Bats and pest control in l’Empordà

Galanthus Eco-Bats project: studying and promoting the potential of bats to control insect pests

Galanthus is a non-profit organisation founded in 1999 that since its beginnings has been dedicated to the study and dissemination of the natural values of our environment. It currently has three main lines of work urban biodiversity, flora, and bats.

In the area of urban biodiversity, it is committed to promoting the presence of native animal and plant species in our cities, emphasising their contribution to our own well-being. The activities carried out by the organisation are oriented to conserve and enhance the species that live in urban buildings, managing the habitat and solving any problems they may occasionally cause; To increase the presence of native fauna and flora in urban green spaces; And to naturalise urban aquatic environments (fountains, ponds and ponds) so that they stay in good condition and at the same time improve their environmental quality.

With the current state of globalisation and ease of movement, there is an increasingly worrying flow of species of exotic flora that reach these shores. Some of these plans find the perfect conditions here to thrive and they become invasive, compromising native habitats. Galanthus has a long history of cataloguing flora species and habitats of interest, as well as eliminating invasive alien species and habitat restoration, constantly testing new methods and tools to improve the management of our native habitats.

Bats are one of the most varied and unknown mammal groups in our habitat. Galanthus has been studying their distribution and ecology for more than 15 years, promoting conservation activities, carrying out outreach campaigns to raise public awareness about bats and the ecological importance they have in our ecosystems. In recent years, the organisation’s bat-related activities have focused on the promotion of populations and the evaluation of the ecosystemic services that they offer to us humans (in other words, the benefits they bring), studying the effect they have in pest control within agricultural scenarios, and spreading this knowledge.

Bat hunting a rice borer, one of the main pests of this crop (courtesy of Oriol Massana)

Bat hunting a rice borer, one of the main pests of this crop (courtesy of Oriol Massana)

Bats and pest control

Bats act as natural pest control, providing an ecosystemic service with a considerable positive impact on both the economy and public health. During the last decade, the first studies have confirmed the important role that bats play in controlling of agricultural pests and insect communities in general. We now know, for example, that if all North American bats suddenly disappeared, about $22 billion would have to be spent every year on pesticides to keep agricultural pests at bay. We also know that around 25,000 people in Thailand enjoy food security, thanks to the voracious appetite of the bats that consume the rice fields’ pests, which would otherwise devastate the crops.

In 2015 Galanthus, together with the Museum of Natural Sciences of Granollers and the Asociación de Defensa Vegetal del arroz del Delta del Ebro, published the results of tests carried out on rice fields in the Ebro Delta, demonstrating that where established populations were over 12 bats per hectare of rice fields, the control they exercise on pests represented a saving of about €50 per year in pesticides, in addition to the resulting environmental benefits. This first success story encouraged the research team to conduct trials in other contexts to see how these results could be extrapolated in other agricultural settings.

 Box-shelter occupied by bats in the rice fields of the Ebro Delta (courtesy of Oriol Massana)

Box-shelter occupied by bats in the rice fields of the Ebro Delta (courtesy of Oriol Massana)

For this reason, Galanthus intends to start a new trial in a different context, this time in the rice paddies of Empordà, with the following objectives:

  • Collect scientific and exportable data on the effect of bats on aquatic insect pests (mosquitoes, rice borer and chironomids) in the Empordà rice paddies.
  • Implement an exemplary experience of ecological pest management.
    Promote the use of ecological means of pest control, for a healthier environment and production.
  • Encourage the largest number of producers to integrate bats as one more resource for pest control.
  • Encourage the implementation of the experience at an international level, especially in developing countries where rice is a fundamental part of people’s diet.

At the research level, essentially the plan is to contrast two hypotheses:

  1. Bats consume the flying phases (not the larvae) of the various species of mosquitoes, chironómidos, and of the rice borer in the surroundings of the Empordà rice paddies. Consumption will be proportional to the density of bats.
  2. It is possible to increase populations of bats in the medium term and permanently by supplying artificial shelters around the fields.
Experimental project design

Experimental project design

In order to test these hypotheses, the following experimental design is proposed:

  • Twenty plots of rice fields with similar environmental characteristics are selected.
  • In 10 of them, shelters for bats are placed, looking for the most favorable site and orientation to encourage the rapid occupation of the boxes.
  • Over a period of 4 years, a detailed survey is carried out in all the plots looking at: a) the evolution of the agricultural pests being studied (rice borer); b) of the bat populations in the boxes (in the plots where they are sited); c) bat activity in the crop fields during the peak pest season (July-September).
  • At the time that bat populations are established, faeces from the shelter boxes will be collected to determine, by genetic analysis, if there is consumption of the rice borer.

The spread in use of any new or alternative agronomic methods can not occur if it the knowledge is not disseminated. This is why, in addition to its research aspect, the project also places strong emphasis upon the campaign to communicate the results. If positive results are obtained, it follows that the maximum possible number of farmers will be encouraged to integrate this approach and work to encourage bat populations as a more ecological pest control method.

Four areas of activity are planned as part of the project’s outreach campaign:

Firstly, the creation of a web space for the project, where the motivations of the project, the current state, the progress and the results achieved can all be presented, and more general information about bats and pest control will be posted. It also includes the organisations participating in the project; It will answer queries and requests from the public or institutions. The website is

An informative video will also be made on the importance of bats in pest control in rice fields and their impact worldwide. It will have a duration of 1:50 minutes and will be a 3D animation in figurative style.

On a more dynamic level, the social networks of the participating organisations will be used to publicise the project. Galanthus and the Museum of Granollers, between them, have 3164 Facebook followers and 1418 on Twitter, and this number is expected to increase as support grows.

Finally, the public and private media will be used to publicise the initiative and to broaden the awareness campaign. The results will be published in scientific journals in the agronomic sector io ensure their impact, as has already taken place with the trial of the Ebro Delta mentioned above.

The project starts in September 2016, and the following deadlines are proposed:

  • March 2017: Have the web page and video broadcast finalised.
  • April 2017: Before the bats come out of hibernation, have all breeding boxes placed on the selected farm plots.
  • July-September 2017 to 2020: Field data collection on bat and pest densities in all plots.
  • July 2017 to October 2020: Analysis of the data collected during the summer campaigns.
  • December 2020: publication of the results obtained.

A few words from the beneficiaries

We would like to express our sincere thanks to the Alchimia Solidaria Foundation for the support it has given us in starting this project. As an organisation that has been working on conservation and dissemination of nature for almost 20 years, we know how difficult it is to get support for these types of environmental projects, which are often not seen as priorities by our society.

In this sense, the commitment of the Foundation has been fundamental to begin the project, and we are especially grateful for the sensitivity that Alchimia Solidaria has shown us.

Thank you very much !!

2 thoughts on “Bats and pest control in l’Empordà

  1. 30 July 2018 at 5:27

    Thanks for sharing !

    1. armin
      1 August 2018 at 8:15

      Thank you for reading us!!! *_^

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