Institute of Ecology at National Autonomous University of Mexico
Mexico National Bat Monitoring
Bats perform a number of ecological services essential for ecosystem integrity and human well-being including pollination, seed dispersal, and insect population control. Threats such as habitat destruction, wind farming, and white-nose syndrome kill millions of bats each year, but there is little information to evaluate short and long-term population trends of bats in tropical countries. Acoustic monitoring of bats is rapidly becoming the tool of choice to document bats at large spatiotemporal scales. However, most bat monitoring programs occur on localized scales in temperate areas and center on only a few species, over short time periods. These programs are limited in scope due to high costs and human resource requirements. In the tropics, there is currently no standardized effort to monitor bat populations, even in the short term. The Mexican Federal Government asked Dr. Rodrigo Medellín to design a long-term, nationwide bat monitoring program to add bats to the existing National Forest Inventory (NFI), one of the best large-scale longitudinal natural resource monitoring programs in the world. The NFI is an enormous effort that deploys staff over 60,000 points across Mexico which are visited every 5 years (12,000 points per year), and tracks not only forest resources, but population data for birds, large mammals, invertebrates, fish, and reptiles. Thus, there is a need in Mexico to develop an efficient, sustainable, consistent acoustic monitoring protocol for bats across the entire country.
Key Objectives and Activities
The goal is to design and implement a standardized, nationwide, long-term acoustic bat-monitoring program in Mexico, integrating the latest technology in bat detectors and automated data analysis. This project will develop and validate acoustic monitoring protocols at a small number of sites, providing a proof-of-concept for expanding the spatiotemporal scale of acoustic monitoring, and generating best-practices for monitoring in other locations. Bat occurrence data will be contributed to Mexico’s premier open-access biodiversity data repository, CONABIO, and made available to scientists, stakeholders, and land managers. These data will facilitate assessments of natural and anthropogenic impacts on bat populations, and can be used to develop mitigation, restoration, or conservation strategies.
- Establish 16 locations for permanent acoustic bat monitoring stations in two biosphere reserves in Mexico with contrasting ecosystems: Chamela-Cuixmala Biosphere Reserve (tropical dry forest) and Montes Azules Biosphere Reserve (tropical rain forest).
- Conduct two cycles of standardized acoustic bat monitoring at each reserve and produce a collection of pre-filtered bat recordings.
- Analyze all sound files containing a bat call using a combination of already published software (AVISOFT) and a custom software to identify each recording to the family or sonotype level.
- Make the complete database containing the data produced during the first year of monitoring available to the public through CONABIO.
- Offer a workshop for two staff members in charge of monitoring programs in each reserve where personnel will be trained on bat identification, acoustic bat monitoring techniques and technology, design and implementation of nation-wide, long-term monitoring programs.
- Conduct a six-day long workshop for members of the Bat Conservation Africa (BCA) network to facilitate transfer of knowledge and technology and strengthen the infrastructure of bat conservation programs in Africa.
The aim of this project and its leaders is the incorporation of bat distribution data in the National Forestry Inventory (NFI), and the use of that information by thousands of Mexicans and non-Mexicans, in support of research and conservation decision-making.
This project will generate a validated monitoring protocol that establishes a set of rules and criteria for how acoustic bat surveys, including metadata of environmental conditions, should be conducted on large spatiotemporal scales. This standardization is essential to permit comparison of data taken at different locations or times, and by different workgroups throughout Mexico. Results of nationwide monitoring will crucially enhance the understanding of bat species distribution, diversity, abundance, and activity patterns in relation to different environmental conditions and threats, contributing to effective species and habitat conservation. An additional outcome will be the use of the tools and techniques pioneered in Mexico by this project by African bat researchers, to foster enhanced bat research and monitoring in sub-Saharan Africa.
Last Updated: February 28th, 2017
Primary Software Platforms
The bat acoustic calls will be analyzed and processed by integrating AVISOFT, an existing bioacoustics software platform, with custom-built software, to automate the classification of bat calls. Data on bat distribution, diversity, and relative abundance will be managed in CONABIO’s software for data management, BIOTA.
Results to Date
The team has successfully completed four pilot deployments, two in each of two different habitat types (tropical forest and dry forest). With each deployment, they learned more about the optimal equipment settings, enabling them to fine tune subsequent deployments. By this iterative, adaptive management process, they now feel they have arrived at an effective standardized monitoring protocol. Nearly all of the data gathered have been analyzed, and the group is continuing to improve algorithms that enable identification of bats at the Family or even the Genus level based on calls. Throughout this process, they have exceeded goals in capacity building, training more staff at Montes Azules Biosphere Reserve on deployment than proposed, and on a wider range of analysis software than expected. Some training is still forthcoming, as hurricane Patricia resulted in the postponement of the workshop in Chamela-Cuixmala Biosphere Reserve. Nevertheless, a number of key pieces are already in place for successful transfer of technology for this project and these reserves and others are well situated to take over acoustic monitoring at the conclusion of the project period. In addition to reserve staff training and engagement, the team has produced a field manual for deployment of monitoring stations, and it has been agreed that CONABIO will host the resulting database.
Currently the group plans that the workshop with bat conservation experts in Africa to facilitate export of knowledge will take place in early 2017 in Kenya.
Dr. Medellín and his group have demonstrated flexibility that enabled them to make the most of unanticipated delays and challenges. Bioacoustic monitoring technology is advancing rapidly, such that cutting-edge gear is quickly superseded by smaller, more sensitive, more reliable equipment. Waiting as long as possible to obtain the very latest technology is preferable, but risks delaying implementation if delivery takes longer than anticipated. The team capitalized off the time afforded by such delays to conduct additional training.
Ecological field studies are beholden to whims of nature; unpredicted events can be both challenges and opportunities. Hurricane Patricia caused the postponement of the workshop to train staff at Chamela-Cuixmala Biosphere Reserve. However, the natural disaster also offered a natural experiment on which to test the efficacy of the protocol. The team will return to Chamela-Cuixmala for a third sampling cycle, training reserve staff and gathering post-disturbance data to determine whether the monitoring protocol can be used to assess the response of the bat community to changes brought by the hurricane.
- López-Hoffman, L, R Wiederholt, C Sansone, KJ Bagstad, P Cryan, JE Diffendorfer, J Goldstein, K LaSharr, J Loomis, G McCracken, RA Medellín, A Russell & D Semmens. 2014. Market forces and technological substitutes cause fluctuations in the value of bat pest-control services for cotton. PLoS One, 9(2): 7 pages. DOI:10.1371/journal.pone.0087912 (link)
Project Director Biography
Dr. Rodrigo Medellín researches conservation of mammals with emphasis on applied and policy-driven science, as a Senior Professor at the Institute of Ecology UNAM. He is an established leader in the field of mammal conservation, and is President of the Society for Conservation Biology (2013-2015), and Scientific Councilor of the Convention on Migratory Species. The majority of Medellín’s work is dedicated to bats: he founded RELCOM, a network for conservation of bats in Latin America in 2007, and currently co-chairs the IUCN Bat Specialist Group. He has authored more than 170 publications trained more than 40 graduate students, and has projects or students in 16 countries on five continents. He is a Rolex Award Laureate, and 2012 Whitley Gold Award winner.
Notes from JRS
In 2014, JRS called for proposals that feature innovations in biodiversity informatics and Dr. Medellín’s proposed large scale bat monitoring is innovative and holds the potential to lower costs, increase scale, and automate biodiversity monitoring activities. With encouragement from JRS, the project team included training and technology transfer to Africa, which we hope might plant the seeds of future collaborations and projects. This award is JRS’ third for bats, making bats the mammal with most JRS grants. Today, this project from UNAM and the investment in the work of Dr. Bruce Miller and Dr. Bruce Patterson remain un-linked. We hope that our efforts to make bat call data accessible and better documented will help support global collaboration and knowledge transfer regarding the biodiversity monitoring of this important species.