نتایج جستجو برای: beak

تعداد نتایج: 1228  

Journal: :Poultry science 2009
S N Henderson J T Barton A D Wolfenden S E Higgins J P Higgins W J Kuenzel C A Lester G Tellez B M Hargis

Beak trimming is necessary in commercial broiler breeders to prevent or decrease trauma as they mature. Two common beak-trimming methods were evaluated by early performance comparison with nontrimmed chicks (NBT). The robotic electrocautery device (ECD) trims and cauterizes the beak tip. The robotic infrared beak-trimming device (IBT) applies an infrared light beam to destroy the live basal tis...

Journal: :The Journal of experimental biology 1993
M W Westneat J H Long W Hoese S Nowicki

The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza ge...

Journal: :The Journal of experimental biology 2001
H Williams

As do many songbirds, zebra finches sing their learned songs while performing a courtship display that includes movements of the body, head and beak. The coordination of these display components was assessed by analyzing video recordings of courting males. All birds changed beak aperture frequently within a single song, and each individual's pattern of beak movements was consistent from song to...

2011
Heng-wei Cheng

among the major stressors in poultry that cause suffering and death of chickens. Beak trimming, removal of 1/3 to 1/2 of the beak, is a routine husbandry procedure practiced in the poultry industry, including laying hens, broiler breeders, turkey and ducks, to prevent those undesirable behaviors. However, beak trimming is a painful procedure. There is a considerable body of morphological, neuro...

Journal: :Turkish veterinary journal 2021

The aim of this study was to determine the type lesions in birds referred clinic with complaint beak deformity, potential presence among bird species, and possible causes report what treatment should be applied. Twenty-six individuals from several species broken abnormal deformities were presented our clinics. Different forms observed, some determined as unknown. Beak wild mostly traumatic frac...

2018
Stella X. Chen Philip R. Cohen

The term "parrot beak nail" describes a morphologic change of the nail plate characterized by excessive forward curvature. It may be associated with systemic disease or, most commonly, occurs as an idiopathic finding complicated by delayed nail plate trimming. The characteristics of parrot beak nails in ten men are described, and the features of this acquired nail deformity are reviewed. Of the...

Journal: :Journal of embryology and experimental morphology 1979
F G Wouterlood W van Pelt

The effect of removal of the lower beak on the development of the interorbital septumprenasal process (ISPP) complex was studied in chick embryos. In normal development the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process increases. At the same time the angle between the ventral contour of the interorbital septum and the basal plate increase...

Journal: :Developmental dynamics : an official publication of the American Association of Anatomists 2006
Ping Wu Ting-Xin Jiang Jen-Yee Shen Randall Bruce Widelitz Cheng-Ming Chuong

Avian beak diversity is a classic example of morphological evolution. Recently, we showed that localized cell proliferation mediated by bone morphogenetic protein 4 (BMP4) can explain the different shapes of chicken and duck beaks (Wu et al. [2004] Science 305:1465). Here, we compare further growth activities among chicken (conical and slightly curved), duck (straight and long), and cockatiel (...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2010
Joris Soons Anthony Herrel Annelies Genbrugge Peter Aerts Jeffrey Podos Dominique Adriaens Yoni de Witte Patric Jacobs Joris Dirckx

Darwin's finches have radiated from a common ancestor into 14 descendent species, each specializing on distinct food resources and evolving divergent beak forms. Beak morphology in the ground finches (Geospiza) has been shown to evolve via natural selection in response to variation in food type, food availability and interspecific competition for food. From a mechanical perspective, however, be...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Ricardo Mallarino Peter R Grant B Rosemary Grant Anthony Herrel Winston P Kuo Arhat Abzhanov

Bird beaks display tremendous variation in shape and size, which is closely associated with the exploitation of multiple ecological niches and likely played a key role in the diversification of thousands of avian species. Previous studies have demonstrated some of the molecular mechanisms that regulate morphogenesis of the prenasal cartilage, which forms the initial beak skeleton. However, much...

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