Citizen Science Confirms the Rarity of Fruit Bat Pollination of Baobab (Adansonia digitata) Flowers in Southern Africa

Abstract

The iconic African baobab tree (Adansonia digitata) has "chiropterophilous" flowers that are adapted for pollination by fruit bats. Although bat pollination of baobabs has been documented in east and west Africa, it has not been confirmed in southern Africa where it has been suggested that hawk moths (Nephele comma) may also be involved in baobab pollination. We used a citizen science approach to monitor baobab tree and flower visitors from dusk till midnight at 23 individual baobab trees over 27 nights during the flowering seasons (November-December) of 2016 and 2017 in northern South Africa and southern Zimbabwe (about 1650 visitors). Insect visitors frequently visited baobab flowers, including hawk moths, but, with one exception in southeastern Zimbabwe, no fruit bats visited flowers. Citizen science enabled us to substantiate preliminary conclusions about the relative importance of moth versus bat pollination of baobabs in southern Africa, with important implications for resource management.Diversity 2020, 12, x FOR PEER REVIEW 3 of 20 average minimum and maximum temperatures in the area have increased by around 1.2 °C and the number of extremely hot days (>35 °C) per summer has increased by 22 days [29,30].

Evidence for hawkmoth pollination in the chiropterophilous African baobab (Adansonia digitata)

“…Although previous research, all of it conducted in West or East Africa, has shown that African baobabs are primarily bat‐pollinated (Jaeger, 1945, 1950, 1954; Harris and Baker, 1959; Start, 1972; Ayensu, 1974; Baum et al, 199; Djossa et al, 2015), at our study sites in South Africa we observed high visitation rate of hawkmoths, but no bat visits. The lack of flower‐visiting bats is corroborated by citizen science efforts conducted with local residents (Taylor et al, 2020) and by observations during other flowering seasons by one the authors (SMV). This is not the first time that a plant classified as having a bat pollination syndrome is not, in fact, bat‐pollinated in some populations (Rivera‐Marchand & Ackerman 2006).…”

“…; Coe & Isaac, 1965). In contrast to the abundant work in East and West Africa, we are aware of no documentation of bat pollination of baobabs in Southern Africa and a recent citizen science effort failed to document bat visits to flowers in these populations (Taylor et al, 2020).…”

Jewels of Africa: Citizen Science on the African Continent

“…Taylor, et al, [35] as the use of chemicals or protecting other species that the moths need in their life cycle. Thus, these results are of importance to policy makers and resource managers ensuring that management decisions take into account the importance of these pollinators.…”

From Phenology and Habitat Preferences to Climate Change: Importance of Citizen Science in Studying Insect Ecology in the Continental Scale with American Red Flat Bark Beetle, Cucujus clavipes, as a Model Species

“…Moreover, such observations allow to monitor migratory birds, e.g., [ 30 , 31 , 32 , 33 , 34 ]; rare and endangered species, e.g., [ 35 , 36 , 37 , 38 ]; expansion of pests, e.g., [ 20 , 39 , 40 ]; or alien and/or invasive species, e.g., [ 18 , 22 , 39 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ] as well as colonization of new human-made habitats, e.g., [ 51 ]. In addition, numerous studies show that data collected by amateur scientists allow to describe new interactions between species, e.g., [ 17 , 52 ], to investigate animal phenology, e.g., [ 53 ], and behavior, e.g., [ 54 ], to find changes in species abundance and demography, e.g., [ 55 , 56 , 57 ], and other threats for local fauna and flora being important for nature conservation, e.g., [ 8 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ].…”