Flight, symmetry and barb angle evolution in the feathers of birds and other dinosaurs.

To evaluate the potential use of mineral content as a marker for identifying origins of wintering Redhead ducks along the coast of the Gulf of Mexico, we determined concentrations (ppm) of calcium (Ca), copper (Cu), magnesium (Mg), manganese (Mn), potassium (K), sodium (Na), and zinc (Zn) in wing feathers by atomic absorption spectrophotometry (AAS). Samples available for study included pairs of whole wings from Texas saltwater habitat (n = 653 birds), Florida saltwater habitat (n = 287 birds), and South Dakota pond habitat (n = 34 birds), and pairs or single secondary feathers from Louisiana saltwater habitat (n = 287 birds) and Texas pond habitat (n = 2257 birds). We found no differences between secondary feathers from the left and right wings from the same individual, but secondary feathers did differ from primaries from the same individual in Mg and Zn Concentrations of Ca were higher (P < 0.05) in flight feathers of juveniles (< 1 yr of age) than in those of adults Feathers from females had higher (P < 0.05) Zn than those from males among both adults and juveniles. Concentrations of Ca and Zn in feathers of Texas pond birds were higher (P < 0.05) than concentrations in feathers from Redheads from other geographic areas sampled. Magnesium from feathers of birds taken in Texas ponds and Louisiana saltwater habitat was higher (P < 0.05) than in feathers of Redheads from the other three areas Zinc concentrations in feathers of birds from Texas ponds were higher (P < 0.05) than those in feathers from Louisiana birds, and Zn in feathers from birds from both of those sites was higher (P < 0.05) than in feathers from Redheads from the other three areas. Because of the extremely high variability in mineral concentrations of Redhead feathers as determined by atomic absorption spectrophotometry, use of this technique to identify geographic origins, if based on the elements used in this study, is too uncertain to be reliable.

Is external contamination with organic pollutants important for concentrations measured in bird feathers?

The evolutionary history of large carnivorous mammals through the Ice Age have been investigated for the Italian peninsula. No endemisms are recorded in the mainland of Italy and large carnivore species composition reflected the similar fauna of European continent. Morpho-ecological adaptation of extinct Plio-Pleistocene species have been investigated throughout temporal PaleoCommunities (9 PCOMs – spanning 3.2 to 0.3 Ma) with statistical accuracy. Trophic apparatus of extant and extinct species was investigated with a geometric morphometric analysis of mandible shape while locomotory habits were assessed using long bone indices. The mandible shape analysis performed on extant Carnivora taxa confirms their morphological differences due principally to taxonomic affiliation (family). Although, when phylogenetic history is controlled with comparative methods, significant differences still to occur among taxa with different diets and between small and large forms (threshold posed at 7 kilograms). Interestingly, both mandibular regions (corpus and ascending ramus) are informative of Carnivora ecological adaptations and they result integrated at a macroevolutionary scale. This survey allows to consider geometric morphometric as a reliable technique to apply on fossil mandibles. Feeding habits have been predicted with a good degree of accuracy in several PlioPleistocene large carnivores on the basis of mandible shape data. The latter data –selecting only the corpus regionhave been considered also to perform a morphospace comparison between large carnivore guilds of Italian PCOMs and extant guilds representative of five mainland ecosystems worldwide. Disparity values computed for mandibular corpus shape of Plio-Pleistocene guilds did not differ significantly from extant guilds. Morphological variability in mandible shape is negatively influenced by number of species in each guild as well as number of prey confirming that ecomorph specialization does not occur at the extreme region of morphospace. Long bone proportions of Plio-Pleistocene large carnivores are grouped in the variability of extant species. Although some phenomena of morphological convergences occur among extinct and extant taxa because of similar locomotor adaptation (e.g. cursorial) and same body size constraint. These morphoecological data were also used to predict the relative adaptability of Plio-Pleistocene species to certain habitats (grassland and tropical). The macroecological analysis of presence/absence data confirms the striking relationship between the abundances of both predators and their prey thought Ice Age. On the other hand no morphoecological coordinate changes occurs between predators and their prey. It is noteworthy that large carnivores are overrepresented in the Italian fossil record and became rarer from Galerian to the Aurelian (also because of a possible interaction with human activities). A GIS model was then computed to compare large mammal communities toward Plio-Pleistocene in Italy. Structural changes occurred in large herbivore communities from Villafranchian through the Aurelian because of climate changes. On the other hand, the spatial structure of large carnivore communities was more affected by their prey during the Villafranchian, while in the Galerian and Aurelian there was a greater influence of uncontrolled factors like climate and human activity as well.

Feathers accurately reflect blood mercury at time of feather growth in a songbird

The effect of strains on fertility, hatchability, and embryo mortality of indigenous chicken reared in the high rain forest zone of Nigeria was investigated. In this investigation, indigenous chicken with normal feathered phenotype, naked neck, and frizzle feathered phenotype which consisted of 10 cocks and 35 hens as the parents were used. They were put in 7 breeding groups: (1) Normal feathered cock with normal feathered hen (na × na ); (2) Naked neck cock with naked neck hens (Na × Na); (3) Frizzle feathered cock with frizzle feathered hens (Ff × Ff); (4) Frizzle feathered cocks with normal feathered hens (Ff × na); (5) Naked neck cock with normal feathered hens (Na × na); (6) Normal feathered cock with naked neck hens (na × Na), and (7) Normal feathered cock with frizzle feathered hens (na × Ff). The hens were five in each group and artificial insemination of the desired cock for each group was carried out twice a week before eggs were collected for incubation. Results from data analysis showed no significant difference (P>0.05) in fertility and embryo mortality within breeding groups. Egg fertility ranged from 58.82% for Na × na to 91.38% for Ff × na strain. Significant strain effect (P<0.05) was recorded for hatchability with highest value of 86.36% for na × na and the least value of 55.56% for Na × Ff strain. The Ff × Ff also had the highest embryo mortality of 34.36%. It was concluded that continuous reduction in the population of indigenous chicken with major gene of frizzling and naked neck may be attributed to greater loss of the chicks before hatching. There is need for adequate conservation of these rare genes in order to prevent them from going to extinction. Key words: Hatchability, pure, crossbred chicken, normal feather, frizzle feather, naked neck, embryo mortality.

Although many Mesozoic fossil birds have been found with primary feathers preserved, these structures have rarely been included in morphometric analyses. This is surprising because the flight feathers of modern birds can contribute approximately 50% of the total wing length, and so it would be assumed that their inclusion or exclusion would modify functional interpretations. Here we show, contrary to earlier work, that this may not be the case. Using forelimb measurements and primary feather lengths from Mesozoic birds, we constructed morphospaces for different clades, which we then compared with morphospaces constructed for extant taxa classified according to flight mode. Consistent with older work, our results indicate that among extant birds some functional flight groups can be distinguished on the basis of their body sizes and that variation in the relative proportions of the wing elements is conservative. Mesozoic birds, on the other hand, show variable proportions of wing bones, with primary feather length contribution to the wing reduced in the earlier diverging groups. We show that the diverse Mesozoic avian clade Enantiornithes overlaps substantially with extant taxa in both size and limb element proportions, confirming previous morphometric results based on skeletal elements alone. However, these measurements cannot be used to distinguish flight modes in extant birds, and so cannot be used to infer flight mode in fossil forms. Our analyses suggest that more data from fossil birds, combined with accurate functional determination of the flight styles of living forms is required if we are to be able to predict the flight modes of extinct birds

The results of a 4 year project investigating species of mites infesting wing primary feathers on 21 species of Passeriformes are reported. The majority of species were identified as belonging to the genus Proctophyllodes Robin, 1877 with one new host record. In addition Pteronyssoides obscurus Berlese 1884 was found on European swallows, also a new host record. A novel method to enable quantification of mite intensities without causing harm to the birds was devised and evaluated. This relied on visual inspection of wing primary feathers and assignment of subjective infestation scores to individual feathers, the sum of the individual scores comprising the primary feather total mite infestation score (PTMIS). Comparisons between species revealed that birds could be grouped into four categoris depending on their infestation intensity with mites. Swallows, sand martins and greenfinches showed the highest prevalence and most intense infestations (mean PTMIS ≥ 6.8). Blackbirds, blackcaps, serins, goldfinches, Cetti's warblers, great tits and house sparrows showed moderate levels of infestation with prevalence in the range 60–90.9% but a mean PTMIS lower than in the former group (1.6–5.8). The third group comprised Sardinian warblers, nightingales and short-toed tree creepers and was characterized by a prevalence of mites ≥ 40% and a mean PTMIS of 0.6–1.4. The final group, representing wrens, chiffchaffs, fan-tailed warblers and waxbills were without detectable mites, the only exception being wrens on which mites were identified in only three birds of the 32 sampled. These results are interpreted in the light of published information and possible explanations for the observations are discussed.

The evolution of bilaterally symmetric feathers is a fundamental process leading toward flight. One major unsolved mystery is how the feathers of a single bird can form radially symmetric downy feathers and bilaterally symmetric flight feathers. In developing downy feather follicles, barb ridges are organized parallel to the long axis of the feather follicle. In developing flight-feather follicles, the barb ridges are organized helically toward the anterior region, leading to the fusion and creation of a rachis. Here we discover an anterior-posterior molecular gradient of wingless int (Wnt3)a in flight but not downy feathers. Global inhibition of the Wnt gradient transforms bilaterally symmetric feathers into radially symmetric feathers. Production of an ectopic local Wnt3a gradient reoriented barb ridges toward the source and created an ectopic rachis. We further show that the orientation of the Wnt3a gradient is dictated by the dermal papilla (DP). Swapping DPs between wing covert and breast downy feathers demonstrates that both feather symmetry and molecular gradients are in accord with the origin of the DP. Thus the fates of feather epidermal cells are not predetermined through some molecular codes but can be modulated. Together, our data suggest feathers are shaped by a DP--> Wnt gradient-->helical barb ridge organization-->creation of rachis-->bilateral symmetry sequence. We speculate diverse feather forms can be achieved by adjusting the orientation and slope of molecular gradients, which then shape the topological arrangements of feather epithelia, thus linking molecular activities to organ forms and novel functions.

Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic.

At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the "rachis dominated" tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the "proximally ribbon-like" pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds.

During the moult of primary wing feathers in birds it is likely that new feather material is being produced at an approximately constant rate if the energetic requirements of the birds are met. In moult regression analyses it is, therefore, desirable to transform moult measurements into a variable based on the amount of new feather material produced because of its linear properties. This can be achieved if the mass of each primary feather is known, and used as a weighting factor in a moult index. These primary feather masses would have to be known for every species being analysed. As an alternative, it is here tested if feather mass indices may be sufficient replacements for species-specific feather masses. Thirty-five species of birds with known primary feather masses were divided into four wing-shape groups, and a feather mass index was built for each group. Within each group, comparisons were made between estimates of moult parameters using the moult index with those using the known primary feather masses. Within groups there were no significant differences between any of the moult estimates.

Molecular Phylogenetics and The Evolution of Labral Spines among Eastern Pacific Ocenebrine Gastropods

Nunukan chicken is a local chicken from East Kalimantan which spreads out in Tarakan and Nunukan Islands . The chicken has a specific buff color and Columbian type feather and also has very late feathering (VLF) trait . The Nunukan cocks and hens have no wing and tail primary feather; the tail feathers are short and fragile . The VLF trait is known to have association with a K gene on the Z chromosome. The chicken is efficient in protein metabolism . Sulfur amino acids (cystine and methionine) that needed for feather growth, could be utilized for meat and egg production . The egg production of Nunukan chicken was better than the Kampung chicken . The average of hen day, hen house and peak production of Nunukan chicken was 45 . 39.1 and 62%, respectively, while the Kampung chicken was 35 .9, 30 .9 and 48%, respectively . Based on genetic analysis, the external genotype characteristic of the Nunukan chicken is ii ce ss Idld pp. It means that the phenotype appearance of the Nunukan chicken was columbian and gold feathering type, yellow and white shank color and single comb type. This phenotype is similar to Merawang Chicken . The genetic introgression of the Nunukan chicken is affected by the Rhode Island Red with the genetic introgression value of 0.964 . Key words: Nunukan chicken, character, genetic; phenotype characteristics, utilization

Biases in the per-taxon origination and extinction rates of fossil taxa

The primary feathers of birds are subject to cyclical forces in flight causing their shafts (rachises) to bend. The amount the feathers deflect during flight is dependent upon the flexural stiffness of the rachises. By quantifying scaling relationships between body mass and feather linear dimensions in a large data set of living birds, we show that both feather length and feather diameter scale much closer to predictions for geometric similarity than they do to elastic similarity. Scaling allometry also indicates that the primary feathers of larger birds are relatively shorter and their rachises relatively narrower, compared to those of smaller birds. Two-point bending tests indicated that larger birds have more flexible feathers than smaller species. Discriminant functional analyses (DFA) showed that body mass, primary feather length and rachis diameter can be used to differentiate between different magnitudes of feather bending stiffness, with primary feather length explaining 63% of variance in rachis stiffness. Adding fossil measurement data to our DFA showed that Archaeopteryx and Confuciusornis do not overlap with extant birds. This strongly suggests that the bending stiffness of their primary feathers was different to extant birds and provides further evidence for distinctive flight styles and likely limited flight ability in Archaeopteryx and Confuciusornis.