Pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer livelihoods, social and cultural values. They also play a role in the maintenance of wider biodiversity and ecosystems (Potts et al., 2016). In the tropics, plant animal mutualisms are vital for ecosystem function (Wright, 2002).
Pollinators increase Plant Diversity
Pollinators play a major role in developing and enhancing the world’s flowering plants. Pollination is amongst the most crucial forms of plant-animal interactions, with the others being paratism and herbivory. In fact, pollinators are responsible for the vast diversity of flowering species. Most of the flowering plants on the earth need help with pollination. Pollination is defined as the transfer of pollen grains from the male anther of a flower to the female stigma of a flower. This results in the fertilization of the plant and later yields fruits and seeds. It is an essential part of the ecosystem.
Pollinating animals move from plant to plant carrying pollen on their bodies. Somewhere around 75% – 95% of all flowering plant life on the earth want assist with pollination. They want pollinators to proceed their generation which indicates the capacity that 1 out of each and every three bites of meals you eat is there due to the fact of pollinators.
Birds, butterflies, moths, flies, bats and most commonly bees are the best examples of pollinators. They play a crucial role in the food production process. According to the Food and Agriculture Organization(FAO) report pollinators contribute around $235 billion and $577 billion to the annual world food production. Absence of pollinators affects the complete human race and the terrestrial ecosystem. They help to endure our ecosystem and produce natural resources. With climate change impacting the ecology of some pollinator species, we can only be fearful of what is to come!
Our Crops depend on Bees as Pollinators
Bees are excellent pollinators. They are responsible for broad amount of food we consume on daily basis. As per the poet Kahlil Gibran ‘bees require flowers for food whereas flowers need bees to reproduce’. As pollinators, bees play a phase in each and every issue of the ecosystem. They assist the boom of trees, flowers, and different plants which serve as food and refuge for creatures massive and small. Bees are so important, in fact, that hundreds of thousands are spent renting hives to pollinate farmers’ crops. They enhance the quality of crops from its nutritional value to its shelf life.
Beekeeping has a major potential as a side income for agriculturists. Simply using artificial beehives around farms not only increases pollination of crops but also provides a side income in the form of honey collection. Known as apiculture, this practice is done across the Western Ghats to minimize human elephant conflict.
Over a third of the food we devour relies on pollination through bees. One estimate states that pollination by wild bees contributes an average $3,251 per hectare per year to crop production. Bees make contributions to complex, interconnected ecosystems that permit a diverse wide variety of distinct species to co-exist. They are the crucial and active members of the food chain. There are over 21,000 bee species in the world which are contributing their life in pollination.
Unfortunately Bees are racing towards extinction!
In recent years, beekeepers have noticed colony losses, particularly in Western EU countries. However, many different parts of the world, such as the US, Russia and Brazil experiencing the same problem. Therefore, it is surely a global issue. As such, bee populations are hastily declining around the world due to habitat loss, disease, pollution, global warming, nutrient deficient and the use of pesticides, among other elements. Notably, around 46% of honey bee colonies were lost in 2020 and wild bee populations saw drastic declines. There are over 20,000 species of wild bees. Unfortunately, one out of six bee species are already domestically extinct. Climatic change is a major threat to bees. Specifically, the fluctuations in temperature are disrupting bee behavior.
Bees are counted under an endangered species. Protection of bees or pollinators is ultimately connected to the protection of our ecosystem. Bee populations are necessary for making sure a wholesome environment. There are several ways to protect bees. Plant a garden for bees which helps to create habitat for them. Reduce the usage of pesticides as much as possible. Gaining knowledge on how to protect bees is the very first step towards their conservation. Protect pollinators as around 90% human life is based on them.
Bats are also crucial Pollinators!
Bat pollination occurs in over 528 species in 67 families and 28 orders of angiosperms worldwide (Kunz et al., 2011). In the Old World tropics, several studies have examined the pollination effectiveness of bat pollinators (Bumrungsri et al., 2008, 2009; Acharya et al., 2015; Nor Zalipah et al., 2016; Aziz et al., 2017; Stewart and Dudash, 2017).
The Taxonomy of Pollinator Bats
The two families that contain nectar-feeding bats include Pteropodidae (Old World flying foxes and their relatives) and Phyllostomidae (American leaf-nosed bats). Specifically, the former occurs throughout tropical and subtropical regions of Africa, Asia and Australia. Meanwhile, the latter inhabits the tropical and subtropical regions of the Americas. These two families occur in different suborders of Chiroptera (Yinpterochiroptera and Yangochiroptera for pteropodids and phyllostomids, respectively) and are only distantly related. The Pteropodidae contains 43 genera and about 186 species (Simmons, 2005).
The family Phyllostomidae is younger than the Pteropodidae and dates from 39 Ma (Jones et al., 2005; Teeling et al., 2005). Moreoever, the taxonomic richness of flower-visiting bats in both hemispheres varies among regions and within regions with latitude, habitat and elevation (Fleming, 1993, 1995). For instance, Pteropodid bats, are known to pollinate flowers of about 168 species in 100 genera and 41 families (Kunz et al., 2011). Furthermore, bats within the family Pteropodidae are classified into two feeding guilds: obligate nectarivores (nectarivorous) and frugi-nectarivores (frugivorous).
These two bat guilds have been demonstrated to have different foraging times (Stewart et al., 2014). As such, nectarivorous bats show higher effectiveness as pollinators (Stewart and Dudash, 2017).Consequently , little is known about the community structure of bat pollination interactions, with very few exceptions (Sritongchuay and Bumrungsri, 2016; Stewart and Dudash, 2017). Nonetheless, these two families of bats (Pteropodidae in the Old World and Phyllostomidae in the New World) play important roles in plant pollination.
Role of Bats in the Ecosystem
High Ecological Diversity
- Within mammals, bats are, undoubtedly, one of the most important taxa since represent the highest number of species after rodents, which means for about 21.89 % of all the mammalian richness (Mammal Diversity Database 2020).
- Furthermore, bats display a high ecological diversity because are involved in multiple trophic interactions (Kasso & Balakrishnan 2013), thus contributing to a variety of ecosystem services (Kunz et al. 2011).
Bats are crucial pollinators
- Bat pollination occurs in more than 528 species of 67 families and 28 orders of angiosperms worldwide . Pteropodid bats are known to pollinate flowers of about 168 species of 100 genera and 41 families and phyllostomid bats pollinate flowers of about 360 species of 159 genera and 44 families.
- New World bats play a significant role in ecosystem functioning and are imperative for maintaining environmental Services .In the last few decades, the relationship between biodiversity and ecosystem functioning has become a key framework for understanding species’ roles in the provision of ecosystem services (Luck et al. 2009; Cadotte et al. 2011; Luck et al. 2012).
- It is well-recognized the central role of mammals in mediating ecological processes such as seed dispersal, seed predation, pollination, pest control, energy flow, predation, herbivory, and ecosystem engineering (Lacher et al. 2019).
Bats increase Plant Fitness
- Bats perform a prime function on plant fitness by enhancing their reproductive effectiveness in two essential components:
- Carrying a substantial amount of pollen on their bodies and depositing myriad of pollen grains on stigmas (Fleming et al. 2009; Muchhala & Thompson 2010) and
- Promoting outcrossing through carrying pollen over long distances among individuals, thus reducing levels of genetic subdivision between plant populations and, consequently, increasing the area of plant genetic neighborhoods (Fleming et al. 2009; Lacher et al. 2019).
- The durian tree is native to south-eastern Asia. There, its flowers are known to be visited by bats of the suborder Megachiroptera (VAN DER PIJL,). Although bat pollination is relatively uncommon when compared with bird or insect pollination, it involves an impressive number of economically and ecologically important plants. Particularly, beyond the economic value of plant pollination and seed dispersal services, plant-visiting bats provide important ecological services by facilitating the reproductive success and the recruitment of new seedlings . Many of these plants are among the most important species in terms of biomass in their habitats. For instance, bat-pollinated columnar cacti and agaves are dominant vegetation elements in arid and semiarid habitats of the NewWorld .
- Unlike 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
Bat Pollination is very Economic
- As pollinators, tropical bats provide invaluable support to many local and national economies . Large-scale cash crops that are originally pollinated or dispersed by bats include wild bananas, mangos, breadfruits, agave, durians, and petai of which durians and petai currently rely on bats for pollination .
- Agave macroacantha is extremely dependent on nocturnal pollinators for its reproductive success of which bats are especially important for its successful pollination .
- The Mahwa tree or honey tree (Madhuca indica) is pollinated by bats. These pollination services highlight one of the highly valued ecosystem services provided by plant visiting bats both culturally and economically. For example, the timber of this tree is used for making farm cart wheels in India. Moreover, the flowers are used as food and for preparing a distilled spirit and its sun-dried fruits for human consumption and the oil extracted from flowers and seeds as ingredients for soaps, candles, cosmetics, lubricants, and medicines .
“Pollination of the flowers of trees and vines by bats (Chiroptera) is characteristically a tropical phenomenon”
Conservation Value
Some of these pollinators (bats) are migratory, and have been reported to be steadily declining. A continuing decline in the populations of pollinators may hamper the successful sexual reproduction of the plant host and may put its survival under risk . Unfortunately these crucial creatures are under threat of the illegal wildlife trade. Well Covid is the not the only disaster which the illegal wildlife trade can cause!
Effective Pollinators
Compared with most insects, flower-visiting birds and bats are much larger, have greater energy requirements because of their endothermic metabolism, can carry larger pollen loads, are longer-lived and may be cognitively more sophisticated. Birds and bats are excellent in promoting outcrossing, and as a result, most vertebrate-pollinated plants have hermaphroditic breeding systems; very few are dioecious (Renner and Ricklefs, 1995).
Written by: Shreya Pandey and Akriti Kashyap