Routes of migrating soaring birds

Soaring migrants travelling through Israel use three principal routes which are used in the opposite directions during the spring and autumn: (1) the Western Route lies mainly along the western edge of the central mountain range, (2) the Eastern Route lies mainly along the Jordan Valley, crossing the mountain range during part of the day, continuing southward along the Dead Sea towards the Sinai, and joining the Western Route in autumn and (3) the Southern-Elat Mountains Route. The geomorphological structure of Israel, with a central mountain range dividing the country roughly into three landscape units, plays a central role in route selection. In the autumn, the Western Route migration axis is deflected at the beginning of the day from east to west for 10–25 km, depending on weather conditions and the flock's roosting locations. Between 10.00 h and 11.00 h, the daily breeze blowing from the Mediterranean Sea influences the migration axis, which is slowly deflected back to the east. A parallel deflection of the migration axis occurs in the Eastern Route in the autumn. The route moves southwest over the eastern slopes of the central mountain range during the morning hours and over the slope, which absorbs direct radiation from the sun, creating good soaring conditions. Towards late afternoon, when the breeze from the sea starts, the axis is deflected to the east, to the Jordan Valley. In the Elat Mountains, the wind flow plays a similar role, but because the topography of the southern Arava Valley causes a change in wind direction, the axis moves during the day in a north-south direction. In addition to the axis movement on a daily scale, a seasonal deflection of the migration axis from east to west also exists. During autumn migration, early migrants (e.g. White Storks Ciconia ciconia) tend to travel on an eastern route, while late migrants (e.g. White Pelican Pelecanus onocrotalus) travel along the Mediterranean coast. This fluctuation was probably because of sub-optimal soaring conditions along the coastal plain during August. In September, temperature differences between the sea and land decrease and the influence of the marine inversion gradually declines, until its influence disappears completely in October. A comparison of the numbers of soaring birds seen over Israel in the autumn and spring shows significant seasonal differences in the use of the various routes. For example, only one species, the Steppe Eagle Aquila nipalensis, flies over the Elat Mountains in the autumn, compared to more than 30 species in the spring. In the autumn, White Storks pass over only along the Jordan Valley axis, whereas in the spring, about half the migrating storks also pass over the western edge of the central mountain range. Honey Buzzards Pernis apivorus fly along the Western Route in large numbers in the autumn, while concentrating almost totally over the Elat Mountains in the spring. These differences are related to the global migration routes between the breeding and the wintering grounds in relation to the Red Sea, which birds avoid crossing, thus causing them to follow different routes in autumn, and spring.     

The magnitude and timing of migration by soaring raptors, pelicans and storks over Israel

The magnitude and timing of the autumn and spring migrations of 35 species of medium-and large-sized raptors, White Pelicans Pelicanus onocrotalus and White Storks Ciconia ciconia were studied in Israel. Observations were carried out from the ground by a line of observers covering most of the width of Israel across the line of migration and by radar. There was a high correlation between the counts obtained by ground observers and by radar. On average, about half a million raptors (mainly Lesser Spotted Eagles Aquila po-marina, Honey Buzzards Pernis apivorus and Levant Sparrowhawks Accipiter brevipes), 250,000 White Storks and 70,000 White Pelicans passed during autumn, and about a million raptors (mainly Honey Buzzards, Steppe Buzzards Buteo vulpinus, Steppe Eagles Aquila nipalensis and Black Kites Milvus migrans) and 450,000 White Storks passed during spring. Peak numbers were higher–over a million raptors and half a million White Storks. There was high interyear variation in the number of migrants recorded during the study, probably caused by weather and counting efforts. For some species, the whole world (Lesser Spotted Eagle and Levant Sparrowhawk) or Palaearctic (White Pelican) population passes over Israel during migration, allowing an estimate of the world populations of these species. Mean dates of arrival of most raptors are highly predictable, with confidence limits ranging between 1.5 and 5.5 days. The migration periods of White Storks and White Pelicans are longer and their mean day of appearance is less predictable (confidence limits range from 4.2 to 13.8 days). During autumn, 90% of the migrating populations of nocking species, such as Levant Sparrowhawk, Lesser Spotted Eagle, Honey Buzzard and Red-footed Falcon Falco vespertinus, pass within 13, 15, 16 and 18 days, respectively, while nonflocking species, such as Egyptian Vulture Neophron percnopterus, Marsh Harrier Circus aeruginosus and Short-toed Eagle Circaetus gallicus, generally take twice as long to pass. Similar passage periods were recorded in spring. For most species, the autumn migration period was longer than the spring migration period, probably because in autumn adults move before the young birds. Three factors affected the timing and spread of the migration wave: age at first breeding, diet and size of the breeding area.     

8. MINUTES OF THE ANNUAL CENERAL MEETING OF THE SOUTH AFRICAN ORNITHOLOGICAL SOCIETY

Four ringing stations of the SE European Bird Migration Network in Egypt (at the coasts of the Mediterranean and Red seas, in the Nile Valley, and at the northern edge of the Sahara) provided data on birds resting in adequate habitats. At three stations more birds per day were caught in spring than in autumn. Deviating geographical conditions induced high capturing numbers at the Red Sea coast, particularly in autumn. Differences between spring and autumn may indicate loop migration and/or seasonally differing flight or resting strategies. Wing-length distribution may indicate passage of different populations through Egypt. In autumn, birds with low fat scores were caught in high proportion after the crossing of the Mediterranean Sea, while average fat scores increased in birds approaching the edge of the Sahara.     

SPRING MIGRATION AT THE BOSPHORUS

During observations made at the Bosphorus from 23 March to 6 April 1965, 3473 raptors were seen; the majority were Spotted/Lesser Spotted Eagles and Honey Buzzards. The migration of the main species is considered in some detail and attempts are made to correlate this with the prevailing weather. Comparisons are made with the records of observers both in spring and autumn at the Bosphorus and in spring at Gibraltar. Honey Buzzards pass in spring a month later at Gibraltar than at the Bosphorus. It is suggested that this is related to the timing of spring in the breeding areas to which these birds are returning. Notes on the observations of passerine movements and a night migration of Black Storks are also included.     

Around the Mediterranean: an extreme example of loop migration in a long‐distance migratory passerine

An important issue in migration research is how small‐bodied passerines pass over vast geographical barriers; in European–African avian migration, these are represented by the Mediterranean Sea and the Sahara Desert. Eastern (passing eastern Mediterranean), central (passing Apennine Peninsula) and western (via western Mediterranean) major migration flyways are distinguished for European migratory birds. The autumn and spring migration routes may differ (loop migration) and there could be a certain level of individual flexibility in how individuals navigate themselves during a single migration cycle. We used light‐level loggers to map migration routes of barn swallows Hirundo rustica breeding in the centre of a wide putative contact zone between the northeastern and southernwestern European populations that differ in migration flyways utilised and wintering grounds. Our data documented high variation in migration patterns and wintering sites of tracked birds (n = 19 individuals) from a single breeding colony, with evidence for loop migration in all but one of the tracked swallows. In general, two migratory strategies were distinguished. In the first, birds wintering in a belt stretching from southcentral to southern Africa that used an eastern route for both the spring and autumn migration, then shifted their spring migration eastwards (anti‐clockwise loops, n = 12). In the second, birds used an eastern or central route to their wintering grounds in central Africa, shifting the spring migration route westward (clockwise loops, n = 7). In addition, we observed an extremely wide clockwise loop migration encompassing the entire Mediterranean, with one individual utilising both the eastern (autumn) and western (spring) migratory flyway during a single annual migration cycle. Further investigation is needed to ascertain whether clockwise migratory loops encircling the entire Mediterranean also occur other small long‐distance passerine species.     

THE AUTUMN MIGRATION OF SOARING BIRDS AT THE BOSPHORUS

The migration of soaring birds was observed at Küçük Çamlica at the southern end of the Bosphorus between 14 July and 8 November 1966. Simultaneous watches were also carried out at other points on the Bosphorus on a number of dates. The largest movements of birds of prey occurred on days of light northeasterly winds, the largest movements of storks on days of light winds with a southerly component. On most days the stream of migrants appeared to be concentrated over the southern end of the Bosphorus. Migration frequently occurred right throughout the day, though the peak period was usually not spread over more than three hours. Figures are given for the daily times of migration of the commonest soaring birds. Daily counts of soaring birds (storks, raptors and Cranes) migrating over the Bosphorus at Küçük Çamlica are given. The main species found migrating were (with total number recorded in brackets) White Stork Ciconia ciconia (207,145), Black Stork C. nigra (6,194), Honey Buzzard Pernis upivorus (8,997), Buzzard Buteo buteo (12,949), "Spotted" Eagle Aquila clanga/pomarina (4,309) and sparrowhawk Accipiter nisus / brevipes (5,224). The autumn migration of 1966 is discussed in detail in a systematic list. Buzzards B. buteo were recorded in large numbers for the first time at the Bosphorus, and were the commonest bird of prey. Cranes Grus grus were also recorded for the first time. Comparison is made between our results and those of previous workers, though differences of coverage rule out any firm conclusions.     

Blackaps Sylvia atricapilla stopping over at the desert edge; physiological state and flight-range estimates

Migrating Blackcaps Sylvia atricapilla were mist netted at the desert edge in northern Israel and in Elat (southern Israel) during spring and autumn migrations between 1970 and 1991. Birds in spring in northern Israel were representative of birds that had completed the crossing of the Sahara, while those in Elat still had to cross the 150 km of the Negev Desert, which separates Elat and northern Israel. In autumn, birds captured in northern Israel were representative of those about to cross the Sahara Desert, while those in Elat had already started to cross the desert. The data allowed analysis of seasonal and location differences in the physiological state of Blackcaps before and after crossing the Sahara. Data analysed included body mass, visible fat score and calculated fat content. Autumn migrants were in better physiological condition than spring migrants at both locations, probably as a consequence of their migration route through fertile areas in autumn compared with the crossing of the Sahara in spring. Body mass was less variable after the Sahara crossing in spring than before the crossing in autumn. In spring, 71% and 67% of the birds were fat depleted (fat scores 0 and 1) at Elat and in northern Israel, respectively, while in autumn 34% and 42% were fat depleted. Blackcaps at Elat were 1.6 g lighter than those in northern Israel in autumn and 1.9 g lighter in spring. Potential flight ranges were estimated on the basis of meteorological conditions and flight altitude of passerines above the Negev in Israel (northern Sahara edge) during migration and on a simulation model that considered both energy and water as potential limiting factors for flight duration and distance. The simulation model predicted that half of the Blackcaps that stopped over in Elat and the majority of those that stopped over in northern Israel could not make a nonstop flight over the Sahara Desert in autumn without the assistance of at least an 8 m per s tailwind. Such a wind would still not be sufficient for 34% of the birds in Elat and 42% in northern Israel, and clearly they had insufficient fat reserves to cross the Sahara in a single flight. Although the fattest Blackcaps had accumulated sufficient fat to enable them to traverse the Sahara in a single flight, they probably faced dehydration by at least 12% of their initial body mass when they reached the southern Sahara edge. These birds should use intermittent migration with stopovers at sites with drinking and feeding potential. Their decision to stop over during the day in the desert at sites with shade but without food and water would be beneficial if the meteorological conditions during daytime migration imposed greater risks of dehydration than at night. Spring migrants could not reach their breeding areas in Europe without feeding, but those examined in Elat could cross the remainder of the desert in a single flight.     

THE VISIBLE MIGRATION OF RAPTORS OVER THE MALTESE ISLANDS

Whilst the large migrations of raptors at the Bosphorus and at the Straits of Gibraltar have been documented in some detail, the movements which take place across the Mediterranean itself have been neglected. This paper reports observations of the visible migration of raptors over the Maltese Islands during 1969–73. The largest numbers of raptors were recorded both in spring and autumn during contrary winds or overcast conditions. Normally very few were seen before the early afternoon at either season, in spite of the much shorter minimum sea-crossing in autumn. Large passages occurred in winds with easterly or westerly components. It is therefore concluded that eastward drift does not greatly affect the numbers seen in Malta, as had been suggested by De Lucca (1969); rather that most influxes occurred in the late afternoon during unfavourable meteorological conditions. At other times most migration was probably above the visible range. The number of raptors observed on passage in the Maltese Islands was small compared with movements at the Bosphorus or at Gibraltar. Nevertheless, the numbers of the narrow-winged species (i.e., Ospreys, harriers and falcons) compare favourably with records at the narrow crossings. The only large soaring species commonly seen in Malta was the Honey Buzzard. Evidence is presented which suggests that the volume of Honey Buzzard migration across the central Mediterranean may be much larger than was formerly realized.     

Mining citizen science data to explore stopover sites and spatiotemporal variation in migration patterns of the red-footed falcon

Citizen science data have already been used to effectively address questions regarding migration, a fundamental stage in the life history of birds. In this study, we use data from eBird and from 3 additional regional citizen science databases to describe the migration routes and timing of the red-footed falcon Falco vespertinus in the Mediterranean region across 8 years (2010–2017). We further examine the seasonal and yearly variation in migration patterns and explore sites used during the species migration. Our results suggest that the autumn passage is spatially less variable and temporally more consistent among years than in spring and that birds migrate faster in spring than in autumn. The species seems to be more prevalent along the Central Mediterranean during spring migration, probably as a result of the clockwise loop migration that red-footed falcons perform. There was a high variation in annual median migration dates for both seasons as well as in migration routes across years and seasons. Higher variation was exhibited in the longitudinal component thus indicating flexibility in migration routes. In addition, our results showed the species’ preference for lowlands covered with cropland and mosaics of cropland and natural vegetation as stopover sites during migration. Stopover areas predicted from our distribution modeling highlight the importance of the Mediterranean islands as stopover sites for sea-crossing raptors, such as the red-footed falcon. This study is the first to provide a broad-scale spatiotemporal perspective on the species migration across seasons, years and flyways and demonstrates how citizen science data can inform future monitoring and conservation strategies.     

Molecular Evidence for Lessepsian Invasion of Soritids (Larger Symbiont Bearing Benthic Foraminifera)

The Mediterranean Sea is considered as one of the hotspots of marine bioinvasions, largely due to the influx of tropical species migrating through the Suez Canal, so-called Lessepsian migrants. Several cases of Lessepsian migration have been documented recently, however, little is known about the ecological characteristics of the migrating species and their aptitude to colonize the new areas. This study focused on Red Sea soritids, larger symbiont-bearing benthic foraminifera (LBF) that are indicative of tropical and subtropical environments and were recently found in the Israeli coast of the Eastern Mediterranean. We combined molecular phylogenetic analyses of soritids and their algal symbionts as well as network analysis of Sorites orbiculus Forskål to compare populations from the Gulf of Elat (northern Red Sea) and from a known hotspot in Shikmona (northern Israel) that consists of a single population of S. orbiculus. Our phylogenetic analyses show that all specimens found in Shikmona are genetically identical to a population of S. orbiculus living on a similar shallow water pebbles habitat in the Gulf of Elat. Our analyses also show that the symbionts found in Shikmona and Elat soritids belong to the Symbiodinium clade F5, which is common in the Red Sea and also present in the Indian Ocean and Caribbean Sea. Our study therefore provides the first genetic and ecological evidences that indicate that modern population of soritids found on the Mediterranean coast of Israel is probably Lessepsian, and is less likely the descendant of a native ancient Mediterranean species.     

Untersuchungen zur Zoogeographie der Euphausiaceen (Crustacea) des Roten Meeres

A joint programme on “Biota of the Red Sea and the Eastern Mediterranean” has been carried out by the Hebrew University of Jerusalem and the Smithsonian Institution of Washington between 1967 and 1972 in order to study the role played by the Suez Canal as a route for faunal exchanges between the Red Sea and Eastern Mediterranean. The euphausiids of this material have been examined and additional samples of zooplankton have been taken in the Gulf of Elat (Aqaba) in 1973 in order to study the vertical distribution of the euphausiids. Four species have been found to occur in the Northern Red Sea and the Gulf of Elat:Euphausia diomedeae, E. sanzoi, Stylocheiron affine andS. abbreviatum. Seven species were found in the Eastern Mediterranean of whichEuphausia brevis is the dominant species. The present studies revealed that an exchange of Euphausiacea through the Suez Canal does not take place. The species of the Red Sea belong to the Indopacific fauna. Despite the particular historic-geographical and ecological situation of the Red Sea, no endemisms or subspecies have evolved there within the Euphausiacea.     

RAPTOR MIGRATION ACROSS THE STRAITS OF GIBRALTAR

The visible migration of birds of prey at Gibraltar is analysed from records kept throughout the spring passages of 1967–70 and the autumn passages of 1967–69. In early spring most visible passage is noted in the afternoons, whereas radar observations by Houghton (1970) indicate passage in the mornings. Later in the year an additional burst of visible passage sometimes occurs in the early morning, but it is concluded that most morning movements take place above visible range. Visible migration is recorded on most days of westerly wind during the migration seasons at Gibraltar. Passage is rarely seen when the winds are easterly. It is argued that under the latter conditions a strong upcurrent of air (standing wave) is formed over Gibraltar, and that this carries nearly all migrants above visible range.
Observations of visible passage elsewhere in the Straits suggest that, in spring, raptors of all species cross on a broad front from Tangier to Ceuta, except Honey Buzzards, which probably cross chiefly near Ceuta. In autumn, all species from northern Europe cross chiefly between Tarifa and to the east of Gibraltar, while birds from western Iberia probably cross mainly near Tarifa.
The periods of passage of the common migrant species are summarised.
On the basis of visual observations and published radar results, it is argued that raptors can compensate for lateral drift by the wind and so fly on chosen courses; but that in very strong cross-winds, e.g. the easterly Levanters, they may have to let themselves be drifted off-course.     

The effect of wind, season and latitude on the migration speed of white storks Ciconia ciconia, along the eastern migration route

The relation between wind, latitude and daily migration speed along the entire migration route of white storks was analysed. Mean daily migration speed was calculated using satellite telemetry data for autumn and spring migration of white storks from their breeding grounds in Germany and Poland to wintering grounds in Africa and back. The National Center for Environmental Prediction (NCEP) reanalysis data were used to systematically fit 850 mb wind vectors to daily migration speed along the migration route. White storks migrated significantly faster and had a shorter migration season in autumn (10 km/h) compared to spring (6.4 km/h). In autumn mean daily migration speed was significantly slower in Europe (8.0 km/h) than in the Middle East (11.1 km/h) and Africa (11.0 km/h). In spring mean daily migration speed was significantly faster in Africa (10.5 km/h) as birds left their wintering grounds than in the Middle East (4.3 km/h). Migration speed then increased in Europe (6.5 km/h) as birds approached their breeding grounds. In both spring and autumn tailwind (at 850mb) and latitude were found to be significant variables related to daily migration speed.     

THE MIGRATION OF RAPTORS AND STORKS THROUGH THE NEAR EAST IN AUTUMN

Between 1963 and 1965 three expeditions have investigated the autumn migration of raptors and storks, on two occasions in southeast Turkey, and once in Lebanon.
Nearly all the soaring birds leaving Europe by the Bosphorus cross Asia Minor and turn south at the Gulf of Iskenderun. The commonest of these migrants are White Stork Ciconia ciconia , Honey Buzzard Pernis apivorus , and Eagles Aquila spp.
Other species such as Common Buzzard Buteo buteo are not usually seen crossing the Bosphorus, but occur in large numbers in the flocks seen south of the Gulf of Iskenderun. It is suggested that these are birds from Russia and north Turkey. Common Buzzards also occur on Cyprus in autumn, but their point of origin is not clear. Short-toed Eagles Circuetus gullicus and vultures join the migration from their breeding grounds in Turkey and the Levant.
Different species tend to migrate at different times of year. White Storks, Egyptian Vultures Neophron percnopterus and Black Kites Milvus migruns move chiefly between late August and mid-September, while eagles Aquilu spp. start in late September and continue until November. Other species are intermediate, or spread their migration out over a longer period.
The volume of migration at different times of day is discussed. No general conclusions are possible but in 1964 a correlation was obtained between cloud cover and the start of the migration.     

Advanced departure dates in long-distance migratory raptors

Evidences for phenological changes in response to climate change are now numerous. One of the most documented changes has been the advance of spring arrival dates in migratory birds. However, the effects of climate change on subsequent events of the annual cycle remain poorly studied and understood. Moreover, the rare studies on autumn migration have mainly concerned passerines. Here, we investigated whether raptor species have changed their autumn migratory phenology during the past 30 years at one of the most important convergent points of western European migration routes in France, the Organbidexka pass, in the Western Pyrenees. Eight out of the 14 studied raptor species showed significant phenological shifts during 1981–2008. Long-distance migrants displayed stronger phenological responses than short-distance migrants, and advanced their mean passage dates significantly. As only some short-distance migrants were found to delay their autumn migration and as their trends in breeding and migrating numbers were not significantly negative, we were not able to show any possible settling process of raptor populations. Negative trends in numbers of migrating raptors were found to be related to weaker phenological responses. Further studies using data from other migration sites are necessary to investigate eventual changes in migration routes and possible settling process.     

BIRD MIGRATION OVER THE MALTESE ISLANDS

The present paper is based on data obtained during several years' observations and three recent surveys. Little has previously been published on migration through the Maltese Islands. The geographical, vegetational and climatic factors of the islands are discussed in so far as they affect the migrants. Visible migration is seen with anticyclonic weather and westerly winds. Birds are found grounded after night migration in cyclonic weather with southwesterly or easterly winds, much larger numbers and variety being seen with the latter. When there is a deterioration in the weather during the night, a large influx of birds is seen on the following morning, and in addition large flocks of migrating Turtle Doves are seen. Several trans-Saharan migrants may pass in smaller numbers during autumn than spring, but the difference may be more apparent than real because in early autumn the birds may depart after only a very short stay, and a few conspicuous species are absent or scarce. By contrast several species which winter north of the Sahara pass only or in much larger numbers during autumn, and these more than make up for those which are absent or rare. There is no evidence from bird ringing that in spring Malta regularly gets birds from Tunisia, at any rate from that part covered by the ringing stations (Cap Bon, Enfidaville, Gabes). The migrants which pass through Malta probably originate from an area in North Africa around Tripoli and some way westwards of it. During autumn the bulk of recoveries is from eastern European countries with a smaller percentage from northern and central Europe. Several species or groups of species are dealt with individually. In the discussion stress is laid on the very close relationship between migration and weather, especially the wind component. The comparatively small numbers of birds seen at Malta probably form part of a larger movement travelling on a broad front. It is argued that the large “falls” of migrants in bad weather result from drift acting on a mass passing mainly to one side or the other of the islands. Since much larger densities are seen with easterly than with westerly winds, it follows, if the hypothesis of drift be correct, that the numbers of birds travelling to the east of Malta are larger than those to the west of it. Moreover, since day migrants are seen with westerly winds and the bulk of night migrants with easterly ones, it is inferred that day migrants normally pass to the west, and the bulk of night migrants to the east, of the Maltese Islands. A parallel is drawn between the autumn migration and the performance of racing pigeons which are flown from the north and NE at this season.     

Does targeted management work for red-legged partridges <Emphasis Type="Italic">Alectoris rufa</Emphasis>? Twelve years of the ‘Finca de Matallana’ demonstration project

After the implementation of a management package for red-legged partridges (Alectoris rufa) (including habitat improvement, legal predator removal, supplementary feeding and watering and shooting restrain) in an agricultural Mediterranean area of Spain (308 ha), spring pair densities increased from 2.92 to 12.66/km² in 9 years, together with summer densities (from 24 to 98 birds/km²) and autumn densities (from 16.5 to 86 birds/km²). We recorded an overall decrease in the over-winter survival of partridges and an increase in their over-summer survival as time progressed. Productivity doubled in 5 years and densities of wild rabbits (Oryctolagus cuniculus) significantly increased. Hence, this study shows that a feasible and affordable combination of management tools worked to improve partridge populations, and also helped the recovery of wild rabbits. The study site supported the presence of 42 ‘red-listed’ species (including 21 species of raptors).     

MIGRATION IN IRAQ

Migration in Iraq is discussed on the basis of three years' experience supplemented by data from other unpublished sources and the literature.
The migration of certain passerine and near-passerine species is considered, particularly as regards comparative numbers seen in spring and autumn, and the question of their passages between breeding quarters in the Palaearctic and winter quarters in Africa, in relation to weather, geography and ecology of the Middle East. Of about 50 species discussed, half are clearly more abundant in spring, and most of the rest probably are; thus supporting the idea that such species in autumn may make longer unbroken flights than in spring. For a number of these species the nearness of the breeding quarters to Baghdad is stressed.
Exceptions are Streptopelia turtur , Alaudidae, hirundines and perhaps Motacilla flava , which are prominent, and even the only, visible daylight migrants among such small birds. These cross Iraq from east to west in autumn in vast numbers and are thought to migrate round the Fertile Crescent past Damascus, rather than fly direct towards Africa. Comparisons are made with the Mediterranean region and the rest of the Arabian peninsula, and some comments are added on the matter of broad-front and narrow-front migrations.
In an appendix the most important aspects of migration of large non-passerine birds in Iraq are discussed.     

Wind conditions facilitate the seasonal water‐crossing behaviour of Oriental Honey‐buzzards Pernis ptilorhynchus over the East China Sea

Migratory raptors rarely fly over stretches of water larger than 25 km, although different species undertake water crossings of varying lengths, depending mainly on their wing morphology. Oriental Honey‐buzzards fly c. 680 km over the East China Sea in autumn from breeding areas in Japan to wintering areas in Southeast Asia, but avoid this long water crossing in spring. We investigated the effects of weather on this exceptional migratory behaviour and its seasonality through a maximum entropy niche modelling approach. We used data collected through satellite tracking of 31 adult birds as presence points and a set of variables related to wind, precipitation and convective condition as environmental predictors. Results of modelling showed very different, almost non‐overlapping, areas suitable for migration over the East China Sea region in autumn and spring. Suitable migration routes in autumn mostly occurred over the sea, whereas suitable areas for spring migration mostly occurred over land, suggesting that circumnavigating the East China Sea is preferable in spring. At the regional scale, wind conditions facilitate water‐crossing behaviour of Oriental Honey‐buzzards in autumn, but not in spring. Specifically, suitable tailwinds over the sea enable water‐crossing in autumn, whereas in spring, wind support and convective conditions are best over land. Our modelling did not suggest any importance of convective conditions for autumn migration. However, we expect that at smaller temporal scales, convective conditions would be a considerable facilitator of the water‐crossing behaviour in this species.     

Blackcaps Sylvia atricapilla stopping over at the desert edge; inter- and intra-sexual differences in spring and autumn migration

Spring and autumn Palaearctic-African migration patterns of Blackcaps Sylvia atricapilla during stopover at Elat, Israel, showed that males appeared significantly earlier than females during spring but not during autumn migration, suggesting that in males there is a stronger drive to reaching breeding territories early. The difference in mean appearance dates between sexes in spring tended to be greatest in years when the males appeared earliest. Longer spread of passage (the dates between which the central 50% of individuals were captured) for each sex in spring was found in years with an early mean passage datebut was significant only for females. These observations suggest that the timing of Blackcap migration is governed not only by endogenous factors but also by exogenous factors, and when the environmental conditions are unfavourable, the differences in passage dates between sexes decrease and the passage lengths shorten. The early individuals (both males and females) that stopped over at Elat in spring were those with relatively small body size (as indicated by relatively short wings) and relatively large fat reserves and in good body condition (as indicated from fat score and body mass/wing-length ratio). No differences in body size between early and late transients were detected during the autumn migration, but late birds of both sexes carried larger fat reserves. These phenomena may be explained either by leap-frog migration or by differential fitness among wintering males and females or both, with only the fittest Blackcaps being capable of an early departure. These individuals probably face much less intensive intra- and interspecific competition with residents and other transients in stopover sites than do later transients.