Gray-hooded Flycatcher (Mionectes -rufiventris) in forest fragments from southeastern Brazil. Nest and or nest site reuse between some years was frequent within a single breeding season by the Sepia-capped Flycatcher. Nest reuse, however, was not related to nesting success in the previous breeding attempt. Nest turnover rates (movement to a new site between years) were low for L. amaurocephalus, intermediate for L. euleri and high for M. rufiventris.     

Prevalence of blood parasites in European passeriform birds

Variation in the prevalence of blood parasites among species of birds has been used to test hypotheses about the effects of sexual selection and parental investment on disease resistance, and how vector abundance influences infection. However, the factors causing this variation are still poorly understood. We assessed the statistical effects of biogeographic, plumage-related and life-history traits on the prevalence of the blood parasites Plasmodium, Haemoproteus, Leucocytozoon and Trypanosoma in European passerine birds. Most of the variation in parasite prevalence occurred at low taxonomic levels. Brighter male plumage and greater host body mass were associated with higher prevalence, explaining 32% of the total variation. Male plumage brightness remained a significant factor when we controlled for phylogenetic effects. These relationships were driven primarily by simuliid-transmitted parasites (Leucocytozoon, Trypanosoma), which were more frequent in species with northern distributions. Host species with greater maximum longevity and shorter nestling periods had higher prevalences of Plasmodium; however, the effect was not stable after controlling for phylogeny using pairwise contrasts. Coevolution between hosts and parasites appears to create temporal and spatial variation that disconnects haematozoan prevalence from evolutionarily conservative life-history traits while creating some positive associations with traits that are phylogenetically labile. Clearly, ecologists should be cautious in relating patterns of variation in haematozoan prevalence to particular host traits.     

Prevalence of blood parasites in seabirds - a review

Introduction

While blood parasites are common in many birds in the wild, some groups seem to be much less affected. Seabirds, in particular, have often been reported free from blood parasites, even in the presence of potential vectors.

Results

From a literature review of hemosporidian prevalence in seabirds, we collated a dataset of 60 species, in which at least 15 individuals had been examined. These data were included in phylogenetically controlled statistical analyses of hemosporidian prevalence in relation to ecological and life-history parameters. Haemoproteus parasites were common in frigatebirds and gulls, while Hepatozoon occurred in albatrosses and storm petrels, and Plasmodium mainly in penguins. The prevalence of Haemoproteus showed a geographical signal, being lower in species with distribution towards polar environments. Interspecific differences in Plasmodium prevalence were explained by variables that relate to the exposure to parasites, suggesting that prevalence is higher in burrow nesters with long fledgling periods. Measures of Plasmodium, but not Haemoproteus prevalences were influenced by the method, with PCR-based data resulting in higher prevalence estimates.

Conclusions

Our analyses suggest that, as in other avian taxa, phylogenetic, ecological and life-history parameters determine the prevalence of hemosporidian parasites in seabirds. We discuss how these relationships should be further explored in future studies.

     

Phylogeny and character evolution in the Empidonax group of tyrant flycatchers (Aves: Tyrannidae): a test of W. E. Lanyon's hypothesis using mtDNA sequences

We sequenced mitochondrial DNA from four protein-coding genes for 26 taxa to test W. E. Lanyon's hypothesis of intergeneric relationships and character evolution in the Empidonax group of tyrant flycatchers. Three genera in this group (Empidonax, Contopus, and Sayornis) successfully occupy north temperate habitats for breeding, while the remaining genera (Mitrephanes, Cnemotriccus, Aphanotriccus, Lathrotriccus, and Xenotriccus) are restricted to neotropical latitudes. Lanyon hypothesized two major clades in the group based on differences in syringeal morphology and proposed relationships among genera using a combination of morphologic, behavioral, and allozymic characters. The mtDNA data strongly support Lanyon's division of genera into two clades. In addition, the molecular and nonmolecular data sets agree in uniting Aphanotriccus and Lathrotriccus as sister taxa, with Cnemotriccus as basal to these genera. Species of Aphanotriccus, Lathrotriccus, and Cnemotriccus form a clade that exploits a distinctive nesting niche relative to other members of the Empidonax group. Within the second major clade, mtDNA sequences support a reconstruction based on allozymes that places Contopus and Empidonax as sister taxa. This hypothesis contradicts that of Lanyon, who allied Contopus with Mitrephanes on the basis of similarity in foraging mode. Genera in the Empidonax group are members of a larger assemblage that radiated in South America. Occupancy of temperate habitats by certain genera in this group is coincident with their evolution of migratory behavior and with independent diversification in foraging modes that reduces potential competition in sympatry.     

Blood parasites of some birds from Colombia

Blood films from 421 birds of 142 species, representing 29 avian families, from the environs of Cali, Colombia, were examined for blood parsites. Only 30 (7.1%) birds of 26 species harbored hematozoa. Species of Haemoproteus (3.1%) and microfilaria (2.3%) were the most commonly encountered blood parasites; species of Leucocytozoon, Plasmodium, Akiba and Lankesterella were found in a few birds. Mixed infections with more than one genus of blood parasite were rare; most infections encountered were of low intensity.     

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.     

Upper quaternary vegetational and climatic sequence of the fuquene area (Eastern Cordillera,Colombia)

In this paper the results of a pollen-analytical study of three bore holes of lake deposits in the Fuquene-Valle de Ubaté area, Colombian Cordillera Oriental (5° N; elev. 2,580 m) are given. By means of ¹⁴C dates and comparison with other pollen diagrams and dates from the Eastern Cordillera, it was possible to correlate the local pollen zones and chronostratigraphical units with the European chronostratigraphical sequence. The longest diagram (Fuquene II) represents some 30, 000 years, including part of the Middle Pleniglacial, the Upper Pleniglacial, the Late Glacial and the Holocene.During the Middle Pleniglacial, Polylepis wood was an important constituent of the vegetation. During climatic extremes of the Upper Pleniglacial an open páramo vegetation existed.During the main part of the Upper Pleniglacial (from ca. 21,000 to ca. 13,000 B.P.) the lake level was low and the climate dry. The lake level rose again in the beginning of the Late Glacial, and the area around the lake became forested. At the beginning of the El Abra Stadial (Late Dryas Stadial) there was a marked cooling and the lake became lower once more; this had a great impact on the vegetation which became partly open again. The beginning of the Holocene is marked by a gradual increase of forest elements, especially of Quercus (oak.) Oak forests dominated the area during the greater part of the Holocene. During the “hypithermal”, elements growing today at a lower level, such as Cecropia, Acalypha (and possibly Alchornea), must have been growing in the area, intermixed with the oak forest. At the same time there was a considerable increase of Urticaceae in the undergrowth of these forests. The vegetation zones were probably situated several hundreds of metres higher than they are at the present time.The influence of man on vegetation had started already before the beginning of our era, but there is a sudden increase of this influence (e.g., increase of Dodonaea, decrease of Quercus and Urticaceae) somewhere around 2,000 B.P. Later on, the diagram shows the rapid ultimate decline of the forest elements and an increase of Gramineae. Today nothing is left of the original oak forests and their place is taken by arable land or by secondary plant communities with low brushwood.In the lake sediments, thin layers of volcanic ash were found dated approximately 9,000 B.P., 11,000 B.P., and 21,000 B.P., respectively; a series of three ash-layers was deposited between approximately 22,000 B.P. and 26,000 B.P. and one possibly at approximately 30,000 B.P. These layers have been found in several other sections in the Eastern Cordillera and are the basis for a tephrochronology.     

Prevalence and diversity patterns of avian blood parasites in degraded African rainforest habitats

Land use changes including deforestation, road construction and agricultural encroachments have been linked to the increased prevalence of several infectious diseases. In order to better understand how deforestation affects the prevalence of vector-borne infectious diseases in wildlife, nine paired sites were sampled (disturbed vs. undisturbed habitats) in Southern Cameroon. We studied the diversity, prevalence and distribution of avian malaria parasites ( Plasmodium spp.) and other related haemosporidians (species of Haemoproteus and Leucocytozoon ) from these sites in two widespread species of African rainforest birds, the yellow-whiskered greenbul ( Andropadus latirostris , Pycnonotidae) and the olive sunbird ( Cyanomitra olivacea , Nectariniidae). Twenty-six mitochondrial cytochrome b lineages were identified: 20 Plasmodium lineages and 6 Haemoproteus lineages. These lineages showed no geographic specificity, nor significant differences in lineage diversity between habitat types. However, we found that the prevalence of Leucocytozoon and Haemoproteus infections were significantly higher in undisturbed than in deforested habitats ( Leucocytozoon spp. 50.3% vs. 35.8%, Haemoproteus spp. 16.3% vs. 10.8%). We also found higher prevalence for all haemosporidian parasites in C. olivacea than in A. latirostris species (70.2% vs. 58.2%). Interestingly, we found one morphospecies of Plasmodium in C. olivacea , as represented by a clade of related lineages, showed increased prevalence at disturbed sites, while another showed a decrease, testifying to different patterns of transmission, even among closely related lineages of avian malaria, in relation to deforestation. Our work demonstrates that anthropogenic habitat change can affect host–parasite systems and result in opposing trends in prevalence of haemosporidian parasites in wild bird populations.     

Reproductive effort and blood parasites of breeding pied flycatchers: the need to control for interannual variation and initial health state

The association between reproductive effort, as assessed by experimentally altered clutch size, and prevalence of blood parasite infections was studied during two breeding seasons in the pied flycatcher ( Ficedula hypoleuca ). Only in the first study year (1998), enlarged clutches resulted in more fledged young and birds presumably responded to the intended experimental increase in reproductive effort by increasing their provisioning rates. Only on this study year, female body mass was negatively affected by the clutch size manipulation. For both sexes, no significant effect of experimental treatment on the prevalence of blood parasite infections ( Trypanosoma spp., Haemoproteus balmorali ) on day 13 after chick hatching was found in both study years. However, only in the first study year, when the intended increase in parental reproductive effort was achieved, we found a higher within female seasonal increase in Trypanosoma spp. prevalence for birds with enlarged clutches compared to those with control and reduced clutches. In this year, the Trypanosoma spp. prevalence was significantly higher than in the second study year. These results suggest that more than one year has to be covered, and that the knowledge of the premanipulative health status of parents can facilitate detection of the proposed trade-off between reproductive effort and immunocompetence.     

Molecular phylogeny and evolutionary history of the tit-tyrants (Aves: Tyrannidae)

Tit-tyrants of the genus Anairetes presently consist of six species; five inhabit various regions along the Andean cordillera of South America and one is endemic to the Juan Fernandez Islands off the coast of Chile. Data from mtDNA ND2 and Cyt b sequences were used to construct a phylogeny for all Anairetes species as well as Uromyias agilis, a closely related genus, and Stigmatura as an outgroup, to determine their relationships and history of radiation in South America. Results strongly supported the following paired relationships: A. nigrocristatus-A. reguloides, A. flavirostris-A. alpinus, and A. parulus-A. fernandezianus. This dataset, however, could not resolve basal nodes; therefore relationships among these pairs remains obscure. Moreover the genus Uromyias, controversially separated on morphological criteria from Anairetes, fell within the Anairetes clade, although its exact position could not be ascertained with confidence. The molecular data indicate that this group probably radiated within the past 2 million years, concomitant with highly accentuated cycles of global climatic change. Certain high altitude areas within the Andes may have been stable during global climatic changes and may have served as refugia during the Plio-Pleistocene.     

Prevalence and loads of gastrointestinal parasites of goats in the communal areas of the Eastern Cape Province of South Africa

A longitudinal survey was conducted to determine the prevalence and loads of gastrointestinal parasites in goats raised by communal farmers of Qaukeni (QA) and Nkosana (NK) communities of Eastern Cape Province of South Africa between June 2007 and April 2008. One hundred and seventy one goats were weighed and had faecal samples collected from their recta in four seasons; cold-dry, hot-dry, hot-wet and the post-rainy seasons. The samples were examined by the modified McMaster technique for nematode egg types. Goats in QA weighed more (P < 0.05) than those in NK in the post-rainy, cold-dry and hot-dry seasons. However, in the hot-wet season, goats in NK had higher (P < 0.05) weights than those in QA. The most frequently detected gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in QA and 96.1 ± 12.01 in NK), followed by coccidial oocysts (53.3 ± 8.76 in QA and 68.8 ± 8.00 in NK). The other identified nematodes were Strongyloides and Trichostrongylus egg types. Higher loads (P < 0.05) of strongyle eggs were observed in the hot-wet and post-rainy seasons, whilst the other egg types showed a peak in the hot-wet season. Strongyle egg counts were higher (P < 0.05) in NK compared to QA. The results indicate that strongyles are the major gastrointestinal egg types negatively affecting body weights of goats.     

Does morphology predict behavior? Correspondence between behavioral and morphometric data in a Tyrant‐flycatcher (Tyrannidae) assemblage in the Santa Marta Mountains,Colombia

ABSTRACT Morphology is commonly used as a predictor of ecological relationships among species when studying local assemblages of Neotropical birds. Nevertheless, most evidence supporting ecomorphological correspondence in birds comes from studies of communities and not from local assemblages and, moreover, from temperate latitudes. To increase our understanding of ecomorphological correspondence in Neotropical assemblages, we used three multivariate approaches to evaluate correspondence between morphological and foraging behavior data in a tyrant‐flycatcher assemblage (N= 12 species) in the Santa Marta Mountains in Colombia. Principal components analyses revealed similar species ordinations when using morphological measurements (beak size and shape, tarsus length, wing length, and tail length) or behavioral data (behavioral types of searching for prey and prey capture) separately. Discriminant function analyses tested the ability of morphological traits to predict foraging behavior, showing that more than 90% of all measured individuals (N= 267) were correctly classified in previously defined categories of search and attack behavior. Finally, Canonical correlation analyses revealed a significant correlation between morphological data and two independent datasets of search and attack behavior. Our results demonstrate that morphology can accurately predict ecology in an assemblage of Neotropical tyrannids, and similar results have been reported in previous studies of temperate Tyrant‐flycatchers. Our results also show that bill size and shape, wing length, and tarsus length are the best predictors of foraging behavior in this assemblage. Testing for ecomorphological correspondence in other Neotropical taxa would help identify subsets of phenotypic traits that could be used for a practical, but reliable, determination of ecological relationships within different assemblages.