Megachiropteran Bats Research Articles

Conflict and congruence in a combined DNA-morphology analysis of megachiropteran bat relationships (Mammalia: Chiroptera: Pteropodidae).

The phylogeny of megabats (Mammalia: Chiroptera: Megachiroptera) has been addressed only on molecular grounds, as little effort has previously been made to describe the impressive morphological variation of the group in terms of phylogenetically informative characters. Here we provide a morphological matrix of 236 characters from the integument, dentition, cranial and post-cranial skeleton, digestive apparatus and urogenital system. This data set covers most characters discussed previously in more restricted taxonomic contexts, as well a large number of new characters. Our aim was to generate a phylogenetic hypothesis for megabats based on a combined analysis of morphological characters and available gene sequence data from four mitochondrial and one nuclear loci. We used direct optimization under conventional equal costs, as well as under a cost ratio that maximizes homology when inapplicables (gaps) are present. Our results contradict the allegedly high level of conflict between the molecular and morphological partitions. We found that, although morphology alone recovered trees different and to some extent incompatible with those from previous molecular analyses, the combination of the two sources of evidence easily accommodated the morphological and molecular signals, yielding a resolved and relatively well-supported phylogeny of Megachiroptera that is in reasonable agreement with the current morphology-based taxonomy of the group. Overall congruence favored the maximization of homology by a narrow margin. In addition, partial analyses showed that implied weighting of morphology performed slightly better than equal weighting with respect to the combined analyses.

Echolocation signal structure in the Megachiropteran bat Rousettus aegyptiacus Geoffroy 1810

Rousettus aegyptiacus Geoffroy 1810 is a member of the only genus of Megachiropteran bats to use vocal echolocation, but the structure of its brief, click-like signal is poorly described. Although thought to have a simple echolocation system compared to that of Microchiroptera, R. aegyptiacus is capable of good obstacle avoidance using its impulse sonar. The energy content of the signal was at least an order of magnitude smaller than in Microchiropteran bats and dolphins (approximately 4 x 10(-8) J m(-2)). Measurement of the duration, amplitude and peak frequency demonstrate that the signals of this animal are broadly similar in structure and duration to those of dolphins. Gabor functions were used to model signals and to estimate signal parameters, and the quality of the Gabor function fit to the early part of the signal demonstrates that the echolocation signals of R. aegyptiacus match the minimum spectral spread for their duration and amplitude and are thus well matched to its best hearing sensitivity. However, the low energy content of the signals and short duration should make returning echoes difficult to detect. The performance of R. aegyptiacus in obstacle avoidance experiments using echolocation therefore remains something of a conundrum.

Affording larger brains: testing hypotheses of mammalian brain evolution on bats.

Several major hypotheses have been proposed to explain how larger brains in mammals, such as those of humans, are afforded in energetic terms. To date, these have been largely tested on primates, with some cross-mammal analysis. We use morphological, ecological, and metabolic data for 313 species of bats to examine the allometry of brain mass and to test key predictions from three of these hypotheses: the direct metabolic constraint, expensive tissue, and maternal energy hypotheses. We confirm that megachiropteran bats (entirely fruit-eating) have larger brains for their body mass than microchiropteran bats (fruit-eating and non-fruit-eating) and fruit-eating species (Megachiroptera and Microchiroptera) have larger brains than non-fruit-eating species (Microchiroptera). Although our analyses demonstrate little or no support for any of the three hypotheses, we show that 95.9% of the variance in brain mass can be explained by the independent effects of gestation length and body mass. This indicates that among bats, the duration of maternal investment plays an important role in the adult brain mass finally obtained. These analyses serve to emphasis the crucial importance of testing the general applicability of macroevolutionary hypotheses (often developed in isolation in one clade) in multiple clades with different evolutionary histories.

A phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) based on direct optimization analysis of one nuclear and four mitochondrial genes.

The phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) has been investigated using several different molecular datasets. These studies differed widely in taxonomic and locus sampling, and their results tended to lack resolution of internal nodes and were themselves largely incongruent. To address this, we assembled a data set of 5 loci (up to 3.5 kbp from 12S rDNA, 16S rDNA, tDNA-valine, cytochrome b, and the nuclear gene c-mos) for 43 species of megachiropterans and 6 microchiropteran outgroups. We analyzed these data with direct optimization under equal costs for substitutions and indels. We used POY in a parallel setting, and searches consisted of replicated swapping + refinements (ratcheting, tree fusing, and iterative pass optimization). Our results indicate that Megachiroptera and all recognized genera (including Pteropus) are monophyletic, and that Melonycteris is the sister group of the clade containing all the other genera. Clades previously proposed using molecular data, as well as many new and traditional groups, were well-supported, and various sources suggest that the degree of conflict with morphological data may be considerably less marked than previously supposed. Analysis of individual loci suffer 70% loss in the number of compatible groups recovered across all analyses with respect to combined analyses. Our results indicate that, within Megachiroptera, nectarivory and cave-dwelling originated several times, but echolocation (used for obstacle detection) evolved only once. Megachiropterans likely originated in SE Asia-Melanesia, and colonized Africa at least four times.

A phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) based on direct optimization analysis of one nuclear and four mitochondrial genes

The phylogeny of megachiropteran bats (Mammalia: Chiroptera: Pteropodidae) has been investigated using several different molecular datasets. These studies differed widely in taxonomic and locus sampling, and their results tended to lack resolution of internal nodes and were themselves largely incongruent. To address this, we assembled a data set of 5 loci (up to 3.5 kbp from 12S rDNA, 16S rDNA, tDNA-valine, cytochrome b, and the nuclear gene c-mos) for 43 species of megachiropterans and 6 microchiropteran outgroups. We analyzed these data with direct optimization under equal costs for substitutions and indels. We used POY in a parallel setting, and searches consisted of replicated swapping + refinements (ratcheting, tree fusing, and iterative pass optimization). Our results indicate that Megachiroptera and all recognized genera (including Pteropus) are monophyletic, and that Melonycteris is the sister group of the clade containing all the other genera. Clades previously proposed using molecular data, as well as many new and traditional groups, were well-supported, and various sources suggest that the degree of conflict with morphological data may be considerably less marked than previously supposed. Analysis of individual loci suffer 70% loss in the number of compatible groups recovered across all analyses with respect to combined analyses. Our results indicate that, within Megachiroptera, nectarivory and cave-dwelling originated several times, but echolocation (used for obstacle detection) evolved only once. Megachiropterans likely originated in SE Asia-Melanesia, and colonized Africa at least four times.

Roosting ecology and social organization of the spotted-winged fruit bat, Balionycteris maculata (Chiroptera: Pteropodidae), in a Malaysian lowland dipterocarp forest

The aims of this study were to investigate the roosting ecology and social organization of the spotted-winged fruit bat, Balionycteris maculata (Megachiroptera), within an old-growth Malaysian dipterocarp forest, and test the hypothesis that males spend a significantly greater proportion of the night in the immediate vicinity of their day roosts than females. Balionycteris maculata roosted in cavities and formed small harem groups that consisted of one adult male accompanied by up to nine adult females and their dependent young. Both male and female bats foraged locally, within approximately 1 km of their roost sites. However, in contrast to females, which remained away from the roost site throughout the night, both harem and solitary adult males divided their nightly activity between foraging and returning to their roost sites. Individual females were also found roosting sequentially with up to three different males. Hence, these results suggest that B. maculata has a resource-defence polygynous mating system, in which the roost cavity may represent a critical and defendable resource by which males recruit and gain improved reproductive access to females. Roost cavities occupied by B. maculata were found within a number of different forest structures, including ant nests, termite nests and the root masses of epiphytes. The consistent shape and position of the cavities, along with a single observation of cavity enlargement, provide the first evidence of roost-cavity excavation, by a megachiropteran bat, within the nests of social insects. Although the cues by which females select their roost sites are unclear, some aspect of roost cavity size, or condition, may provide a possible means by which females can assess the reproducÍtive fitness of potential mates.

The endemic Comoros Islands fruit bat Rousettus obliviosus: ecology, conservation, and Red List status

Rousettus obliviosus is a megachiropteran bat endemic to the Comoros Islands in the western Indian Ocean. The species is broadly distributed on Grande Comore, Mohéli, and Anjouan, but appears to be absent from Mayotte. Roost sites were found to be both shallow and deep caves, in dark locations with infrequent human disturbance. Colony size ranged from 100 to several thousand and at two sites seasonal variation was observed. Total estimated population size was 7,100–17,100. R. obliviosus fed on a variety of native and non-native tree fruits and flowers, and was found in native forest habitats, underplanted forest and agricultural areas. R. obliviosus is a manoeuvrable flyer able to hover for brief periods and may echolocate. A small range, sensitivity to disturbance, limited roost site availability and deforestation combine to threaten this species. We suggest that the current IUCN Red List status of Lower Risk: near threatened should be revised to Vulnerable. Protection of roost sites, further surveys to identify additional roosts, further ecological research, and protection of remaining forest are conservation priorities for R. obliviosus.

Seasonality and synchrony of reproduction in three species of nectarivorous Philippines bats

BackgroundDifferences among species and among years in reproductive seasonality (the tendency for clusters of events to fall at approximately the same point in each year) and synchrony (amount of clustering of events within a year) have been intensively studied in bats, but are difficult to assess. Here, we use randomization methods with circular statistics to test for synchrony and seasonality of reproduction in three species of nectarivorous megachiropteran bats on Negros Island in the central Philippines.ResultsIn Rousettus amplexicaudatus, estimated dates of birth were both highly synchronous and highly seasonal. In Macroglossus minimus, estimated births were seasonal and significantly clustered within years, but within each year births occurred over a broad period, indicating a low level of synchrony. In Eonycteris spelaea, estimated births were also seasonal and had statistically significant synchrony, with birth periods within years intermediate in synchrony between R. amplexicaudatus and M. minimus. All three species had a similar seasonal pattern, with two birth periods in each year, centered on March or April and August or September. In one species, R. amplexicaudatus, primigravid females (in their first pregnancy) produced their young in June and July, a birth period significantly different in timing from the two birth periods of older adult females. This more conservative pattern of young females may allow higher survival of parents and offspring at cost of a lost reproductive opportunity. There was weak evidence that in some years primigravid females of M. minimus might differ in timing from older adults. There were few significant differences in reproductive timing among different years, and those differences were generally less than two weeks, even during a severe drought in the severe el Niño of 1983.ConclusionThe results suggest that these species follow an obligately seasonal pattern of reproductive timing with very little phenotypic plasticity. The resampling methods were sensitive to differences in timing of under two weeks, in some cases, suggesting that these are useful methods for analyses of seasonality in wild populations of bats.

The distribution and relative abundance of megachiropteran bats in Southern Ghana

The distribution and relative abundance of megachiropteran bats in Southern Ghana

Somatotopic organization and cortical projections of the ventrobasal complex of the flying fox: an "inverted" wing representation in the thalamus

The present study investigates the somatotopic representation in the somatosensory thalamus of a megachiropteran bat. Using standard microelectrode mapping techniques, representational maps were generated for the ventrobasal (Vb) and posterior (Po) thalamic complexes of the Grey-headed flying fox. Anatomical tracing from neocortical injections provided additional data confirming the somatotopy found physiologically. A full representation of the body surface innervated by the trigeminal and spinal nerves was found. However, in contrast with other mammals, the representations of the forelimb and adjacent thoracic trunk within the thalamus were inverted. This means that the distal portions of the wing membrane and the tips of the digits were represented dorsally in Vb, and the thoracic trunk was represented ventrally. In Po the digit tips were represented in the ventral most portion and the thoracic trunk in the dorsal portion of the nucleus.These results are discussed in relation to similarities of megachiropteran somatosensory thalamic nuclei to those of other mammalian species and in relation to the formation of thalamic somatotopic maps and fiber sorting.

Soaring and non-soaring bats of the family pteropodidae (flying foxes, Pteropus spp.): wing morphology and flight performance.

On oceanic islands, some large diurnal megachiropteran bat species (flying foxes; Pteropus spp.) frequently use thermal or slope soaring during foraging flights to save energy. We compared the flight morphology and gliding/soaring performance of soaring versus non-soaring Pteropus species, one pair on American Samoa and one pair on the Comoro Islands, and two other soaring/flap-gliding species and one non-soaring species. We predicted that the soaring species should have a lower body mass, longer wings and, hence, lower wing loadings than those species that use mainly flapping flight. This would give a lower sinking speed during gliding, a higher glide ratio, and enable the bats to make tighter turns with lower sinking speeds than in the non-soaring species. We theoretically calculated the gliding and circling performances of both the soaring and non-soaring species. Our results show that there are tendencies towards longer wings and lower wing loadings in relation to body size in the gliding/soaring flying foxes than in the non-soaring ones. In the species-pair comparison of the soaring and non-soaring species on American Samoa and the Comoro Islands, the soarers on both islands turn out to have lower wing loadings than their non-soaring partners in spite of opposite size differences among the pairs. These characteristics are in accordance with our hypothesis on morphological adaptations. Most differences are, however, only significant at a level of P<0.1, which may be due to the small sample size, but overlap also occurs. Therefore, we must conclude that wing morphology does not seem to be a limiting factor preventing the non-soarers from soaring. Instead, diurnality in the soaring species seems to be the ultimate determinant of soaring behaviour. The morphological differences cause visible differences in soaring and gliding performance. The glider/soarers turn out to have lower minimum sinking speeds, lower best glide speeds and smaller turning radii than the non-soarers. When the wing measurements and soaring performance are normalized to a body mass of 0.5 kg for all species, the minimum sinking speed becomes significantly lower (P<0.05) in the three soaring and the one flap-gliding species (0.63 m s(-)(1)) than in the three non-soaring species (0.69 m s(-)(1)). Interestingly, the zones in the diagrams for the glide polars and circling envelopes of these similar-sized bats become displaced for the glider/soarers versus the non-soarers. The glide polars overlap slightly only at the gliding speeds appropriate for these bats, whereas the circling envelopes do not overlap at the appropriate bank angles and turning radii. This points towards adaptations for better gliding/soaring performance in the soaring and gliding species.

Testes mass in megachiropteran bats varies in accordance with sperm competition theory

Sperm competition is a widespread phenomenon influencing a range of characters, including investment in gonadal tissue. Conspecific proximity is one factor which can influence the risk of sperm competition and hence testicular investment, and decreased confidence of paternity may be one cost of group living. Aspects of female biology may also influence spermatogenic investment and sperm morphology. This study examines the associations between relative testes mass and roost-group size across 17 species of Megachiroptera. Associations between breeding season duration and investment in spermatogenesis are also examined, as are associations between female reproductive tract dimensions and testes mass and dimensions of spermatozoa across all bats. Relative testes mass was significantly positively associated with roost-group size at a species level and after appropriate phylogenetic control (pairwise comparisons and comparison of independent contrasts). There were no significant relationships between breeding season duration and relative testes mass. Across all bats, neither testes mass nor sperm length were significantly related to dimensions of the female tract. The results are discussed in the context of sperm competition.

Observations on the Foraging Behavior of a Tent Roosting Megachiropteran Bat Cynopterus sphinx

BiotropicaVolume 30, Issue 2 p. 321-324 Observations on the Foraging Behavior of a Tent Roosting Megachiropteran Bat Cynopterus sphinx G. Marimuthu, Corresponding Author G. Marimuthu Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Corresponding author.Search for more papers by this authorK. E. Rajan, K. E. Rajan Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Search for more papers by this authorA. John Koilraj, A. John Koilraj Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Search for more papers by this authorS. Suthakar Isaac, S. Suthakar Isaac Department of Zoology St. John's College Palayamkottai–627 002 Tirunelveli, IndiaSearch for more papers by this authorJ. Balasingh, J. Balasingh Department of Zoology St. John's College Palayamkottai–627 002 Tirunelveli, IndiaSearch for more papers by this author G. Marimuthu, Corresponding Author G. Marimuthu Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Corresponding author.Search for more papers by this authorK. E. Rajan, K. E. Rajan Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Search for more papers by this authorA. John Koilraj, A. John Koilraj Department of Animal Behavior and Physiology School of Biological Sciences Madurai Kamaraj University, Madurai–625021, India.Search for more papers by this authorS. Suthakar Isaac, S. Suthakar Isaac Department of Zoology St. John's College Palayamkottai–627 002 Tirunelveli, IndiaSearch for more papers by this authorJ. Balasingh, J. Balasingh Department of Zoology St. John's College Palayamkottai–627 002 Tirunelveli, IndiaSearch for more papers by this author First published: 15 March 2006 https://doi.org/10.1111/j.1744-7429.1998.tb00066.xCitations: 19 Received 18 January 1996; revision accepted 4 December 1996. AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume30, Issue2June 1998Pages 321-324 RelatedInformation

Natural history of the New Georgia Monkey-faced Bat Pteralopex sp. nov. from the Solomon Islands

The megachiropteran bat genus Pteralopex, Monkey-faced bats, is restricted to the Solomon Islands and Fiji. No other field study has been conducted on any of the five known species. From February to May 1992, the New Georgia Monkey-faced Bat was studied to determine its distribution, assess its conservation status and to provide ecological data for management. We found New Georgia Monkey-faced Bats Pteralopex sp. nov. at four sites on the islands of Vangunu and New Georgia, but not on Kolombangara. Bats were most common around an old village site abandoned approximately 90 years ago, in undisturbed rainforest, and adjacent gardens. Pteralopex sp. nov. was absent from areas of regrowth after logging or cyclone damage. It roosts in the hollows of tall canopy or emergent trees (particularly Ficus spp.), either singly or in small groups. Like other megachiropterans, Pteralopex sp. nov. eats a wide range of fruit and flowers. Young were born throughout the study, from February to May. This species' restricted range and susceptibility to hunting make it vulnerable, especially in the short term if its habitat is affected by logging or cyclones. Old village sites may be important for Pteralopex and other wildlife in the Solomon Islands.

Anatomical and physiological investigation of auditory input to the superior colliculus of the echolocating megachiropteran bat Rousettus aegyptiacus.

The objective of this study was to investigate whether a representation of auditory space in the superior colliculus (SC) of the echolocating megachiropteran bat (Rousettus aegyptiacus) exists. Additionally the subcortical auditory connectivity of the SC was investigated. A total of 207 units were recorded in five awake animals while presenting acoustic stimuli (white noise, clicks, and pure tones) at different positions in space. Six units responded to acoustic stimulation. Three of these located within the superficial layers and one located in the intermediate layers were classified as omnidirectional units. Two units were located within the deep layers. One was classified as a hemifield unit, and the other as a frontal unit. All units responded phasically to acoustic stimulation with a latency of 4-150 ms. None of them could be activated by visual stimuli. We further examined the interaction of paired auditory and visual stimulation in 116 visually responsive units. Responses to visual stimulation were markedly altered by acoustic stimulation in 5 units. The influence of the acoustic stimuli was temporally and spatially restricted, and resulted either in a reduction or an elevation of unit responsiveness. Horseradish peroxidase was injected into the SC of eight animals to investigate the auditory subcortical connectivity of the SC. Retrograde labeling in auditory structures was rare compared with labeling found in nonauditory structures (e.g., retina, substantia nigra, parabigeminal nucleus). In auditory structures retrograde labeling was found mainly in the external nucleus of the inferior colliculus and in the nucleus of the brachium of the inferior colliculus. To a lesser extent it was found in the nucleus sagulum and in the area medial to the lemniscal nuclei. In one case the dorsal nucleus of the lateral lemniscus and the anterolateral periolivary nucleus were labeled. Our results reveal only a sparse auditory input into the SC of the flying fox, R. aegyptiacus. On the basis of single-unit recordings, we did not find an elaborate representation of auditory space as it is described for several other species. The existence of auditory and bimodal neurones, in combination with their response properties, nonetheless indicate that there might be a representation of auditory space in the SC of R. aegyptiacus.

Thermoregulation, energy metabolism, and torpor in blossom‐bats, Syconycteris australis (Megachiroptera)

Since little information is available on torpor in bats of the suborder Megachiroptera, we investigated whether the small (18 g) blossom‐bat Syconycteris australis displays torpor in the laboratory. Bats entered daily torpor when food and water were withheld for one night and the air temperature (Ta) was below about 26°. Torpor began shortly after lights went on in the morning and lasted for a maximum of 12 hours. During torpor at Ta18°, metabolic rates fell to a minimum of about 15% of that in resting individuals at the same Ta, and to about 40% of the basal metabolic rate. The body temperature (Tb) during torpor was metabolically defended at or above about Tb 18°. Individuals that did not enter torpor in the morning reduced their Tb from about 34.5°, observed in resting individuals that had been fed during the previous night, to values between 30.2 and 32.8°, and the resting metabolic rate fell by about 25%. The ability to undergo short periods of torpor may explain why the distribution range of S. australis extends much further south than that of other small Australian megachiropteran bats.

Observations on the Distribution and Ecology of Bats in Uganda

ABSTRACT Bat community patterns in Uganda are examined in relation to their occurrence in the different vegetation zones of the country. The data available so far cover only three of the country's floristic regions. These data suggest that the northern drier region U1 has more microchiropteran bats and that species diversity of megachiropteran bats tends to increase in the more forested western U2 and southern U4 regions. Species accounts in the appendix largely summarise the known information, they reveal that much more work is required to fully document the bats of Uganda.

Regular pulse emission in some megachiropteran bats.

We recorded vocalizations of megachiropteran bats, Cynopterus brachyotis, C. horsfieldi, Megaerops ecaudatus and Macroglossus sobrinus as they were held in our hands, in a hanging position or moved up and down, simulating flight. All four species produced regular audible tone pulses with a frequency spectrum of less than 9 kHz (peak at 4-6 kHz). The duration of a single pulse varied from 14.9 to 23.6 msec on average among these species. The interpulse interval was between 108.3 and 127.7 msec. In M. ecaudatus and M. sobrinus, double pulses were occasionally emitted, with interpulse intervals averaging 39 msec and 31 msec, respectively. The regular pulse emission may indicate that the bats studied use sounds to probe space.

The ecology of bats in south-east Australian forests and potential impacts of forestry practices: a review

Bats are important contributors to Australia's mammal diversity and are ecologically diverse, feeding on insects, fish, small vertebrates, nectar, pollen and fruit. As such they are likely to play key ecological roles as regulators of invertebrate populations and pollinators of forests. Although somewhat contradictory, current evidence suggest that logging impacts on the species richness and activity of insectivorous bats when forest structural complexity and the number of available roosting hollows are reduced. Inconsistent results concerning impact on species richness stem from methodological problems with bat surveys. "Rare" species are often recorded in low numbers, preventing habitat preferences and disturbance impacts from being determined. Radio-telemetry has demonstrated that roosts in hollows of mature trees are a critical resource for many species of bats due to species specific requirements. However, it is not yet possible to state whether bat populations are directly limited by the availability of hollows in areas where a mosaic of logged and unlogged forest exists. Although data on foraging areas are extremely limited, some species appear to be flexible, capable of flying across open areas and exploiting those rich in invertebrates. Some species (e.g., Vespadelus) show a high degree of site attachment, possibly indicating a susceptibility to logging, however, the extent of site fidelity for most species is unknown. As pollinators, megachiropteran bats are likely to play a key role in maintaining the genetic diversity currently present in eucalypts by facilitating long-distance movement of pollen. Areas that are productive in nectar and pollen have a high conservation value for these bats and many other nectarivores, however, the age at which important nectar-producing trees flower is generally not known. The extent to which wildlife prescriptions, such as habitat trees and mosaics of small reserves, mitigate these impacts on bat species requires urgent research.

Reproductive Biology of Ravenala madagascariensis Gmel. as an Alien Species

The exotic arborescent monocot species from Madagascar, Ravenala madagascariensis, was studied in suburban gardens in Darwin, Australia. Inflorescences are long-lived branched spikes produced at right angles to a spectacular fan-like array of foliage. They are composed of a variable number of green boat-like bracts which contain a dilute liquid. Each bract subtends a series of individual, stiff, upright, large flowers which appear every 2.3 days, the total number of flowers being variable (up to 29). The slightly musty sweet smelling, creamy white hermaphrodite flowers, sometimes protogynous, opened at night (82.6% of flowers observed). Anthesis lasted, on average, 1.3 days and stigmas were receptive within the 24 hours of flower opening. Initially, nectar production was copious (1400 Al 12 hr-') and concentration moderate (14.5% sucrose equivalents), but maximum production (1600 41 12 hr-') with slightly reduced concentration (12.5% sucrose) occurred at 2400 hr. Seed set occurs in Darwin plants, with the brown seed enveloped in a bright blue aril and displayed very obviously in the dehisced capsule. While autogamy treatments revealed that Ravenala is at least a facultative selfer, in Darwin the flowers were most frequently visited by the megachiropteran bat, Pteropus alecto gouldii, and only occasionally by the smaller bat, Macroglossus lagochilus, and honeyeater birds (Meliphagidae). Apart from reproducing vegetatively, the ability of Ravenala to set seed when grown outside its normal range in the absence of its co-evolved pollinator(s), either by selfing or by using a suitable indigenous pollinator, could allow the species to assume pest status in parts of the tropics where it is planted as an ornamental.