- The new devices, which have already successfully passed the testing phase, make it possible to record the activity of chiroptera colonies in various galleries of Endesa hydroelectric power plants as well as in caves in both Catalonia and Aragon.
- These devices, which have been designed by the Centre de Ciència i Tecnologia Forestal de Catalunya (CTFC), a partner of the project, have a long battery life, which allows a continuous recording without interference over long periods of time and, therefore, a more accurate x-ray of the habits and phenology of the chiroptera.
- The action is part of the Endesabats programme, which studies how bats use the Company's hydroelectric facilities to improve their habitat while making it possible to study and learn about them, which is vital in the preservation of any group of protected spices.
Throughout the year, twelve state-of-the-art recorders will monitor the behaviour of the chiroptera colonies established in galleries and tunnels of various Endesa hydraulic power plants as well as in some surrounding caves. In the case of Aragon, these devices have been placed in various water-source caves and tunnels between Huesca and Mequinenza (in the municipalities of Montesusín and Fayón, among others). In Catalonia, they have been installed in the enclosures of the Camarasa and Canelles power plants, which are both in the Lleida Pyrenees. These devices were produced by the Centro de Ciència y Tecnologia Forestal de Catalunya (CTFC), in collaboration with the Museum of Natural Sciences of Granollers. Since 2013, the CTFC has provided interesting projects and data within the framework of Endesa's Endesabats programme in different areas of Spain. This programme is dedicated to the study of chiroptera in hydraulic facilities and their environments, and aims to increase the knowledge of these species and improve their habitat while obtaining more scientific information, which is highly valuable to contribute to their conservation.
Since its inception, the technicians of CTFC's Endesabasts have monitored the colonies of chiroptera in the caves and tunnels through recordings, captures and phototrap, among other techniques.
The incorporation of these 12 recorders allows a qualitative leap in the project. And, with a schedule set to record sounds one night a week, they can spend more than 5 months recording with no human interference. This point, which might seem anecdotal is, on the contrary, of great relevance. The presence of people, no matter how much insignificant this may be, always interferes in some way in the behaviour of any animal and, in a very special way, in bats. By reducing intrusiveness, much more real information is obtained about the behaviour of these species: when they arrive, when they go hunting, when they reproduce, between which shelters they move during the year, etc., making it possible to obtain a complete x-ray on the behaviour of these colonies. The recorders have a frequency that can record the ultrasounds and identify the different types of chiroptera from specific programmes that automatically identify sounds, together with the experience of the CTFC researchers.
In fact, the tests carried out during the past months have made it possible to obtain the first data at the same time that they have verified the proper functioning of the system. As an example, the recorder installed in the natural cave of Clot de Torrent, in the Aragonese region of La Litera, shows that the cave bat, always present although in low numbers, breeds there and moves towards mating caves from July.
Cave bat (Miniopterus schreibersii) from the Clot de Torrent cave
The large-footed bat arrives at the breeding caves in April, and during the breeding period between May and June, this remains constant until the babies can fly, and a very large increase in contacts is observed in mid-June. Probably, as in other caves, it seems that a large number also leave in August
Large-footed bat (Myotis capaccinii) from the Clot del Torrent cave
The Mediterranean horseshoe bat arrives in May, very late, and breeds in low numbers. It seems as though they leave in August.
Mediterranean horseshoe bat (Rhinolophus euryale) from the Clot del Torrent cave
The small horseshoe bat arrives in April and remains in low numbers, and looks to leave in August.
Small horseshoe bat (Rhinolophus hipposideros) from the Clot del Torrent cave
Another example, in the gallery of the Camarasa dam (Lleida), between April and August, practically 800 auditory contacts of the cave bat (Miniopterus schreibersii) and more than 9,000 large feet bats (Myotis capaccinii) were counted.
These graphs, extracted by the CTFC from ultrasound tracking with the recorders, show how there is a small colony that breeds during the months of May, June and July, and how in August specimens of cave bats and large-feet bats arrive from other caves and underground shelters to mate. This information confirms this location as a mating shelter of great importance with hundreds of specimens.
In addition to these quantitative data, that can establish very precise phenological patterns, the CTFC technicians have been working with the Museu de Granollers and the Government of Aragon to use this technique to extract population estimates. To make this possible, the data obtained is crossed with recordings from thermal or infrared cameras, with the help of other high-sensitivity recorders.
Bats are one of the most unknown groups of mammals in Europe and, at the same time, the second most diverse. All species in this group are protected by law and many of them are endangered. Bats, like insectivores, are a key species in ecosystems and a great ally of agriculture and forestry to control insect pests. That is why the CTFC and Endesabats work in a network with other entities such as SECEMU (Spanish Society for the Study and Conservation of Bats), SARGA (Aragonese Society of Agro-environmental Management) and the Government of Aragon as well as the Granollers Museum, with which they share information and proposals for the conservation of these species.
About Endesabats
With the Endesabats project, and in collaboration with experts from the Biodiversity and Animal Conservation Laboratory of the Centre Tencològic Forestal de Catalunya, Endesa seeks to improve the knowledge and conservation of cave bats, their ecological requirements and their relationship with the operation of hydroelectric power plants. It also wants to highlight the importance of these infrastructures for the threatened chiroptera species, in addition to proposing management measures to ensure their conservation and their presence in these types of facilities.
This project highlights the key role played by the infrastructures of most of the plants providing shelters for bats, favouring them to carry out their life cycle (breeding, mating and hibernation). It also shows how reservoirs favour the community of bats by providing them with hunting areas, such as the calm waters that are concentrated in the dam, and the riparian forest that grows in the vicinity.
These years of study and data collection are allowing Endesa to incorporate various actions to adapt its hydraulic facilities and be able to favour bat colonies. These measures include: conditioning the entrances to the tunnels, placing specific shelter boxes and reducing the luminosity in certain critical points for the chiroptera.
About Endesa
Endesa is the largest electricity company in Spain and the second largest in Portugal. The company is also the second largest gas operator in the Spanish market. Endesa operates an end-to-end business from generation to marketing and through Endesa X also offers value-added services aimed at the decarbonisation of energy uses in homes, companies, industries and public administrations. Endesa is firmly committed to the United Nations SDGs and therefore strongly supports the development of renewable energies through Enel Green Power España, the electrification of the economy and Corporate Social Responsibility. The Endesa Foundation is also active in CSR. Our workforce numbers around 9,600 employees. Endesa is a division of Enel, the largest electricity group in Europe.