beak

Summary

Summary: In some animals, the jaws together with their horny covering. The beak usually refers to the bill of birds in which the whole varies greatly in form according of the food and habits of the bird. While the beak refers most commonly to birds, the anatomical counterpart is found also in the turtle, squid, and octopus. (From Webster, 3d ed & Storer, et al., General Zoology, 6th ed, p491, 755)

Top Publications

  1. Treiber C, Salzer M, Riegler J, Edelman N, Sugar C, Breuss M, et al. Clusters of iron-rich cells in the upper beak of pigeons are macrophages not magnetosensitive neurons. Nature. 2012;484:367-70 pubmed publisher
    ..of magnetite-containing trigeminal afferents located at six specific loci in the rostral subepidermis of the beak. These studies have been widely accepted in the field and heavily relied upon by both behavioural biologists and ..
  2. Schielzeth H, Kempenaers B, Ellegren H, Forstmeier W. QTL linkage mapping of zebra finch beak color shows an oligogenic control of a sexually selected trait. Evolution. 2012;66:18-30 pubmed publisher
    ..Here we analyze whether the genetic architecture of beak color in a population of zebra finches supports this hypothesis...
  3. Van Hemert C, Handel C, O Hara T. Evidence of accelerated beak growth associated with avian keratin disorder in black-capped chickadees (Poecile atricapillus). J Wildl Dis. 2012;48:686-94 pubmed
    We recently documented an epizootic of beak deformities in more than 2,000 Blackcapped Chickadees (Poecile atricapillus) and other wild bird species in North America...
  4. Benkman C. Divergent selection drives the adaptive radiation of crossbills. Evolution. 2003;57:1176-81 pubmed
    ..This work strongly supports a key tenet of the ecological theory of adaptive radiations; namely, divergent selection for utilizing alternative resources is the ultimate cause of adaptive radiations...
  5. Wild J, Kubke M, Pena J. A pathway for predation in the brain of the barn owl (Tyto alba): projections of the gracile nucleus to the "claw area" of the rostral wulst via the dorsal thalamus. J Comp Neurol. 2008;509:156-66 pubmed publisher
    ..The results are discussed in the context of somatosensory projections, primarily in this and other avian species...
  6. Fleissner G, Stahl B, Thalau P, Falkenberg G, Fleissner G. A novel concept of Fe-mineral-based magnetoreception: histological and physicochemical data from the upper beak of homing pigeons. Naturwissenschaften. 2007;94:631-42 pubmed
    ..and X-ray analyses support the hypothesis that delicate iron-containing structures in the skin of the upper beak of homing pigeons might serve as a biological magnetometer...
  7. Grenier J, Greenberg R. A biogeographic pattern in sparrow bill morphology: parallel adaptation to tidal marshes. Evolution. 2005;59:1588-95 pubmed
    ..We, therefore, speculate that tidal marsh ecosystems are likely settings for ecological speciation...
  8. Khalesi B, Bonne N, Stewart M, Sharp M, Raidal S. A comparison of haemagglutination, haemagglutination inhibition and PCR for the detection of psittacine beak and feather disease virus infection and a comparison of isolates obtained from loriids. J Gen Virol. 2005;86:3039-46 pubmed
    Psittacine beak and feather disease (PBFD) is recognized as a threat for endangered psittacine birds in Australia, New Zealand and South Africa...
  9. Hoese W, Podos J, Boetticher N, Nowicki S. Vocal tract function in birdsong production: experimental manipulation of beak movements. J Exp Biol. 2000;203:1845-55 pubmed
    Kinematic analyses have demonstrated that the extent to which a songbird's beak is open when singing correlates with the acoustic frequencies of the sounds produced, suggesting that beak movements function to modulate the acoustic ..

More Information

Publications64

  1. Julian L, Piasecki T, Chrząstek K, Walters M, Muhire B, Harkins G, et al. Extensive recombination detected among beak and feather disease virus isolates from breeding facilities in Poland. J Gen Virol. 2013;94:1086-95 pubmed publisher
    b>Beak and feather disease virus (BFDV) causes the highly contagious, in some cases fatal, psittacine beak and feather disease in parrots...
  2. Smith M, Yanega G, Ruina A. Elastic instability model of rapid beak closure in hummingbirds. J Theor Biol. 2011;282:41-51 pubmed publisher
    The hummingbird beak, specialized for feeding on floral nectars, is also uniquely adapted to eating flying insects. During insect capture the beak often appears to close at a rate that cannot be explained by direct muscular action alone...
  3. Mallarino R, Grant P, Grant B, Herrel A, Kuo W, Abzhanov A. Two developmental modules establish 3D beak-shape variation in Darwin's finches. Proc Natl Acad Sci U S A. 2011;108:4057-62 pubmed publisher
    ..some of the molecular mechanisms that regulate morphogenesis of the prenasal cartilage, which forms the initial beak skeleton. However, much of the beak diversity in birds depends on variation in the premaxillary bone...
  4. Symonds M, Tattersall G. Geographical variation in bill size across bird species provides evidence for Allen's rule. Am Nat. 2010;176:188-97 pubmed publisher
    ..Our results provide the strongest comparative support yet published for Allen's rule and demonstrate that thermoregulation has been an important factor in shaping the evolution of bird bills...
  5. Wiltschko W, Munro U, Ford H, Wiltschko R. Avian orientation: the pulse effect is mediated by the magnetite receptors in the upper beak. Proc Biol Sci. 2009;276:2227-32 pubmed publisher
    ..Structures containing superparamagnetic magnetite have been described in the inner skin at the edges of the upper beak of birds, while single-domain magnetite particles are indicated in the nasal cavity...
  6. Stapput K, Thalau P, Wiltschko R, Wiltschko W. Orientation of birds in total darkness. Curr Biol. 2008;18:602-6 pubmed publisher
    ..A high-frequency field of 1.315 MHz did not affect the behavior, whereas local anesthesia of the upper beak resulted in disorientation...
  7. Sun Y, Ellen E, Parmentier H, van Der Poel J. Genetic parameters of natural antibody isotypes and survival analysis in beak-trimmed and non-beak-trimmed crossbred laying hens. Poult Sci. 2013;92:2024-33 pubmed publisher
    ..study indicated that serum levels of NAb isotypes IgM and IgG at a young age were predictive for survival in non-beak-trimmed purebred laying hens during the laying period...
  8. MacDonald M, Abbott U, Richman J. Upper beak truncation in chicken embryos with the cleft primary palate mutation is due to an epithelial defect in the frontonasal mass. Dev Dyn. 2004;230:335-49 pubmed
    In this study, we used the chicken mutant strain known as cleft primary palate (cpp) to study the mechanisms of beak outgrowth. cpp mutants have complete truncation of the upper beak with normal development of the lower beak...
  9. Slate J. From beavis to beak color: a simulation study to examine how much qtl mapping can reveal about the genetic architecture of quantitative traits. Evolution. 2013;67:1251-62 pubmed publisher
    ..I show that an interpretation of a mapping study of beak color in the zebra finch (Taeniopygia guttata), that suggested genetic variation was determined by a small number ..
  10. Olson V, Owens I. Interspecific variation in the use of carotenoid-based coloration in birds: diet, life history and phylogeny. J Evol Biol. 2005;18:1534-46 pubmed
  11. Abzhanov A, Kuo W, Hartmann C, Grant B, Grant P, Tabin C. The calmodulin pathway and evolution of elongated beak morphology in Darwin's finches. Nature. 2006;442:563-7 pubmed publisher
    ..work has shown that even small differences in any of the three major dimensions (depth, width and length) of the beak have major consequences for the overall fitness of the birds...
  12. Brower A, Cigel F, Radi C, Toohey Kurth K. Beak necrosis in Hungarian partridges (Perdix perdix) associated with beak-bits and avian poxvirus infection. Avian Pathol. 2010;39:223-5 pubmed publisher
    Proliferative growth, consistent with poxvirus infection, encapsulated plastic beak-bits and covered the dorsal portion of the upper beak and nares of adult male and female captive-raised Hungarian partridges...
  13. Van Hemert C, Handel C, Blake J, Swor R, O Hara T. Microanatomy of passerine hard-cornified tissues: beak and claw structure of the black-capped chickadee (Poecile atricapillus). J Morphol. 2012;273:226-40 pubmed publisher
    ..An emerging epizootic of beak deformities among wild birds in Alaska and the Pacific Northwest region of North America recently highlighted the ..
  14. Foster D, Podos J, Hendry A. A geometric morphometric appraisal of beak shape in Darwin's finches. J Evol Biol. 2008;21:263-275 pubmed publisher
    b>Beak size and shape in Darwin's finches have traditionally been quantified using a few univariate measurements (length, depth, width)...
  15. Cunningham S, Castro I, Alley M. A new prey-detection mechanism for kiwi (Apteryx spp.) suggests convergent evolution between paleognathous and neognathous birds. J Anat. 2007;211:493-502 pubmed
    ..Therefore we cite the similar bill-tip anatomy of these two families as an example of convergent evolution across a deep taxonomic divide...
  16. Hill G, Hood W, Huggins K. A multifactorial test of the effects of carotenoid access, food intake and parasite load on the production of ornamental feathers and bill coloration in American goldfinches. J Exp Biol. 2009;212:1225-33 pubmed publisher
    ..These results indicate that pigment intake, food access and parasite load can have complex and variable effects on color displays, and that feather and bill coloration signal different aspects of male condition...
  17. Soons J, Herrel A, Genbrugge A, Aerts P, Podos J, Adriaens D, et al. Mechanical stress, fracture risk and beak evolution in Darwin's ground finches (Geospiza). Philos Trans R Soc Lond B Biol Sci. 2010;365:1093-8 pubmed publisher
    ..a common ancestor into 14 descendent species, each specializing on distinct food resources and evolving divergent beak forms...
  18. Wiltschko R, Schiffner I, Fuhrmann P, Wiltschko W. The role of the magnetite-based receptors in the beak in pigeon homing. Curr Biol. 2010;20:1534-8 pubmed publisher
    Magnetite-containing structures in the upper beak of birds have been described as putative magnetoreceptors [1-4], but so far, all positive evidence indicating their influence on behavior has come from laboratory studies using rather ..
  19. Mullens B, Chen B, Owen J. Beak condition and cage density determine abundance and spatial distribution of northern fowl mites, Ornithonyssus sylviarum, and chicken body lice, Menacanthus stramineus, on caged laying hens. Poult Sci. 2010;89:2565-72 pubmed publisher
    ..Two beak conditions (beak trimmed or beak intact) and 2 housing densities (1 or 2 hens per 25 × 31 cm suspended wire cage) ..
  20. Schneider R. How to tweak a beak: molecular techniques for studying the evolution of size and shape in Darwin's finches and other birds. Bioessays. 2007;29:1-6 pubmed
    ..momentum, a recent paper tackles one of the foremost topics in evolution, that is the origin of species-specific beak morphology in Darwin's finches...
  21. Mallarino R, Campàs O, Fritz J, Burns K, Weeks O, Brenner M, et al. Closely related bird species demonstrate flexibility between beak morphology and underlying developmental programs. Proc Natl Acad Sci U S A. 2012;109:16222-7 pubmed publisher
    ..are generated by alterations in the signaling pathways that regulate growth of the two skeletal components of the beak: the prenasal cartilage (pnc) and the premaxillary bone (pmx)...
  22. Chuong C, Wu P, Plikus M, Jiang T, Bruce Widelitz R. Engineering stem cells into organs: topobiological transformations demonstrated by beak, feather, and other ectodermal organ morphogenesis. Curr Top Dev Biol. 2006;72:237-74 pubmed
    ..Promises and problems in reconstitute feather/hair follicles and other organs are discussed. Finally, simple modification at the topobiological level may lead to novel morphology for natural selection at the evolution level...
  23. Hanuise N, Bost C, Huin W, Auber A, Halsey L, Handrich Y. Measuring foraging activity in a deep-diving bird: comparing wiggles, oesophageal temperatures and beak-opening angles as proxies of feeding. J Exp Biol. 2010;213:3874-80 pubmed publisher
    ..Crucially, and for the first time, two types of beak-opening events were identified...
  24. Podos J, Southall J, Rossi Santos M. Vocal mechanics in Darwin's finches: correlation of beak gape and song frequency. J Exp Biol. 2004;207:607-19 pubmed
    Recent studies of vocal mechanics in songbirds have identified a functional role for the beak in sound production...
  25. Schneider R, Helms J. The cellular and molecular origins of beak morphology. Science. 2003;299:565-8 pubmed
    Cellular and molecular mechanisms underlying differences in beak morphology likely involve interactions among multiple embryonic populations...
  26. Derryberry E, Seddon N, Claramunt S, Tobias J, Baker A, Aleixo A, et al. Correlated evolution of beak morphology and song in the neotropical woodcreeper radiation. Evolution. 2012;66:2784-97 pubmed publisher
    ..we explored the interplay between morphological and vocal evolution in an avian radiation characterized by dramatic beak variation, the Neotropical woodcreepers (Dendrocolaptinae)...
  27. Clabaut C, Herrel A, Sanger T, Smith T, Abzhanov A. Development of beak polymorphism in the African seedcracker, Pyrenestes ostrinus. Evol Dev. 2009;11:636-46 pubmed publisher
    The black-bellied African seedcracker, Pyrenestes ostrinus, exhibits a non-sex-related polymorphism in beak size that enables the small-, large-, and mega-billed morphs to utilize different trophic niches...
  28. Seki Y, Bodde S, Meyers M. Toucan and hornbill beaks: a comparative study. Acta Biomater. 2010;6:331-43 pubmed publisher
    ..The beak of both species is a sandwich-structured composite, having an exterior, or rhamphotheca, consisting of multiple ..
  29. Fletcher N, Riede T, Suthers R. Model for vocalization by a bird with distensible vocal cavity and open beak. J Acoust Soc Am. 2006;119:1005-11 pubmed
    ..cardinalis) have a muscularly distended oropharyngeal-esophageal cavity between the top of the trachea and the open beak. The present paper analyzes the acoustics of this vocal system...
  30. Badyaev A, Young R, Oh K, Addison C. Evolution on a local scale: developmental, functional, and genetic bases of divergence in bill form and associated changes in song structure between adjacent habitats. Evolution. 2008;62:1951-64 pubmed publisher
  31. Alonso Alvarez C, Bertrand S, Devevey G, Gaillard M, Prost J, Faivre B, et al. An experimental test of the dose-dependent effect of carotenoids and immune activation on sexual signals and antioxidant activity. Am Nat. 2004;164:651-9 pubmed
    ..how carotenoid availability and immune activation affected the amount of circulating plasma carotenoids, the beak color, and the antioxidant defenses (assessed as the resistance of red blood cells to a controlled free radical ..
  32. Mathot K, Smith B, Elner R. Latitudinal clines in food distribution correlate with differential migration in the Western Sandpiper. Ecology. 2007;88:781-91 pubmed
    ..We discuss the potential implications of these findings in the context of competing evolutionary hypotheses of differential migration and bill dimorphism in shorebirds...
  33. Fahey A, Marchant Forde R, Cheng H. Relationship between body weight and beak characteristics in one-day-old white Leghorn chicks: its implications for beak trimming. Poult Sci. 2007;86:1312-5 pubmed
    b>Beak trimming is a routine practice used in laying hens to prevent feather pecking and cannibalism...
  34. Hendry A, Grant P, Rosemary Grant B, Ford H, Brewer M, Podos J. Possible human impacts on adaptive radiation: beak size bimodality in Darwin's finches. Proc Biol Sci. 2006;273:1887-94 pubmed
    ..We investigated this possibility by analysing beak size data for 1755 Geospiza fortis measured between 1964 and 2005 on the island of Santa Cruz, Galápagos...
  35. Tian L, Xiao B, Lin W, Zhang S, Zhu R, Pan Y. Testing for the presence of magnetite in the upper-beak skin of homing pigeons. Biometals. 2007;20:197-203 pubmed
    We carried out magnetic and nonmagnetic experiments on fresh, upper-beak skin tissue samples isolated from six pairs of homing pigeons to test whether the tissue contains magnetite particles...
  36. Grant P, Grant B. Unpredictable evolution in a 30-year study of Darwin's finches. Science. 2002;296:707-11 pubmed
    ..fortis (medium ground finch) and Geospiza scandens (cactus finch) changed several times in body size and two beak traits...
  37. Fleissner G, Holtkamp Rötzler E, Hanzlik M, Winklhofer M, Fleissner G, Petersen N, et al. Ultrastructural analysis of a putative magnetoreceptor in the beak of homing pigeons. J Comp Neurol. 2003;458:350-60 pubmed
    ..microscopic methods, we investigated the subcellular organization of afferent trigeminal terminals in the upper beak of the homing pigeon, Columba livia, which are about 5 microm in diameter and contain superparamagnetic magnetite (..
  38. Freire R, Eastwood M, Joyce M. Minor beak trimming in chickens leads to loss of mechanoreception and magnetoreception. J Anim Sci. 2011;89:1201-6 pubmed publisher
    Routine removal of the tip of the beak of chickens within the poultry industry leads to changes in pecking behavior, which have previously been interpreted as being indicative of pain...
  39. Cote J, Arnoux E, Sorci G, Gaillard M, Faivre B. Age-dependent allocation of carotenoids to coloration versus antioxidant defences. J Exp Biol. 2010;213:271-7 pubmed publisher
    ..Using zebra finches (Taeniopygia guttata) as a model species, we assessed circulating carotenoids, beak coloration and the plasma antioxidant status of birds of different ages before and after an inflammatory challenge...
  40. Eraud C, Devevey G, Gaillard M, Prost J, Sorci G, Faivre B. Environmental stress affects the expression of a carotenoid-based sexual trait in male zebra finches. J Exp Biol. 2007;210:3571-8 pubmed
    ..The physiological functions related to self-maintenance that might have benefited from carotenoid saving are discussed...
  41. Palya V, Zolnai A, Benyeda Z, Kovács E, Kardi V, Mato T. Short beak and dwarfism syndrome of mule duck is caused by a distinct lineage of goose parvovirus. Avian Pathol. 2009;38:175-80 pubmed publisher
    From the early 1970s to the present, numerous cases of short beak and dwarfism syndrome (SBDS) have been reported in mule ducks from France. The animals showed strong growth retardation with smaller beak and tarsus...
  42. Fossette S, Gaspar P, Handrich Y, Le Maho Y, Georges J. Dive and beak movement patterns in leatherback turtles Dermochelys coriacea during internesting intervals in French Guiana. J Anim Ecol. 2008;77:236-46 pubmed publisher
    ..the possibility of this active behaviour being associated with foraging, by studying concurrently diving and beak movement patterns in gravid females equipped with IMASEN (Inter-MAndibular Angle SENsor). 2...
  43. Goller F, Mallinckrodt M, Torti S. Beak gape dynamics during song in the zebra finch. J Neurobiol. 2004;59:289-303 pubmed
    ..To determine the contribution of beak movements to sound modification, we studied the beak gape patterns in zebra finches (Taeniopygia guttata)...
  44. Tsudzuki M, Nakane Y, Wada A. Short beak: a new autosomal recessive semilethal mutation in Japanese quail. J Hered. 1998;89:175-8 pubmed
    ..The shank is also thicker than the wild type. The shape of the mutant beak does not show a parrotlike appearance, contrasting with that of other poultry chondrodystrophic mutants reported in ..
  45. Peters A, Denk A, Delhey K, Kempenaers B. Carotenoid-based bill colour as an indicator of immunocompetence and sperm performance in male mallards. J Evol Biol. 2004;17:1111-20 pubmed
    ..Our data provide support for current theories that females could use carotenoid-based sexual signals to detect immune vigour and fertilizing ability of prospective mates...
  46. Birkhead T, Pellatt E, Matthews I, Roddis N, Hunter F, McPhie F, et al. Genic capture and the genetic basis of sexually selected traits in the zebra finch. Evolution. 2006;60:2389-98 pubmed
    ..zebra finch Taeniopygia guttata, we tested two key predictions from this model: (1) that genetic variance exists in beak color which is a sexually selected trait, but also in condition and immune function, and (2) that positive genetic ..
  47. Falkenberg G, Fleissner G, Schuchardt K, Kuehbacher M, Thalau P, Mouritsen H, et al. Avian magnetoreception: elaborate iron mineral containing dendrites in the upper beak seem to be a common feature of birds. PLoS ONE. 2010;5:e9231 pubmed publisher
    ..pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system...
  48. Tattersall G, Andrade D, Abe A. Heat exchange from the toucan bill reveals a controllable vascular thermal radiator. Science. 2009;325:468-70 pubmed publisher
    The toco toucan (Ramphastos toco), the largest member of the toucan family, possesses the largest beak relative to body size of all birds...
  49. Greenberg R, Olsen B. Bill size and dimorphism in tidal-marsh sparrows: island-like processes in a continental habitat. Ecology. 2010;91:2428-36 pubmed
    ..Thus, both a shift in bill size and increases in its dimorphism and variability may be favored by high productivity and abiotic constraints...
  50. Williams H. Choreography of song, dance and beak movements in the zebra finch (Taeniopygia guttata). J Exp Biol. 2001;204:3497-506 pubmed
    ..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...
  51. Louchart A, Viriot L. From snout to beak: the loss of teeth in birds. Trends Ecol Evol. 2011;26:663-73 pubmed publisher
    ..Reviewing these lines of evidence, we propose hypotheses for its causes, with a prominent role for the horny beak during development...
  52. Wu P, Jiang T, Suksaweang S, Widelitz R, Chuong C. Molecular shaping of the beak. Science. 2004;305:1465-6 pubmed
    b>Beak shape is a classic example of evolutionary diversification. Beak development in chicken and duck was used to examine morphological variations among avian species...
  53. Biard C, Hardy C, Motreuil S, Moreau J. Dynamics of PHA-induced immune response and plasma carotenoids in birds: should we have a closer look?. J Exp Biol. 2009;212:1336-43 pubmed publisher
    ..Taking into account the dynamics of the immune response and that of associated physiological parameters would thus yield new insights into our interpretation of variation in PHA response...
  54. Miserez A, Rubin D, Waite J. Cross-linking chemistry of squid beak. J Biol Chem. 2010;285:38115-24 pubmed publisher
    ..dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material...
  55. Grant P, Grant B. Evolution of character displacement in Darwin's finches. Science. 2006;313:224-6 pubmed
    ..Here we report that a Darwin's finch species (Geospiza fortis) on an undisturbed Galápagos island diverged in beak size from a competitor species (G...