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Stewart AB, Srilopan S, Wayo K, Hassa P, Dudash MR, Bumrungsri S. Bat pollinators: a decade of monitoring reveals declining visitation rates for some species in Thailand. ZOOLOGICAL LETTERS 2024; 10:5. [PMID: 38431697 PMCID: PMC10908063 DOI: 10.1186/s40851-024-00228-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/03/2024] [Indexed: 03/05/2024]
Abstract
Bats are important pollinators, but they are difficult to study since they are volant and nocturnal. Thus, long-term studies of nectarivorous bats are scarce, despite their potential to help assess trends in bat populations and their pollination services. We used capture rates of nectarivorous bats at chiropterophilous flowers in order to examine temporal trends in bat visitation in an area that is undergoing extensive land use change. We mist-netted at five bat-pollinated plant taxa (Durio zibethinus, Musa acuminata, Oroxylum indicum, Parkia speciosa, and Sonneratia spp.) in southern Thailand over six years between 2011 and 2021. We found that the most common bat species, Eonycteris spelaea, was the main visitor at all five plant taxa and had consistent visitation rates across all study years. In contrast, two other important pollinators, Macroglossus minimus and M. sobrinus, showed 80% declines in the number of individuals netted at mangrove apple (Sonneratia spp.) and banana (Musa acuminata) flowers, respectively. These findings suggest that E. spelaea (a large, cave-roosting species with a broad diet) is more tolerant of anthropogenic change than are Macroglossus bats (small, foliage-roosting species with specialized diets), which may in turn affect the reproductive success of plants pollinated by these species. Our study demonstrates how decade-long monitoring can reveal species-specific temporal patterns in pollinator visitation, emphasizing the need for tailored conservation plans. While the conservation status of most nectarivorous bats in the area is Least Concern, our results indicate that population studies in Southeast Asia are urgently needed for updated bat species conservation assessments.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand.
| | - Supawan Srilopan
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Kanuengnit Wayo
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Piriya Hassa
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Sara Bumrungsri
- Department of Biology, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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Domingos-Melo A, Cocucci AA, Tschapka M, Machado IC. A negative association between nectar standing crop and pollen transfer suggests nectar functions as a manipulator of pollinating bats. ANNALS OF BOTANY 2023; 131:361-372. [PMID: 36579432 PMCID: PMC9992937 DOI: 10.1093/aob/mcac154] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS Nectar standing crop has a fundamental role in controlling pollinator movements between flowers and individuals within a population. In bat pollination systems, plants take advantage of the cognitive abilities of nectarivorous bats, which integrate complex perceptions of the quality and spatial distribution of resources. Here, we propose that associations between standing crop and pollen transfer help to reveal the role of nectar as a manipulator of pollinator behaviour. METHODS We used Harpochilus neesianus Ness (Acanthaceae), a bat-pollinated shrub from the Brazilian Caatinga, as a model system to assess nectar removal effects and standing crop, respectively, over the night and to test associations between the amount of nectar available to pollinators, and pollen import and export. KEY RESULTS Harpochilus neesianus showed continuous nectar secretion throughout the flower lifespan. Flowers subjected to successive nectar removals produced less nectar than flowers sampled just once, and showed, despite a higher sugar concentration, a lower absolute amount of sugar. Under these conditions, bats may realize that nectar production is decreasing after repeated visits to the same flower and could be manipulated to avoid such already pollinated flowers with little nectar, thus increasing the probability of visits to flowers with a high amount of nectar, and a still high pollen availability on anthers and low pollen deposition on stigmas. We found that during most of the period of anthesis, nectar standing crop volume was positively correlated with the number of pollen grains remaining in the anthers, and negatively with the number of pollen grains deposited on the stigma. CONCLUSIONS Nectar secretion patterns can function as a manipulator of pollinating bats in H. neesianus. We propose that the assessment of variability in nectar secretion in response to removal, and the correlation between nectar standing crop and relative pollen transfer throughout anthesis should be considered in order to understand the role of nectar in the manipulation of pollinators.
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Affiliation(s)
- Arthur Domingos-Melo
- Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Centro de Biociências – Universidade Federal de Pernambuco, Brazil
- Universidade de Pernambuco – Campus Petrolina, Brazil
| | - Andrea A Cocucci
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Cordoba, Argentina
| | - Marco Tschapka
- University of Ulm, Ulm, Germany
- Smithsonian Tropical Research Institute, Ancon, Panamá
| | - Isabel C Machado
- Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Centro de Biociências – Universidade Federal de Pernambuco, Brazil
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Stewart AB, Diller C, Dudash MR, Fenster CB. Pollination-precision hypothesis: support from native honey bees and nectar bats. THE NEW PHYTOLOGIST 2022; 235:1629-1640. [PMID: 35194792 DOI: 10.1111/nph.18050] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/09/2022] [Indexed: 05/28/2023]
Abstract
The evolution of floral traits is often considered to reflect selection for increased pollination efficiency. Known as the pollination-precision hypothesis, increased pollination efficiency is achieved by enhancing pollen deposition on precise areas of the pollinator. Most research to date addressing this hypothesis has examined plant species that are a priori predicted to place pollen precisely, but we still lack comparisons with species predicted to have low pollination efficiency. We studied 39 plant species with diverse floral morphologies and measured the precision of pollen placement on two pollinator groups: honey bees (genus Apis) and nectar bats (family Pteropodidae). Pollen was collected from four locations of each pollinator's body (bees: dorsal thorax, ventral thorax, dorsal abdomen, ventral abdomen; bats: crown, face, chest, wing) to calculate pollen placement precision using Pielou's evenness index. We also quantified variation in floral design by scoring floral symmetry, corolla fusion, floral orientation and stamen number. We confirm the importance of four floral character states (bilateral symmetry, fused corollas, horizontal orientation and reduced stamen number) in promoting precise pollen placement on diverse pollinators. Our findings provide phylogenetically corrected, empirical support that the evolution of the four floral characters reflect selection for enhanced precision of pollen placed on pollinators.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Carolina Diller
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, 234 56, Sweden
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, 57007, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Charles B Fenster
- Oak Lake Field Station, South Dakota State University, Brookings, SD, 57007, USA
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The role of pteropodid bats in pollination of durian (Durio zibethinus) in managed orchards in suburban habitat of Thailand. Urban Ecosyst 2019. [DOI: 10.1007/s11252-019-00919-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Aguilar-Rodríguez PA, Tschapka M, García-Franco JG, Krömer T, MacSwiney G MC. Bromeliads going batty: pollinator partitioning among sympatric chiropterophilous Bromeliaceae. AOB PLANTS 2019; 11:plz014. [PMID: 31186827 PMCID: PMC6537948 DOI: 10.1093/aobpla/plz014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Pollinators can be a limited resource and natural selection should favour differences in phenotypic characteristics to reduce competition among plants. Bats are important pollinators of many Neotropical plants, including the Bromeliaceae; however, the pre-pollination mechanisms for isolation among sympatric bat-pollinated bromeliads are unknown. Here, we studied the mechanisms for reproductive segregation between Pitcairnia recurvata, Pseudalcantarea viridiflora, Werauhia noctiflorens and W. nutans. The study was conducted at Los Tuxtlas Biosphere Reserve, in Veracruz, Mexico We carried out ex situ and in situ manual pollination treatments to determine the breeding system by assessing fruiting and seedling success and sampled bat visitors using mist-nets and infrared cameras. We determined the nocturnal nectar production pattern, estimating the energetic content of this reward. All four bromeliads are self-compatible, but only P. recurvata appears to require pollinators, because the physical separation between anthers and stigma prevents self-pollination, it is xenogamous and presents a strictly nocturnal anthesis. The bats Anoura geoffroyi, Glossophaga soricina and Hylonycteris underwoodi are probable pollinators of three of the studied bromeliads. We did not record any animal visiting the fourth species. The flowering season of each species is staggered throughout the year, with minimal overlap, and the floral morphology segregates the locations on the body of the bat where the pollen is deposited. The most abundant nectar per flower is provided by P. viridiflora, but P. recurvata offers the best reward per hectare, considering the density of flowering plants. Staggered flowering, different pollen deposition sites on the body of the pollinator and differences in the reward offered may have evolved to reduce the competitive costs of sharing pollinators while providing a constant supply of food to maintain a stable nectarivorous bat community.
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Affiliation(s)
- Pedro Adrián Aguilar-Rodríguez
- Centro de Investigaciones Tropicales, Universidad Veracruzana, José María Morelos, Col. Centro, C.P. Xalapa, Veracruz, México
- Department of Zoology, Tel Aviv University, Tel Aviv, Israel
| | - Marco Tschapka
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert Einstein Allee 11, D Ulm, Germany
- Smithsonian Tropical Research Institute, Balboa Ancón, Apartado, Panamá, Republica de Panamáa
| | - José G García-Franco
- Red de Ecología Funcional, Instituto de Ecología, A.C., Carretera Antigua a Coatepec No. 351, El Haya, C.P. Xalapa, Veracruz, México
| | - Thorsten Krömer
- Centro de Investigaciones Tropicales, Universidad Veracruzana, José María Morelos, Col. Centro, C.P. Xalapa, Veracruz, México
| | - M Cristina MacSwiney G
- Centro de Investigaciones Tropicales, Universidad Veracruzana, José María Morelos, Col. Centro, C.P. Xalapa, Veracruz, México
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Bergamo PJ, Wolowski M, Maruyama PK, Vizentin-Bugoni J, Sazima M. Trait patterns across space and time suggest an interplay of facilitation and competition acting on Neotropical hummingbird-pollinated plant communities. OIKOS 2018. [DOI: 10.1111/oik.05571] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Pedro Joaquim Bergamo
- Depto de Biologia Vegetal, Inst. de Biologia, CP 6109, Univ; Estadual de Campinas, BR-13083-970 Campinas SP Brasil
- Programa de Pós-Graduação em Ecologia, Inst. de Biologia, Univ. Estadual de Campinas; Campinas SP Brasil
| | - Marina Wolowski
- Depto de Biologia Vegetal, Inst. de Biologia, CP 6109, Univ; Estadual de Campinas, BR-13083-970 Campinas SP Brasil
- Inst. de Ciências da Natureza, Univ. Federal de Alfenas; Alfenas MG Brasil
| | - Pietro Kiyoshi Maruyama
- Depto de Biologia Vegetal, Inst. de Biologia, CP 6109, Univ; Estadual de Campinas, BR-13083-970 Campinas SP Brasil
- Inst. de Biologia, Univ. Federal de Uberlândia; Uberlândia MG Brasil
| | - Jeferson Vizentin-Bugoni
- Depto de Biologia Vegetal, Inst. de Biologia, CP 6109, Univ; Estadual de Campinas, BR-13083-970 Campinas SP Brasil
- Programa de Pós-Graduação em Ecologia, Inst. de Biologia, Univ. Estadual de Campinas; Campinas SP Brasil
| | - Marlies Sazima
- Depto de Biologia Vegetal, Inst. de Biologia, CP 6109, Univ; Estadual de Campinas, BR-13083-970 Campinas SP Brasil
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