The ringing of the young Peregrine from the cathedral.
What is (scientific) bird ringing? It is marking a bird with a ring engraved with a unique code so as to be able to recognize it individually. And why recognize it individually? To collect information on its movements, longevity, behaviour of an individual, and of several individuals, to obtain real "life stories" that can then be extrapolated to the population of the species studied. In other words, ringing makes it possible to have quite concrete information on the lives of individual birds.
It is often thought that ringing is only a tool to studying migration. And this question often returns: since migrations are well-documented, why still band birds in 2018? Simple! First of all because the migration of birds is a behaviour in perpetual evolution. What was valid information 50 years ago or even 10 years ago, won’t necessarily hold up today. Birds adapt to changing living conditions on the planet as much as possible. Most often, admittedly, following the actions of mankind. This works both ways! The destruction of a marshlands, for example, forces the birds to change their pattern. However, the creation of an artificial lake can offer a new place to rest, or even a new wintering area. Ringing provides a lot of other information on the behaviour of wild birds as well. Let’s consider the couple of Peregrines in the cathedral as an example: the fact that both partners are ringed allows us to observe, with astonishment but certainty, that mother and son can reproduce together with great success. It is thanks to the ringng that we can determine the record age of the female. The typical dispersal strategy of Peregrine falcons can be compared: males move to nest close to their hatching site, while females can roam for hundreds of kilometers. A little more abstract: the study of demography.
By compiling, year after year, for falcon after falcon, the observational data, the re-observational data, and the possible decease of all ringed specimens, we are able to calculate the annual survival rate. This is the percentage of falcons that survive from one year to the next. Our knowledge of this rate is very important because it allows, if necessary, to sound the alarm in time if a new threat endangers the species. Finally, the discovery of dead ringed birds provides information on the causes of mortality. The compilation, also year after year, of all these data, still enables us to follow the evolution of threats and to evaluate if the implemented protective measures are effective. Thus, today we can say that in Belgium, it’s a rarity to find falcons which have been killed by poachers. Very good news indeed!
Of course, this scientific activity can only be carried out within a very strict framework. In order to ring falcons, you must complete an internship of at least two years and you must pass at least a theoretical and a practical exam, before being recognized as a collaborator-ringer of the Royal Belgian Institute of Natural Sciences. Then you can become authorized to band wild birds.
On the 6th of May, the young falcon of the cathedral was ringed. Why today? Because the falcon is now 3 weeks old, which is the ideal age to perfectly position the rings and to determine its sex. From about 3 weeks old, male and female Peregrines are already differentiated by size and weight. The falcon of the cathedral weighs 617 g. It is therefore a male without any doubt. A female should have weighed around 850 g. Quite a substantial difference!
To allow for a more precise observation, in addition to the metal ring engraved with a unique code in 7 characters, completed with the abbreviated address of the Institute, a second ring - in white plastic - was positioned at the left paw. It is engraved with a code in 3 characters (N / 1) which will hopefully help to identify the Peregrine with the telescope - or via a camera - when it has left the territory of the cathedral.