Optimisation du marquage d'oiseaux par la pose de bagues couleurs

How to optimize the number of coloured rings on birds? Coloured rings are commonly used to individualize birds. A combination of colour rings enables to find the unique number registered on the metal ring. These colour rings allow to remotely control birds instead of capturing them again. These rings designed to minimize any potential perturbation for the individuals in their movements, but several papers showed considerable effects on the mate choice, the reproduction or the predation. It is often not necessary or not possible to capture hundreds or thousands of individuals to study the biology or the ecology of birds. To study a small bird population, it is possible to get a big number of colour ring combinations without putting a big number of rings. To put fewer rings is more comfortable for the bird and less time consuming during its manipulation. This article proposes solutions to ringers who wish to optimize the number of colour rings. The mathematical propositions show that it is better to systematically use the metal ring as being a part of the combination. It enables to increase very significantly the number of combinations while reducing the number of rings. To put only two colour rings in addition to the metal ring offers enough
combinations for most of the field ornithological surveys.