The Macroecology of Indian Pollinators: Patterns, Processes and Future Implications
Creators: name: Kallivalappil, Ratheesh
Publisher: name: University of Lincoln
Year: 2023
Subjects: C100 - Biology
C181 - Biodiversity

description: Pollination is a key ecosystem service and vital step in the reproduction of most angiosperms. Therefore, the endangerment and extinction of pollinator species collapse the complex ecological networks and hence threaten both agriculture and biodiversity. A large proportion of the human diet depends directly or indirectly on animal pollination. Both invertebrates and vertebrates pollinate a variety of angiosperms. While much research has been focused on insect pollinators, the role of vertebrate pollinators is not as widely recognized. Vertebrates pollinate a variety of plants including economically important crop species in tropical countries and many of these plants are either completely or partially dependent on pollinators for fruit/seed production. Therefore, declining pollination services in these tropical cultivated goods may result in substantial losses in revenue. Here, my project investigates the extinction risk of global and Indian vertebrate pollinator species using the IUCN extinction risk assessment method. The potential pollinator species have been identified from various primary, peer-reviewed literature sources. I compiled a dataset consisting of 1,554 and 99 vertebrate pollinator species for the globe and India respectively. Additionally, the project explores the economic value of pollination services for Indian vertebrate pollinators.The results for the global extinction risk show asymmetric patterns of threat within the vertebrate groups. Globally, mammal pollinators were more highly threatened than the bird and reptile pollinators, though there were large-scale population declines experienced across all pollinator groups. The narrow ranged pollinators experienced large-scale threat and population decline relative to broad ranged pollinators. Hotspots of threat for vertebrate pollinators are shown in the Andes of South America, Madagascar, and south-eastern Australia. The interactive effect of body mass and body length and significant phylogenetic signal along with various external anthropogenic factors show the extinction risk in global pollinators are a combined effect of both intrinsic biological traits and extrinsic anthropogenic factors across multiple scales. The extinction risk assessment for Indian pollinators show mammals are the only pollinator group threatened with extinction. But both bird and mammal pollinators face population decline, a similar trend reported for the global pollinators. Like global pollinators, the population decline is higher in narrow ranged pollinators than the broad ranged pollinators. Body size does not predict threat and population decline in Indian pollinators, a contradictory result to the global pattern. Absence of phylogenetic signal in threat and population decline show they are evolutionarily not predisposed to extinction. Like global pollinators, most Indian pollinators appear to be threatened by agriculture and biological activities. The value of vertebrate pollination services is estimated to be £2.85 million (?28.2 crores) and the contribution of bird pollinators are higher than mammal pollinators. The study also highlights the beneficial role of bat pollinators to the Indian economy and biodiversity. Thus, it emphasizes the need for the Government of India to revoke the status of fruit bats as vermin and list them as protected in the Schedules of Indian Wildlife Protection Act, 1972.