Pollination of Mucuna mutisiana (Kunth) D.C. by bats Glossophaga soricina and Glossophaga longirostris (Phyllostomidae: Glossophaginae) in the Tropical Dry Forest (BsT) in Northern Colombia

Abstract

Biotic pollination systems can be considered as an ecological process where the interaction between plants and their pollinators determines plant reproduction. It also ensures genetic variability due to pollen transfer between different plants because of cross pollination. It is estimated that bats are pollinating agents to a wide group of plants in the tropics, favoring the transfer of pollen over long distances in plants with flowers that have adaptations for pollination by chiropterans. The objective of my research consisted in describing the biology of pollination of M. mutisiana (Kunth) DC., a fabaceous plant pollinated by swee-tooth bats, in Tropical Dry Forests in the Caribbean region of Colombia. In addition to the possible incidence of the ecological role of nectarivores bats in the dynamics of the Tropical Dry Forest. The results on its phenology shows that the anthesis is twilight starting at 18:00 h. between the months of March and May; and then again October through November, with an approximate duration of 8 to 14 weeks. The maximum flower production happens between the second and third week of flowering with an average of 57 to 108 clusters; 5 to 6 mature flowers opening per night/cluster; and an average of 30 flowers per individual. It was observed that for M. mutisiana pollinisation in BsT to occur, a sudden movement is required to activate the flower opening mechanism towards the subsequent release of the necessary androecium and gynoecium for their reproduction. The flowers size is 6.3 cm (SD = 0.18; N = 25), with maximum peaks of nectar production per night of around 18.58 μl (SD = 18.74; n = 112). Maximum percentage of sugar concentration was 4.68 ºBrix (SD = 5.03; n = 112) at 6:00 p.m. Two potential pollinators bats:  Glossophaga soricina (Pallas 1766) and Glossophaga longirostris (Miller, 1898), visit the flowers of M. mutisiana, with a maximum visit peak of 34.25% (SD = 39.8; n = 112) from 19: 00 a.m. to 9:00 p.m. It was also observed that daylight visits were mostly made by hummingbirds (Antracotoras nigricolis and Phaetornis sp.), At night, other visitors such as opossums (Caluromys sp.) and nocturnal moths of the Sphingidae family were observed. All these observations confirmed the chiropterophilic pollination syndrome in these plant species. Its floral features of attraction and even floral rewards of M. mutisiana showed congruences between the use of the floral resource and the foraging capacity of its main pollinators, which is evidenced by contact between the anthers and pistils with the anteroposterior part of the body of the individuals of this pollinating group In the BsT. Likewise, a high value was found in the relationships that these bats have with the resources offered by the environment, given their flexibility in the diet favoring, not only the pollination systems when there is availability of nectar, but also by combining its nectarivores diet with fruits and insects, allowing these two potential pollinators of M. mutisiana to coexist.