Recoveries by Condition for Aquatic Warbler

The majority of recoveries are of first-year birds ringed on autumn migration and later recaptured on migration, with few on breeding sites. Very few (<1%) Aquatic Warblers have been found dead. Winter recoveries in Senegal in Dec-Feb are a largely a result of a concentrated effort to study the species in the Djoudj National park in the 2000s. Recent effort to ring migrants in the W and SW has also increased the numbers of recoveries. Further developments in tracking might provide new insights for this poorly known species in the future.

Annual Movements for Aquatic Warbler

The first migrants recorded in W Europe in autumn include a higher proportion of adults than later in the year, illustrating the earlier migration of experienced individuals. There is no detailed information to compare the movements of breeding populations from C and E Europe, although adult males breeding in Lithuania and Belarus have been tracked with light loggers (Martin Flade & AWCT pers. com.).

Connectivity by Month by Region for Aquatic Warbler

Autumn migration in W and SW Europe starts during the last dekad of Jul, peaking mid-Aug, althought there are some late records of migrants in mid-Sep, including adults with heavily worn plumage. Spring encounters are along the Mediterranean coasts of Spain, France and Italy during Apr, reaching the breeding grounds in May. From adults tracked with light loggers, they cross the Sahara mid-Aug-mid-Sept in autumn, and mostly in the first two dekads of March in spring (Adamik et al. 2016).

Recoveries by Condition for Black-necked Grebe

Protected species in Europe. Most encounters recorded in SW Europe (about 92%). Despite the differences in sample size, the recoveries coming from dead birds pre-1960 and 1961-90 constituted almost equal share (88 and 89% respectively); the recoveries from shot/hunted birds were more numerous for the latter period (52% vs 38% respectively). Live recoveries of ringed birds heavily predominated after 1990 – 93% of all cases. The recoveries based on by-catch casualties and oil spills had bigger share during the period 1961-90 compared to the subsequent period.

Live recoveries of ringed birds tend to be concentrated in areas with active ringing projects (Czechia, Switzerland, Spain).

Annual Movements for Black-necked Grebe

Those birds breeding in C Europe and migrating SE reach the Balkan Peninsula and Black Sea region as early as Aug, overwintering in the region until early- to mid-Apr. Those taking the SW direction, incl. the W European and Danish breeders, reach the W Mediterranean region and the Atlantic coast as early as Aug, mostly Sep-Oct, the spring return starting in late Mar – Apr. The species undergoes a flightless wing-moulting period in late summer and autumn (Aug to Oct), either staying on the breeding grounds or moving to large wetlands to form – sometimes big, concentrations. Birds marked in Spain have been recorded in NW Africa (Morocco) as wintering between early Aug and mid-Mar. Breeding sites in SW Siberia and adjacent areas are reached as early as Apr, but mostly in May.

Connectivity by Month by Region for Black-necked Grebe

Post-breeding movements of C European breeders start as early as late summer, being more pronounced in mid-autumn; the wintering grounds in W and S Europe are usually reached in late autumn – early winter. Breeding birds in Denmark have been recorded overwintering along the Atlantic Coast, W & C Mediterranean region between early autumn and early spring.

The breeding sites are reached back in mid-spring. A big number of birds marked in Spain during late autumn and early winter have been subsequently recorded as breeding in E Europe and W to C Russia. SW Siberian breeders have been found wintering in Caspian Sea as well (Ilichev 1978). Some birds marked in Spain during autumn migration move S covering short distances to Morocco, occupying their wintering sites between late summer and early spring.

Recoveries by Condition for European Bee-eater

Most encounters are obtained after 2000. They come mainly from May-Aug, peaking in Jul (70% of all records). Most encounters until Jul are based primarily on adults, while those from Aug and early Sep – mainly juveniles. Majority of encounters (ca. 98%) are recorded in C, SC and SW Europe (71, 22, and 5% respectively). Pre-1960 records sample is very limited.  The encounters based on dead birds decreased markedly over the years: from 65% in 1961-1990 to about 1% after 1991; those based on alive birds increased from 65% in 1961-1990 to 98% after 1991. The latter is mostly due to ringing recoveries. Shooting as а factor has been largely reduced from 18% in 1961-1990 to almost none after 1991.

Most of the distant (>=50 km) recoveries are less than 2000km away (but some are more than 5000km).

Annual Movements for European Bee-eater

Post-breeding dispersal takes place from late Jul, autumn migration in Europe is most intensive Aug-Sep. African wintering grounds are reached as early as Sep, the birds stay there until Mar-May (S Africa) or Apr-May (Sahel). Breeding sites are reached from late Apr (S Europe) to mid/late May in C Europe.

Birds from the recently established and heavily increased population in E Germany are tracked via the W & C Mediterranean Sea and Sahara to their wintering grounds in S Congo/N Angola, while those from SE Europe (Bulgaria) migrate via the Middle East and E African Rift Valley to their wintering sites in southern Africa (S Africa, Botswana, Zimbabwe) (Hahn et al. 2020). Tracked birds from the Portugal migrate S to winter in three W African regions:  Senegal/Guinea-Bissau, Mali/Ivory Coast and Benin/Nigeria (Costa et al. 2021).

Connectivity by Month by Region for European Bee-eater

Dispersal movements after the breeding season are evident as early as mid-summer. Within Europe, autumn migration takes place mostly in late summer and early autumn, the encounters progressively decrease afterwards. Birds stay in their wintering grounds in Africa mainly between mid-autumn and mid- to late spring. European breeding grounds are occupied in mid- to late spring, depending on latitude.

An encounter of a bird in Ukraine marked in Italy suggests that at least some birds from the eastern populations use routes across the C Mediterranean Sea as well. 

It was recently found that birds can migrate 14,000 km in the same group and groups that separate during migration can re-join after 5,000 km apart (Dhanjal-Adams et al. 2018).

Recoveries by Condition for Great Grey Shrike

Great Grey Shrikes are recovered throughout the year, with a peak in Oct (~22%). C, W & N Europe hold the bulk of encounters (~80% in total, 34, 24 and 22% respectively). Recoveries of dead birds have decreased from 74% before1961 to 6% after 1991; those of live birds increased from 22% before 1961 to 94% after 1991. Shooting was an important factor in the past, with 32% of total recoveries before 1961, mainly in France and N Italy. Nowadays, most of the recoveries are of live birds either recaptured by ringers or resighted.

Annual Movements for Great Grey Shrike

Post-breeding dispersal starts as early as Jul, more often in Aug, with most autumn movements in Sep-Oct. N European breeders take SW & S routes towards W, C, SC and even SE Europe where they are encountered as early as Sep (the Low Countries), but mostly from Oct-Mar, sometimes even Apr. The C European population migrates short distances, mainly SW, with encounters within the region or in W & SC Europe (France and N Italy, Sep-Feb). There is no breeding population in the British Isles but some birds from the Low Countries, Denmark and Scandinavia are encountered there in winter (Nov-Apr). A bird wintering on the Polish Baltic Sea Coast was encountered during the breeding season in eastern France.

Spring migration takes place mainly during Mar-Apr.

Connectivity by Month by Region for Great Grey Shrike

Autumn movements are evident from late summer, with pronounced migration in early to mid-autumn. The population breeding in N Europe migrates SW & S, reaching primarily W & C Europe, sometimes as far as SE Europe - encounters are mainly between mid-autumn and early spring, with some late migrants recorded in mid-spring. Those C European breeders which migrate mostly move SW, either staying in the same region or moving to the neighbouring regions of W & SC Europe. Some birds from around the N Sea (S Norway, Denmark, Germany, the Low Countries) overwinter in the British Isles. Breeding sites are usually re-occupied in early to mid-spring.

In some populations, mainly females migrate (Harris, Franklin, 2000).

Bird numbers in wintering areas fluctuate, some birds undertake hard-weather movements (Cramp, Perrins, 1993).

Recoveries by Condition for Merlin

Annual Movements for Merlin

Th short distances between breeding and wintering grounds do not inform on the detailed movements of merlins, but the amount of data indicate a probable direct move between grounds, to reach the closest suitable range. Icelandic subaesalon recoveries are concentrated in Ireland and the British Isles, with one down to the Azores. British birds, if moving, concentrate along the Gulf of Biscay, while birds ringed in the West region are either recovered further South in winter, or in the North in summer. Birds from the North move to the SW in parallel lines suggesting no particular migration bottleneck on the way South, and a major wintering range in South-West Europe, from Iberia to Italy.

Connectivity by Month by Region for Merlin

Birds breeding in the British Isles moving to the continent are not the rule, the recorded from the end of September to the end of March in South-West Europe. Birds ringed in the West in winter migrate to the North in summer (recoveries in Sweden and Norway). Birds from the North start to move to the SW in September, with most recoveries in the SW in October, while northern grounds are empty by November. At Falsterbo, Sweden, juveniles showed a pronounced migration peak in late September, and adults migrated earlier than young birds (Kjellén 1992). In the spring, recoveries indicate movements to the North already in March, peak in April, and recoveries in West Europe in May are rare.

Recoveries by Condition for Eurasian Hobby

Dead recoveries dominate across time, though if they represented nearly 85% of data before 1990, this decreased to 63% afterwards – which is still a very high proportion.

Annual Movements for Eurasian Hobby

A tracked adult used a spring migration route 2,000 km farther west than that in autumn, forming a migration loop (Meyburg et al. 2011). Another tracking study of Swedish birds confirmed the autumn route to Libya / Algeria, down to Angola, with the equatorial rainforest representing an ecological barrier (Strandberg et al. 2009). The German bird spent 65% of the year in Africa; its migrations across the Sahara took 4 days, and its spring route passed by Gibraltar (Meyburg et al. 2011).

Connectivity by Month by Region for Eurasian Hobby

Most recoveries of birds from the all regions (North-West, West, North, Central) at more southern latitudes in Europe are from September and October, then April, so with no surprise these months are the main periods when hobbies are on the move in Europe. As an example, recoveries of British birds in the Pyrénées are around mid-October. In November, hobbies are away from Europe, but the recovery database still contain few winter recoveries unusual for the species. At Falsterbo, Sweden, adults migrated late August, juveniles peak in the first half of September (Kjellén 1992). In spring, most returns are noted between mid-April and mid-May.

Recoveries by Condition for Rough-legged Buzzard

Annual Movements for Rough-legged Buzzard

Connectivity by Month by Region for Rough-legged Buzzard

Recoveries by Condition for Purple Heron

Overall, most recoveries due to birds found dead, either shot (33%) or found dead other than shot or intentionally taken or found sick/wounded (35%). This figure, however, has changed over time. Up to 1990, most recoveries were caused by birds found dead/shot. From 1991-present, 48% of recoveries are due to birds found alive identified with leg ring(s) or other means. The proportion of herons dead by shot is nowadays <5%, and the proportion of birds found dead or sick/wounded is 32%.

Annual Movements for Purple Heron

Breeding quarters left around Jul; recoveries in S Europe mostly from Aug to Oct, later in N Africa. Recoveries in the Sahel all year round, owing to ‘summering’ birds, which comprise mostly immatures. Migration to Africa fast; GPS-tracking reveal that birds can reach the Sahel (ca. 4000 km) within 5-7 days from Europe (Van Der Winden et al. 2010). One individual even flew 5600 km non-stop, mostly over sea. Migration occurs mostly at night. Herons can make few one-day stopovers in Europe or N Africa, but the long stopovers used to gain fuel are carried out during a period of weeks before departure or after arrival south of the Sahara (Van Der Winden et al. 2010).

Connectivity by Month by Region for Purple Heron

Recoveries un Europe mostly up to Sep in autumn. Arrival to N Africa mostly in Sep, and to the Sahelian belt in Oct. Movements back to breeding quarters patent in Africa in Mar, also in Europe. Many recoveries in Europe in Apr, showing important passage to breeding quarters. Besides this general pattern: (1) wintering in Europe reported, with recoveries as far as The Netherlands in Dec; (2) summering in Africa also detected, in this last case mostly due to non-breeding, immature birds.

Recoveries by Condition for Black Kite

Overall, most recoveries caused by birds found dead other than shot, also sick/wounded. This pattern, however, has varied with time. Before 1960, most birds were found dead, either by shot (ca. 40%) or found dead, sick or wounded ca. 40%). Since then, the proportion of birds found dead by shot has decreased and, from 1990 to present, roughly 50% of the birds are identified by their metal ring or other marks. However, 45% of birds are still found dead other than shot. This is patent in Africa, where there is a proportionally lesser amount of recoveries of birds seen alive.

Annual Movements for Black Kite

Departure from breeding sites shortly after fledging in adults, in Jul. Premigratory concentrations in Europe in Jul, movement to Africa patent in late Jul/Aug, up to Sep/Oct. Most recoveries in African winter quarters from Oct to Mar. Arrival to breeding quarters varies regionally (from Feb to Apr; delayed arrivals with increasing latitude), also temporal settlement patterns, which can happen in less than 20 days to up to 2 months (Sergio et al. 2007). Satellite telemetry studies reveal that adults improve their pattern of migration as compared to first-/second-year individuals, which has advantages in terms of survival or fitness (Onrubia & Martín 2021). 

Connectivity by Month by Region for Black Kite

Stronger flocking in autumn than in spring (e.g. Agostini et al. 2004). Major passage over S Europe to Africa chiefly channelled through two main geographical straits in autumn: Gibraltar (up to 170,000 birds, peak in Aug, less in Sep) (Martín et al. 2016); Batumi -Georgia- (ca. 100,000 birds, peak in Sep) (Verhelst et al. 2011); weaker passage through C Mediterranean, via the Sicily Strait (Onrubia & Martín 2021). In spring, main flow through: Gibraltar (peak in Feb/Mar); Sinai peninsula (peak Mar/Apr) (Panuccio et al. 2013).

Recoveries by Condition for Black-crowned Night Heron

Both in Europe and Africa, most recoveries are due to birds found dead, with more or less similar proportions between those dead by shot and those found sick/wounded.  An also remarkable proportion of recoveries is associated to unknown causes, but most of these might be due to birds found dead. The number of recoveries of birds seen alive (e.g., identified from leg ring(s)) is relatively marginal in the data set.

Annual Movements for Black-crowned Night Heron

Migration starts mostly in Aug, with substantial movements by Sep onwards. Recoveries in C Africa found from Jan to Dec, but note however that some birds seem to summer in Africa. Most birds would reach C Africa in Sep or later and would leave this region before Mar. The distribution range of birds overwintering in Europe is wide, from SW to SW Europe, also reaching the N Sea and UK; again, high overlap between regions of origin. Differential reporting rate of ring-recovery data in Europe/Africa probably provides an over-representation of those birds spending the winter in Europe (recoveries from Nov to Feb).

Connectivity by Month by Region for Black-crowned Night Heron

Movement patterns fairly similar among regions, so for details see the Annual movements’ section.