Migrating birds avoid flying through fog and low clouds

  • M. PanuccioEmail author
  • G. Dell’Omo
  • G. Bogliani
  • C. Catoni
  • N. Sapir
Original Paper


Different weather conditions are known to affect bird migration, yet the influence of fog and low clouds on migrating birds has been rarely examined so far, and hence, their impact on bird movement is not well understood. Fog avoidance could be a consequence of visual limitations within the fog or may be the outcome of deteriorated soaring conditions due to the obstruction of the sun. We carried out a radar study at the Strait of Messina, which is a bottleneck for migrating birds traversing the Central Mediterranean Sea, to determine if the intensity of diurnal soaring bird migration was influenced by fog and other weather variables. We recorded bird movements using an X-band radar, which can detect birds flying within the fog, and recorded weather conditions using local meteorological observations. We examined if bird passage rate (number of tracks/hour) at the radar site was influenced by fog, wind speed and direction, air temperature and the time of day. Our findings suggest that fog was the most important factor affecting bird migration intensity as recorded by the radar, indicating that birds actively avoided flying into fog. In addition, wind direction affected bird migration intensity, with lower numbers recorded with southerly tailwinds and higher numbers recorded with westerly crosswinds. Our findings highlight a consequence of widespread meteorological conditions, and of fog in particular, on migrating birds, with implications for bird migration navigation, path length and flight energetics.


Avian long-distance migration Bird flight Ecological barrier Fog Radar Soaring raptors 



This work was carried out in the framework of a study commissioned by Terna Rete Italia Spa to Ornis Italica. We thank Jack Ashton-Booth for reviewing the English text. We also thank Viviana Stanzione, Mauro Santini, Giacomo Biasi and Martina Scacco for their help during the fieldwork. We acknowledge the support provided by COST—European Cooperation in Science and Technology through the Action ES1305 “European Network for the Radar Surveillance of Animal Movement” (ENRAM). In particular, the manuscript writing was made during the short-term scientific mission of M. Panuccio: ECOST-STSM-ES1305-141116-081348.

Funding information

M.P. was partially financed through a grant from Crowdfunding Platform “Universitiamo” of the University of Pavia for the project “Wings Over the Straits”.

Supplementary material

484_2018_1656_MOESM1_ESM.doc (27 kb)
Table S1 (DOC 27 kb)
484_2018_1656_MOESM2_ESM.docx (13 kb)
Table S2 (DOCX 12 kb)
484_2018_1656_MOESM3_ESM.docx (11 kb)
Table S3 (DOCX 11 kb)


  1. Agostini N, Cardelli C, Gustin M (2007) Factors shaping pathways of European honey buzzards (Pernis apivorus) during spring migration in the Central Mediterranean basin. J Raptor Res 41:57–61CrossRefGoogle Scholar
  2. Agostini N, Gustin M, von Hardenberg J, Panuccio M (2016) Wind patterns affect migration flyways and flock size of a soaring bird over sea. Avian Biol Res 9:159–166CrossRefGoogle Scholar
  3. Akaike H (1973) Information theory as an extension of the maximum likelihood principle. In: Petrov BN, Csaki F (eds) Second International Symposium on Information. Akademiai Kiado, Budapest, pp 267–281Google Scholar
  4. Alerstam T (1990) Bird migration. Cambridge University Press, CambridgeGoogle Scholar
  5. Alerstam T, Ulfstrand S (1974) A radar study of the autumn migration of wood pigeons Columba palumbus, in southern Scandinavia. Ibis 116:522–542CrossRefGoogle Scholar
  6. Becciu P, Panuccio M, Catoni C, Dell’Omo G, Sapir N (2018) Contrasting aspects of tailwinds and asymmetrical response to crosswinds in soaring migrants. Behav Ecol Sociobiol 72(2):8CrossRefGoogle Scholar
  7. Bechtold P, Köhler M, Jung T, Doblas-Reyes F, Leutbecher M, Rodwell MJ, Vitart F, Balsamo G (2008) Advances in simulating atmospheric variability with the ECMWF model: from synoptic to decadal time-scales. Q J R Meteorol Soc 134:1337–1351CrossRefGoogle Scholar
  8. Bildstein K (2006) Migrating raptors of the world: their ecology and conservation. Cornell University Press, IthacaGoogle Scholar
  9. Bruderer B (1997a) The study of migration by radar. Part 1: the technical basis. Naturwissenschaften 84:1–8CrossRefGoogle Scholar
  10. Bruderer B (1997b) The study of migration by radar. Part 2: major achievements. Naturwissenschaften 84:45–54CrossRefGoogle Scholar
  11. Bruderer B, Boldt A (2001) Flight characteristics of birds: I. Radar measurements of speeds. Ibis 143:178–204CrossRefGoogle Scholar
  12. Buler JJ, Dawson DK (2014) Radar analysis of fall bird migration stopover sites in the northeastern U.S. Condor 116:357–370CrossRefGoogle Scholar
  13. Chiaradia A, McBride J, Murray T, Dann P (2007) Effect of fog on the arrival time of little penguins Eudyptula minor: a clue for visual orientation? J Ornithol 148:229–233. CrossRefGoogle Scholar
  14. Cramp S, Simmons KEL (1980) The birds of the Western Palearctic. Oxford University Press, OxfordGoogle Scholar
  15. Dobson AJ (1990) An introduction to generalized linear models. Chapman and Hall, LondonCrossRefGoogle Scholar
  16. Drewitt AL, Langston RHW (2006) Assessing the impacts of wind farms on birds. Ibis 148:29–42CrossRefGoogle Scholar
  17. Elkins N (2004) Weather and bird behaviour, 3rd edn. T.& A.D. Poyser, LondonGoogle Scholar
  18. Erni B, Liechti F, Underhill G, Bruderer B (2002) Wind and rain govern the intensity of nocturnal bird migration in Central Europe - a log-linear regression analysis. Ardea 90:155–166Google Scholar
  19. Francis CM, Taylor PD, Brzustowski J, Zimmerling JR (2014) Use of marine radar to evaluate collision risk of migrants with wind turbines. In: Proceedings of the 26th International Ornithological Congress 2014, Tokyo, p 24Google Scholar
  20. Hall LS, Fish AM, Morrison ML (1992) The influence of weather on hawk movements in coastal northern California. Wilson Bull 104:447–461Google Scholar
  21. Hedenström A (1993) Migration by soaring or flapping flight in birds: the relative importance of energy cost and speed. Philos Trans Royal Soc B 342:353–361Google Scholar
  22. Heiberger RM (2015) HH: statistical analysis and data display. R package 3:1–23Google Scholar
  23. Horvitz N, Sapir N, Liechti F, Avissar R, Mahrer I, Nathan R (2014) The gliding speed of migrating birds: slow and safe or fast and risky? Ecol Lett 17:670–679Google Scholar
  24. Hüppop O, Dierchke J, Exo KM, Fredrich E, Hill R (2006) Bird migration studies and potential collision risk with offshore wind turbines. Ibis 148:90–109CrossRefGoogle Scholar
  25. Kemp UM, Shamoun-Baranes J, van Gasteren H, Bouten W, van Loon EE (2010) Can wind help explain seasonal differences in avian migration speed? J Avian Biol 41:672–677CrossRefGoogle Scholar
  26. Kerlinger P (1989) Flight strategies of migrating hawks. Chicago University Press, ChicagoGoogle Scholar
  27. Kirsch EM, Wellik MJ, Suarez M, Diehl RH, Lutes J, Woyczik W, Krapfl J, Sojda R (2015) Observation of sandhill cranes’ (Grus canadensis) flight behavior in heavy fog. Wilson J Ornithol 127:281–288CrossRefGoogle Scholar
  28. Klaassen RHG, Hake M, Strandberg R, Alerstam T (2011) Geographical and temporal flexibility in the response to crosswinds by migrating raptors. Proc R Soc B 278:1339–1346CrossRefGoogle Scholar
  29. Lack D (1960) The influence of weather on passerine migration. A review. Auk 77:171–209CrossRefGoogle Scholar
  30. Lambertucci S, Shepard ELC, Wilson RP (2015) Human-wildlife conflicts in a crowded airspace. Science 348:502–504CrossRefGoogle Scholar
  31. Liechti F, Bruderer B (1998) The relevance of wind for optimal migration theory. J Avian Biol 29:561–568CrossRefGoogle Scholar
  32. Mandel JT, Bildstein KL, Bohrer G, Winkler DW (2008) Movement ecology of migration in turkey vultures. PNAS 105:19102–19107CrossRefGoogle Scholar
  33. Mateos-Rodriguez M, Liechti F (2011) How do diurnal long-distance migrants select flight altitude in relation to wind? Behav Ecol 23:403–409CrossRefGoogle Scholar
  34. McCullagh P, Nelder JA (1989) Generalized linear models. Chapman and Hall, LondonCrossRefGoogle Scholar
  35. McLaren J, Shamoun-Baranes J, Bouten W (2012) Wind selectivity and partial compensation for wind drift among nocturnally migrating passerines. Behav Ecol 23:1089–1101. CrossRefGoogle Scholar
  36. Mellone U, Klaassen RH, García-Ripollés C, Limiñana R, López-López P, Pavón D, Strandberg R, Urios V, Vardakis M, Alerstam T (2012) Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies. PLoS One 7:e39833CrossRefGoogle Scholar
  37. Molteni F, Buizza R, Palmer TN, Petroliagis T (1996) The ECMWF ensemble prediction system: methodology and validation. Q J R Meteorol Soc 122:73–119CrossRefGoogle Scholar
  38. Mote WR (1969) Turkey vultures land on vessel in fog. Auk 86:766–767CrossRefGoogle Scholar
  39. Murton RK, Ridpath MG (1962) The autumn movements of the woodpigeon. Bird Study 9:7–41CrossRefGoogle Scholar
  40. Newton I (2007) Weather-related mass-mortality events in migrants. Ibis 149:453–467CrossRefGoogle Scholar
  41. Newton I (2008) Migration ecology of birds. Academic Press, LondonGoogle Scholar
  42. Panuccio M (2011) Wind effects on visible raptor migration in spring at the Strait of Messina, southern Italy. J Raptor Res 45:88–92CrossRefGoogle Scholar
  43. Panuccio M, Stanzione V, Catoni C, Santini M, Dell'Omo G (2016) Radar tracking reveals influence of crosswinds and topography on migratory behavior of European honey buzzards. J Ethol 34:73–77. CrossRefGoogle Scholar
  44. Panuccio M, Duchi A, Lucia G, Agostini N (2017) Species-specific behaviour of raptors migrating across the Turkish straits in relation to weather and geography. Ardeola 64:305–324CrossRefGoogle Scholar
  45. Pastorino A, Ramirez RJ, Agostini N, Dell’Omo G, Panuccio M (2017) Fog and rain lead migrating White storks Ciconia ciconia to perform reverse migration and to land. Avocetta 41:5–12.
  46. Pewsey A, Neuhauser M, Ruxton GD (2013) Circular statistics in R. Oxford University Press, OxfordGoogle Scholar
  47. Pyle P, Nur N, Henderson RP, DeSante DF (1993) The effects of weather and lunar cycle on nocturnal migration of landbirds ad southeast Farallon Island, California. Condor 95:343–361CrossRefGoogle Scholar
  48. Richardson WJ (1990) Timing of bird migration in relation to weather: updated review. In: Gwinner E (ed) Bird migration. Springer-Verlag, Berlin, pp 78–101CrossRefGoogle Scholar
  49. Schmaljohann H, Liechti F, Bächler E, Steuri T, Bruderer B (2008) Quantification of bird migration by radar – a detection probability problem. Ibis 150:342–355CrossRefGoogle Scholar
  50. Shamoun-Baranes J, Baharad A, Alpert P, Berthold P, Yom-Tov Y, Dvir Y, Leshem Y (2003) The effect of wind, season and latitude on the migration speed of white storks Ciconia ciconia, along the eastern migration route. J Avian Biol 34:97–104CrossRefGoogle Scholar
  51. Taylor PD, Brzustowski JM, Matkovich C, Peckford ML, Wilson D (2010) radR: an open-source platform for acquiring and analysing data on biological targets observed by surveillance radar. BMC Ecol 10:22CrossRefGoogle Scholar
  52. Zalles J, Bildstein K (2000) Raptor watch: a global directory of raptor migration sites. BirdLife Conservation Series, No. 9, OxfordGoogle Scholar

Copyright information

© ISB 2019

Authors and Affiliations

  1. 1.MEDRAPTORS (Mediterranean Raptor Migration Network)RomeItaly
  2. 2.Ornis ItalicaRomeItaly
  3. 3.DSTA—Department of Earth and Environmental SciencesUniversity of PaviaPaviaItaly
  4. 4.Animal Flight Laboratory, Department of Evolutionary and Environmental BiologyUniversity of HaifaHaifaIsrael

Personalised recommendations