2023-09-08 09:50:23
A study led by the Doñana Biological Station (EBD), research center of the Higher Council for Scientific Research (CSIC), warns of a “devastating” impact of the wind farms on bats in Cádiz and, possibly, in other areas of Spain.
This is the main conclusion reached by a group of researchers from the EBD-CSIC, the University of Lund (Sweden) and the University of Seville, after analyzing data from Mortality of bats collected between 2005 and 2016 in wind farms in the Andalusian province. The results of the study have been published in the journal Acta Chiropterologica.
Cádiz’s environmental monitoring plans include the daily presence of guards in the parks during daylight hours throughout the year. The guards’ mission is to locate animals killed or injured by wind turbines and order the turbines to stop when there is a risk of collision with a birdor side, especially in the case of threatened species.
Cádiz’s environmental surveillance plans include the daily presence of security guards in the parks during daylight hours throughout the year.
This surveillance plan is the most intensive of those carried out in Spain and is considered exemplary. The data from this plan put the bat carcasses found in the study period at 2,371, belonging to at least 15 different species of the 20 found in the province of Cádiz. The study focused on analyzing in detail the 582 incidents found in 2011year for which the most complete information was available.
High mortality rates
To estimate the true mortality rate, scientists carried out an experiment that consisted of placing more than a hundred bat corpses in nine wind farms to use them as bait and thus evaluate the search efficiency by the guards and the length of time the bodies remain in the field.
The surveillance personnel only located 17% of the corpses placed, despite the fact that the wind turbines were checked daily and were available for at least four consecutive days. Furthermore, the search for bodies was limited to clean areas (platforms and runways) which represent, on average, less than 15% of the potential search surface. Correcting for this detection bias, the researchers estimated an average mortality rate of 41 bats per turbine per year in the study area.
It is worth remembering that bats have a very low birth rate, one offspring (sometimes two) per female per year.
Sonia Sánchez, lead author of the study.
These results estimate that in In 2011, between 33,000 and 37,000 bats died in the wind farms of Cádiz. Likewise, according to the study, some of the prospected areas recorded the highest mortality rates in wind farms in the world documented to date.
“It is worth remembering that bats have a very low birth rate, one offspring (sometimes two) per female per year,” he points out. sonia sanchezlead author of the study.
“Our data reveal a “devastating” impact on bat populations, which in this case affect sedentary species, unlike what happens in other parts of the world, such as in the northern Europe or North Americawhere the most affected bats are migrators,” he continues.
New monitoring methods
A first conclusion of this study is that these environmental surveillance programs are not efficient for the search for bats and probably not for small birds either, since they are focused on large gliding birds and mask very high mortality rates.
The authors therefore recommend that new monitoring methods be implemented, more suitable for small animals, as well as studies to evaluate the real search efficiency of the search programs. environmental surveillance.
Mitigation measures, such as temporarily shutting down turbines during periods of high bat activity, have proven vital.
sonia sanchez
A second conclusion that the researchers reach is that we must urgently adopt preventive measures and effective mitigation measures to protect this group of mammals, which includes many threatened species, against the development of renewable energies.
In this sense, Sánchez recognizes the importance of wind energy as a source of renewable energy to fight against climate change, but calls for the need to balance power generation with the protection of biodiversity.
“Mitigation measures, such as the temporary stoppage of the turbines during periods of high bat activity, have proven to be vital to reduce the impact on these species and achieve that ‘green energy’ that is being talked about so much,” he concludes.
Reference:
Sánchez-Navarro, S. et añ. “High Bat Fatality Rates Estimated at Wind Farms in Southern Spain“. Acta Chiropterologica.
Fuente: Doñana Biological Station (EBD/CSIC)
Rights: Creative Commons.
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