The Wrinkle-Lipped Free-Tailed Bat (Chaerephon plicatus Buchannan, 1800) Feeds Mainly on Brown Planthoppers in Rice Fields of Central Thailand

Pest suppression by bats and management strategies to favour it: a global review

Fighting insect pests is a major challenge for agriculture worldwide, and biological control and integrated pest management constitute well-recognised, cost-effective ways to prevent and overcome this problem. Bats are important arthropod predators globally and, in recent decades, an increasing number of studies have focused on the role of bats as natural enemies of agricultural pests. This review assesses the state of knowledge of the ecosystem services provided by bats as pest consumers at a global level and provides recommendations that may favour the efficiency of pest predation by bats. Through a systematic review, we assess evidence for predation, the top-down effect of bats on crops and the economic value of ecosystem services these mammals provide, describing the different methodological approaches used in a total of 66 reviewed articles and 18 agroecosystem types. We also provide a list of detailed conservation measures and management recommendations found in the scientific literature that may favour the delivery of this important ecosystem service, including actions aimed at restoring bat populations in agroecosystems. The most frequent recommendations include increasing habitat heterogeneity, providing additional roosts, and implementing laws to protect bats and reduce agrochemical use. However, very little evidence is available on the direct consequences of these practices on bat insectivory in farmland. Additionally, through a second in-depth systematic review of scientific articles focused on bat diet and, as part of the ongoing European Cost Action project CA18107, we provide a complete list of 2308 documented interactions between bat species and their respective insect pest prey. These pertain to 81 bat species belonging to 36 different genera preying upon 760 insect pests from 14 orders in agroecosystems and other habitats such as forest or urban areas. The data set is publicly available and updatable.

Coronavirus testing indicates transmission risk increases along wildlife supply chains for human consumption in Viet Nam, 2013-2014

Outbreaks of emerging coronaviruses in the past two decades and the current pandemic of a novel coronavirus (SARS-CoV-2) that emerged in China highlight the importance of this viral family as a zoonotic public health threat. To gain a better understanding of coronavirus presence and diversity in wildlife at wildlife-human interfaces in three southern provinces in Viet Nam 2013-2014, we used consensus Polymerase Chain Reactions to detect coronavirus sequences. In comparison to previous studies, we observed high proportions of positive samples among field rats (34.0%, 239/702) destined for human consumption and insectivorous bats in guano farms (74.8%, 234/313) adjacent to human dwellings. Most notably among field rats, the odds of coronavirus RNA detection significantly increased along the supply chain from field rats sold by traders (reference group; 20.7% positivity, 39/188) by a factor of 2.2 for field rats sold in large markets (32.0%, 116/363) and 10.0 for field rats sold and served in restaurants (55.6%, 84/151). Coronaviruses were also detected in rodents on the majority of wildlife farms sampled (60.7%, 17/28). These coronaviruses were found in the Malayan porcupines (6.0%, 20/331) and bamboo rats (6.3%, 6/96) that are raised on wildlife farms for human consumption as food. We identified six known coronaviruses in bats and rodents, clustered in three Coronaviridae genera, including the Alpha-, Beta-, and Gammacoronaviruses. Our analysis also suggested either mixing of animal excreta in the environment or interspecies transmission of coronaviruses, as both bat and avian coronaviruses were detected in rodent feces on wildlife farms. The mixing of multiple coronaviruses, and their apparent amplification along the wildlife supply chain into restaurants, suggests maximal risk for end consumers and likely underpins the mechanisms of zoonotic spillover to people.

Bats and belief: A sequential qualitative study in Thailand

Bats are wildlife and distribute globally. In Thailand, there are hundreds of bat species in different locations within four regions. However, few motivations and influences for having contact with bats have been documented. This sequential qualitative study was conducted in ten provinces representing the four regions of Thailand from September 2016 to June 2017. The study was designed to obtain information on villagers' attitudes, perceptions, beliefs and cultural contexts in relation to bats. Focus group discussions (FGDs) were conducted with 305 respondents. Of these respondents, 142 (46.6%) reported coming into contact with bats through various activities, such as hunting, eating, cooking, collecting bat guano, cleaning bat feces, and finding carcasses in houses and communities. Villagers called bats by different names in different regions. They reported having been in contact with bats in different ways based on occupations, bat species, bat habitats, attitudes, perceptions, beliefs toward bats, and cultural contexts. Villagers in the northern and northeastern regions reported having regularly eaten bats. In contrast, the respondents in the central region did not eat bats due to local norms, religious beliefs, and regulations. By ethnicity, the Blu and Thai Dum groups reported coming into contact with and eating bats more often than the Thais. Our results provide evidence-based information on the human-bat interface in different regions in Thailand. The results of this qualitative study could be useful for strategic planning of proper education and interventions for bat conservation, bat contact behavior, and risk of bat-borne diseases among villagers in the future.

Local-Scale Bat Guild Activity Differs with Rice Growth Stage at Ground Level in the Philippines

High-flying insectivorous bats, as wide-ranging generalist insectivores, are valuable consumers of high-altitude migrating pests of rice in Southeast Asia. Here, we documented the behavior of relatively low-flying bats over irrigated rice to elucidate their potential role as predators of rice-associated pest insects in the Philippines. Specifically, we tested the local-scale effects of rice stage, particularly seedling and late vegetative stages, and time of night on acoustic activity of bats foraging near ground level within three functional guilds (based on foraging distance from background clutter). We also monitored bat activity from two 50 m-high towers to assess the vertical extent of relatively low-flying guilds, as well as document high-flying bat guild presence and temporal behavior. At ground level, the most active guild biased their activity and feeding over early growth stage fields, but also foraged at tower level. Activity of the bat guild adept at foraging closest to vegetation did not vary with time of night or rice stage and was absent from tower recordings. High-flying bats were predictably rare at rice level, but exhibited high foraging intensity at 50 m. Given the well-documented, sequential arrival of insect guilds with growth stage, these data suggest that at ground level edge-space bats may be important consumers of detritivores (e.g., mosquitoes). Moreover, our data suggest that just as habitat heterogeneity enhances the services of arthropod predators, these management practices also enhance bat activity and, presumably, their contribution to pest suppression.

The Monumental Mistake of Evicting Bats from Archaeological Sites—A Reflection from New Delhi

We highlight the importance of an integrated management policy for archaeological monuments and the insect-eating bats that roost inside them. We refer to India, but the issue is general and of worldwide significance. There is increasing evidence that the ecosystem services provided by insect-eating bats in agricultural fields are of vital economic importance, which is likely to increase as chemical pest-control methods become inefficient due to evolving multi-resistance in insects. We visited five archaeological sites in the city of New Delhi. We found bats at all five locations, and three of them harbored large colonies (many thousands) of mouse-tailed bats and tomb bats. These bats likely disperse over extensive areas to feed, including agricultural fields in the vicinity and beyond. All insect-eating bats should be protected and properly managed as a valuable resource at the archaeological sites where they occur. We firmly believe that “fear” of bats can be turned into curiosity by means of education and that their presence should instead enhance the value of the sites. We suggest some means to protect the bats roosting inside the buildings, while mitigating potential conflicts with archaeological and touristic interests.