Movements and Migration

Northerly populations of the Eurasian Hoopoe are migratory, with western Palearctic breeders largely wintering in Africa, and eastern Palearctic breeders largely wintering in southern Asia. Southbound migration begins shortly after breeding is completed in late July and August with migrants reaching their wintering grounds mostly during October. Northbound migration generally begins in late February and March, with most birds reaching their breeding grounds from late March into early May. African and south Asian populations of Eurasian Hoopoe appear to be largely nonmigratory, with many African birds engaging in short distance movements to less xeric habitats during the dry season, though some populations of Upupa epops senegalensis and Upupa epops waibeli appear to be short-distance partial migrants. Fidelity of breeders to their home territories is moderately high (at least in the Western Palearctic), but fidelity to specific nonbreeding sites among migrants seems to be low, while fidelity to migratory stopover sites is completely unknown.

The Eurasian Hoopoe is predominantly a nocturnal migrant that typically migrates alone or in small groups. It is capable of prolonged flights (at least up to 28 h) and flying at high altitudes (maximum known, 6,400 m). Southbound migration is more leisurely than northbound migration, as is common among Western Palearctic migrants.

Natal Philopatry and Dispersal

More information needed.

Adult Fidelity to Breeding Site and Dispersal

The following data are from the main breeding area in Switzerland, which is somewhat isolated from other breeding populations (85 Bötsch, Y., R. Arlettaz, and M. Schaub (2012). Breeding dispersal of Eurasian Hoopoes (Upupa epops) within and between years in relation to reproductive success, sex, and age. Auk 129(2):283−295. Close ): from 40–50% of females that were 2-years-old or older (ASY) returned to the same home range in the following year or for second broods within the same year, while about 40% of one-year-old (SY) females returned to the same home range in the following year, and 60% used the same home range for second broods. These findings were independent of breeding success. About 60% of ASY males and 50% of SY males used the same home range in consecutive years, again independent of breeding success. However, the likelihood of a male reusing its initial home range for a second brood within the same year varied with breeding success. About 80% of ASY males remained in their original home territory if their first nesting attempt failed or led to only one fledgling, but 90–95% remained if they raised 5–10 fledglings. A similar pattern was seen in SY males, among which 65% remained if their first effort resulted in 0–2 fledglings, but 75–80% reused their home territory if they raised 8–10 fledglings on their first attempt.

Model-averaged dispersal distances between first and second broods showed similar pattern as dispersal distance between years, with males typically dispersing over shorter distances than females. Among birds raising the median number of fledglings, the median dispersal of males was about 0.35 km while the median dispersal of females was about 0.69 km. Distance tended to decline with increased breeding success, with males dispersing approximately 0.59 km when no young were fledged and 0.25 km when 10 young were fledged, and females dispersing about 0.80 km when no young were fledged and 0.62 km when 10 young were fledged.

Fidelity to Overwintering Home Range

Information pertaining to specific sites is lacking, though there are some general data pertaining to wintering areas. Among 12 adults and 6 juveniles bearing geolocators placed upon them at their breeding grounds in Switzerland, all "wintered" in the Sahel from Western Sahara south to southern Guinea and northern Liberia east to southern Algeria, western Niger, and northern Nigeria, with approximately 21% of adults wintering at the same location between years (same location defined as within 150 km), and two birds shifted > 1,000 km between years, with the maximum shift being approximately 1,300 km; the median distance between wintering sites across years for an individual was 411 km (86 van Wijk, R. E., S. Bauer, and M. Schaub (2016). Repeatability of individual migration routes, wintering sites, and timing in a long‐distance migrant bird. Ecology and Evolution 6:8679-8685. Close ). Precipitation patterns in this region can shift along a north-south axis from year to year up to several hundred kilometers due to changes in the Tropical Convergence Zone (87 Lélé, I. M., and P. J. Lamb (2010). Variability of the Intertropical Front (ITF) and Rainfall over the West African Sudan–Sahel Zone. Journal of Climate 23:3984–4004. Close ), and unpredictable outbreaks of desert locust (Schistocerca gregaria; 88 Lecoq, M. (1978). Biologie et dynamique d’un peuplement acridien de zone soudanienne en Afrique de l'Ouest (Orthoptera, Acrididae). Annales de la Société entomologique de France 14:603–681. Close , 89 Tratalos, J. A., R. A. Cheke, R. G. Healey, and N. C. Stenseth (2010). Desert locust populations, rainfall and climate change: Insights from phenomenological models using gridded monthly data. Climate Research 43:229–239. Close ), a potential food source (90 Stoate, C., and S. J. Moreby (1995). Premigratory diet of trans-Saharan migrant passerines in the western Sahel. Bird Study 42:101-106. Close , 91 Trierweiler, C., W. C. Mullié, R. H. Drent, K. M. Exo, J. Komdeur, F. Bairlein, A. Harouna, M. De Bakker, and B. J. Koks (2013). A Palaearctic migratory raptor species tracks shifting prey availability within its wintering range in the Sahel. Journal of Animal Ecology 82:107–120. Close ), could affect interannual food availability. The combination of both environmental stochasticity and (partly related) food availability, could well explain changes in exact wintering sites between years within an individual, which would result in low wintering site fidelity (86 van Wijk, R. E., S. Bauer, and M. Schaub (2016). Repeatability of individual migration routes, wintering sites, and timing in a long‐distance migrant bird. Ecology and Evolution 6:8679-8685. Close ).

The northernmost populations of Eurasian Hoopoe (Upupa epops epops) in Europe and Asia are entirely migratory, but in the southern portions that taxon's breeding range, it is a partial migrant (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close , 59 Brazil, M. (2009). Birds of East Asia: China, Taiwan, Korea, Japan, and Russia. Christopher Helm, London, UK. Close ). Most European breeders "winter" south of the Sahara Desert in the Sahel, with some wintering on the Iberian Peninsula and in northwestern Africa, while migrating Asian breeders appear to spend the nonbreeding season in southern Asia (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close , 92 Inskipp, C., and T. P. Inskipp (1985). A Guide to the Birds of Nepal. Croom Helm, London. Close , 61 Grimmett, R., C. Inskipp, and T. Inskipp (1999). A Guide to the Birds of India, Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and the Maldives. Princeton University Press, Princeton, NJ, USA. Close , 7 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close , 59 Brazil, M. (2009). Birds of East Asia: China, Taiwan, Korea, Japan, and Russia. Christopher Helm, London, UK. Close ). Breeding populations in the Himalayas (Upupa epops ceylonensis) retreat downslope from higher elevations for the nonbreeding season, while some birds breeding at lower elevations may migrate south (92 Inskipp, C., and T. P. Inskipp (1985). A Guide to the Birds of Nepal. Croom Helm, London. Close , 61 Grimmett, R., C. Inskipp, and T. Inskipp (1999). A Guide to the Birds of India, Pakistan, Nepal, Bangladesh, Bhutan, Sri Lanka, and the Maldives. Princeton University Press, Princeton, NJ, USA. Close ); additionally, birds may move, at least locally, in India in response to the monsoon season (93 Champion-Jones, R. N. (1937). The Ceylon Hoopoe (Upupa epops ceylonensis Reichb.). Journal of the Bombay Natural History Society 39:418. Close ). The movements of African populations are not well understood, but Upupa epops africana does not appear to undertake an organized directional migration, with some (many?) individuals dispersing after breeding to spend the dry season at more mesic locations. The two Central African subspecies (Upupa epops senegalensis and Upupa epops waibeli) appear to be a short distance partial migrants. Southbound migration among northerly or high elevation populations of the Eurasian epops group mostly takes place from late July into October, while northbound migration is mostly from late February into April, with a tail extending well into May.

Post-breeding

Those migrant Eurasian Hoopoe that breed in the Western Palearctic initiate their southward journey from late July through August (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close , 94 Gorman, G. (1996). The Birds of Hungary. Christopher Helm, London. Close , 81 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey: The Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close , 95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close , 96 van Wijk, R. E., M. Schaub, and S. Bauer (2017). Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird. Behavioral Ecology and Sociobiology 71:73. Close ), and have largely departed (except for those wintering on the Iberia Peninsula) by September's end, though some linger into October in southern Europe and Türkiye. For instance, all but the last few individuals have typically exited Ukraine by late September, Poland by mid-September, and France by the end of September; in Italy, most have departed or passed through by the end of August, but a few linger into October, and in Greece all but the last few are gone by the end of September, with a few lingering into October, and in northern/central Türkiye, the last individuals are typically seen around 3 October, while in southern Türkiye, the last have generally departed by 10 October (81 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey: The Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close , 97 Grishchenko, V. N. (2002). Phenology of autumn migration of the hoopoe in Ukraine. Випуск 11:257-259. Close , eBird data, accessed 22 February 2024). Data regarding the timing of these birds' passage migration are sparse, but in Israel southbound migration stretches from mid-July into mid-November, and peaks August–September (75 Shirihai, H. (1996). The Birds of Israel: A Complete Avifauna and Bird Atlas of Israel. Academic Press, London, UK. Close ). Western Palearctic breeders generally arrive in the sub-Saharan portion of their wintering grounds from late September through mid-October (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close , 98 Zimmerman, D.A., D. A. Turner, and D. J. Pearson (1999). Birds of Kenya and Northern Tanzania. Field Guide. Princeton University Press, Princeton, New Jersey. Close , 95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close , 96 van Wijk, R. E., M. Schaub, and S. Bauer (2017). Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird. Behavioral Ecology and Sociobiology 71:73. Close ). The first southbound migrants seem to arrive in Hong Kong in late August (99 Carey, G. J., M. L. Chalmers, D. A. Diskin, P. R. Kennerley, P. J. Leader, M. R. Leven, R. W. Lewthwaite, D. S. Melville, M. Turnbull, and L. Young (2001). The Avifauna of Hong Kong. Hong Kong Bird Watching Society, Hong Kong. Close ). Based on the number of birds sited, migrants first arrive in Sri Lanka in early October and continue to appear through November, and perhaps into December (eBird data, accessed 23 February 2024).

Some details of Eurasian Hoopoe migration have been revealed by studies in Switzerland. In one such study, 57 individuals bore geolocators placed upon them at their breeding grounds. Those birds departed on southbound migration on the median date of 16 August ± 15 d, and their median arrival date in the African Sahel, their nonbreeding grounds, was 23 September ± 22 d; no difference between males and females was detected (96 van Wijk, R. E., M. Schaub, and S. Bauer (2017). Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird. Behavioral Ecology and Sociobiology 71:73. Close ). In a smaller study, three individuals (two females and a male) from the same population in Switzerland were noted to pause for a month during southbound migration at points roughly halfway between breeding and nonbreeding areas, with females departing Switzerland 27 July–2 August and arriving at their nonbreeding areas 2–12 September, and the male first heading south around 26 August and arriving at its nonbreeding grounds in October (95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close ).

Pre-breeding

Northbound migration of Western Palearctic breeders generally commences in mid-to-late February with birds first arriving at breeding grounds near the northern edge of the European range in mid-to-late March (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close , 96 van Wijk, R. E., M. Schaub, and S. Bauer (2017). Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird. Behavioral Ecology and Sociobiology 71:73. Close ). Departure from Hong Kong appears to begin in late February, with the last migrants departing in May (99 Carey, G. J., M. L. Chalmers, D. A. Diskin, P. R. Kennerley, P. J. Leader, M. R. Leven, R. W. Lewthwaite, D. S. Melville, M. Turnbull, and L. Young (2001). The Avifauna of Hong Kong. Hong Kong Bird Watching Society, Hong Kong. Close ), and departure from Sri Lanka probably begins in late January, with the last northbound birds likely leaving in early May (eBird data, accessed 23 February 2024).

Northbound migration through Israel stretches from mid-Febuary through mid-May, peaking from mid-March to mid-April (75 Shirihai, H. (1996). The Birds of Israel: A Complete Avifauna and Bird Atlas of Israel. Academic Press, London, UK. Close ). In Morocco and Malta, the first northbound migrants are found in early January in southern Morocco, mid-January in northern Morocco, and early February in Malta, with peak passage stretching from mid-February into April throughout, and the last migrants detected in May (100 Smith, K. D. (1965). On the birds of Morocco. Ibis 107(4):493–526. Close , 101 Sultana, J. and C. Gauci (1982). A New Guide to the Birds of Malta. The Ornithological Society, Malta. Close , 102 Thévenot, M., R. Vernon, and P. Bergier (2003). The Birds of Morocco: An Annotated Checklist. Tring, United Kingdom. Close ). In southern Iberia, northbound migration begins in February and peaks during March (103 Finlayson, C. (1992). Birds of the Strait of Gibraltar. T. & A. D. Poyser, London, UK. Close , 104 Tellería, J. L., B. Asensio, and M. Díaz (1999). Aves Ibéricas II. Paseriformes. J. M. Reyero, Madrid, Spain. Close ). In northern Iberia, southern France, and central Italy, northbound passage is first detected in early March, peaks from late March to early April, and then decreases progressively until mid-May (105 Blondel, J., and P. Isenmann (1981). Guide des oiseaux de Camargue. Delachaux and Niestlé Editors., Neuchâtel-Paris, France. Close , 106 Spina, F., A. Massi, A. Montemaggiori, and N. Baccetti (1993). Spring migration across central Mediterranean: general results from the “Progetto Piccole Isole”. Vögelwarte 37:1-94. Close , 107 Spina, F., and S. Volponi (2008). Atlante della migrazione degli uccelli in Italia. Bd. 1. Non-Passeriformi. Tipografia, Rome, Italy. Close , 108 Lozano, C. B., and D. Robson (2011). Hoopoe (Upupa epops). In Spring Migration in the Western Mediterranean and NW Africa. Monografies del Museu de Ciències Naturals, Barcelona, Spain. pp. 47–53. Close ). In Türkiye, the first spring migrants typically appear in mid-March, with northbound passage peaking during the first half of April and then tailing off into mid-May (81 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey: The Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close ).

To the north, the first individuals arrive in northern Mongolia in mid-April (31 Krištín, A., and G. M. Kirwan (2020). Eurasian Hoopoe (Upupa epops), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. Close , eBird data, accessed 23 February 2024), in Hungary from late March–early April (94 Gorman, G. (1996). The Birds of Hungary. Christopher Helm, London. Close ), and in Poland during late March or early April (eBird data, accessed 23 February 2024). Based on >50 birds bearing geolocators, the return to the breeding grounds in Switzerland was mostly from late March through mid-April (96 van Wijk, R. E., M. Schaub, and S. Bauer (2017). Dependencies in the timing of activities weaken over the annual cycle in a long-distance migratory bird. Behavioral Ecology and Sociobiology 71:73. Close ). One female carrying a geolocator departed the Sahel on 10 March and arrived in Switzerland on 2 April, while another departed on 20 March and arrived on 20 April, with pauses in Adrar, Algeria and the Balearic Islands between 8–18 April (95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close ).

Routes

Based on banding results, European breeders show an east/west divide during southbound migration that stretches from Germany, through Austria and Switzerland, to northern Italy; birds west of this line were typically migrating towards the southwest (mean ~ 225^o) and birds east of this line were typically migrating southeast (mean ~ 165^o; 109 Reichlin, T. S., M. Schaub, M. H. M. Menz, M. Mermod, P. Portner, R. Arlettaz, and L. Jenni (2009). Migration patterns of Hoopoe Upupa epops and Wryneck Jynx torquilla: an analysis of European ring recoveries. Journal of Ornithology 150(2):393-400. Close ). A study followed 54 birds with geolocators on their southbound migration from Switzerland, and 18 went south via the Iberian Peninsula, 25 via the islands between Iberia and Italy, and 11 headed south through mainland Italy (86 van Wijk, R. E., S. Bauer, and M. Schaub (2016). Repeatability of individual migration routes, wintering sites, and timing in a long‐distance migrant bird. Ecology and Evolution 6:8679-8685. Close ). Stable isotope analysis suggest that Eurasian Hoopoe breeding in Spain and Switzerland have somewhat similar wintering areas, with a concentration in the southern Iberian Peninsula and the north coast of Africa (from coastal Morocco to west coastal Libya), and another in the Sahel from Senegal and Guinea east to southern Niger and northern Cameroon, with smaller numbers farther east in the Sahel to western Ethiopia and very few east to Somalia (110 Reichlin, T. S., K. A. Hobson, S. L. Van Wilgenburg, M. Schaub, L. I. Wassenaar, M. Martín-Vivaldi, R. Arlettaz, and L. Jenni (2013). Conservation through connectivity: can isotopic gradients in Africa reveal winter quarters of a migratory bird? Oecologia 171:591–600. Close ); while the conclusions based on isotope analysis could be in agreement with that from banding results, the route by which Iberian breeding birds might reach East Africa remains unaddressed. Northbound migration routes are far less studied. The northbound routes of three individuals breeding in Switzerland were generally east of their southbound route, generally traveling north via Algeria but south through Morocco (95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close ).

Migration of African Breeding Populations

In Africa, Upupa epops africana appears to disperse in a "disorganized" fashion over small distances, but does not truly migrate (111 Roberts, A. (1932). Migration of African birds. Ostrich 3:97-109 Close , 21 Skead, C. J. (1950). A study of the African Hoopoe. Ibis 92:434–463. Close ), though some South African breeders may move north to Mozambique and Zimbabwe during the Austral winter (2 Fry, C. H., S. Keith, and E. K. Urban, Editors (1988). The Birds of Africa. Volume 3. Parrots to Woodpeckers. Academic Press, London, UK. Close ). Among the Central African subspecies group, Upupa epops senegalensis appears to be largely nonmigratory, but there is some movement during the nonbreeding season (dry season; roughly October to April) of birds from the northern portion of its range into southern portion of its breeding range (3 Borrow, N., and R. Demey (2001). Birds of Western Africa. Christopher Helm, London, UK. Close ) and beyond, as far south as southern Cameroon and southern Somalia (2 Fry, C. H., S. Keith, and E. K. Urban, Editors (1988). The Birds of Africa. Volume 3. Parrots to Woodpeckers. Academic Press, London, UK. Close ), and Upupa epops waibeli migrates to equatorial Uganda and Kenya during its nonbreeding season, from June–August (2 Fry, C. H., S. Keith, and E. K. Urban, Editors (1988). The Birds of Africa. Volume 3. Parrots to Woodpeckers. Academic Press, London, UK. Close , 98 Zimmerman, D.A., D. A. Turner, and D. J. Pearson (1999). Birds of Kenya and Northern Tanzania. Field Guide. Princeton University Press, Princeton, New Jersey. Close ).

Fidelity to Migratory Routes

Among 12 adults and 6 juveniles bearing geolocators placed upon them at their breeding grounds in Switzerland, 69% of adults used the same southbound route in the following year and 75% of first-time migrants followed the same route in the subsequent year, noting that the definition of route is general and does not pertain to specific locations (86 van Wijk, R. E., S. Bauer, and M. Schaub (2016). Repeatability of individual migration routes, wintering sites, and timing in a long‐distance migrant bird. Ecology and Evolution 6:8679-8685. Close ).

Duration, Timing, and Altitude of Migration

In one study (112 Liechti, F., S. Bauer, K. L. Dhanjal-Adams, T. Emmenegger, P. Zehtindjiev, and S. Hahn (2018). Miniaturized multi-sensor loggers provide new insight into year-round flight behaviour of small trans-Sahara avian migrants. Movement Ecology 6:1–10. Close ), 19 Eurasian Hoopoe that bred in Switzerland were fitted with light-weight multi-sensor loggers (hereafter, sensors). These individuals migrated largely at night (median 88%). For flights >4 h in duration, 90% of departures took place between 1 h before and 2 h after sunset and largely, the birds landed before dawn. Notably, 7% of migratory jumps lasted >12 h, with the longest flight lasting 28 h. The median altitude while migrating was 1,150 m above sea-level on southbound migration and 1,630 m above sea-level during northbound migration. The maximum altitude was 4,584 m. Southbound migration involved a median of 115 h of flying time to cover a median distance of 3,769 km, while northbound migration involved 117 h of flying time to cover the same distance. Though the maximum altitude during migration in this study was 4,584 m, in the Himalayas, migrants have been found as high as 6,400 m (113 Ali, S., and S. D. Ripley (1983). Handbook of the Birds of India and Pakistan. Volume 4. 2nd edition. Oxford University Press, Delhi, India. Close ).

While the flight time for northbound and southbound migration were essentially equal in the above study, another study found that the total time was rather different, with two females taking a mean of 40 d to complete southbound migration but only 26.5 d to complete northbound migration (95 Bächler, E., S. Hahn, M. Schaub, R. Arlettaz, L. Jenni, J. W. Fox, V. Afanasyev, and F. Liechti (2010). Year-round tracking of small trans-Saharan migrants using light-level geolocators. PLOS One 5(3):e9566. Close ). A southbound migration that is approximately 1.5x longer (in time) than that of northbound migration is consistent with findings in other Palearctic migrants, indicating greater time constraints during northbound migration (114 Fransson, T. (1995). Timing and speed of migration in north and west European populations of Sylvia warblers. Journal of Avian Biology 26:39-48. Close , 115 Alerstam, T. (2003). Bird Migration Speed. In Avian Migration (P. Berthold, E. Gwinner, and E. Sonnenschein, Editors), Springer Press, Berlin, Germany. pp. 253–267. Close , 116 Newton, I. (2008). The Migration Ecology of Birds. Academic Press, London, UK. Close ).

Social Behavior in Migration

The Eurasian Hoopoe usually migrates singly or in small groups, but larger flocks are sometimes encountered (1 Cramp, S., Editor (1985). The Birds of the Western Palearctic. Volume 4. Oxford University Press, Oxford, UK. Close ), such as a loose group of 103 at Sohag in Egypt's Nile Valley in mid-October (117 Horváth, L. (1959). The results of the Zoological collecting trip to Egypt in 1957, of the Natural History Museum, Budapest. 7. The ornithological results. Annales Historico-Naturales Musei Nationalis Hungarici 51:451–481. Close ), flocks of up to 70 on passage through eastern Arabia (43 Jennings, M. C. (2010). Atlas of the Breeding Birds of Arabia. Fauna of Arabia 25. King Abdulaziz City for Science and Technology, Saudi Wildlife Commission & Senckenberg Forschungsinstitut und Naturmuseum, Riyadh, Saudi Arabia & Frankfurt am Main, Germany. Close ), and as many as 138 at Tripoli, Libya, in late August (118 Bundy, G. (2009). Unusually large assembly of Hoopoes. British Birds 102(11):635–636. Close ).

The lungs of migratory Eurasian Hoopoe from Europe (Upupa epops epops) were compared to those of the sedentary subspecies (Upupa epops major) in Egypt; the predominant difference was that the blood-gas barrier in the lungs of nominate epops was far thinner than that in the lungs of major, thus facilitating oxygen exchange during breathing and consistent with the intense metabolic demands generated during migration (119 Maina, J. N., A. S. King, and G. Settle (1989). An allometric study of the pulmonary morphometric parameters in birds, with mammalian comparison. Philosophical Transactions of the Royal Society of London Series B 326:1–57. Close , 120 El-Bakary, N., A. Ibrahim, G. Abd-Allah, S. El-Naby, and L. E. Deef Deef (2013). Comparative histological and ultrastructural studies on lung of the Egyptian Hoopoe (Upupa epops major) and the European Hoopoe (Upupa epops epops). Catrina: The International Journal of Environmental Sciences 8:101–106. Close ).