Kristen Lear | Bat Conservation | Bats, Agaves, and People

Mexico

Bats, Agaves, and People

Identifying ecologically- and socially-appropriate strategies for restoring foraging resources for an endangered pollinating bat in northeast Mexico.

Background

The Mexican long-nosed bat (Leptonycteris nivalis) is a rare but vital pollinator, classified as endangered by the IUCN due to drastic declines of over 50% in the past 10 years—a decline expected to continue without immediate conservation action. Each spring, the females migrate 1200 km northward from central Mexico to northeast Mexico and the U.S. southwest, where they give birth to their young. During their journey, they rely on the nectar and pollen of agave plants for food, and during foraging provide critical pollination services to the plants. Agaves, in turn, help maintain healthy ecosystems by providing food for numerous insect, bird, and mammal species, stabilizing soils in their desert and forest ecosystems, and contributing to healthy water sources. Agaves are also important economic and cultural resources for farmers and rural Mexican communities that harvest them for beverages (including tequila and mezcal), food, fibers, and livestock fodder.

One of the proposed threats to the Mexican long-nosed bat is the loss of critical food resources like agaves across their migratory range. Significant portions of natural agave habitat is being lost to expansion of large-scale agriculture and development, and foraging areas are being fragmented. Direct harvest of agaves for products like tequila and mezcal and other uses can also impact agave populations. Conservation efforts are focusing on enhancing food resources for the Mexican long-nosed bat across their range. Bat conservationist Rodrigo Medellin and the Tequila Interchange Project are making strides with implementing a “bat-friendly” tequila and mezcal label in central Mexico to encourage producers to set aside a portion of their crop to flower for the bats.

However, important areas of the bats' migratory range are outside the legal production areas for tequila and mezcal, so other conservation strategies are needed. In the U.S. Southwest and northern Mexico, Bat Conservation International and partners, including Arizona's Borderlands Restoration Network, are establishing agave restoration programs to increase foraging resources for the bats. However, much is still unknown about the bats' foraging requirements, the impacts of agave use and other land uses on agave and bat populations, and the best approaches for promoting agave restoration with local communities and stakeholders. I worked around two important roosting caves for the species in northeast Mexico (Nuevo Leon and Coahuila) where rural communities harvest agaves for many important uses. Through my work, I aimed to identify locally-appropriate approaches for enhancing agave habitat in northeast Mexico to conserve these endangered bats.

My PhD Research

My dissertation research was comprised of two main components: 1) identifying ecologically- and socially-appropriate ways to implement agave restoration and bat-friendly agave management with rural communities in northeast Mexico, and 2) understanding the effects of agave harvest and management on agaves (both at the individual and population level) and identifying potential trade-offs and synergies between bat and human use of agaves. (The full dissertation can be downloaded here, and a recording of my defense can be watched here)

For the first component, I used an interdisciplinary approach that combined methods from the natural and social sciences to: 1) identify where (i.e. in which communities and where within those communities) to target bat-friendly management with rural communities; and 2) understand how to implement bat-friendly management in the communities. Both of these require understanding the foraging requirements of the bats (for example, do they prefer areas with clumps of many flowering agaves, or areas with individual flowering agaves scattered over a wider area?) as well as understanding the unique social, economic, and political contexts of rural communities that harvest agaves and what factors make adoption of agave restoration and bat-friendly management practices more or less feasible. To do this, I conducted foraging studies of Mexican long-nosed bats using infrared cameras, and conducted interviews and household surveys with community leaders and agave harvesters. With this approach, I gained understanding of how to tailor agave programs to the bats' foraging needs, as well as understand how to work with local communities to do conservation actions that support their livelihoods.

The second part of my research sought to better understand how agave harvest is actually affecting agave populations (and therefore the bats' food resource) in northeast Mexico. To do this, I took an ethnoecological approach with interviews focused on the impacts of harvesting practices and other land uses on agaves. From interviews with community leaders and agave harvesters, I discovered that agave harvest is not always detrimental to agave growth and reproduction, and in some cases can actually stimulate growth and help maintain agave populations. This is an important finding with implications for how we design and promote agave restoration with communities. This analysis provided a more nuanced understanding of the effects of agave harvest and helped us critically assess common assumptions (e.g. that "all harvest is bad for agaves and bats"), and ultimately has allowed us to identify potential trade-offs and synergies between bat and human use of agaves.

In summary, my research helped: 1) identify priority areas for agave restoration work; and 2) understand how to tailor programs for the local contexts of each community and how these programs can benefit local communities. I worked to ensure that my research had practical application to management and conservation practice by partnering with a local conservation NGO, Especies, Sociedad y Habitat, A.C. (based in Monterrey, Nuevo Leon), to conduct my research, and I also worked to ensure that my research contributed to range-wide conservation of the Mexican long-nosed bat through my involvement and collaboration with the bi-national Nivalis Conservation Network.

Symposium on Integrative Conservation, University of Georgia, February 2017

Committee and Collaborators

Committee: Jeffrey Hepinstall-Cymerman (UGA Warnell School of Forestry and Natural Resources); Elizabeth King (UGA Warnell School of Forestry and Natural Resources and Department of Ecology); Laura German (UGA Department of Anthropology); Clint Moore (UGA Warnell School of Forestry and Natural Resources); Meredith Welch-Devine (UGA Graduate School and Department of Anthropology)