Abstract

We present a method for remote classification of birds based on eye-safe fluorescence lidar techniques. Mechanisms of quenching are discussed. Plumage reflectance is related to plumage fluorescence. Laboratory measurements on reflectance and fluorescence are presented, as well as test-range measurements. Also we present examples of birds’ in-flight lidar returns. The methods are suitable for studies of night migrating species and high-altitude classification with implications for the detailed understanding of bird migration and global virus spread.

© 2010 Optical Society of America

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  1. I. Newton, The Migration Ecology of Birds (Academic, 2008).
  2. T. Alerstam and Å. Lindström, “Optimal bird migration: the relative importance of time, energy and safety,” in Bird Migration: Physiology and Ecophysiology, E.Gewinner, ed. (Springer-Verlag, 1990), pp. 331–351.
  3. T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
    [CrossRef]
  4. B. Bruderer and F. Liechti, “Höhe und Richtung von Tag- und Nachtzug im Herbst über Südwestdeutschland,” Ornitol. Beob. 95, 113–128 (1998).
  5. S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
    [CrossRef]
  6. P. Kerlinger and F. R. Moore, “Atmospheric structure and avian migration,” in Current Ornithology, D.M.Power, ed. (Plenum, 1989), Vol. 6, pp. 109–141.
  7. Å. Lindström, “The role of predation risk in stopover habitat selection in migrating bramblings, Fringilla montifringilla,” Behav. Ecol. 1, 102–106 (1990).
    [CrossRef]
  8. S. Åkesson and A. Hedenström, “How migrants get there: migratory performance and orientation,” BioScience 57, 123–133 (2007).
    [CrossRef]
  9. M. B. Casement, “Migration across the Mediterranean observed by radar,” Ibis 108, 461–491 (1966).
    [CrossRef]
  10. J. L. F. Parslow, “The migration of passerine night migrants across the English channel studied by radar,” Ibis 111, 48–79(1969).
    [CrossRef]
  11. D. H. W. Adams, “Radar observations of bird migration in Cyprus,” Ibis 104, 133–146 (1962).
    [CrossRef]
  12. T. Alerstam, “Nocturnal migration of Thrushes Turdus-Spp in Southern Sweden,” Oikos 27, 457–475 (1976).
    [CrossRef]
  13. B. Bruderer and F. Liechti, “Quantification of bird migration—different means compared,” in Proceedings of the Bird Strike Committee, Europe (1994), Vol. 22, pp. 243–254.
  14. T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
    [CrossRef]
  15. S. A. Gauthreaux, Jr., “A portable ceilometer technique for studying low level nocturnal migration,” Bird Banding 40, 309–320 (1969).
    [CrossRef]
  16. S. Åkesson, “Coastal migration and wind drift compensation in nocturnal passerine migrants,” Ornis Scand. 24, 87–94 (1993).
    [CrossRef]
  17. S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
    [CrossRef]
  18. F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).
  19. F. Liechti, “Calibrating the moon-watching method—changes and limits,” Avian Ecol. Beh. 7, 27–41 (2001).
  20. F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
    [CrossRef]
  21. P. H. Zehtindijev and F. Liechti, “A quantitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe—a coordinated moon-watching study,” Avian Sci. 3, 37–45 (2003).
  22. B. Bruderer and E. Weitnauer, “Radar observations of the migration and night flights of the swift Apus-Apus,” Rev. Suisse Zool. 79, 1190–1200 (1972).
    [PubMed]
  23. J. Bäckman and T. Alerstam, “Confronting the winds: Orientation and flight behaviour of roosting swifts, Apus apus,” Proc. R. Soc. London Ser. B 268, 1081–1087 (2001).
    [CrossRef]
  24. T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
    [CrossRef] [PubMed]
  25. F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).
  26. C. J. Pennycuick, “Soaring behavior and performance of some East African birds observed from a motor glider,” Ibis 114, 178–218 (1972).
    [CrossRef]
  27. S. Svanberg, “Fluorescence spectroscopy and imaging of LIDAR targets,” in “Laser Remote Sensing, T.Fujii and T.Fukuchi, eds. (CRC Press, 2005).
    [CrossRef]
  28. S. Svanberg, “LIDAR,” in Springer Handbook of Lasers and OpticsF.Träger, ed. (Springer, 2007), pp. 1031–1052.
  29. S. Svanberg, “Laser fluorescence spectroscopy in environmental monitoring,” in Optoelectronics for Environmental Science, S.Martellucci and A.N.Chester, eds. (Plenum, 1990).
  30. K. S. Repasky, J. A. Shaw, R. Scheppele, C. Melton, J. L. Carsten, and L. H. Spangler, “Optical detection of honeybees by use of wing-beat modulation of scattered laser light for locating explosives and land mines,” Appl. Opt. 45, 1839–1843(2006).
    [CrossRef] [PubMed]
  31. D. S. Hoffman, A. R. Nehrir, K. S. Repasky, J. A. Shaw, and J. L. Carlsten, “Range-resolved optical detection of honeybees by use of wing-beat modulation of scattered light for locating land mines,” Appl. Opt. 46, 3007–3012 (2007).
    [CrossRef] [PubMed]
  32. M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
    [CrossRef] [PubMed]
  33. Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).
  34. H. Dingle, Migration: The Biology of Life on the Move (Oxford U. Press, 1996).
  35. S. Jaques and B. Pogue, “Tutorial on diffuse light transport,” J. Biomed. Opt. 13, 041302 (2008).
    [CrossRef]
  36. V. Tuchin, “Tissue optics,” in Light Scattering and Instruments for Medical Diagnosis, 2nd ed. (SPIE Press, 2007).
  37. G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 1: Mechanisms and Measurements (Harvard U. Press, 2006).
  38. G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 2: Function and Evolution (Harvard U. Press, 2006).
  39. L. Pauling and R. B. Corey, “The structure of feather rachis keratin,” Proc. Natl. Acad. Sci. USA 37, 256–261 (1951).
    [CrossRef] [PubMed]
  40. D. J. Brink and N. G. van der Berg, “Structural colours from the feathers of the bird Bostrychia hagedash,” J. Phys. D 37, 813–818 (2004).
    [CrossRef]
  41. E. G. Bendit and D. Ross, “A technique for obtaining the ultraviolet absorption spectrum of solid keratin,” Appl. Spectrosc. 15, 103–105 (1961).
    [CrossRef]
  42. D. Osorio and M. Vorobyev, “A review of the evolution of animal colour vision and visual communication signals,” Vision Res. 48, 2042–2051 (2008).
    [CrossRef] [PubMed]
  43. A. T. Bennett and M. Thery, “Avian color vision and coloration: multidisciplinary evolutionary biology,” Am. Nat. 169, S1–S6 (2007).
    [CrossRef]
  44. J. Reneerkens and P. Korsten, “Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus,” J. Avian Biol. 35, 405–409 (2004).
    [CrossRef]
  45. S. M. Doucet and G. E. Hill, “Do museum specimens accurately represent wild birds? A case study of carotenoid, melanin, and structural colours in long-tailed manakins Chiroxiphia linearis,” J. Avian Biol. 40, 146–156 (2009).
    [CrossRef]
  46. D. Osorio and A. Ham, “Spectral reflectance and directional properties of structural coloration in bird plumage,” J. Exp. Biol. 205, 2017–2027 (2002).
    [PubMed]
  47. R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
    [PubMed]
  48. E. Warrant and D. E. Nilsson, eds. Invertebrate Vision(Cambridge U. Press, 2006).
  49. J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
    [CrossRef]
  50. A. M. Pena, M. Strupler, T. Boulesteix, and M. C. Schanne-Klein, “Spectroscopic analysis of keratin endogenous signal for skin multiphoton microscopy,” Opt. Express 13, 6268–6274 (2005).
    [CrossRef] [PubMed]
  51. A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.
  52. G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).
  53. S. Jacques, “Origins of tissue optical properties in the UVA, visible and NIR regions,” in TOPS on Advances in Optical Imaging and Photon Migration II (Optical Society of America, 1996), pp. 364–367.
  54. A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
    [CrossRef]
  55. J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
    [CrossRef] [PubMed]
  56. J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
    [CrossRef]
  57. K. J. McGraw and G. E. Hill, “Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season,” Can. J. Zool. 82, 734–738 (2004).
    [CrossRef]
  58. K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
    [CrossRef]
  59. E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
    [CrossRef]
  60. A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
    [CrossRef]
  61. G. Pohland and P. Mullen, “Preservation agents influence UV-coloration of plumage in museum bird skins,” J. Ornithol. 147, 464–467 (2006).
    [CrossRef]
  62. X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
    [CrossRef]
  63. C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
    [CrossRef]
  64. S. C. V. Raman, “The theory of the Christiansen experiment,” Proc. Indian Acad. Sci. A29, 381–390 (1949).
  65. G. P. Kulemin, Millimeter Wave Radar Targets and Clutter (Artech House, 2003).
  66. I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
    [CrossRef]
  67. P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
    [CrossRef]
  68. P. Weibring, H. Edner, and S. Svanberg, “Versatile mobile lidar system for environmental monitoring,” Appl. Opt. 42, 3583–3594 (2003).
    [CrossRef] [PubMed]
  69. P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments,” Appl. Opt. 40, 6111–6120(2001).
    [CrossRef]
  70. P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments: erratum,” Appl. Opt. 41, 434–436 (2002).
    [CrossRef]
  71. E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
    [CrossRef]
  72. H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
    [CrossRef]
  73. U. P. Hoppe, G. H. Hansen, and W. Eriksen, “ALOMAR—Ground-based monitoring of stratospheric ozone and related atmospheric parameters,” in 27th International Symposium on Remote Sensing of Environment (1998), pp. 244–247.
  74. Kipp & Zonen, Delft, the Netherlands (2010), www.kippzonen.com.
  75. Alternatively Optech Inc., Kiln, Miss., USA (2010), www.optech.com
  76. M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
    [CrossRef] [PubMed]

2009 (4)

M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
[CrossRef] [PubMed]

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

S. M. Doucet and G. E. Hill, “Do museum specimens accurately represent wild birds? A case study of carotenoid, melanin, and structural colours in long-tailed manakins Chiroxiphia linearis,” J. Avian Biol. 40, 146–156 (2009).
[CrossRef]

X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
[CrossRef]

2008 (4)

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
[CrossRef] [PubMed]

D. Osorio and M. Vorobyev, “A review of the evolution of animal colour vision and visual communication signals,” Vision Res. 48, 2042–2051 (2008).
[CrossRef] [PubMed]

S. Jaques and B. Pogue, “Tutorial on diffuse light transport,” J. Biomed. Opt. 13, 041302 (2008).
[CrossRef]

2007 (9)

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

A. T. Bennett and M. Thery, “Avian color vision and coloration: multidisciplinary evolutionary biology,” Am. Nat. 169, S1–S6 (2007).
[CrossRef]

J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
[CrossRef]

S. Åkesson and A. Hedenström, “How migrants get there: migratory performance and orientation,” BioScience 57, 123–133 (2007).
[CrossRef]

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

D. S. Hoffman, A. R. Nehrir, K. S. Repasky, J. A. Shaw, and J. L. Carlsten, “Range-resolved optical detection of honeybees by use of wing-beat modulation of scattered light for locating land mines,” Appl. Opt. 46, 3007–3012 (2007).
[CrossRef] [PubMed]

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

2006 (4)

G. Pohland and P. Mullen, “Preservation agents influence UV-coloration of plumage in museum bird skins,” J. Ornithol. 147, 464–467 (2006).
[CrossRef]

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

K. S. Repasky, J. A. Shaw, R. Scheppele, C. Melton, J. L. Carsten, and L. H. Spangler, “Optical detection of honeybees by use of wing-beat modulation of scattered laser light for locating explosives and land mines,” Appl. Opt. 45, 1839–1843(2006).
[CrossRef] [PubMed]

2005 (1)

2004 (3)

J. Reneerkens and P. Korsten, “Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus,” J. Avian Biol. 35, 405–409 (2004).
[CrossRef]

D. J. Brink and N. G. van der Berg, “Structural colours from the feathers of the bird Bostrychia hagedash,” J. Phys. D 37, 813–818 (2004).
[CrossRef]

K. J. McGraw and G. E. Hill, “Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season,” Can. J. Zool. 82, 734–738 (2004).
[CrossRef]

2003 (3)

P. Weibring, H. Edner, and S. Svanberg, “Versatile mobile lidar system for environmental monitoring,” Appl. Opt. 42, 3583–3594 (2003).
[CrossRef] [PubMed]

P. H. Zehtindijev and F. Liechti, “A quantitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe—a coordinated moon-watching study,” Avian Sci. 3, 37–45 (2003).

T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
[CrossRef]

2002 (4)

E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
[CrossRef]

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

D. Osorio and A. Ham, “Spectral reflectance and directional properties of structural coloration in bird plumage,” J. Exp. Biol. 205, 2017–2027 (2002).
[PubMed]

P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments: erratum,” Appl. Opt. 41, 434–436 (2002).
[CrossRef]

2001 (5)

P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments,” Appl. Opt. 40, 6111–6120(2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

F. Liechti, “Calibrating the moon-watching method—changes and limits,” Avian Ecol. Beh. 7, 27–41 (2001).

J. Bäckman and T. Alerstam, “Confronting the winds: Orientation and flight behaviour of roosting swifts, Apus apus,” Proc. R. Soc. London Ser. B 268, 1081–1087 (2001).
[CrossRef]

2000 (1)

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

1998 (1)

B. Bruderer and F. Liechti, “Höhe und Richtung von Tag- und Nachtzug im Herbst über Südwestdeutschland,” Ornitol. Beob. 95, 113–128 (1998).

1997 (1)

E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
[CrossRef]

1996 (2)

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

1995 (2)

F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).

G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).

1993 (2)

S. Åkesson, “Coastal migration and wind drift compensation in nocturnal passerine migrants,” Ornis Scand. 24, 87–94 (1993).
[CrossRef]

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

1990 (1)

Å. Lindström, “The role of predation risk in stopover habitat selection in migrating bramblings, Fringilla montifringilla,” Behav. Ecol. 1, 102–106 (1990).
[CrossRef]

1976 (1)

T. Alerstam, “Nocturnal migration of Thrushes Turdus-Spp in Southern Sweden,” Oikos 27, 457–475 (1976).
[CrossRef]

1972 (2)

C. J. Pennycuick, “Soaring behavior and performance of some East African birds observed from a motor glider,” Ibis 114, 178–218 (1972).
[CrossRef]

B. Bruderer and E. Weitnauer, “Radar observations of the migration and night flights of the swift Apus-Apus,” Rev. Suisse Zool. 79, 1190–1200 (1972).
[PubMed]

1969 (2)

S. A. Gauthreaux, Jr., “A portable ceilometer technique for studying low level nocturnal migration,” Bird Banding 40, 309–320 (1969).
[CrossRef]

J. L. F. Parslow, “The migration of passerine night migrants across the English channel studied by radar,” Ibis 111, 48–79(1969).
[CrossRef]

1966 (1)

M. B. Casement, “Migration across the Mediterranean observed by radar,” Ibis 108, 461–491 (1966).
[CrossRef]

1962 (1)

D. H. W. Adams, “Radar observations of bird migration in Cyprus,” Ibis 104, 133–146 (1962).
[CrossRef]

1961 (1)

1951 (1)

L. Pauling and R. B. Corey, “The structure of feather rachis keratin,” Proc. Natl. Acad. Sci. USA 37, 256–261 (1951).
[CrossRef] [PubMed]

1949 (1)

S. C. V. Raman, “The theory of the Christiansen experiment,” Proc. Indian Acad. Sci. A29, 381–390 (1949).

Adams, D. H. W.

D. H. W. Adams, “Radar observations of bird migration in Cyprus,” Ibis 104, 133–146 (1962).
[CrossRef]

Åkesson, S.

S. Åkesson and A. Hedenström, “How migrants get there: migratory performance and orientation,” BioScience 57, 123–133 (2007).
[CrossRef]

T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Åkesson, “Coastal migration and wind drift compensation in nocturnal passerine migrants,” Ornis Scand. 24, 87–94 (1993).
[CrossRef]

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Alerstam, T.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
[CrossRef]

J. Bäckman and T. Alerstam, “Confronting the winds: Orientation and flight behaviour of roosting swifts, Apus apus,” Proc. R. Soc. London Ser. B 268, 1081–1087 (2001).
[CrossRef]

T. Alerstam, “Nocturnal migration of Thrushes Turdus-Spp in Southern Sweden,” Oikos 27, 457–475 (1976).
[CrossRef]

T. Alerstam and Å. Lindström, “Optimal bird migration: the relative importance of time, energy and safety,” in Bird Migration: Physiology and Ecophysiology, E.Gewinner, ed. (Springer-Verlag, 1990), pp. 331–351.

Altshuler, G. B.

G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).

Anand, P.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Anand, U.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Andersson, S.

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

Andrews, L. S.

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

Armenta, J. K.

J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
[CrossRef] [PubMed]

Bäckman, J.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

J. Bäckman and T. Alerstam, “Confronting the winds: Orientation and flight behaviour of roosting swifts, Apus apus,” Proc. R. Soc. London Ser. B 268, 1081–1087 (2001).
[CrossRef]

Bargalgli, R.

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Bendit, E. G.

Benham, C. D.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Bennett, A. T.

A. T. Bennett and M. Thery, “Avian color vision and coloration: multidisciplinary evolutionary biology,” Am. Nat. 169, S1–S6 (2007).
[CrossRef]

Bennett, A. T. D.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Boulesteix, T.

Briantais, J. M.

A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.

Brink, D. J.

D. J. Brink and N. G. van der Berg, “Structural colours from the feathers of the bird Bostrychia hagedash,” J. Phys. D 37, 813–818 (2004).
[CrossRef]

Bruderer, B.

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

B. Bruderer and F. Liechti, “Höhe und Richtung von Tag- und Nachtzug im Herbst über Südwestdeutschland,” Ornitol. Beob. 95, 113–128 (1998).

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).

B. Bruderer and E. Weitnauer, “Radar observations of the migration and night flights of the swift Apus-Apus,” Rev. Suisse Zool. 79, 1190–1200 (1972).
[PubMed]

B. Bruderer and F. Liechti, “Quantification of bird migration—different means compared,” in Proceedings of the Bird Strike Committee, Europe (1994), Vol. 22, pp. 243–254.

Brydegaard, M.

M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
[CrossRef] [PubMed]

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Carlsten, J. L.

Carsten, J. L.

Casement, M. B.

M. B. Casement, “Migration across the Mediterranean observed by radar,” Ibis 108, 461–491 (1966).
[CrossRef]

Cecchi, G.

Cerovic, Z. G.

A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.

Chu, A. C.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Church, S. C.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Corey, R. B.

L. Pauling and R. B. Corey, “The structure of feather rachis keratin,” Proc. Natl. Acad. Sci. USA 37, 256–261 (1951).
[CrossRef] [PubMed]

Cuthill, I. C.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

de Beule, P. A. A.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Delhey, K.

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

Dingle, H.

H. Dingle, Migration: The Biology of Life on the Move (Oxford U. Press, 1996).

Doucet, S. M.

S. M. Doucet and G. E. Hill, “Do museum specimens accurately represent wild birds? A case study of carotenoid, melanin, and structural colours in long-tailed manakins Chiroxiphia linearis,” J. Avian Biol. 40, 146–156 (2009).
[CrossRef]

Dove, C. J.

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

Dufresne, E. R.

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

Dunn, P. O.

J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
[CrossRef] [PubMed]

Dunsby, C.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Edner, H.

Ehlers, A.

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

Ericson, P. G. P.

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

Eriksen, W.

U. P. Hoppe, G. H. Hansen, and W. Eriksen, “ALOMAR—Ground-based monitoring of stratospheric ozone and related atmospheric parameters,” in 27th International Symposium on Remote Sensing of Environment (1998), pp. 244–247.

Estep, L. K.

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

Fan, J.

X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
[CrossRef]

Ferrara, R.

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Foerschler, M. I.

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

French, P. M. W.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Galletly, N. P.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Gauthreaux, S. A.

S. A. Gauthreaux, Jr., “A portable ceilometer technique for studying low level nocturnal migration,” Bird Banding 40, 309–320 (1969).
[CrossRef]

Gorton, H. L.

E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
[CrossRef]

Griffith, S. C.

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

Guan, Z. G.

M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
[CrossRef] [PubMed]

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Gudmundsson, G. A.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

Ham, A.

D. Osorio and A. Ham, “Spectral reflectance and directional properties of structural coloration in bird plumage,” J. Exp. Biol. 205, 2017–2027 (2002).
[PubMed]

Hansen, G. H.

U. P. Hoppe, G. H. Hansen, and W. Eriksen, “ALOMAR—Ground-based monitoring of stratospheric ozone and related atmospheric parameters,” in 27th International Symposium on Remote Sensing of Environment (1998), pp. 244–247.

Hart, N. S.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Hauber, M. E.

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

Hedenström, A.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

S. Åkesson and A. Hedenström, “How migrants get there: migratory performance and orientation,” BioScience 57, 123–133 (2007).
[CrossRef]

T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
[CrossRef]

Hellgren, O.

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

Henningsson, S. S.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

Hill, G. E.

S. M. Doucet and G. E. Hill, “Do museum specimens accurately represent wild birds? A case study of carotenoid, melanin, and structural colours in long-tailed manakins Chiroxiphia linearis,” J. Avian Biol. 40, 146–156 (2009).
[CrossRef]

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

K. J. McGraw and G. E. Hill, “Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season,” Can. J. Zool. 82, 734–738 (2004).
[CrossRef]

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 1: Mechanisms and Measurements (Harvard U. Press, 2006).

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 2: Function and Evolution (Harvard U. Press, 2006).

Hoffman, D. S.

Hoppe, U. P.

U. P. Hoppe, G. H. Hansen, and W. Eriksen, “ALOMAR—Ground-based monitoring of stratospheric ozone and related atmospheric parameters,” in 27th International Symposium on Remote Sensing of Environment (1998), pp. 244–247.

Hunt, S.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Ilyasovand, K.

G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).

Jacobs, J. F.

J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
[CrossRef]

Jacques, S.

S. Jacques, “Origins of tissue optical properties in the UVA, visible and NIR regions,” in TOPS on Advances in Optical Imaging and Photon Migration II (Optical Society of America, 1996), pp. 364–367.

Jaques, S.

S. Jaques and B. Pogue, “Tutorial on diffuse light transport,” J. Biomed. Opt. 13, 041302 (2008).
[CrossRef]

Johansson, T.

Johnsen, A.

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

Karlsson, H.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

Kempenaers, B.

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

Kerlinger, P.

P. Kerlinger and F. R. Moore, “Atmospheric structure and avian migration,” in Current Ornithology, D.M.Power, ed. (Plenum, 1989), Vol. 6, pp. 109–141.

König, K.

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

Koper, G. J. M.

J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
[CrossRef]

Korsten, P.

J. Reneerkens and P. Korsten, “Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus,” J. Avian Biol. 35, 405–409 (2004).
[CrossRef]

Kulemin, G. P.

G. P. Kulemin, Millimeter Wave Radar Targets and Clutter (Artech House, 2003).

Lardelli, R.

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

Liechti, F.

P. H. Zehtindijev and F. Liechti, “A quantitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe—a coordinated moon-watching study,” Avian Sci. 3, 37–45 (2003).

F. Liechti, “Calibrating the moon-watching method—changes and limits,” Avian Ecol. Beh. 7, 27–41 (2001).

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

B. Bruderer and F. Liechti, “Höhe und Richtung von Tag- und Nachtzug im Herbst über Südwestdeutschland,” Ornitol. Beob. 95, 113–128 (1998).

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).

B. Bruderer and F. Liechti, “Quantification of bird migration—different means compared,” in Proceedings of the Bird Strike Committee, Europe (1994), Vol. 22, pp. 243–254.

Lindström, Å.

Å. Lindström, “The role of predation risk in stopover habitat selection in migrating bramblings, Fringilla montifringilla,” Behav. Ecol. 1, 102–106 (1990).
[CrossRef]

T. Alerstam and Å. Lindström, “Optimal bird migration: the relative importance of time, energy and safety,” in Bird Migration: Physiology and Ecophysiology, E.Gewinner, ed. (Springer-Verlag, 1990), pp. 331–351.

Lundin, P.

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Maserti, B. E.

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

McGraw, K. J.

K. J. McGraw and G. E. Hill, “Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season,” Can. J. Zool. 82, 734–738 (2004).
[CrossRef]

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 2: Function and Evolution (Harvard U. Press, 2006).

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 1: Mechanisms and Measurements (Harvard U. Press, 2006).

Melton, C.

Moore, F. R.

P. Kerlinger and F. R. Moore, “Atmospheric structure and avian migration,” in Current Ornithology, D.M.Power, ed. (Plenum, 1989), Vol. 6, pp. 109–141.

Moya, I.

A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.

Mullen, P.

G. Pohland and P. Mullen, “Preservation agents influence UV-coloration of plumage in museum bird skins,” J. Ornithol. 147, 464–467 (2006).
[CrossRef]

Murphy, M.

E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
[CrossRef]

Naylor, A.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Nehrir, A. R.

Newton, I.

I. Newton, The Migration Ecology of Birds (Academic, 2008).

Nilsson, D. E.

E. Warrant and D. E. Nilsson, eds. Invertebrate Vision(Cambridge U. Press, 2006).

Ornborg, J.

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

Osorio, D.

D. Osorio and M. Vorobyev, “A review of the evolution of animal colour vision and visual communication signals,” Vision Res. 48, 2042–2051 (2008).
[CrossRef] [PubMed]

D. Osorio and A. Ham, “Spectral reflectance and directional properties of structural coloration in bird plumage,” J. Exp. Biol. 205, 2017–2027 (2002).
[PubMed]

Ounis, A.

A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.

Pantani, L.

Paproth, H.

F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).

Parslow, J. L. F.

J. L. F. Parslow, “The migration of passerine night migrants across the English channel studied by radar,” Ibis 111, 48–79(1969).
[CrossRef]

Partridge, J. C.

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Pauling, L.

L. Pauling and R. B. Corey, “The structure of feather rachis keratin,” Proc. Natl. Acad. Sci. USA 37, 256–261 (1951).
[CrossRef] [PubMed]

Pena, A. M.

Pennycuick, C. J.

C. J. Pennycuick, “Soaring behavior and performance of some East African birds observed from a motor glider,” Ibis 114, 178–218 (1972).
[CrossRef]

Peter, D.

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

Peters, A.

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

Pogue, B.

S. Jaques and B. Pogue, “Tutorial on diffuse light transport,” J. Biomed. Opt. 13, 041302 (2008).
[CrossRef]

Pohland, G.

G. Pohland and P. Mullen, “Preservation agents influence UV-coloration of plumage in museum bird skins,” J. Ornithol. 147, 464–467 (2006).
[CrossRef]

Prikhodko, C. V.

G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).

Prum, R. O.

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

Quinn, T.

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

Ragnarson, P.

E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
[CrossRef]

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Raimondi, V.

Raman, S. C. V.

S. C. V. Raman, “The theory of the Christiansen experiment,” Proc. Indian Acad. Sci. A29, 381–390 (1949).

Reneerkens, J.

J. Reneerkens and P. Korsten, “Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus,” J. Avian Biol. 35, 405–409 (2004).
[CrossRef]

Repasky, K. S.

Riemann, I.

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

Rijke, A. M.

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

Rosén, M.

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

Ross, D.

Runemark, A.

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Schanne-Klein, M. C.

Scheppele, R.

Shaw, J. A.

Shawkey, M. D.

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

Sheldon, B. C.

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

Spangler, L. H.

Stamp, G. W.

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Stark, M.

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

Strandberg, R.

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

Strupler, M.

Sundnér, B.

Svanberg, S.

M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
[CrossRef] [PubMed]

P. Weibring, H. Edner, and S. Svanberg, “Versatile mobile lidar system for environmental monitoring,” Appl. Opt. 42, 3583–3594 (2003).
[CrossRef] [PubMed]

P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments: erratum,” Appl. Opt. 41, 434–436 (2002).
[CrossRef]

P. Weibring, T. Johansson, H. Edner, S. Svanberg, B. Sundnér, V. Raimondi, G. Cecchi, and L. Pantani, “Fluorescence lidar imaging of historical monuments,” Appl. Opt. 40, 6111–6120(2001).
[CrossRef]

E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
[CrossRef]

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

S. Svanberg, “Fluorescence spectroscopy and imaging of LIDAR targets,” in “Laser Remote Sensing, T.Fujii and T.Fukuchi, eds. (CRC Press, 2005).
[CrossRef]

S. Svanberg, “LIDAR,” in Springer Handbook of Lasers and OpticsF.Träger, ed. (Springer, 2007), pp. 1031–1052.

S. Svanberg, “Laser fluorescence spectroscopy in environmental monitoring,” in Optoelectronics for Environmental Science, S.Martellucci and A.N.Chester, eds. (Plenum, 1990).

Svensson, E.

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Thery, M.

A. T. Bennett and M. Thery, “Avian color vision and coloration: multidisciplinary evolutionary biology,” Am. Nat. 169, S1–S6 (2007).
[CrossRef]

Tuchin, V.

V. Tuchin, “Tissue optics,” in Light Scattering and Instruments for Medical Diagnosis, 2nd ed. (SPIE Press, 2007).

Ursem, W. N. J.

J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
[CrossRef]

van der Berg, N. G.

D. J. Brink and N. G. van der Berg, “Structural colours from the feathers of the bird Bostrychia hagedash,” J. Phys. D 37, 813–818 (2004).
[CrossRef]

van Noordwijk, H.

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

Vorobyev, M.

D. Osorio and M. Vorobyev, “A review of the evolution of animal colour vision and visual communication signals,” Vision Res. 48, 2042–2051 (2008).
[CrossRef] [PubMed]

Wallinder, E.

E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
[CrossRef]

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Wan, X.

X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
[CrossRef]

Wang, X.

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

Warrant, E.

E. Warrant and D. E. Nilsson, eds. Invertebrate Vision(Cambridge U. Press, 2006).

Waters, K.

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

Weibring, P.

Weitnauer, E.

B. Bruderer and E. Weitnauer, “Radar observations of the migration and night flights of the swift Apus-Apus,” Rev. Suisse Zool. 79, 1190–1200 (1972).
[PubMed]

Wellenreuther, M.

M. Brydegaard, Z. G. Guan, M. Wellenreuther, and S. Svanberg, “Insect monitoring with fluorescence lidar techniques: feasibility study,” Appl. Opt. 48, 5668–5677 (2009).
[CrossRef] [PubMed]

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

Whittingham, L. A.

J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
[CrossRef] [PubMed]

Willoughby, E. J.

E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
[CrossRef]

Wu, H.

X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
[CrossRef]

Zehnder, S.

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

Zehtindijev, P. H.

P. H. Zehtindijev and F. Liechti, “A quantitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe—a coordinated moon-watching study,” Avian Sci. 3, 37–45 (2003).

Adv. Study Behav. (1)

I. C. Cuthill, J. C. Partridge, A. T. D. Bennett, S. C. Church, N. S. Hart, and S. Hunt, “Ultraviolet vision in birds,” Adv. Study Behav. 29, 159–214 (2000).
[CrossRef]

Am. Nat. (1)

A. T. Bennett and M. Thery, “Avian color vision and coloration: multidisciplinary evolutionary biology,” Am. Nat. 169, S1–S6 (2007).
[CrossRef]

Appl. Opt. (6)

Appl. Spectrosc. (1)

Avian Ecol. Beh. (1)

F. Liechti, “Calibrating the moon-watching method—changes and limits,” Avian Ecol. Beh. 7, 27–41 (2001).

Avian Sci. (1)

P. H. Zehtindijev and F. Liechti, “A quantitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe—a coordinated moon-watching study,” Avian Sci. 3, 37–45 (2003).

Behav. Ecol. (2)

Å. Lindström, “The role of predation risk in stopover habitat selection in migrating bramblings, Fringilla montifringilla,” Behav. Ecol. 1, 102–106 (1990).
[CrossRef]

K. Delhey, A. Peters, A. Johnsen, and B. Kempenaers, “Seasonal changes in blue tit crown color: do they signal individual quality?,” Behav. Ecol. 17, 790–798 (2006).
[CrossRef]

Biol. J. Linn. Soc. (1)

J. Ornborg, S. Andersson, S. C. Griffith, and B. C. Sheldon, “Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus,” Biol. J. Linn. Soc. 76, 237–245(2002).
[CrossRef]

BioScience (1)

S. Åkesson and A. Hedenström, “How migrants get there: migratory performance and orientation,” BioScience 57, 123–133 (2007).
[CrossRef]

Bird Banding (1)

S. A. Gauthreaux, Jr., “A portable ceilometer technique for studying low level nocturnal migration,” Bird Banding 40, 309–320 (1969).
[CrossRef]

Can. J. Zool. (1)

K. J. McGraw and G. E. Hill, “Plumage color as a dynamic trait: carotenoid pigmentation of male house finches (Carpodacus mexicanus) fades during the breeding season,” Can. J. Zool. 82, 734–738 (2004).
[CrossRef]

Funct. Ecol. (1)

A. Peters, K. Delhey, S. Andersson, H. van Noordwijk, and M. I. Foerschler, “Condition-dependence of multiple carotenoid-based plumage traits: an experimental study,” Funct. Ecol. 22, 831–839 (2008).
[CrossRef]

Ibis (4)

M. B. Casement, “Migration across the Mediterranean observed by radar,” Ibis 108, 461–491 (1966).
[CrossRef]

J. L. F. Parslow, “The migration of passerine night migrants across the English channel studied by radar,” Ibis 111, 48–79(1969).
[CrossRef]

D. H. W. Adams, “Radar observations of bird migration in Cyprus,” Ibis 104, 133–146 (1962).
[CrossRef]

C. J. Pennycuick, “Soaring behavior and performance of some East African birds observed from a motor glider,” Ibis 114, 178–218 (1972).
[CrossRef]

J. Avian Biol. (4)

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Nocturnal autumn bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

S. Zehnder, S. Åkesson, F. Liechti, and B. Bruderer, “Seasonal and diurnal patterns of nocturnal bird migration at Falsterbo, South Sweden,” J. Avian Biol. 32, 239–248 (2001).
[CrossRef]

J. Reneerkens and P. Korsten, “Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus,” J. Avian Biol. 35, 405–409 (2004).
[CrossRef]

S. M. Doucet and G. E. Hill, “Do museum specimens accurately represent wild birds? A case study of carotenoid, melanin, and structural colours in long-tailed manakins Chiroxiphia linearis,” J. Avian Biol. 40, 146–156 (2009).
[CrossRef]

J. Biomed. Opt. (1)

S. Jaques and B. Pogue, “Tutorial on diffuse light transport,” J. Biomed. Opt. 13, 041302 (2008).
[CrossRef]

J. Exp. Biol. (2)

D. Osorio and A. Ham, “Spectral reflectance and directional properties of structural coloration in bird plumage,” J. Exp. Biol. 205, 2017–2027 (2002).
[PubMed]

J. K. Armenta, P. O. Dunn, and L. A. Whittingham, “Quantifying avian sexual dichromatism: a comparison of methods,” J. Exp. Biol. 211, 2423–2430 (2008).
[CrossRef] [PubMed]

J. Field Ornithol. (1)

F. Liechti, B. Bruderer, and H. Paproth, “Quantification of nocturnal bird migration by moonwatching: comparison with radar and infrared observations,” J. Field Ornithol. 66, 457–468(1995).

J. Ornithol. (2)

G. Pohland and P. Mullen, “Preservation agents influence UV-coloration of plumage in museum bird skins,” J. Ornithol. 147, 464–467 (2006).
[CrossRef]

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “The Alps, an obstacle for nocturnal broad front migration—a survey based on moon-watching,” J. Ornithol. 137, 337–356 (1996).
[CrossRef]

J. Phys. D (1)

D. J. Brink and N. G. van der Berg, “Structural colours from the feathers of the bird Bostrychia hagedash,” J. Phys. D 37, 813–818 (2004).
[CrossRef]

J. R. Soc. Interface (2)

R. O. Prum, E. R. Dufresne, T. Quinn, and K. Waters, “Development of colour-producing beta-keratin nanostructures in avian feather barbs,” J. R. Soc. Interface 6, S253–S265 (2009).
[PubMed]

M. D. Shawkey, M. E. Hauber, L. K. Estep, and G. E. Hill, “Evolutionary transitions and mechanisms,” J. R. Soc. Interface 3, 777–786 (2006).
[CrossRef] [PubMed]

J. Therm. Biol. (1)

C. J. Dove, A. M. Rijke, X. Wang, and L. S. Andrews, “Infrared analysis of contour feathers—the conservation of body heat radiation in birds,” J. Therm. Biol. 32, 42–46(2007).
[CrossRef]

Microsc. Res. Tech. (1)

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70, 154–161 (2007).
[CrossRef]

Oikos (2)

T. Alerstam, “Nocturnal migration of Thrushes Turdus-Spp in Southern Sweden,” Oikos 27, 457–475 (1976).
[CrossRef]

T. Alerstam, A. Hedenström, and S. Åkesson, “Long-distance migration: evolution and determinants,” Oikos 103, 247–260(2003).
[CrossRef]

Opt. Express (1)

Ornis Scand. (1)

S. Åkesson, “Coastal migration and wind drift compensation in nocturnal passerine migrants,” Ornis Scand. 24, 87–94 (1993).
[CrossRef]

Ornitol. Beob. (2)

F. Liechti, D. Peter, R. Lardelli, and B. Bruderer, “Herbstlicher Vogelzug im Alpenraum nach Mond-Beobachtungen—Topographie un Wind beeinflussen den Zugverlauf,” Ornitol. Beob. 93, 131–152 (1996).

B. Bruderer and F. Liechti, “Höhe und Richtung von Tag- und Nachtzug im Herbst über Südwestdeutschland,” Ornitol. Beob. 95, 113–128 (1998).

Phys. Scr. (1)

E. Wallinder, H. Edner, P. Ragnarson, and S. Svanberg, “Vertically sounding ozone LIDAR system based on a KrF excimer laser,” Phys. Scr. 55, 714–718 (1997).
[CrossRef]

PLoS Biol. (1)

T. Alerstam, M. Rosén, J. Bäckman, P. G. P. Ericson, and O. Hellgren, “Flight speeds among bird species: allometric and phylogenetic effects,” PLoS Biol. 5, e197 (2007).
[CrossRef] [PubMed]

Polym. Test. (1)

X. Wan, J. Fan, and H. Wu, “Measurement of thermal radiative properties of penguin down and other fibrous materials using FTIR,” Polym. Test. 28, 673–679 (2009).
[CrossRef]

Proc. Indian Acad. Sci. (1)

S. C. V. Raman, “The theory of the Christiansen experiment,” Proc. Indian Acad. Sci. A29, 381–390 (1949).

Proc. Natl. Acad. Sci. USA (1)

L. Pauling and R. B. Corey, “The structure of feather rachis keratin,” Proc. Natl. Acad. Sci. USA 37, 256–261 (1951).
[CrossRef] [PubMed]

Proc. R. Soc. London Ser. B (2)

T. Alerstam, J. Bäckman, G. A. Gudmundsson, A. Hedenström, S. S. Henningsson, H. Karlsson, M. Rosén, and R. Strandberg, “A polar system of intercontinental bird migration,” Proc. R. Soc. London Ser. B 274, 2523–2530 (2007).
[CrossRef]

J. Bäckman and T. Alerstam, “Confronting the winds: Orientation and flight behaviour of roosting swifts, Apus apus,” Proc. R. Soc. London Ser. B 268, 1081–1087 (2001).
[CrossRef]

Prog. Org. Coatings (1)

J. F. Jacobs, G. J. M. Koper, and W. N. J. Ursem, “UV protective coatings: a botanical approach,” Prog. Org. Coatings 58, 166–171 (2007).
[CrossRef]

Rev. Sci. Instrum. (1)

P. A. A. de Beule, C. Dunsby, N. P. Galletly, G. W. Stamp, A. C. Chu, U. Anand, P. Anand, C. D. Benham, A. Naylor, and P. M. W. French, “A hyperspectral fluorescence lifetime probe for skin cancer diagnosis,” Rev. Sci. Instrum. 78, 123101(2007).
[CrossRef]

Rev. Suisse Zool. (1)

B. Bruderer and E. Weitnauer, “Radar observations of the migration and night flights of the swift Apus-Apus,” Rev. Suisse Zool. 79, 1190–1200 (1972).
[PubMed]

Sci. Total Environ. (1)

H. Edner, P. Ragnarson, S. Svanberg, E. Wallinder, R. Ferrara, B. E. Maserti, and R. Bargalgli, “Atmospheric mercury mapping in a cinnabar mining area,” Sci. Total Environ. 133, 1–15(1993).
[CrossRef]

Tech. Phys. Lett. (1)

G. B. Altshuler, K. Ilyasovand, C. V. Prikhodko, “Optical properties of human hair,” Tech. Phys. Lett. 21, 216–218 (1995).

Vision Res. (1)

D. Osorio and M. Vorobyev, “A review of the evolution of animal colour vision and visual communication signals,” Vision Res. 48, 2042–2051 (2008).
[CrossRef] [PubMed]

Wilson Bull. (1)

E. J. Willoughby, M. Murphy, and H. L. Gorton, “Molt, plumage abrasion, and color change in Lawrence’s Goldfinch,” Wilson Bull. 114, 380–392 (2002).
[CrossRef]

Other (19)

G. P. Kulemin, Millimeter Wave Radar Targets and Clutter (Artech House, 2003).

U. P. Hoppe, G. H. Hansen, and W. Eriksen, “ALOMAR—Ground-based monitoring of stratospheric ozone and related atmospheric parameters,” in 27th International Symposium on Remote Sensing of Environment (1998), pp. 244–247.

Kipp & Zonen, Delft, the Netherlands (2010), www.kippzonen.com.

Alternatively Optech Inc., Kiln, Miss., USA (2010), www.optech.com

A. Ounis, Z. G. Cerovic, J. M. Briantais, and I. Moya, “DE-FLIDAR: a new remote sensing instrument for estimation of epidermal UV absorption in leaves and canopies,” in Proceedings of European Association of Remote Sensing Laboratories (EARSeL)-SIG-Workshop LIDAR (EARSeL, 2000), Vol. 1, pp. 196–204.

S. Jacques, “Origins of tissue optical properties in the UVA, visible and NIR regions,” in TOPS on Advances in Optical Imaging and Photon Migration II (Optical Society of America, 1996), pp. 364–367.

E. Warrant and D. E. Nilsson, eds. Invertebrate Vision(Cambridge U. Press, 2006).

S. Svanberg, “Fluorescence spectroscopy and imaging of LIDAR targets,” in “Laser Remote Sensing, T.Fujii and T.Fukuchi, eds. (CRC Press, 2005).
[CrossRef]

S. Svanberg, “LIDAR,” in Springer Handbook of Lasers and OpticsF.Träger, ed. (Springer, 2007), pp. 1031–1052.

S. Svanberg, “Laser fluorescence spectroscopy in environmental monitoring,” in Optoelectronics for Environmental Science, S.Martellucci and A.N.Chester, eds. (Plenum, 1990).

V. Tuchin, “Tissue optics,” in Light Scattering and Instruments for Medical Diagnosis, 2nd ed. (SPIE Press, 2007).

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 1: Mechanisms and Measurements (Harvard U. Press, 2006).

G. E. Hill and K. J. McGraw, eds., Bird Coloration Volume 2: Function and Evolution (Harvard U. Press, 2006).

Z. G. Guan, M. Brydegaard, P. Lundin, M. Wellenreuther, A. Runemark, E. Svensson, S. Åkesson, and S. Svanberg, “Fluorescence lidar for studies of movements of insects and birds,” in Proceedings of the 25th International Laser Radar Conference ILRC25 (2010).

H. Dingle, Migration: The Biology of Life on the Move (Oxford U. Press, 1996).

I. Newton, The Migration Ecology of Birds (Academic, 2008).

T. Alerstam and Å. Lindström, “Optimal bird migration: the relative importance of time, energy and safety,” in Bird Migration: Physiology and Ecophysiology, E.Gewinner, ed. (Springer-Verlag, 1990), pp. 331–351.

B. Bruderer and F. Liechti, “Quantification of bird migration—different means compared,” in Proceedings of the Bird Strike Committee, Europe (1994), Vol. 22, pp. 243–254.

P. Kerlinger and F. R. Moore, “Atmospheric structure and avian migration,” in Current Ornithology, D.M.Power, ed. (Plenum, 1989), Vol. 6, pp. 109–141.

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Figures (12)

Fig. 1
Fig. 1

(a) Left, typical feather from pigeon; the melanin concentration is higher in the top part. Barbs are connected to the central trunk. Right, transmittance image at 590 nm ; the barbules are attached to the two barbs and are neatly arranged, covering each other. A single barbule dangling from its barbicels transmits roughly half of the light. (b) When a UV laser pulse impinges on the plumage, a polarized specular angle- dependent elastic echo returns. After internal scattering events, polarization is lost and the echo is emitted omnidirectionally. Part of the excitation light will be quenched by the melanin granules with low fluorescent yield; remaining UV light is absorbed in the keratin matrix and produces broad emission. Emitted light will, in turn, be quenched by present chromophores on its way to the surface. The shorter the wavelength, the shorter the mean absorption depth, d, the less excitation quenching, and the more fluorescence resembles reflectance. See Eq. (1). Transmission electron image (TEM) (with permission from M. D. Shawkey [76]). The darker embedded spots arise from melanin granules.

Fig. 2
Fig. 2

(a) Ground truth measurements were performed with a compact combined reflectance and fluorescence sensor. Various excitation wavelengths for fluorescence, as well as broadband light for elastic measurement, is provided by a selection of LEDs. (b) The Lund mobile lidar system was emitting at 266 and 355 nm in this study. A two degrees of freedom scanning mirror allows the beam direction to be controlled. The returning light is collected by a 40 cm telescope. The return can be discretized according to polarization and wavelength with a number of PMTs. (c) In-flight European starlings were recorded at an 85 m distance during another experiment on damselfly dispersal [33].

Fig. 3
Fig. 3

Reflectance spectra, curves colored according to appearance to humans. From top: light brown, reed warbler; white, white wagtail head; light gray, white wagtail chest; red, European robin; yellow, blue tit (note the sharp feature of the carotenoid lutein); orange, whinchat; brown, reed warbler; black, rook; and structural blue, blue tit.

Fig. 4
Fig. 4

Fluorescence spectra excited at 355 nm , curves colored according to appearance to humans. From top: light brown, reed warbler; white, white wagtail head; light gray, white wagtail chest; yellow, blue tit; orange, whinchat; red, European robin; brown, great reed warbler; structural blue, blue tit; and black, rook.

Fig. 5
Fig. 5

Fluorescence spectra excited at 255 nm , selected examples; curves colored according to appearance to humans. From top: light brown, reed warbler; white, white wagtail head; red, European robin; yellow, blue tit; light gray, white wagtail chest; brown, reed warbler; gray, white wagtail; structural blue, blue tit; black iridescent, European starling; and black, rook.

Fig. 6
Fig. 6

Correlations in the EEM for a yellow-chested blue tit, with fluorescence exaggerated for demonstration purposes. The elastic diagonal (yellow curve, R) shows the reflectance of solid keratin with a carotenoid absorption dip. The fluorescence emission spectrum at 266 nm excitation (purple curve, E) shows the imprint of the absorbing carotenoid. Traditional methods for reflectance in ornithology sum all excitation elements (green curve, F) and assume fluorescence to be negligible. In ornithological LIF lidar, we can expect a fluorescence element F ( λ ex , λ em ) to be negatively correlated with the reflectance E ( λ ex ) ; this explains why the structural blue plumage with high UV reflectance appears dark in fluorescence in Figs. 4, 5. This is known as excitation quenching. In contrast, F ( λ ex , λ em ) can be expected to be positively correlated with the reflectance R ( λ em ) ) due to emission quenching; this explains why red reflecting plumage appear even redder in fluorescence. Data extracted and remodeled from [37], Chap. 5, pp. 40, 49.

Fig. 7
Fig. 7

Scatterplot of first and second principal components from Fig. 5.

Fig. 8
Fig. 8

Single-shot echo from starling in flight. Elastic echoes arise from quartz window and metal fence. The relative areas under the European starling echo can be used for classification purpose.

Fig. 9
Fig. 9

False color RGB representation or T-scan of complete lidar data acquired during 10 s . Blue, elastic; green, blue fluorescence; red, yellow fluorescence. Regions of interest are marked.

Fig. 10
Fig. 10

Intensity of the three cross sections marked in Fig. 9 plotted versus time. Notice the interplay, which allows estimating bird–beam overlap and also simultaneous determination of active fluorescence and passive reflectance.

Fig. 11
Fig. 11

Scatterplot showing selected species with 355 nm excitation; total normalized fluorescence on the Y axis and redshift on the X axis. Dots are colored according to the human visual perception. From upper left: brown, reed warbler; red, European robin; black, European starling; black, rook; and blue, blue tit.

Fig. 12
Fig. 12

Scatterplot showing selected species with 266 nm excitation; total fluorescence on the Y axis and redshift on the X axis. Dots are colored according to the human visual per ception. From upper left: gray, European blackcap; beige, reed warbler; black, European starling; and black, rook.

Tables (2)

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Table 1 Latin Names, Popular Names, Apparent Color and Sex of All Samples Presented in Figures Throughout This Paper a

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Table 2 Optical Component List for the Three-PMT System

Equations (1)

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R sample ( λ ) R white ( λ ) = ( 1 exq ( λ ex ) ) F sample ( λ em ) F white ( λ em ) ,

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