Ecosystem services, tropical agriculture, forestry and habitat regeneration provided by bats
The value of wildlife to sustainable agricultural, forestry, and natural ecosystems is increasingly recognised. Concerns about the adverse effects of pesticides highlight the importance of natural pest controllers, and the value of natural pollination services in agricultural and forestry systems.
Bats, which form a third of all mammal species globally, are estimated to be wortharound £23 billion per year to the agricultural economy of the USA (minimum estimate £3.7bn pa), through the prevention of insect damage to crops such as cotton (Boyles et al. 2011). Recent work has demonstrated that bat predation not only prevents direct damage to corn from ear-worm moth caterpillars, but consequent reductions in fungal infections improve crop quality (Main and Boyles, 2015).
Almost all published research on the ecosystem services provided by bats has been conducted in North America. In Europe and neighbouring states, a network of scientists is currently being established to address this question, and to investigate the potentially disruptive effects of climate change (COST Action EU grant co-written by applicant, €500,000, https://climbats.eu/). However, there is almost no research in DAC ODA recipient countries, despite the potentially enormous contribution to the ecological and economic sustainability of agriculture and forestry there. One of the very few research papers available estimates that the wrinkle lipped bat (Tadarida plicata), predating upon a major rice pest (Sogatella furcifera) prevents the loss of 2,900 metric tonnes of rice annually: enough to feed Thailand’s population of 66.8 million for a week (Wanger et al. 2014).
In addition to impacts on economics and food security, there may also be benefits to farmer health: research in Iberia is currently investigating the impact of bat roost provision in paddy fields on mosquito bite rates (Puig-Montserrat in prep). Tropical bats include not only insect consumers, but also nectivorous and frugivorous species that disperse seed and pollinate plants. The wild relatives of important crops such as banana, cocoa and avocado, together with hundreds of commercially important timber trees, are bat-pollinated, and bats are vital to tropical forest succession and regeneration (Muscarella & Flemming 2007), being able to transport pollen and seeds across fragmented habitats and for much greater distances than most other ecosystem service providers. In Indonesia, the exclusion of bats from commercial cacao plantations by netting at night decreased yield by 30% (Mass et al. 2013). The global value of bat pollination has been estimated at $200 billionn pa (Gallai et al. 2009) and this is likely tobe a substantial underestimate since it predated molecular techniques able to identify the full range of species involved. Nevertheless, in most countries in the Global South, bats are regarded as pests and are widely persecuted. In addition deforestation, particularly at the interface of agricultural/urban areas and natural habitats, is a major cause of roost loss and population decline.
In this project, we seek to identify commercially, medically,and ecologically important species of insects, pollen and seeds in samples collected from bats. This will build capacity at Sussex, interest from local partners in the target countries, and provide pilot data to support larger grant applications.
- Sustainable Development Goals
This project examined the following SDGs:
SDG 2 – Zero Hunger
SDG 11 – Sustainable Cities and Communities
SDG 12 – Responsible Consumption and Production
SDG 15 – Life on Land
Find out more about the UN Sustainable Development Goals.
The first step in assessing the ecosystem services provided by bats is to identify the species of insects, fruit and pollen concerned. Establishing the interaction of bats with ecologically or economically important species will permit further research intervention studies. This project collaborates with patners in Ecuador and Malawi and work has begun on amassing sample libraries (bat faecal samples, insect prey and plant samples), during University field courses.
The Santa Lucia and Tesoro Escondido are community-led eco-reserves in the Choco region of Ecuador (highlands and lowlands respectively). Both include agro-forestry (silvopasture, small scale banana and cocoa plantations) and border deforested subsistence farming areas. In Malawi, Vwaza and Kuti wildlife reserves are relatively small national parks that border subsistence mixed agricultural lands. Our partners, Conservation Research Africa and Bats without Borders, have strong ties with local communities and work on conflict resolution (for example, by excluding bats from buildings). In Ecuador, an export licence for samples has been submitted as part of a collaborative project (The effectiveness of the Choco-Andean Ecological Corridor as a connectivity facilitator between Cotacachi Cayapas Reserve and forestremnants in northwest Ecuador, and a travel grant application has been made to National Geographic’s EO Wilson Fund. These applications involve the following: Universidad de San Francisco Quito (Ecuador); Fundación Cambugán (Ecuador); Santa Lucia Reserva (Ecuador); Fundación Jocotoco (Ecuador); Natural History Museum, London; University of Lincoln (UK); University of Sussex); whilst permits are already in place for Malawi from the Department of National Parks and Wildlife.
Traditionally, microscopy has been the technique used to identify the insects, fruit and pollen in bat faeces. However, the lack of distinguishing morphological features, the reliance on hard and identifiable parts remaining post digestion, and the lack of microscopy reference libraries makes this work extremely challenging. Recent technological advances mean that molecular ‘metabarcoding’, using next generation sequencing platforms, can identify multiple species within single samples (Pompanon et al. 2012; Zeal et al. .2011; Galan et al. 2018). This technique has been applied to identify insect remains in bat faeces from a range of species, but has very rarely been used in DAC ODA-recipient countries. Metabarcoding has also been used to identify bee-transported pollen (Bell et al. 2016), but we know of only two applications with bats (Lim et al. 2018, Edwards 2018). Considerable effort has been deployed recently to development and optimise metabarcoding techniques, making this application particularly timely (Alberdi et al. 2018; Mata et al. 2019). Access to support and training workshops from the laboratories that pioneered the use of insect prey metabarcoding in Europe, is available via the EU Cost Action Programme. Technical Programme. We will analyse samples collected from 60 bats for this pump-priming project, divided approximately equally between samples collected from Ecuador and Malawi. The robust identification of dietary species from bat droppings reqires significant biological replicates (Mata et al, 2018). Thus we will analyse eight individual stool samples (droppings) per bat.
Timeline and funding
April 2020-March 2021
- Principle Investigator (PI) and Co-Investigators
- Project team
- Dr Ana Mariscal, San Francisco University, Quito
- Rachel Cooper-Bohannon, Bats without Borders
- Emma Stone, Conservation Research Africa
Where we worked