نتایج جستجو برای: feathers

تعداد نتایج: 2568  

2016
Roslyn Dakin Owen McCrossan James F. Hare Robert Montgomerie Suzanne Amador Kane

Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus) perform a complex, multimodal "train-rattling" display in which they court females by vibrating the iridescent feathers in their elaborate train ornament. Here we study how feather biomec...

2011
Arun Gupta Ramanan Perumal Rosli Bin Mohd Yunus Nuruldiyanah Binti Kamarudin

The present research was conducted to extract keratin protein from chicken feathers. Protein is an important nutrient needed by our body to maintain body structures and is an important ingredient for cosmetic products. Chicken feathers have high level of keratin protein content and can become a suitable protein source. The main processes involved are first dissolving chicken feathers using diff...

2011
Holly E. Barden Roy A. Wogelius Daqing Li Phillip L. Manning Nicholas P. Edwards Bart E. van Dongen

Recent studies have shown evidence for the preservation of colour in fossilized soft tissues by imaging melanosomes, melanin pigment containing organelles. This study combines geochemical analyses with morphological observations to investigate the preservation of melanosomes and melanin within feathers of the Early Cretaceous bird, Gansus yumenensis. Scanning electron microscopy reveals structu...

Journal: :Integrative zoology 2006
Xing Xu

Recent discoveries of feathered dinosaurs from Early Cretaceous deposits in Liaoning, China, have not only lent strongest support for the dinosaurian hypothesis of bird origins, but have also provided much-needed information about the origins of feathers and avian flight. Preliminary analysis of character evolution suggests that the major avian osteological characters were acquired during the e...

Journal: :Environmental monitoring and assessment 2008
Joanna Burger Michael Gochfeld Christian Jeitner Daniel Snigaroff Ronald Snigaroff Timothy Stamm Conrad Volz

Concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium were examined in the down feathers and eggs of female common eiders (Somateria mollissima) from Amchitka and Kiska Islands in the Aleutian Chain of Alaska to determine whether there were (1) differences between levels in feathers and eggs, (2) differences between the two islands, (3) positive correlations betwee...

Journal: :The Journal of experimental biology 2013
Christopher J Clark Damian O Elias Richard O Prum

Males in the 'bee' hummingbird clade produce distinctive, species-specific sounds with fluttering tail feathers during courtship displays. Flutter may be the result of vortex shedding or aeroelastic interactions. We investigated the underlying mechanics of flutter and sound production of a series of different feathers in a wind tunnel. All feathers tested were capable of fluttering at frequenci...

2016
Gustavo M.E.M. Prado Luiz Eduardo Anelli Setembrino Petri Guilherme Raffaeli Romero

Here we describe three fossil feathers from the Early Cretaceous Santana Formation of the Araripe Basin, Brazil. Feathers are the most complex multiform vertebrate integuments; they perform different functions, occurring in both avian and non-avian dinosaurs. Despite their rarity, fossil feathers have been found across the world. Most of the Brazilian feather fossil record comes from the Santan...

2009
JACQUELINE M. PARITTE JEFFREY F. KELLY

—Stable-isotope analysis of feathers is an increasingly important source of information on diet and movement of birds. Feathers are typically cleaned with a solvent before analysis, but the effects of this cleaning on the resulting data have not been examined critically. We conducted an experiment to determine whether a cleaning regime affected hydrogen ( D), carbon ( C), and nitrogen ( N) ...

Journal: :Proceedings. Biological sciences 2012
Lee Koren Shinichi Nakagawa Terry Burke Kiran K Soma Katherine E Wynne-Edwards Eli Geffen

Potential mechanistic mediators of Darwinian fitness, such as stress hormones or sex hormones, have been the focus of many studies. An inverse relationship between fitness and stress or sex hormone concentrations has been widely assumed, although empirical evidence is scarce. Feathers gradually accumulate hormones during their growth and provide a novel way to measure hormone concentrations int...

2017
Jacquie Jacob

Ducks have many of the same basic external parts as other fowl, such as chickens. However, some unique characteristics exist in the external anatomies of ducks. For example, a duck's head (shown in Figure 1) differs from a chicken's head in several ways. Ducks have no comb and, other than the crested duck, no head covering other than feathers. The bill of a duck is flatter than the beak of a ch...

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