“Passive Integrated Transponders” or “round-lipped rings” in the marking of Chiroptera in the wild and in captivity.

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Main researcher: Adrià López Baucells

Institution: Museu de Granollers-Ciències Naturals

Description:
Marking of bats has been, and still is, a widely-used tool since the early days of research in the field of migrations of these animals, both with ecological and with epidemiological focuses. In recent years, North America has seen a very significant proliferation of the fungal infection known as “White Nose Syndrome”, although in Europe it is also a leading issue and one in which the scientific community is greatly involved. Determining the migration routes of chiroptera is very important both for the adequate management of the environment for their conservation and for reliably predicting the possible expansion routes of these infections, as well as for preventing the decline of the species. There are various marking methodologies (wing tattooing, wing piercing, ringing, microchips, etc.) used for these studies, each one with advantages and drawbacks.

Ring marking is the most widespread methodology internationally. In its early days, the same closed aluminium rings as were used for birds were employed, but they were positioned on the forearm with the subsequent piercing of the patagium. After a long period of marking and as a result of the high mortality observed, it was decided in 1953 to create another type of ring that had less impact: the round-lipped ring, with smooth edges and that did not close completely to avoid causing damage to the wing, which is the one used nowadays. It appears that the use of rings has led to the decline of some chiroptera populations in Europe and North America, which has been a major topic of controversy for many years, and some countries have banned rings in the study of chiroptera.

Another type of marking has recently appeared, which has a great potential for use in this type of research: transponders. This technology is based on the sub-epidermal insertion of microchips measuring less than 10 mm in length called “Passive Integrated Transponders” (PIT), precisely because they remain passive and are only activated when they are within range of a reader. Initially, it would appear to be a much less invasive methodology than ringing, but it has not received widespread acceptance by the scientific community, with allegations that it is not a scientifically tested methodology with chiroptera (there is no evidence of its innocuousness) and the high price it entails in small local studies.

The aim of the project is to test the viability of PITs in comparison with ringing under strictly scientific and statistical procedures to be able to produce an official publication with the results of the study that will enable us to better assess the marking system (less invasive for the animals) in chiroptera migration studies.

The study contains four different blocks with the aim of covering all the aspects of the methodologies for comparison:

1. Study in a cave-dwelling species (Miniopterus schreibersii) in the wild.
2. Study in a crevice-dwelling species (Pipistrellus pygmaeus) in the wild.
3. Study in a crevice-dwelling species (Pipistrellus pygmaeus) in captivity.
4. Extensive bibliographical revision and collation of data locally and internationally.

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