Geometric morphometrics of the skull of Tinamidae (Aves, Palaeognathae)

The Tinamidae comprise exclusively Neotropical palaegnathous birds, with homogeneous body morphology and no sexual dimorphism. The goal of this work was to explore the variation in skull morphology between taxa and its possible correspondence with features such as diet or gender using geometric morphometric tools. Eleven landmarks were analyzed in 53 skulls of 4 genera that inhabit grasslands: Nothoprocta, Eudromia, Nothura and Rhynchotus. Intrageneric and intergeneric variability was analyzed. The genera studied here can be distinguished based on the geometric shape of their skull, with prenarial region length and neurocranium shape as the most outstanding features. In the genus Eudromia, males and females could be differentiated, while in the genus Nothoprocta, the species differentiated according to their trophic habits. This study allows establishing that genera and, in some cases, the gender of the Tinamidae can be differentiated based on cranial shape.     

The digital tendon locking mechanism of the avian foot (Aves)

Summary Representatives of all avian orders were studied in order to establish that the tendon-locking mechanism (TLM), consisting of local specialization of the flexor tendons and the adjacent portion of the flexor tendon sheath, is by no means rare, but rather, constitutes the prevalent condition in a large majority of the avian species sampled. The areas of tubercles on the tendons and the adjacent sheath plications intermesh with one another thereby forming a true tendon-locking mechanism that maintains the distal and other interphalangeal joints of the digits in the flexed position. The TLM seems to function not only in perching, but in a wide variety of other activities of the avian foot including swimming, wading, prey-grasping, clinging, hanging, and tree climbing. The basic structural components of the mechanism are remarkably similar in the divergent avian groups adapted for these activities. Ultrastructural detail of the TLM was studied by means of scanning and transmission electron microscopy. Interdigital variation in distribution of the TLM in all of the digits of individuals were made as were comparisons of the interspecific distribution of the TLM. An analysis of the biomechanics involved in engaging the elements of the TLM and how they produce locking of the flexed joints of the digits includes a consideration of the roles of the podothecal pads, ungual flexor processes, and the elastic flexor and extensor ligaments of the toes. The components of the TLM are differentiated in early fetal development establishing that the TLM components are not acquired adventitiously in response to such factors as posthatching mechanical stresses.     

The automating skeletal and muscular mechanisms of the avian wing (Aves)

The avian wing possesses the ability to synchronize flexion or extension of the elbow and wrist joints automatically. Skeletal and muscular mechanisms are involved in generating this phenomenon. The drawing-parallels action of the radius and ulna coordinates the movements of the forearm with the carpus. Movement of the radius along the length of the forearm isnot dependent on the shape disparity between the dorsal and ventral condyles of the humerus, nor is it generated by the shape of the dorsal condyle itself. Instead, shifting of the radius toward the wrist occurs during humeroulnar flexion when the radius, being pushed by muscles toward the ulna, is deflected off theIncisura radialis toward the wrist. Movement of the radius toward the elbow occurs during the latter stages of humeroulnar extension when, as the dorsal condyle of the humerus and the articular surface of the ulna's dorsal cup roll apart, the radius gets pulled by the humerus and its ligaments away from the wrist. Synchronization of the forearm with the manus is accomplished by twojoint muscles and tendons.M. extensor metacarpi radialis and the propatagial tendons act to extend the manus in unison with the forearm, whileM. extensor metacarpi ulnaris helps these limb segments flex simultaneously.M. flexor carpi ulnaris, in collaboration with the drawing-parallels mechanisms, flexes the carpus automatically when the elbow is flexed, thereby circumducting the manus from the plane of the wing toward the body. In a living bird, these skeletal and muscular coordinating mechanisms may function to automate the internal kinematics of the wing during flapping flight. A mechanized wing may also greatly facilitate the initial flight of fledgling birds. The coordinating mechanisms of the wing can be detected in a bird's osteology, thereby providing researchers with a new avenue by which to gauge the flight capabilities of avian fossil taxa.     

Biomechanics of the skull and the beak in Rampnastos (Ramphastidae, Aves) I. Description of anatomical elements

The different cranial kinetic systems described in Birds are limited in Ramphastos by the dorsal and backward position of the nostrils, the shape of the fronto-nasal suture, the lateral fit-in between nasal, lacrymal and frontal bones, and the divergent directions of the 2 otic processes of the quadrate, 5 ligaments joint the posterior skull elements to the quadrate and the mandible. Small sesamoid bones strengthen the external jugo-mandibular ligament in its retro-articular portion. The nomenclature of the aponeuroses is not useful by itself to compare the organizations and homology of the diverses muscular layers in the different birds groups. The differences observed in the relative position of the muscular bundles have to be related to the shape and particular relationships between skeletal structures. We have to consider the osteo-muscular systems as a whole and analyse them from a functional viewpoint.     

Speciation in an avian complex endemic to the mountains of Middle America (Ergaticus, Aves: Parulidae)

The implementation of the phylogeographic approach for the study of biodiversity is critical in poorly sampled regions like the montane systems of Middle America, as complex evolutionary histories often result in the presence of independent lineages not properly considered by traditional taxonomy. Herein we sequenced 2370 bp of mtDNA (ND2, cyt b and ATPase) from 81 individuals of Ergaticus, a complex of birds endemic to the montane forests of Middle America. Although current taxonomy recognizes two species, the results reveal considerable genetic structure with the presence of four mtDNA lineages. Two of these lineages within Ergaticus ruber evidence the need of a revaluation of the species limits for this taxon. The general phylogeographic pattern can be explained as a consequence of relative isolation of the populations in different mountain ranges separated by low elevation barriers. Most population groups did not show signals of demographic expansion with the exception of the one corresponding to clade 1. The divergence time estimates point to the Pleistocene as an important time period for the diversification of this complex.     

Ancient differentiation in the single-island avian radiation of endemic Hispaniolan chat-tanagers (Aves: Calyptophilus)

The simple geographic structure of island systems often makes them tractable for studies of the patterns and processes of biological diversification. The Calyptophilus chat-tanagers of Hispaniola are of general evolutionary interest because their multiple lineages might have arisen on a single island, of conservation concern because several isolated populations are nearly extinct, and taxonomically ambiguous because they have been variously lumped or split into one to four species. To explore the context of diversification of the seven extant Calyptophilus populations, we conducted a multilocus coalescent analysis based on sequences of mitochondrial ND2 and three nuclear intron loci. We then compared patterns of phylogeographic genetic variation with the morphological differences that distinguish these populations. Mitochondrial haplotypes formed two reciprocally monophyletic groups separated by a large magnitude of nucleotide divergence. Intron structure largely paralleled the geographic grouping pattern of the mitochondrial DNA (mtDNA), but these groups were only reciprocally monophyletic at one of the three introns. Also, the magnitude of between-group divergence was much lower in the introns than mtDNA genealogies. Multilocus coalescent analyses inferred a nonzero divergence time between these two major geographic groups, but suggested that they have experienced a low level of gene flow. All four markers showed substantial allele sharing within each of the two groups, demonstrating that many now separated montane populations do not have long histories of isolation. Considered in concert, our multilocus phylogeographic reconstructions support the recognition of two species within the Calyptophilus complex, and raise the possibility that these taxa differentiated prior to the fusion of the two palaeo-islands that form present-day Hispaniola.     

Multiple cenozoic invasions of Africa by penguins (Aves, Sphenisciformes)

Africa hosts a single breeding species of penguin today, yet the fossil record indicates that a diverse array of now-extinct taxa once inhabited southern African coastlines. Here, we show that the African penguin fauna had a complex history involving multiple dispersals and extinctions. Phylogenetic analyses and biogeographic reconstructions incorporating new fossil material indicate that, contrary to previous hypotheses, the four Early Pliocene African penguin species do not represent an endemic radiation or direct ancestors of the living Spheniscus demersus (blackfooted penguin). A minimum of three dispersals to Africa, probably assisted by the eastward-flowing Antarctic Circumpolar and South Atlantic currents, occurred during the Late Cenozoic. As regional sea-level fall eliminated islands and reduced offshore breeding areas during the Pliocene, all but one penguin lineage ended in extinction, resulting in today's depleted fauna.     

A phylogenetic supertree of the fowls (Galloanserae, Aves)

The fowls (Anseriformes and Galliformes) comprise one of the major lineages of birds and occupy almost all biogeographical regions of the world. The group contains the most economically important of all bird species, each with a long history of domestication, and is an ideal model for studying ecological and evolutionary patterns. Yet, despite the relatively large amount of systematic attention fowls have attracted because of their socio‐economic and biological importance, the species‐level relationships within this clade remain controversial. Here we used the supertree method matrix representation with parsimony to generate a robust estimate of species‐level relationships of fowls. The supertree represents one of the most comprehensive estimates for the group to date, including 376 species (83.2% of all species; all 162 Anseriformes and 214 Galliformes) and all but one genera. The supertree was well‐resolved (81.1%) and supported the monophyly of both Anseriformes and Galliformes. The supertree supported the partitioning of Anseriformes into the three traditional families Anhimidae, Anseranatidae, and Anatidae, although it provided relatively poor resolution within Anatidae. For Galliformes, the majority‐rule supertree was largely consistent with the hypothesis of sequential sister‐group relationships between Megapodiidae, Cracidae, and the remaining Galliformes. However, our species‐level supertree indicated that more than 30% of the polytypic genera examined were not monophyletic, suggesting that results from genus‐level comparative studies using the average of the constituent species’ traits should be interpreted with caution until analogous species‐level comparative studies are available. Poorly resolved areas of the supertree reflect gaps or outstanding conflict within the existing phylogenetic database, highlighting areas in need of more study in addition to those species not present on the tree at all due to insufficient information. Even so, our supertree will provide a valuable foundation for understanding the diverse biology of fowls in a robust phylogenetic framework.     

The lack of binding of methyl-n-amyl ketone (MAK) to rat liver DNA as demonstrated by direct binding measurements, and 32P-postlabeling techniques.

It has been reported that 14C-labeled methyl-n-amyl ketone (MAK, 2-heptanone) is able to bind spontaneously, in vitro, to isolated rat liver DNA to the extent of 400 pmol/mg DNA; and that 14C-MAK, when given by gavage to female Fischer 344 rats, resulted in HPLC chromatograms of isolated, hydrolyzed liver DNA in which some radiolabel was not associated with the four normal DNA bases dA, dT, dC, and dG. The present studies were undertaken to re-examine the hypothesis that MAK is able to bind to rat liver DNA. In the in vitro study, liver nuclear DNA was incubated with [2-14C]-labeled MAK (25 mCi/mmol) in the absence, or in the presence of rat liver microsomes, precipitated, washed free of unbound MAK, and counted by scintillation spectrometry. No binding to DNA by MAK was detectable. In the in vivo study, groups of five female F344 rats were exposed by inhalation to 0, 80, 400, or 1000 ppm MAK for 6 h/day for 10 days. DNA was purified from the liver nuclei of the 0 and 1000 ppm dosed animals, and 32P-postlabeling techniques were used to assay for adducts. No DNA adducts were detected using these techniques. It was concluded that MAK lacks the ability to bind to rat liver DNA in vitro and in vivo.     

Nuclear DNA from old collections of avian study skins reveals the evolutionary history of the Old World suboscines (Aves, Passeriformes)

Museum study skins represent an invaluable source of DNA for phylogenetics, phylogeography and population genetics. This becomes evident by comparing the number of study skins of birds housed in museums worldwide ( c . 10 million) with the corresponding number of tissue samples (probably fewer than 500 000). While the laboratory techniques used hitherto have primarily allowed PCR-based studies of mitochondrial genes from museum skins, we present here the first avian phylogeny based on a large number of nuclear sequences. The targeted fragment sizes and the properties of the primers used are important contributory factors to obtain good amplification results. In this study we routinely amplified fragments of c. 350 bp nuclear DNA. This advance in methodology opens up a new avenue for the use of avian museum skins, as nuclear DNA is especially useful when studying ancient patterns of diversification. The phylogenetic hypothesis of the Old World suboscines (Eurylaimides) presented herein strongly supports a monophyletic origin of the pittas (Pittidae). The phylogeny further suggests that pittas could be divided into three major groups, in agreement with the external morphological variation found in this group. The broadbills (Eurylaimidae) as currently defined are, on the other hand, found to be a paraphyletic family, as both Sapayoa aenigma and the asities (Philepittidae) are nested among them. Based on the phylogenetic results we suggest a revised classification of the Old World suboscines (Eurylaimides).     

On the phylogenetic relationships of trogons (Aves, Trogonidae)

Although trogons (Aves, Trogonidae) are well characterized by the possession of heterodactyl feet, their phylogenetic relationships to other extant birds still are only poorly understood. Molecular studies did not show conclusive results and there are amazingly few comparative studies of the anatomy of trogons. Virtually the only hypothesis on trogon relationships that was supported with derived morphological characters is a sister group relationship to alcediniform birds (bee-eaters, kingfishers, and allies), which share a derived morphology of the columella (ear-ossicle) with trogons. However, in this study a very similar columella is reported for the oilbird (Steatornithidae) and additional previously unrecognized derived osteological characters are presented, which are shared by trogons and oilbirds. A numerical cladistic analysis of 28 morphological characters also resulted in monophyly of Trogonidae and Steatornithidae, although the corresponding node was not retained in a bootstrap analysis.     

Skull and mandible formation in the cuckoo (Aves, Cuculidae): contributions to the nomenclature in avian osteology and systematics

The study of the contributions of different bones to the formation of the skeleton in birds is necessary: (1) to establish homologies in comparative anatomy; (2) to delimit each bone structure correctly, mainly in relation to the skull and mandible where the bones are fused to each other in adults; and (3) to standardize nomenclature in avian osteology. In this paper at least one young specimen belonging to each sub-family of Cuculidae was examined in order to identify each bone in terms of boundaries and contributions to skull and mandible formation. These cuckoos specimens were also compared with adults and young of turacos and hoatzin. The results show little variation of skull and jaw among the young cuckoos studied compared with the variations among adult specimens. However, it provides new suggestions for the boundaries and nomenclature of certain osseous structures in the skull and mandible of birds, specifically fissura zona flexoria craniofacialis, prominetia frontoparietalis, crista temporalis transversa, processus squamosalis, fossa laterosphenoidalis, tuberculum laterosphenoidale and processus retroangularis. This study also provides more reliable homologies for use in cladistic analysis and above all it contributes to the phylogenetic position of Cuculidae within Neognathae, specifically the skull formation suggest that turacos and hoatzin are more similar to each other than either is to the cuckoos.     

The pterolichoid feather mites (Acarina, Astigmata) of the Megapodiidae (Aves, Galliformes)

The pterolichoid feather mites of megapodes are reviewed. Named taxa are briefly discussed and most are figured. The Pterolichidae (Pterolichinae) are: Ascetohchus Perez & Atyeo, three species; Echinozonus Atyeo & Perez, six species; Pereziella Atyeo, two species; and Phycoferus Atyeo & Perez, two species. New pterolichine taxa, with the type species listed first, include: Botryaspis cordiforma gen. et sp.n. and B. cordata gen. et sp.n.; Cycloprotarsus lineatus gen. et sp.n., C. centralis gen. et sp.n. and C. monacrotrichus gen. et sp.n.; Eurypterolichus gen.n. for Pterolichus navicula comb.n. Trouessart & Neumann and E. coniger gen. et sp.n.; Goniodurus gen.n. for Pterolichus ( Pseudalloptes ) quadratus comb.n. Trouessart and G. bilobatus gen. et sp.n.; Haptepigynus gen.n. for Pterolichus ( Pseudalloptes ) tridentiger comb.n. Trouessart and H. holonotus gen. et sp.n.; Heliaspis ventralis gen. et sp.n.; Leipobius ocellatus gen. et sp.n.; Maleolichus maleo gen. et sp.n.; Mayracarus gen.n. for Pterolichus (P.) tritilobus comb.n. Trouessart; Megapodobius arcuatus gen. et sp.n. and M. striatus gen. et sp.n.; Oxygynurus brevissimus gen. et sp.n., O. longicaulis gen. et sp.n., O. mediocaulis gen. et sp.n. and O. parvicaulis gen. et sp. n.; Prionoturus amembranatus gen. et sp. n.; Talegallobius bidentatus gen. et sp.n.; and Tanysomacarus imperfectus gen. et sp.n. and T. brachymeles gen. et sp.n. A new taxon of the Thoracosathesidae is: Thoracosathes caudiculata sp.n. Keys are provided and host- commensal associations are discussed. All taxa are restricted to the Megapodiidae. Cheylabis fuscina Trouessart is assigned to Pereziella and has as a synonym P. dupilcata Atyeo.     

Electromyographic studies of the syrinx in parrots (Aves,Psittacidae)

Summary The vocal organ (syrinx) of a bird may contain either extrinsic muscles alone or both extrinsic and intrinsic muscles. The former arise and insert on the trachea and affect the syrinx only indirectly; the latter also arise on the trachea but insert directly on syringeal elements. It is widely supposed that syringeal muscles can affect modulations of the sounds the birds make, and further, that the intrinsic muscles are closely associated with such a function. However, the exact roles of the two groups of muscles have not been directly observed.The psittacid syrinx, which has one (for practical purposes) pair of extrinsic and two pairs of intrinsic muscles, is about as simple as one can find in birds capable of uttering a wide variety of sounds. We have taken electromyograms from the syringeal muscles of five species of parrots. In all of these, the extrinsic sternotrachealis showed the simple activation pattern activity previously described from several non-passerine species that possess only extrinsic muscles. The intrinsic muscles, however, showed a variety of activity patterns. The relatively simple call of Cyanoliseus patagonus again showed the simple activation pattern. In Myiopsitta monachus, the muscles showed a string of pulses that matched to pulses of sound in a strongly amplitude modulated call. Agapornis roseicollis used at least two distinct patterns, each associated with a different call.The results are consistent with an hypothesis that, because of their indirect attachment of the syrinx, extrinsic muscles are poorly suited to the production of precise, rapid changes in syringeal action, but rather will function in an on-off switch capacity. Intrinsic muscles are so situated that, given proper neurological stimulus, they can effect a variety of alterations in the sound pattern. Hence, intrinsic muscles are necessary for the evolution of large vocabularies and variable vocal behavior.     

A revision of the family Ciconiidae (Aves)

Behavioural and morphological characteristics of all members of the stork family are summarized. References are given to other papers where these subjects are discussed in greater detail for each group of storks. Based on the evidence now available, a revised classification is suggested (Table II) which divides the Ciconiidae into three tribes, six genera, and 17 species. The following genera (of Peters, 1931) are synonymized with other existing genera: Ibis, Sphenorhynchus, Dissoura, Euxenura , and Xenorhynchus. It is further suggested that Scopus should be placed in a suborder of its own and that Balaeniceps be placed in a monotypic family adjacent to the Ciconiidae, pending further study.     

Feather mites (Acarina) of the parakeet, Melopsittacus undulatus (Shaw) (Aves: Psittacidae)

The parakeet (or budgerigar) has been transported to many regions of the world. Two species of feather mites, Protolichus lunula (Robin) (Pterolichoidea: Pterolichidae) and Dubininia melopsittaci n. sp. (Analgoidea: Xolalgidae), are specific to this host; from distribution records, these ectoparasites probably have been distributed worldwide with their hosts.     

Explosive avian radiations and multi-directional dispersal across Wallacea: evidence from the Campephagidae and other Crown Corvida (Aves)

The systematic relationships among avian families within Crown Corvida have been poorly studied so far and as such been of limited use for biogeographic interpretations. The group has its origin in Australia and is thought to have colonized Africa and the New World via Asia beginning some 35 Mya when terranes of Australian origin approached Asian landmasses. Recent detailed tectonic mapping of the origin of land masses in the region around Wallace's line have revealed a particularly complex movement of terranes over the last 20-30 Myr. Thus the biogeographic dispersal pattern of Crown Corvida is a particularly exciting case for linking vicariance and dispersal events with Earth history. Here we examine phylogenetic affinities among 72 taxa covering a broad range of genera in the basal radiations within Crown Corvida with an emphasis on Campephagidae and Pachycephalidae. Bayesian analyses of nuclear DNA sequence data identified the family Campephagidae as monophyletic but the large genus Coracina is not. Within the family Pachycephalidae the genera Pachycephala and Colluricincla are paraphyletic with respect to each other. The resulting phylogeny suggests that patterns of dispersal across Wallace's line are complex and began at least 25 Mya. We find evidence of explosive radiations and multi-directional dispersal within the last 10 Myr, and three independent long distance ocean dispersal events between Wallacea and Africa at 10-15 Mya. Furthermore, the study reveals that in the Campephagidae a complex series of dispersal events rather than vicariance is the most likely explanation for the current biogeographic pattern in the region.     

The use of auxiliary courts by the lek-forming White-bearded Manakin Manacus manacus (Aves, Pipridae)

The White-bearded Manakin is a passerine specially noted for elaborate courtship. Each resident male has a cleaned oval court delimited by saplings in leks. No study mentions the use of more than one court by a territorial male during the breeding season. We report the use of auxiliary courts by males in the lowland forest of southeastern Brazil and discuss its probable function in attracting females for mating. Additionally, we experimentally modified a male’s main courts, testing that auxiliary courts serve as alternative display places. Twelve males from four different leks were observed for 145 h. Six males used from one to four auxiliary courts located 1.0 to 8.1 m from their main courts. The males that also used auxiliary courts displayed more than males that used only the main court. Nevertheless, the proportion of female visits per display time indicates that males that used only the main court have greater efficiency in attracting potential mates. Individual males responded differently to the experimental modification of their main courts, but one male avoided the modified court. The use of auxiliary courts may be a strategy adopted mainly by peripheral males to attract females that visit more successful males with central territories on the lek. In the short term, auxiliary courts function as optional display places in cases of loss of the main court. In the long term, the use of auxiliary courts may be involved in the temporal persistence of lek areas.