Recuperaciones por condición para Ganso del Nilo

More than half of the reencounters refer to birds that were alive and identified by other means, predominantly metal or colour rings being read in the field. Many colour ring readings are not yet included in atlas. One quarter are shot birds, which mainly occur in the Netherlands, where culling takes place since the 1990s and gradually increased to 20,000 birds annually and caused the population growth to level off (Gyimesi & Lensink 2012). Just 3% are ring recoveries, all in Germany and Belgium. 12% were found dead, most during the winter months, as Egyptian geese are sensitive to cold weather and population size in the Netherlands was reduced during severe winters (Lensink 1999).

Movimientos anuales para Ganso del Nilo

Little variation in time and place visible, with year-round concentrations in Greater London, Brussels and surroundings, Amsterdam, The Hague and German Ruhrgebiet, from where scattered encounters follow river Rhine towards SE. Scattered encounters away from these core areas in N and E Germany occur sparsely in all months.

Conectividad por mes por región para Ganso del Nilo

Limited movement in England, mostly from inland sites during Jun-Jul to coast in Aug-Mar. Most birds in W Europe ringed as nestling or during moult in Belgium in May-Sep. These connect predominantly towards N and NE in the Netherlands and Germany in all months, with a tendency towards longer connections towards NE into Germany occurring in Oct-Mar. In C Europe, longest movements by birds in Dec-Mar connecting to Belgium and Netherlands in May-Sep. Movements in other months relatively short distance in all directions and months.

Recuperaciones por condición para Tórtola europea

Despite its long-term decline, the species is still hunted and most recoveries are of shot individuals. However, the development of demographic studies means that 45% of the recoveries have been of live birds since 1991. There was a peak in recoveries in the mid-1960s, then a continuous decline related to the similar decline in Turtle Dove numbers overall. The majority of recoveries of hunted Turtle Doves were in the 1960s and 1970s.

Movimientos anuales para Tórtola europea

There is currenlty no evidence of strong connectivity between the wintering grounds in the Sahel and breeding regions, so it is possible that wintering Turtle Doves spread across the Sahel, whatever their origin, and that breeding populations across Europe are panmictic (mating is not structured; Calderón et al. 2016). The precise delimitation of migration divides is not yet totally clear, especially in the S regions, from France to the Balkans.

Conectividad por mes por región para Tórtola europea

The timing of migration is similar along all flyways. Birds are on the breeding grounds in Jun-Jul and in their S distribution ranges in Sep-Apr. S migration starts in Aug, with a peak in mid-Sep in S Europe. N migration continues into May. High numbers are hunted on passage in Sep, Apr and May, hence the timing of recoveries largely depends on hunting activities.

Recuperaciones por condición para Cuco común

Approximately half of the encounters refer to birds recovered dead, of which the majority were not shot or otherwise intentionally taken. Some 39% of encounters refers to ringing recoveries, but has increased especially in recent decades. Until 1990, approximately half of the encounters referred to birds found sick or wounded, while more recently this category made up less than 20% of encounters. Bird are mainly shot at stopovers in S Europe and N Africa.

Movimientos anuales para Cuco común

Long-distance migrant spending only a very limited time at the European breeding grounds, arriving in late Apr and initiating southward migration already in late Jun. Migrates to C African wintering grounds via stopovers in the Baltic, S Europe, N Africa and the Sahel. Arrival at wintering grounds in Nov – Dec. Northward migration initiated in Feb. Satellite tracking revealed clockwise loop migration for all populations, with the northward route always being west of the southward route (Willemoes et al. 2014).

Conectividad por mes por región para Cuco común

Connections are restricted to movements within Europe as encounters from the wintering grounds are largely lacking. Cuckoos are present at the European breeding grounds between Apr – Jul and most encounters are from this period. Connections between Iberia and Italy and more northern areas in Feb suggests the northward migration route. During southward migration in Jul – Sep, birds from the British Isles, the Low Countries and France connect to Iberia, Italy and the Balkans. Fennoscandian and C European populations connect to Italy and the Baltic during Jul – Sep and do not use the route via Iberia. 

Recuperaciones por condición para Barnacla carinegra

Most recoveries are readings of metal or colour rings. Pre-1960 all recoveries from shot birds. Hunting ceased latest in Denmark in 1972. Most ringing activities took place in 1980ies and 1990ies with activity concentrated during spring. Hence, most recoveries are from same period.

Movimientos anuales para Barnacla carinegra

Wintering dark-bellied birds found furthest south in November through January, with movements from English and French coasts to Wadden Sea starting in February through April. Mass migration during the lasts days of May when winds are favourable through the Baltic to Arctic Russian staging sites and on to Siberian breeding sites in June. Autumn migration in September to Wadden Sea and on to UK and France in October. Svalbard recoveries very few but suggest movement of light-bellied birds from Denmark and Northumbria in April/May and back in September. Canadian breeders leave for Iceland end of August and September, main arrival in Ireland in October, spring migration to Iceland end April/May, on to Greenland and Canada in June.

Conectividad por mes por región para Barnacla carinegra

North-west region (UK, Ireland, Iceland) holds wintering birds from each of the three populations. Birds wintering in Ireland are connected to Greenland and in Canada in summer. Birds wintering in the Northeast tightly linked to wintering sites in Northern Denmark and found on Svalbard in summer, dark-bellied birds wintering in the Southwest connect to breeding sites in Siberia in summer. Connections to wintering sites in France almost absent. Birds wintering on the French coast connect straight to Siberian breeding grounds, or via the Wadden Sea in spring. Birds in the Dutch Wadden Sea in May are tightly connected to Siberia in summer, pointing to importance of the area as spring hub before migration. Pattern is somewhat biased as most ringing takes place in May in the Dutch Wadden Sea.

Recuperaciones por condición para Cisne chico

Most encounters after 1980, with clear peak from 2016, and mainly during winter months in Western Europe. Small peak in August caused by ringing activities during moult in breeding area. Nearly all encounters refer to rings or colour marks being read in the field. Reports of shot birds very rare, and all but one from Russia.

Movimientos anuales para Cisne chico

In November – February, all encounters concentrated in UK, Netherlands, NW Belgium and northern Germany, with occasional encounters further south. First movements towards NE along Elbe river and in Denmark begin March, Poland mid-March and first encounters Baltic end March. Low countries vacated by end March. Encounters scattered in Poland and Baltic, Finnish Gulf, Russian lakes and White Sea reached by end April. Few encounters in May, concentration in Russian breeding area from mid-May to end August. Nearly all encounters end September - begin October in Northern Baltic, move into southern Baltic and low countries by mid-October.

Conectividad por mes por región para Cisne chico

Encounters in winter in UK mainly connected to wintering sites in low countries in previous or subsequent winters suggesting frequent exchange. Few connections with Baltic. Birds in winter in Western and Central Europe show well connected network among main wintering sites within the area and are strongly connected to Baltic in April and October, and to Russian breeding area in May- August. A colour-marked Bewick’s swan caught on Iceland in its second calendar year in July and subsequently observed in Western Europe many times constitutes a rare exception to the pattern.

Recuperaciones por condición para Milano negro

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.

Movimientos anuales para Milano negro

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). 

Conectividad por mes por región para Milano negro

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).

Recuperaciones por condición para Carraca europea

Most old recoveries are of dead birds, even until 1990. Afterwards, a classical shift towards live recoveries is observed (~75%), including reads of colour rings and live recaptures. There are also unusual numbers of dead recoveries of electrocuted individuals.

Movimientos anuales para Carraca europea

Rollers display a broad-front migration across the Mediterranean Basin in autumn and eastern populations visit the Arabian Peninsula in spring. Autumn movements were, on average, in a more southerly direction for juveniles than adults, which were more easterly.

Conectividad por mes por región para Carraca europea

Most en route recoveries are from April and September in North Africa and the Middle East. Breeding sites are occupied from May to August, though there are some dispersal movements at the end of the summer before the start of the southward migration at the end of the August / beginning of September. Birds from Central Europe, where most of the ringing effort occurred, are in northern Egypt as early as the last days of August. In the Middle East, most spring recoveries are obtained in the second half of April. The juveniles seem to leave the breeding range later than the adults. Recent tracking data provide more detailed phenology of migration.

Recuperaciones por condición para Colimbo ártico

Protected species throughout most of Europe, game species in Russia but apparently not intensively hunted. N Europe accounts for most of the encounters (ca. 65%). About one third of all encounters obtained during the 1960s. Most encounters (ca. 62%) come from the period May-Aug. The percentage of recoveries based on dead birds stayed pretty high in the past (72% pre-1960, ca. 92% during 1961-90) but decreased markedly to 48% after 1990. Currently, more than half (ca. 51%) of all recoveries come from alive birds thanks to colour marking studies.

Drowning in fishing nets stays rather stable negative factor over the years – 16-17% from the total sample (33% of all dead birds in Finland; Saurola et al. 2013).

Movimientos anuales para Colimbo ártico

The species undergoes a flightless wing-moulting period of about a 6-8 weeks in spring, still on the non-breeding grounds (Russell 2020). Post-breeding movements start as early as Aug, breeding sites are left in Oct at latest. Birds breeding in Fennoscandia are encountered in the North/Baltic Sea region in Aug before continuing to their wintering grounds in S Europe (data from the Bay of Biscay, Adriatic, Marmara & Black Seas) which are reached as early as late Sep/Oct. Satellite tagging revealed almost straight autumn flights from Finland to the Black Sea (Lindholm, Forsten, 2020).

Birds stay on their wintering sites until Apr-May. Baltic Sea region is an important stopover area in spring as well (May, from Feb-Mar in mild winters) (Skov et al. 2011). Breeding sites are occupied as early as Apr but in N Siberia – late Jun (spring-thaw dependent).

Conectividad por mes por región para Colimbo ártico

Birds stay on their breeding grounds until late summer – early autumn. Breeding birds both from the Fennoscandian and Siberian populations stopover in the Baltic Sea region (the latter covering much longer routes W to N Europe) before continuing further SW, S & SE to their wintering grounds which are reached most often in mid-autumn – the Atlantic coast, Mediterranean & Black Seas, as well as some suitable wetlands inland. A bird has been found wintering (Dec) in two consecutive years at sites ca. 600km apart in the C Mediterranean Sea. Another bird marked in the S Ural Mts. has been subsequently encountered in E Black Sea (Ilichev 1978). Wintering grounds are left mid- to late spring and breeding sites are usually reached in late spring.

Recuperaciones por condición para Barnacla cuelliroja

Nearly 70% of recoveries are of live birds, although 20% were shot. In recent decades fewer than 10% of recoveries are of shot birds.

Movimientos anuales para Barnacla cuelliroja

Recoveries during autumn passage in Kazakhstan and Russia occur in Oct. Some birds reach the wintering grounds in Oct (Netherlands), but the majority of winter recoveries are in Dec and Feb (Hungary, Bulgaria). Spring passage encounters occur in mid-Mar (Germany) and the end of Apr (Russia). The only encounter in the breeding area is at the beginning of Jun.

Conectividad por mes por región para Barnacla cuelliroja

Only scant information is available. A bird ringed in Feb in the Netherlands and shot on Yamal in early Jun is the only connection between wintering and breeding grounds. A bird on passage in Kazakhstan in Oct was found on a main wintering site in Bulgaria in Feb. Two birds ringed in Moscow at the end of Oct and recovered in the Netherlands are of dubious origin. A bird breeding on a small islet in the Finnish Gulf, far outside the normal range, has been recorded in Helsinki city park in Sep and Oct. Finally, a bird on passage outside range in Germany in Mar was recovered west of Ufa, southern Russia, in Apr.

Recuperaciones por condición para Cerceta común

Overall, half of this species recoveries (>50%) are due to shot, because this species is hunted across much of Europe. Before 1960, recoveries from shooting were 44%, increasing up to 57% in 1961–1990, then decreasing up to 36% from 1991 to present. In this last period, it is remarkable that a high proportion of recoveries (58%) was due to birds captured alive, due to the efforts in ringing stations. The proportion of recoveries identified by other means like nasal saddles still represent a small proportion (<1%). Nasal saddles, however, revealed to be very useful to address population dynamics studies at certain sites (Caizergues et al. 2011).

Movimientos anuales para Cerceta común

Post-breeding migration starts as early as Jul. Birds remain at their wintering areas from Aug/Sep to Jan/Mar (Guillemain et al. 2006). Breeding grounds reached up to May. These estimates confirmed by by tracking data from birds from Italy (Giunchi et al. 2019). Tracking data also show that teals have slow speeds of migration (ca. 36 km/day) caused by long stopovers (Giunchi et al. 2019).

Conectividad por mes por región para Cerceta común

Temporal pattern similar between regions, i.e. independent of distance of migration. Post-breeding movement starts as early as Jun/Jul. Wintering areas reached since Aug/Sep. Return to breeding areas peak in Mar; by May most birds found at their breeding sites. Two juvenile recoveries in tropical Africa in Mar and two adults in E Asia in Oct and Nov.