Conservación de quirópteros en el Sur de Europa

This doctoral thesis aims to advance the knowledge about bat populations in southern Europe, with special emphasis on two aspects: their winter activity in temperate climates of southern Europe and their relationship with environmental variables, and the impact of wind energy infrastructure development on this faunal group. The expansion of renewable energy, especially wind energy, is crucial in the strategy to mitigate climate change. However, there is growing concern about the impacts this energy source may have on biodiversity, with bats being particularly sensitive, and the need to develop tools to properly assess these impacts and mitigate their effects. In this line, the results and conclusions obtained in the works composing this thesis seek to provide new information to aid in the development of bat conservation measures and to understand the mechanisms explaining bat mortality in wind farms, which in turn allows the development of practical tools that managers or researchers can use for decision-making related to future installations or restructurings of existing ones. In the first chapter, we delve into the winter activity of these animals. It is well known that bats include a hibernation period in their annual biological cycle during the coldest months. However, in regions like southern Europe, where winter temperatures are milder, bats show different ecological requirements for winter activity, which has implications for their management and conservation. In our study, we recorded winter activity of at least four species (Eptesicus isabellinus, Nyctalus leisleri, Pipistrellus pipistrellus, and Pipistrellus pygmaeus), which was directly related to the daily maximum temperature. This study provides relevant information to understand how climatic conditions influence bat winter activity, anticipating possible ecological consequences under future climate change scenarios. In the second chapter, we investigated the temporal patterns of bat mortality in wind farms in the province of Cádiz, using a dataset spanning 11 years (2009 - 2019) across 904 wind turbines in the province of Cádiz. A total of 2,858 deaths corresponding to 10 different genera were reported, although over 90% of the affected animals were individuals from the genera Pipistrellus, Eptesicus, and Nyctalus. Bat mortality occurred throughout the year, including winter months in the case of the genus Pipistrellus, although most deaths occurred during summer and autumn, especially in August and September. Mortality correlated positively with daily maximum temperature, increasing from 20°C and more markedly when the temperature exceeded 30°C. These results highlight the importance of regional projections from global climate models, with increasing maximum temperatures and milder winters, predictably increasing bat mortality in wind farms in the coming decades. In the third chapter, using the same dataset, we conducted a spatial pattern analysis of bat mortality. To do this, we applied spatial modeling techniques to our data, considering the effect of different variables related to landscape, land use, topography, and technical characteristics of the wind turbines. The results show an evident spatial aggregation of mortality, as almost half of bat deaths were concentrated in only 10% of wind farms and 8% of turbines. The developed models suggest that proximity to bodies of water was the main factor to consider when assessing the danger of a wind turbine for bats. Additionally, a larger rotor diameter also implied a higher risk of mortality. Considering current trends in wind energy development, which involve replacing current turbines with larger capacity ones and, consequently, larger dimensions than current ones, and the increasingly lower presence of water bodies accessible to these animals due to drought, this study highlights the need to analyze the location of future wind turbines beforehand to minimize their impact on this faunal group. Finally, in the last chapter of this doctoral thesis, it has been demonstrated how the use of Stochastic Dynamic Models (StDM) offers a very effective tool for making predictions about the evolution of bat mortality under different scenarios. In this context, a dynamic systems model based on the same dataset considered in the previous chapters was developed. This model considered spatiotemporal gradients encompassing environmental, meteorological, and wind farm technical variables. Scenarios were projected 10 years into the future and encompassed, for three different groups of wind farms categorized based on historical mortality data, the current situation prolonged over time, the implementation of mitigation measures, the repowering of these wind farms, and the application of mitigation measures in repowered wind farms. Simulations obtained from these scenarios emphasize the effectiveness of implementing simple mitigation measures to significantly reduce bat mortality in all considered scenarios. The implementation of such measures is especially critical in low-risk repowered wind farms, where mortality increases almost 1000% compared to the same unrepowered wind farm. Our results support that, in the current context of climate change, bat winter activity will increase in our study area, as well as their susceptibility to the impact of wind farms. It is therefore essential to develop conservation strategies that anticipate these scenarios and implement measures to mitigate the impact on bats of wind energy development, which paradoxically is proposed as an essential measure to mitigate the effects of climate change itself.

Author dc:creator

• Salguero Pérez, María del Mar

Advisors dc:contributor.advisor

• Muñoz Arroyo, Gonzalo
• Muñoz Gallego, Antonio Román

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 Internacional

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc-nd/4.0/

Language dc:language.iso

spa

Handle dc:identifier.uri

http://hdl.handle.net/10498/36009

OAI identifier oai:identifier

oai:rodin.uca.es:10498/36009