Bats and Ecosystem Management

Bats are among the most misperceived and undervalued animals on the planet. For wildlife ecologists, they are wonderful and incredibly fascinating creatures, but people’s feelings about bats are often negative, perhaps because bats are so mysterious. Unfortunately, these fears and myths about bats threaten conservation, biodiversity, and the entire ecosystem. Bats are among the most diverse and geo-graphically dispersed group of living mammals. They contribute to several ecosystem services and act as biological pest crop control agents. Their abundance may reflect changes in populations of arthropod prey species. Also, bats have significant potentials as bioindicators that demonstrate measurable responses to climate change and habitat loss and that induce large-scale impacts on the biota. Indeed, bat conservation is fundamental not only for biodiversity, but also because these flying mammals provide essential ecological and economic services to humans.

DOI: http://dx.doi.org /10.5772/intechopen.101600 Ecosystem services are the benefits obtained from the environment that increase human well-being. Economic valuation is conducted by measuring the human welfare gains or losses resulting from changes in the provision of ecosystem services. Bats, which live on all continents except Antarctica, are essential members of many types of ecosystems, ranging from rainforests to deserts. By fulfilling their ecosystem roles, bats promote biodiversity and support the health of their ecosystems. Due to the rich diversity of dietary habits of bats, ranging from species that feed on insects and other arthropods to those that feed on fruit, nectar, and flowers, they have long been postulated to play important roles in ecological and economic services. Moreover, other species that feed on seeds, frogs, fish, small mammals, and even blood also play important roles in ecosystems as predators or prey in ecosystems sustainability. Modifying ecosystems to facilitate socioeconomic development is necessary but how can we avoid damaging important ecosystem services? As a prerequisite, we need to understand how ecosystem services contribute to people's livelihoods and well-being.

Ecological services
Bats have long been known as the main contributor to remarkable ecosystem benefits, are significant suppressors of agricultural pests [43][44][45][46], consume important disease vectors, such as malaria-bearing mosquitos [47], with an important role in seed dispersal, pollination, material and nutrient distribution, and recycle [48].
One of the most troubling problems of the farming industry is insect pests, which affect crop production worldwide. Inhibitors of natural insect pests such as bats, as major predators of arthropods, provide valuable ecosystem benefits for crops cultivation [48,49]. Indeed, herbivorous arthropods destroy approximately 25-50% of crops worldwide [50,51], in response to these threats, it is clear that the application of synthetic pesticides has increased which in turn has led to several unintended consequences including human health risks, degradation of ecosystem function, evolved toxicity resistance by pests, and severe alterations in the agribusiness dynamics [50,52,53].
Indeed, the elimination of beneficial vertebrate predators that act as biocontrol of insects, such as bats, insect species that are not normally considered pests are often elevated to pest status [53,54]. Thus, the promotion of biological controls can reduce the widespread and indiscriminate use of chemical pesticides [55]. About 99% of potential crop pests are limited by natural ecosystems [53,56] of which some fraction can be attributed to predation by bats [57]. For example, a colony of 150 big brown bats (Eptesicus fuscus) in the midwestern United States annually consume approximately 600,000 spotted cucumber beetles (Diabrotica undecimpunctata), 194,000 June beetles (Scarabidae), 158,000 leafhoppers (Cicadellidae), and 335,000 stinkbugs (Pentatomidae), which are severe crop pests [58]. A Brazilian free-tailed bat (Tadarida brasiliensis) can eat up to 20 females of corn earworm moth (Helicoverpa zea), one of the costliest agricultural pest insects in one night [59]. In fact, each moth can potentially produce 10,000 crop-damaging caterpillars each night [60]. Bats are just one of several groups of animals that naturally prey on mosquitoes. A Florida colony of 30,000 southeastern myotis (Myotis austroriparius) eats 50 tons of insects annually, including more than 15 tons of mosquitoes (Figure 1) [61,62].
Therefore, insectivorous bat species, which largely feed on airborne insects and other arthropods, considerably contribute to the suppression of insects that harm the agricultural industry or transmit specific pathogens to humans, consequently contributing to the maintenance of ecosystem stability.
Another important ecosystem service provided by bats is pollination. Although, bat pollination is relatively uncommon when compared with bird or insect pollination, it involves an impressive number of economically and ecologically important plants [63]. Plant-visiting bats play a remarkable role in facilitating reproductive success and the recruitment of new seedlings [48]. For instance, bat-pollinated columnar cacti (Cactaceae) and agaves (Asparagaceae) are among the most important species as dominant vegetation elements in arid and semiarid habitats (Figure 2) [48].
Furthermore, seed dispersal is a major way in which animals contribute to ecosystem succession by depositing seeds from one area to another [64]. Frugivorous bats play a tremendous role in dispersing the seeds of tropical trees and shrubs to produce fleshy fruits as 50-90% of these trees are adapted to the consumption of vertebrates [65]. Generally, frugivorous bats help maintain the diversity of forests by dispersing seeds across different ecosystems, often introducing novel plant species into previously disturbed landscapes [64].
In contrast to predation, which is an antagonistic population interaction, pollination, and seed dispersal are mutualistic population interactions in which plants provide a nutritional reward (nectar, pollen, and fruit pulp) for a beneficial service [48]. Indeed, frugivorous bats as well as nectarivorous bats provide valuable ecosystem services by pollinating plants, dispersing pollen, and thus helping to maintain the genetic diversity of flowering plants.
Bats offer an important multisensory role in assessing ecosystem health either by directly contributing to regulating services to agricultural production or indirectly  by providing forage and nesting habitat for pollinators and seed dispersers. To some extent, bat guano has great ecological potential for soil fertility and nutrient distribution, as bats sprinkle them over the landscape overnight, they facilitate nutrient redistribution within ecosystems [66]. In other words, bat guano supports a great diversity of organisms including arthropods, fungi, bacteria, and lichens representing different trophic levels by supporting their ecosystems [67].
Moreover, bats have enormous potential as bioindicators of both disturbance and the existence of contaminants [68]. They show taxonomic stability, trends in their populations can be monitored, short-and long-term effects on populations can be measured and widely distributed worldwide [68][69][70]. Since insectivorous bats occupy high trophic levels, they are sensitive to the accumulations of pesticides and other toxins, and changes in their abundance may reflect changes in populations of arthropod prey species [71]. In particular, changes in bat numbers or activity can be related to climate change, deterioration of water quality, agricultural intensification, loss and fragmentation of habitats, fatalities at wind turbines, disease, pesticide use, and overhunting [68], and hence bat populations are affected by a wide range of stressors that affect many other taxa. Overall, there is an urgent need to implement a global effort for monitoring bat populations, to ensure that their role as bioindicators can be used to their full potential.

Economic services
Estimating the economic importance of bats in agricultural systems is challenging; however, the bats value in pest suppression illustrates an important agricultural service by increasing the monetary gain of farmers, and consequently supporting food security [49]. They consume enormous quantities of insect pests that cost farmers and foresters billions of dollars annually [59]. In USA, due to the fact of insect pests are eliminated by bat predation, the estimated value of bats as a result of reduced costs of pesticide applications is in the range of $3.7-$53 billion per year [66]. These estimates include the reduced costs of unnecessary pesticide applications to suppress insects consumed by bats [72].
Bats provide substantial ecosystem services worldwide, and their benefits to human economies are not limited to agricultural pest control. For example, pioneering research in tropical ecosystems shows the importance of plant-visiting bats in the pollination of valuable fruit crops [73,74]. There are 289 Old World tropical plant species, which rely on pollination and seed dispersal services by bats for their propagation, providing human with about 448 products in a variety of categories, for instance, wood products (23%); food, drinks and fresh fruit (19%); medicine (15%); dye, fiber, animal fodder, fuel wood, and others (43%) [57]. In addition to some cash crops such as wild bananas (Musa acuminata), mangos (Mangifera indica), breadfruits (Artocarpus altilis), agave (Agave spp.), and durians (Durio spp.) they rely on bats for pollination [57]. Durian, a wildly popular fruit worth more than $230 million per year in Southeast Asia, opens its flower at dusk and relies almost exclusively on fruit bats for pollination [57]. In general, according to the vital role that bats play in the global pollination services, their total economic value is up to $200 billion [75]. Furthermore, bats have a tremendous economic value in maintaining forests through dispersing the seeds of crucial plants for forest reemerging [76]. For instance, the estimated economic value of bat seed dispersal services to giant oak (Quercus virginiana) is $212,000 for acorn seeding and $945,000 for planting saplings [77].
Bats provide some of the world's finest natural fertilizers known as Guano [78]. Since there are high concentrations of nitrogen and phosphorous in guano [79], it provides some of the world's finest natural fertilizers [78]. For instance, in Texas the Brazilian free-tailed bat guano has been extracted for fertilizer in thousands of tons from Bracken Cave alone with the current retail sales ranging from $2.86 to $12.10 per kilogram [78].
Finally, it is important to recognize the extraordinary value of bats to ancient and contemporary traditions and science. Recently, bats provide esthetic contributions through cave visits, nocturnal tours in national parks, and educational nature programs. Like other wildlife recreational activities, bat watching is considerably growing [80]. Besides providing adventure and life memories to the public, it generates income for the communities and companies involved [80]. For instance, Congress Avenue Bridge, one of the largest urban bat colonies in the USA, is visited by 200-1500 visitors every evening with a value of $3 million per year [80,81]. Bats also commonly appear as symbols or logos in popular movies (e.g., Batman), products (e.g., Bacardi rum), and holidays (e.g., Halloween), and all major revenue-generating endeavors [82]. Moreover, many novel technological advances have been inspired by bat echolocation and locomotion, such as sonar systems, biomedical ultrasound, sensors for autonomous systems, wireless communication, and BATMAVs (bat-like motorized aerial vehicles) [83]. Also, in the medical sector, the saliva of vampire bats with its anticlotting chemicals has been investigated as a potential anticoagulant for people who are at high risk of blood clots and strokes [84].
Although, some of these services provide direct benefits to humans (e.g., food, fuel, fiber, and fertilizer), most ecosystem services offer indirect benefits (e.g., pest suppression, seed dispersal, and pollination). Often, little attention is paid to "free" services provided by ecosystems either because the benefits of the services are not fully understood by decision makers or because the benefits accrue to non-owners of the ecosystem providing the service [48]. Information on nonmarket values of ecosystem services can be used to inform decisions regarding whether to protect existing ecosystem services, improve the current provision of ecosystem services, or restore previously lost ecosystem services [4,85].
Finally, although much of the public and some policy makers may view the precipitous decline of bats worldwide as only of academic interest, the economic and ecological consequences of losing so many bats could be substantial. Thus, a deeper understanding of bat-human inter-relationships, the importance of bat diversity, and ecosystem management is crucial for healthy ecosystems and human well-being (Figure 3).

Ecosystem management
The management and protection of ecosystems are essential to the functioning of ecosphere processes and for the well-being of the biotic and abiotic components of the Earth. Different sectors of society view ecosystem management in terms of their own economic, cultural and societal needs. Management should involve all stakeholders and balance local interests with the broader public interest. Effective ecosystem management depends on both cultural and biological diversity, the dynamic relationship within a species, among species and between species and their abiotic environment, as well as the physical and chemical interactions within the environment [87].
There are different perspectives of environmental management, one of which deals with human needs as central such as protecting a young forest because it may be able to be logged in the future which is known as anthropocentric perspective. While the egocentric perspective deals with the needs of environments as central, for example allowing farmers to extract less water from the river to permit more water to flow downstream [88]. Thus, we must appropriately value and manage ecosystems because of their multiple values to humanity and/or because of their value to other ecosystems and both scenarios lead to a healthier environment and more human well-being.
As human numbers increase and people encroach deeper into the remaining natural habitats, human-bat interactions are becoming more frequent, with often undesirable consequences for both humans and bats [14]. However, bats are often considered keystone species, as they play an important role in many ecosystem services [89], bat populations are declining worldwide mainly because of habitat destruction [90] and increased population control [91,92]. Additionally, the lack of knowledge about bats makes them an easy target for disease-related fears [93][94][95] and a potential target for persecution [28,96].
Indeed, bat management requires a comprehensive approach that must consider the development of culturally appropriate strategies that minimize zoonotic health risks and support bat diversity and its associated ecosystem services [97]. However, even with some communities expressing positive attitudes toward bats, bat control efforts and roost destruction are significant threats to the taxon. Thus, healthy comprehensive management depends on a robust understanding of the importance of bat diversity and emphasizes the non-lethal actions by the general public, health officials, and pest/wildlife managers [98]. It is essential to document people's relationship with bats and to incorporate these perceptions into educational efforts and management decisions, consequently increasing the potential for successful conservation efforts. While comprehensive management can be more costly in the short term (compared to typical pest control efforts), the long-term results should provide the best sustainable outcomes that are satisfactory to people, bats, and the environment [99].
The key to sustainable development is to strike a balance between the exploitation of natural resources for socio-economic development and the preservation of ecosystem services. In other words, healthy ecosystems are a prerequisite for sustainable development and all ecosystem services provided by different vertebrate animals, such as bats, compromise options for present and future generations. Hence, it is important to demonstrate that undervaluing one ecosystem service is likely to lead to the loss of many.

Author details
Kareem M. Soliman* and Wiame W. Emam Faculty of Science, Ain Shams University, Cairo, Egypt *Address all correspondence to: dr_kariemsoliman@yahoo.com

Conclusion
In conclusion, for the benefit of present and future generations, bat management by governmental agencies and NGOs needs to be evaluated. Additionally, more understanding is needed of how ecosystem services provided by bats contribute to livelihoods and how far the benefits provided by bats elevate their detrimental impact. Furthermore, in the context of accelerating environmental change, there is an urgent need to identify ecosystem conservation, restoration, and management strategies that are likely to support biodiverse and adaptive ecosystems in the future. We hope that increased awareness about these nocturnal, fast-flying, and secretive mammals can help build synergies between international scientific knowledge, conservation priorities, and local cultural values, which together can promote the benefits of the ecosystem services provided by bats (Video 1, https:// www.merlintuttle.org/video/the-importance-of-bats/).