Formerly www.swift.utigges.il.eu.org

Hints for ringers

Ringing Common Swifts presents several difficulties. The unique way of life of the species does not make it easy to catch the birds and the lack of suitable rings for their elliptical section legs makes for further problems.

Handling advice for Swift ringers

• Swifts should only be handled by experienced ringers.
• A calm quiet atmosphere should be maintained.

First aid advice for Swift ringers

No statistics are available for injuries sustained during swift ringing. They do happen. When planning a ringing event please take the following precautions:

• A suitable box with a soft cloth on the base readily to hand for any casualty.
• Establish where the nearest avian veterinary surgeon is based. Make sure they are available and familiar with the advice for injured Swifts by
  Christiane Haupt. (http://www.commonswift.org/Veterinary-Help-for-Common-Swifts.html)
• This initial examination should establish if the casualty has a fatal problem.
• Locate the nearest specialist carer and their availability for rehabilitation.
• If the swift will not fly willing from an open hand never throw the bird or abandon it.

 Providing the casualty has not sustained a fatal fracture and suitable care is available recovery chances are very good.

The leg of the Common Swift is not round, but of elliptical shape and feathered              Photo: G. Kaiser

The following is a collection of the various experiences and opinions of different ringers, everyone of whom is a long-term Swift ringer.

Ringing in the field

Pierfrancesco Micheloni specialises to in catching flying Swifts. He uses a mist net in his small town garden. The net is about seven metres high and twelve metres long and is fixed on pine trees, which are not much bigger than the net. From May to the beginning of July he catches about 500 Common Swifts this way. Another good method is to place the nets near a lake with low herbal vegetation such as Sylibus marianum, which attracts insects, but any similar place would work as well. He uses recordings of Common Swift calls to attract the birds down to the net level. The method of attracting the birds by their own sounds works only with non-breeding Common Swifts in the trapping area; the breeders are not interested in these sounds (see how to attract Common Swifts at http://www.commonswift.org/Attracting-Common-Swifts.html).

The best time period for ringing flying non-breeding Common Swifts is from the 8th to the 14th week of the Common Swift calendar (see http://www.commonswift.org/The-Swift-Calendar.html). Outside colonies, the morning is usually a productive time to catch and ring Swifts. But flocks of non-breeders can appear in loose formations at any time, anywhere. Within colonies the best time to catch and ring is in the morning and evening.

At reservoirs and beside lakes, a technique called ‘flick-netting’ can be used. Two ringers hold the poles with the net attached. They hold the net horizontally to the ground until a Common Swift approaches, then they very quickly raise it to the vertical catching the Swift in flight. This can be a very successful method on a summer evening.

For ringing Common Swifts in the wintering grounds, luck is essential. One should pick a nice damp day and a tree lined avenue or a similar topographical setting, set a mist net with one end static and the other end held horizontal by the ringer. When the Swifts come along on their feeding flights one just swings the net pole upright and they should fly in.

Ringing on the nest

Ringing at the nest is both problematic and controversial. In the experience of Erich Kaiser, the bond of parent Swifts to their nest is highest shortly after egg laying (5th and 6th Common Swift calendar week). So this would be a good, but short "window“ to ring the adults and to avoid desertions from the nest, which would cause the death of the siblings and the failure of a whole generation. But many other ringers have different experiences and find certain "ringing windows" not necessary.

When the chicks are very young and only a few days old, one of the parents may be found in the nest with them during the day, so it is better to avoid the early chick period to minimise disturbance. Allon Bear rings at night because this way it is very likely to ring the whole family in one visit. A good period is when the nestlings are big enough but before they are ready to leave the nest. If one or both parents are missing he keeps on visiting until he has caught them both. About 7% of the adults left the nest after they were returned after ringing or control, but no dead chicks were found in the nest in later ringing rounds, so that one can assume that desertion did not happen.

Mauro Ferri co-operates with the ringing team of Fausto Minelli and they ring mainly at the nest. Well before the birds return from Africa to their nests, the nest sites are cleaned. Trash, debris and carcasses are removed and the nest site is disinfected with an insecticide specifically for eliminating ectoparasites on birds. These products can be obtained from veterinary practices. Non-specific insecticides must not be used.

For this Italian team the best time to ring breeders on the nest is the 5th to the 8th week of their stay (see http://www.commonswift.org/The-Swift-Calendar.html). The approach to the nest sites should always be done without noise or fast movements. Every reachable nest site should be checked. The Common Swifts are caught on the nests between 21.00 and 23.00 hours. In North Central Italy, this is about 01.30 to 03.30 hours after sunset. Both parent birds are taken at the same time from the nest. Recovered rings are controlled and birds with no rings are ringed. The eggs are counted and noted and when there are already chicks, their age is estimated for a later ringing. After control and ringing both parents are returned together, and after the chicks.

The best time to ring pulli is when they are about 3 to 5 weeks old (10th to the 12th calendar week; to check the chicks age, see the growth documentation at http://www.commonswift.org/nestlings_english.html). Preferred time of day is late afternoon, aiming to cease the ringing activities before sunset. The approach to the nest sites is again made in silence. Every nest is checked and the notes from the first visit can be helpful here. The visit to every nest starts with the adults when they are present; if they have no ring, they are ringed. The rings of those adults who have one are controlled, not disturbing them any more than necessary, but they do have to be taken out from the nest as well to achieve this. The chicks are ringed and put back on the nest before the adults.

A third ringing effort has to be made later for missing adults and those chicks that were too young during the second run.

Desertion from handling adult birds at the nest has not been noted by this team. Dead chicks and adults recovered during the three ringing efforts have been in all causes caused by Edible Dormice (Glis glis). They often kill the birds by typically biting them on their shoulders, leaving the carcasses to mummify inside the nest box, It is not known why they do this, it is certainly not for food.

Dick A. Jonkers follows a different concept. After experiencing desertions, he does not ring birds on the nest anymore. To catch flying Common Swifts he uses mist nets. The best places are at fish ponds with many insects and at the times with least wind, and when the Swifts are flying low. Other good places are near hedges. This netting is done with two people, each holding a pole of the net.

Likewise, to avoid desertion, Bernard Genton does not ring adults at the nest. He rings the pulli when they are at least 30 days old between 3 and 4 pm. At this time the colony is mostly devoid of adults. The non-breeders are out and the parents no longer have to guard the nest site so are away from the nest too, feeding.

In the Museum of Natural History in Oxford George Candelin's team performs nest box checks and ringing in the late morning on a Saturday every week during the season. Swifts are aerial birds and it must be difficult for them to come from the wide open sky into a small enclosure so they are nervous; noise, light and disturbance will cause desertion until they have gained confidence. So the team rings the pulli at 5 weeks after hatching (= 14th calendar week); they have found that it is also safe to handle the adults at this time. Adults on eggs, or with naked and downy young are never touched as there is a high risk of desertion. Desertion rates for pairs that are prospecting, nest-building or incubating are about 68%, but at 5 weeks the desertion rate falls to about 0.1%.

When the young are nearly ready to fledge (week 5 onwards, see http://www.commonswift.org/The-Swift-Calendar.html) the adults will have more confidence and will have a bond with the young so it is safe to handle them then.

The problems of ring design

The elliptically shaped leg of the Common Swift requires a special ring, not yet available in all countries or ringing societies. In addition, the foot of the chick is fatter than the foot of an adult bird.

In Israel Allon Bear uses CC rings which are made in Sweden. They fit perfectly to the Common Swift’s leg. The measurements of the ring are 3.5 x 5.5 x 0.6mm. These rings are also used in Switzerland. But in Italy and Germany the local ringing organisations do not employ this ring. Pierfrancesco Micheloni as well as the Fausto Minelli and Mauro Ferri team use INFS-Ozzano E. (model W) aluminium rings of 3 mm. Pierfrancesco Micheloni cuts a tiny piece off from the length. It is necessary to check the ring after fixing to the foot. It must move easily and not be too tight; otherwise it could damage the leg.

The elliptical section of the Common Swift's leg requires a special ring                 Photo: Pierfrancesco Micheloni

The INFS-Ozzano E 3mm aluminium ring is used in Italy. A piece is removed to enable it to fit the Swift's leg                                                                                                        Photo: Pierfrancesco Micheloni

If the ring does not fit correctly, it may get lost or slip down and amputate the Common Swift’s foot.

Here a badly-fitted ring has slipped down and deformed the Common Swift’s foot Photo: Pierfrancesco Micheloni

In Germany the ring in common use has to trimmed by 1 mm Photo: Erich Kaiser

In the UK the BTO uses a special ring made by Porzana Ltd. of Icklesham in Sussex, which is used only on the Common Swift and the Kingfisher. They are designed to be variable in size, and can be shaped to the individual or species. They are described as 2.5/4.0 mm (i.e. they can be shaped elliptically with a standard diameter of 2.5 mm x 4.0 mm) but they can be overlapped to provide a smaller ring if need be. The aluminium alloy used is 4.0 mm wide and is 0.38 mm thick. The shape is like a number '6' (see photos). This ring is made of soft aluminium and is rolled onto the leg with the fingers. It is closed using the fingers or the third hole in the BTO small ringing pliers. The bird is held in a standard ringer's grip with the bird's head between the index and middle fingers.

For details of the ring, please look at http://blx1.bto.org/btos/ringingSales.html. This ring is used about 2500 times a year.

Special rings for Common Swifts used in Great Britain

The British ring is shaped like a number “6”                                                                     Photo: George Candelin           

The ring is very soft and can be closed by using the fingers.                                           Photo: George Candelin

To fit it you first roll in the short end then close the long end over to form a circle.           Photo: George Candelin

In Switzerland ringers use the special Swedish ring for the Common Swift. It is made of aluminium with a special alloying which makes it more pliable. It weights 0.09 g and the sizes are 3.75 mm inner diameter, and breadth of 5 mm. It is described as "Calibre S".

The special ring for Common Swifts used in Switzerland is 13,8 mm long                          Photo: Bernard Genton

The Swiss ring is 5 mm broad                                                                            Photo: Bernard Genton                                                

In the Netherlands aluminium rings of the Vogeltrekstation in Heteren are in use. These rings have a diameter of 3.5 mm with a width of 4.0 mm.

How to perform the ringing

To ring a Common Swift one first prepares the ring and opens it so that the leg will fit into the space available. One then takes the bird into one hand, head towards oneself. In England BTO ringers are trained to hold the bird with the head away from oneself. One gently pulls the foot between the 2nd and 3rd finger and slips the ring over it. Then the ring is closed by pressing it gently with the fingers. One has to be careful so that the two ends meet each other exactly. Then one clamps the ring shut with the special pliers. By international agreement chicks are always ringed on their left foot (seen with the eyes of the ringed bird) and adults on the right foot. After closing the ring, check the ring by turning it and by slipping it up and down a bit to see it is closed, movable and not stuck, and most important, cannot slip down over the foot and cripple the bird.

Hold the bird head pointing as shown & take the foot carefully between three fingertips Photo: Ulrich Tigges

Take the prepared ring and slip it over the foot, then slightly close it                    Photo: Ulrich Tigges

Lock the ring very carefully with the pliers as shown                                                        Photo: Ulrich Tigges

Ageing the Chicks and Adults

To determine the age of pulli (chicks) on the nest, see the photographic study of nestlings at (http://www.commonswift.org/nestlings_english.html).

With the help of the wing feathers it is possible to establish the age of flying Common Swifts from the first until the second year. Fledged birds born in the current year have white edges to the flight feathers and white “scalloping” on the feathers of the head and body; this wears away during the winter months and following summer.

The following photos were all taken in Ancona Province, Central Italy by Pierfrancesco Micheloni, who also determined the age of the birds.

The individual in the next two photos is one year old (born the previous year).

The hand feathers are not yet moulted                                        Photo: Pierfrancesco Micheloni

In addition, the arm feathers have not yet moulted                                  Photo: Pierfrancesco Micheloni

This Common Swift is two years old.

The primaries have moulted with the exception of the outer one, which is very worn. Note that the inner feathers are bluish, rounded and strong                                                                   Photo: Pierfrancesco Micheloni

The next two photos show an adult Common Swift at least three years old.

An adult Common Swift (three years old)                                                Photo: Pierfrancesco Micheloni

 Photo: Pierfrancesco Micheloni

In both photos the contrast between inner and outer primary is obvious, but the outermost feather (no. 10) is not so worn as in a two year old bird

Note that an unshed 10th (outermost) primary is found in 30% of adult Swifts in Europe (APUSlist No. 0062).

In the Americas ringers face the same problems as in Eurasia. Charles Collins writes that he has problems with getting "bands" (i.e. rings) for Swifts. A larger diameter band is required to fit the thick, but short, Swifts' legs but as these rings are far too long they have to be cut down. This has to be done for both White-tipped Swift Aeronautes montivagus in Venezuela and White-throated Swift A. saxatalis in western North America.

 

Contributors: Paolo Politi, Istituto Nazionale per la Fauna Selvatica (Ozzano) Pierfrancesco Micheloni, Mauro Ferri, Erich Kaiser, Oxford University Museum of Natural History George Candelin, Jan Holmgren, Gillian Westray, Schweizerische Vogelwarte Dr. Matthias Kestenholz, Allon Baer, Bernard Genton, Alan Martin of Porzana Ltd., Dick A. Jonkers, Yaron Baser, Eric Öhman of I.Ö. Mekaniska AB, Charles T. Collins and Edward Mayer, who edited the English text.

Manufacturers of dedicated rings for the Common Swift (Apus apus):

I.Ö. Mekaniska AB in Sweden

http://web.telia.com/~u36307969/

Porzana Ltd in the United Kingdom

http://www.porzana.co.uk/