1 A TEST OF THE POLLINATION SYNDROME CONCEPT USING

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A TEST OF THE POLLINATION SYNDROME CONCEPT USING
THE JAMAICAN BLUE MAHOE, HIBISCUS ELATUS
By
Heidi M. Lovig
A Thesis Presented to
The Faculty of Humboldt State University
In Partial Fulfillment of the Requirements for the Degree
Master of Science in Biology
Committee Membership
Dr. Michael R. Mesler, Committee Chair
Dr. Mathew D. Johnson, Committee Member
Dr. Erik S. Jules, Committee Member
Dr. Joseph M. Szewczak, Committee Member
Dr. Michael R. Mesler, Graduate Coordinator
May 2013
ABSTRACT
A TEST OF THE POLLINATION SYNDROME CONCEPT USING
THE JAMAICAN BLUE MAHOE, HIBISCUS ELATUS
Heidi M. Lovig
In this study I tested the ability of the pollination syndrome model to predict the
most effective pollinator of a tropical forest tree, Hibiscus elatus (Malvaceae), at three
sites in Jamaica, West Indies. The floral characteristics of this species suggested
pollination by both bees and bats. Bat syndrome traits include large bowl-shaped flowers
borne on stout pedicles that open in the late afternoon or early evening, thick and waxy
petals, and copious amounts of dilute nectar secreted at night. Bee-related floral traits
include brightly colored petals with nectar guides, diurnal nectar secretion, and a sweet
fragrance. This combination of floral syndromes did not accurately predict the most
common and effective pollinators of these flowers: bats accounted for almost all
pollination while day-flying visitors (honeybees, hummingbirds, flies and wasps) and
other night-flying-visitors (moths, flies, and wasps) contributed minimally. This
conclusion rests on the much higher visit rates of bats, their much higher likelihood of
contacting anthers and stigmas during visits, and the fact that > 99% of pollination
occurred at night. The bee syndrome traits of H. elatus are probably vestiges inherited
from a bee-pollinated ancestor that have been retained due to lack of fitness trade-offs. H.
elatus is likely in a transitional state evolving towards increased specialization for
pollination by bats.
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ACKNOWLEDGEMENTS
I would like to extend my appreciation to my advisor, Dr. Michael Mesler, for all his
guidance and enthusiasm throughout this project.
Thank you to my committee members, Dr. Mathew Johnson for his assistance in
obtaining research permits and logistical support in Jamaica, Dr. Joseph Szewczak for the
use of his camera equipment and Dr. Erik Jules for his writing critiques.
My grateful thanks to Ted Weller for his valuable instruction on how to mist net for bats.
A special thanks to Rose Dana, and Jay, Jayne and Heather Lovig for all their assistance
and support as field technicians in Jamaica; without their help this project would have not
been possible.
And thank you to Tim Carpenter for his support and encouragement throughout this
study.
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TABLE OF CONTENTS
ABSTRACT ……………………………………………………………………ii
ACKNOWLEDGEMENTS ……………………………………………………iii
TABLE OF CONTENTS ……………………………………………………....iv
INTRODUCTION ……………………………………………………………..1
METHODS …………………………………………………………………….4
RESULTS ……………………………………………………………………...10
DISCUSSION ……………………………………………………………….....13
LITERATURE CITED ………………………………………………………...18
TABLES .............................................................................................................25
LIST OF FIGURES …………………………………………………………....30
FIGURES ............................................................................................................31
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1
INTRODUCTION
The pollination syndrome model is arguably the most familiar and influential idea
in the field of pollination biology (Fenster et al. 2004, Ollerton et al. 2009). Although still
contentious, there is compelling evidence for the existence of floral trait correlations
(syndromes) that transcend taxonomic affinity and predict the most effective pollinators
of a given plant species (Stebbins 1970, Armbruster 1988, 2011, Buzato 1994, Fenster et
al. 2004, Paw 2009). According to the model, trait correlations emerge as unrelated plants
specialize on functionally equivalent pollinators that impose similar selective pressures
based on their size, morphology, perceptual ability, and foraging behavior (Stebbins
1970, Faegri & van der Pijl 1979). For example, bat pollinated flowers are large and
sturdy, bloom at night, produce musty fragrances and copious dilute nectar — features
that make adaptive sense in the context of bat biology (Faegri & van der Pijl 1979,
Fleming et al. 2009).
Although syndrome traits often successfully predict the most effective pollinator
of a given plant (e.g. Armbruster 1988, 2011, Pauw 2009, Arditti et al. 2012, Kishore et
al. 2012), cases where specialized flowers are visited by more than one functional group
are common (Herrera 1996, Waser et al. 1996, Fleming 2001, Fenster et al. 2004,
Grombone-Guaratini et al. 2004, Waser and Ollerton 2006). Such unpredicted
generalization does not necessarily weaken the floral syndrome paradigm (Fenster et al.
2004, Ollerton et al. 2009) and often reflects the broad perceptual range and opportunistic
foraging of pollinators. For example, in southern Arizona bees avidly visit Agave
palmeri, a classically bat-adapted flower, to obtain "left over" nectar that was secreted the
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night before (Howell & Roth 1981, Slauson 2000). Even though the flowers of this
species have no apparent adaptations for bee pollination, bees are nevertheless one of the
major pollinators (Slauson 2000).
Less common are cases where generalization is actually predicted by floral traits
because flowers are adapted to more than one group of pollinator (e.g., Sazima et al.
1994, Buzato et al. 1994, Etcheverry and Alemán 2005, Liu et al. 2006, MarténRodríguez et al. 2009). For example Abutilon rufinerve (Malvaceae) has floral
adaptations for bats and hummingbirds, and it is effectively pollinated by both taxa
(Buzato et al. 1994). Such dual pollination systems may represent an intermediate stage
in the transition from one specialized state to another in response to changes in the
composition of pollinator communities (Gottsberger 1986, Buzato et al. 1994).
Alternatively, they may represent an adaptive equilibrium where both functional groups
exert selective pressure on floral traits (Muchhala 2008). Since switching between
pollinator types has been a major feature of angiosperm adaptive radiation (van der Neit
& Johnson 2012), studying species with mixed pollination syndromes promises to
increase our understanding of the kinds of ecological conditions that favor specialization
versus generalization in plant-pollination systems.
My study tested the ability of the floral phenotype to predict the most effective
pollinator(s) of Hibiscus elatus, a tropical tree whose flowers appear to have traits
associated with both bee and bat pollination syndromes (Faegri & van der Pijl 1979,
Fryxell 2001, Helversen 2003, Fleming et al. 2009, Lovig unpublished data). Little is
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known about the pollination biology of this plant, though it has been cited as a bat
pollinated species by Fleming et al. (2009). Preliminary observations in Jamaica revealed
that its flowers are visited by bats at night, but also by bees and hummingbirds during the
day. I asked the following questions: (1) Do the flowers of H. elatus have traits
associated with more than one of the classical pollination syndromes? (2) Do the floral
traits successfully predict the most effective pollinators of this species? (3) What
percentage of pollen deposition occurs at night vs. during the day?
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METHODS
Study organism and study sites— H. elatus is a tree endemic to Jamaica and Cuba
(Fryxell 2001). This species is widely distributed in Jamaica from sea level to 1200 m,
but does not occur in the immediate costal zone (Adams 1971, 1972, Fryxell 2001). Trees
reach 25 m in height, and remain in flower for approximately 3 to 4 months, producing 1
to 40 large bowl-shaped flowers per day (Fryxell 2001, Lovig, unpublished data; Figure 2
A). Flowers are borne on stout pedicles at the tips of branches, and are most abundant in
the top 2/3 of the canopy. Traits that suggest pollination by bees include brightly colored
petals (yellows and oranges) with prominent red nectar guides at the base, and a sweet
fragrance; bat syndrome traits include a stout pedicle, tick waxy petals, large bowl shaped
corollas, a large corolla aperture (29 mm, on average), and the fact that stigmas extended
well beyond the base of the corolla (~98 mm) (Faegri & van der Pijl 1979, Fryxell 2001,
Helversen 2003, Fleming et al. 2009, Lovig unpublished data). Accessible flowers
positioned on the tips of branches and the copious amounts of pollen correspond to both
syndromes, while the red flowers produced by some trees relates to neither syndrome
(Faegri & van der Pijl 1979, Fleming et al. 2009). Buds open in the late afternoon into the
night and flowers senesce completely after 48 hours, but are no longer visited after about
24 hours (Lovig, unpublished data). Flowers are bisexual. Anthers are dehisced and
stigmas receptive at anthesis. Filaments are fused into a tube that extends from the base
of the corolla aperture and rests on the flower's lower petal. The filament tube curves
slightly upward and the stigma extends from its tip. Stigmas are receptive both night and
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day (hydrogen peroxide test: Lovig, unpublished data). Each capsule produces a
maximum of about 100 seeds (Lovig, unpublished data).
Fieldwork was carried out from December 2010 - January 2011 and from
December 2011 - January 2012 at three sites in Jamaica, West Indies. Sites were chosen
to represent a range of conditions with the hope of capturing potential variation in
pollinator assemblages: (1) Kew Park, a coffee plantation surrounded by patches of
forest, Westmoreland Parish (333 m: 18°15' N, 77°56' W), (2) Bunker's Hill, a wet
limestone forest, Trelawney Parish, (198 m: 18°22' N, 77°42' W), and (3) Holywell, a
recreational reserve surrounded by dense closed-canopy montane forest, in the Blue and
John Crow Mountains National Park, St. James Parish, (1067 m: 18°5' N, 76°43' W).
Studies were conducted during peak flowering periods on 21 trees (5 at Kew Park, 8 at
Bunker's Hill, and 8 at Holywell). All trees at each site producing at least 2 flowers per
day within reach of a 15-foot ladder were used. However the majority of trees did not
satisfy these conditions, which limited sample sizes.
Pollen deposition, day and night— Pollen loads on stigmas were counted to determine
how much pollen was deposited during the day versus at night. One or more pairs of
mature buds were selected on survey trees each morning. When more than one pair of
flowers was selected on a single tree, the pairs were spaced as far apart as possible to
minimize non-independence. One bud from each pair was left un-bagged so that flowers
were exposed to nocturnal visitation. The second bud was either covered with a thin
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nylon mesh bag or taped shut (tape was used on windy nights to prevent bag-induced
autogamy). The bag or tape was removed at sunrise so that flowers were open to visits
during the day. Stigmas were collected at sunrise (night pollination) or within one hour of
sunset (day pollination), and the number of pollen grains was counted with a dissection
microscope (Figure 2 B). A total of 75 pairs of stigmas was examined across the three
sites.
Visitor surveys—A combination of visual surveys (day) and video recordings (day and
night) was used to study visitor behavior. Videos were recorded using 1 of 4 cameras: (1)
ARCHOS mobile video recorder AV 500 series infrared-security camera, (2) Sony HD
handheld video recorder, (3) Sony digital HD infrared-video camera recorder HDR-SR11
#1, and (4) Sony digital HD infrared-video camera recorder HDR-SR11 #2. External
infrared lights powered by 12volt motorcycle batteries were used to illuminate flowers
during nocturnal video recordings. Cameras and infrared lights were mounted on either a
modified 12-foot extendable painters-pole, or a 15-foot bamboo ladder.
I filmed patches of 1-4 flowers during the day from 0615-1500 and at night from
1815- 0530. Across all sites, I filmed a total of 43 flowers on 9 trees at night for 2.1 hours
on average (range 0.1-8.0 h), and 29 flowers on 8 trees during the day for 1.0 hours on
average (range 0.2-3.6 h). A total of 91 hours of nocturnal video and 29.2 hours of
diurnal video were taken. Diurnal visual surveys were conducted from 0615-1800 on 251
flowers on 18 trees for a total of 61 hours. I watched 1-4 flowers per 10-min visual
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survey. Videos and visual surveys were analyzed (videos with VLC media player) to
identify visitors, the probability of stigma and/or pollen contact during a visit, and to
determine visitation rates (visits flower-1 hour-1). Visits by nectar robbers were not
included in the above analysis.
All visitors could be identified to functional group: bats, hummingbirds, bees,
wasps, flies (gnats and other small-bodied flies), hawkmoths and other moths. All bee
visits were by Apis mellifera. I mist-netted to capture bats and identify them. One to three
mist nets (70/2 2.6 meters tall, 4 shelves, black nylon, 6-8 meters wide) were placed 1/2-1
meter above the ground near the study trees for 2-4 hours between 1900 and 0130 on
sampling nights. I obtained pollen samples from captured bats by applying and removing
a piece of 3M Scotch transparent tape to the crown of the head, the chest, and the belly
(Nathan Muchhala 2007). Tape was mounted on slides and later examined for H. elatus
pollen with a compound microscope. Hummingbirds and bats were identified using
standard references (Raffaele et al. 2003, Genoways et al. 2005). Flies, wasps,
hawkmoths, and other moths were not identified to species.
Relative pollinator importance— I calculated importance values to estimate the relative
contributions of different visitors to pollen deposition using the equation:
PI = V ⋅ Fpollen ⋅ Fstigma
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where V is the rate of visitation (visits/flower/hour), and Fpollen and Fstigma are the fraction
of visits where pollen or stigmas were contacted, respectively (Armbruster 1988, 2011,
Martén-Rodríguez et al. 2009). The product of Fpollen ⋅ Fstigma was calculated in lieu of
determining the number of grains deposited per visit. The relative importance of each
group (WPI) was calculated by adding all PI values together then dividing each group's
value by the total.
Nectar secretion and flower morphology— Pattern of nectar secretion was estimated for
30 flowers by removing all the nectar three times at approximately 12-hour intervals;
sampling periods correspond to nectar produced during the first night (measured at 04:5509:55), the next day (measured at 15:45-20:05), and the second night (measured at 05:5011:15). Flowers were covered 1-3 hours before anthesis with cages and were only
uncovered only during sampling occasions to prevent visitors from removing nectar.
Logistic considerations made it impossible to sample all flowers at the same time, so
night-time samples may include a small amount of day-time secretion. Nectar volume
was measured with a 1-mL blunt-tipped graduated syringe by removing all fluid from the
base of the nectary; all remaining liquid was removed and measured with 10-μL or 20-μL
microcapillary tubes. Nectar sugar concentration was measured with a Bellingham and
Stanley pocket refractometer for each sample.
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Statistical analysis— One-way ANOVAs were used to test for differences in the amount
of pollen deposited among sites at night or during the day. I used a paired t-test to
determine if there was a difference in the number of pollen deposited on stigmas during
the day and at night, pooling all pairs of flowers across sites. Because I sometimes
sampled more than one pair of stigmas from the same tree, there is the potential of nonindependence. I used two sample t-tests to determine if there were differences in the
amount of nectar secreted over the first night and during the day at both sites, and if there
was a difference in the amount of nectar secreted between sites. Visitation rates could not
be analyzed statistically because the video and visual survey data were collected in
different ways.
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RESULTS
Pollen deposition during the day and night— Although the number of grains deposited
at night varied among sites (p < 0.001), in all cases night-time deposition far exceeded
day-time deposition (p = 0.02, Table 1). Stigmas exposed during the night received an
average of almost 600 grains, which was more than 40 times the number received by
stigmas exposed during the day (~14 grains). Moreover, all night-time stigmas received
at least some pollen, while a large fraction (20% - 27% depending on site) of day-time
stigmas received no pollen (Table 1). With few exceptions, pollen on stigmas consisted
entirely of conspecific pollen.
Visitor surveys—Flowers were visited both night and day. Nocturnal visitors included
bats and moths (sphingids and small-bodied moths). Bats could not be reliably identified
from video recordings, but two phyllosdotmids, Monophyllus redmani and Glossophaga
soricina, captured in mist nets carried heavy loads of H. elatus pollen (Figure 1, Table 2).
Two fruit bats, Artibeus jamaicensis and Ariteus flavescens were also captured, but
carried no pollen. Diurnal visitors included Apis mellifera and three species of humming
birds: Trochilus polytmus, Mellisuga minima, and Anthracothorax mango. Flies and
wasps visited flowers both night and day.
There was variation in visit rates between sites, but overall, bats were the most
common visitors (0.35 - 0.15 visits flower-1 hour-1, depending on site, Table 3). All other
day and night visitors were much less frequent, with few exceptions: hawkmoths visited
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at 0.14 visits flower-1 hour-1 at Kew Park, and Apis mellifera visited at 0.10 visits flower-1
hour-1 at Holywell (Table 3).
Visitors interacted with flowers (Figure 2) differently based on their respective
morphologies and feeding behaviors, which affected their likelihood of contacting pollen
and stigma. Bats either hovered or alighted on flowers directly on top of anthers and
stigmas during visits. This behavior accounted for the bat's high rate of contact with
pollen (85.8 %), and stigmas (68.1 %) when they entered flowers (Table 4). All other
visitors were much less likely to contact pollen and stigmas (Table 4). In general, Apis
mellifera either landed on anthers to collect pollen occasionally crawling over stigmas
prior to departing, or landed on corollas, and crawled into flowers to obtain nectar. The
foraging behavior of both hawkmoths and moths prevented them from contacting
reproductive parts. Hawkmoths hovered far above sexual structures while feeding, and
small moths landed on corollas and crawled into flowers to obtain nectar. Hummingbirds
robbed nectar by inserting their bill between the calyx and corolla, or perching on the
corolla to feed, avoiding reproductive parts. Dipterans did contact pollen and stigmas, but
likely did not transfer much pollen due to their relatively small size.
Relative pollinator importance— Based on relatively high visit rates and contact
probabilities, bats likely accounted for more than 99% of total pollen deposition on
stigmas (Table 5). This value matched the pattern of pollination: depending on site, ~96%
- 98% of pollen deposition occurred during the night (Table 4).
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Nectar secretion— There was a significant difference in the amount of nectar secreted
over the first night and during the day at both sites; Bunker's Hill (P < 0.001), Kew Park,
(P < 0.001). Also, there was significant variation in the amount of nectar produced
between sites during the first night (P = 0.039) and during the day (P = 0.012). Nectar
production was greatest during the first night (1.84 ml, Figure 3). Much less nectar was
produced during the following day (0.29 ml) and second night (0.08 m, Figure 3). Nectar
sugar concentration decreased from 13.7 % after the first night, to 9.4 % after the first
day, and 2.8% after the second night (Figure 3).
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DISCUSSION
The flowers of H. elatus present an apparent mix of bat and bee pollination
syndrome traits. Many of the traits suggest pollination by bats; the large flowers are
borne on stout pedicles and open in the late afternoon or early evening, the petals are
thick and waxy, and copious amounts dilute nectar are secreted at night. However, the
brightly colored petals with nectar guides, and a sweet fragrance, suggest pollination by
bees. The fact that flowers remain open and stigmas are receptive both at night and
during the day suggest potential pollination by both groups. Based on this mix of traits,
the floral syndrome model would predict pollination by bats at night and bees during the
day. However, this was not the case. Pollinator importance values and pollen deposition
on stigmas show H. elatus has a specialized pollination system that relies almost entirely
on glossophagine bats. Since bees provided virtually no fitness contribution to H. elatus,
its bee-related traits are likely vestiges inherited from a bee-pollinated ancestor.
Ecological conditions in Jamaica may have favored a shift from bee to bat pollination and
the evolution of floral adaptations for bats.
The relative importance of a given pollinator depends on both the number of
visits and the quality of visits (Muchhala 2009). Bats visited flowers often, about once
every 1-2 hours, while all other visitors were much less frequent. The quality of bat visits
was also much higher. Bats routinley contacted anthers and stigmas during visits. In
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contrast, even though honeybees, hawkmoths and other moths contacted anthers
frequently at some sites, their probability of contacting stigmas was very low. These two
components, visit rate and visit quality, combined to indicate that bats were the near
exclusive pollinators of H. elatus (relative PI value > .99) in this study. The fact that
almost all pollen deposition (~97 %) occurred at night provides confirmation that bats
were the primary pollinators.
The effectiveness of bats as pollinators can be attributed to their close
morphological fit with the flowers. The width of the corolla aperture (26 mm on average)
was the primary feature influencing a visitor's probability of contacting anthers and/or
stigmas during a visit. The close match between the body size of the bats and the width of
the corolla aperture, assured that bats were consistently guided into flowers immediately
above exerted staminal column, which maximized the probability of contact with anthers
and stigmas. In contrast, the fit between body size and flower width for smaller visitors
like bees, flies, and wasps was poor. These visitors were able to maneuver around
reproductive structures when entering flowers and seldom contacted anthers and stigmas
as they foraged for nectar. Even when pollen-foraging honeybees landed on anthers, they
did so well below the position of the stigmas. Although hummingbirds were frequent
visitors, they very rarley entered flowers from the front: instead, they typically robbed
nectar from between the calyx and corolla, which precluded them from contact with
anthers and stigmas.
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Since native bees do not pollinate H. elatus, and thus are not contemporary agents
of natural selection, its apparent bee-related floral tratis require an explanation. The most
likely scenario is that these traits were inherited from a bee-pollinated ancestor.
Consistent with this view, the closest relative of H. elatus is a widespread coastal shrub,
H. tiliaceus (Takayama et al. 2005, 2006b). The pollination bioogy of this species is
poorly known, but its flowers are visited by large-bodied carpenter bees (Xylocopa) in the
Galapagos Islands and probably elsewhere (McMullen 1989). Several of the floral traits
of H. tiliaceus match the apparent bee-traits of H. elatus: brightly colored petals (yellow,
orange, and red) with conspicious red nectar guides, diurnal nectar secretion, and a
pleasant fragrance (Fryxell 2001, Abe 2006, Elevitch 2006). Thus, I regard the beerelated traits of H. elatus as vestiges of a bee-pollinated ancestor like H. tiliaceus. The bat
adaptations of H. elatus flowers appear to have been added to the bee syndrome plan.
There is no reason to believe that the pre-existing bee adaptation would have diminished
the attractiveness of H. elatus flowers to bats. For example, although Neotropical bat
flowers typically produce fetid or musty sulfur-containing fragrance compounds, some
bats (including Glossophaga soricina) use spatial memory instead of olfaction to locate
blossoms (Voss 1980, von Helversen 1993, 2003, Carter et al. 2010). Likewise, although
bat flowers are usually drab, the flowers of many chiropterophilous species are brightly
colored (Baker 1961, Johnson & Steiner 2000, Fleming et al. 2009). In the absence of
strong adaptive trade offs, the traits adapted for bees have been maintained.
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Ecological conditions in Jamaica likely favored a shift from bee to bat pollination.
Compared to many other oceanic islands, the bee fauna of Jamaica is relatively
depauperate (Adams 1972, Raw 1985). Notably, bee species diversity and abundance
drop with an increase in elevation. Currently, there are only six large bee species known
to pollinate trees on the island, and only three of these are found above 300 meters in
places where H. elatus occurs (Raw 1985). As the immediate ancestors of H. elatus
adapted to higher elevation inland sites, they likely encountered a bee fauna that was less
reliable than it had been on the coast. In contrast bats were probably widespread and
relativley abundant inland, as they are today (Genoways 2005). Under these condition,
mutations that favored pollination by bats would have been favored (Stebbins 1970,
Waser et al. 1996).
Bat pollination has evolved in several different angiosperm lineages from
ancestors that were pollinated either by bees, birds, or non-flying mammals (Fleming et
al. 2009). To date, however, relatively few studies have examined the shift to bat
pollination in an explicitly phylogenetic context (Tripp & Manos 2008, van der Neit &
Johnson 2012), which hinders our understanding of the origin of bat-related floral
adaptations. Assuming that H. tiliaceus is pollinated by bees, my study adds another
example of the kinds of trait changes associated with an evolutionary shift from bee to
bat pollination. Some of the important modifications that likely evolved to facilitate bat
pollination in H. elauts included thicker and waxier petals, thicker pedicel to support
visitation by large vertebrates (Glossophaga soricina clings to flowers during visits (
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Sazima et al. 1999)), an increase in dilute nectar production at night and an increase in
overall flower size: petal length 2-3 times longer in H. elauts (7-12 cm) vs. H. tiliaceus
(4-6 cm), and the staminal column extends much further from the corolla in H. elatus (79 cm) vs. H. tiliaceus (2.5-3 cm) (Fryxell 2001).
In conclusion, the floral traits of H. elatus did not perfectly predict its pollinators.
Although the floral phenotype suggests generalization on bats and bees, pollination was
overwhelmingly by bats. I propose that the mix of syndrome traits represents a
transitional state in which H. elatus is evolving towards increased floral specialization for
pollination by bats. Although maintenance of bee adaptations was likely essential for the
initial transition from bee to bat pollination, these adaptations are now vestigial, and we
can expect them to decay over time.
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25
TABLE 1. Mean number and range of conspecific pollen grains (± s.d.) deposited on H. elatus stigmas and the percent of
pollen deposited on stigmas at night and during the day. Sites are Kew Park (KP), Bunker’s Hill (BH), and Holywell (HW).
Fls is the total number of flowers sampled for pollen day or night at each site.
Nocturnal
Diurnal
% Pollen deposited
Site
Fls
Range
Mean
(± s.d.)
Fls
Range
Mean
(± s.d.)
Night
Day
KP
30
44 – 1348
819.77
374.70
30
0 – 12
17.27
31.54
97.9 %
2.1 %
BH
30
26 – 822
461.93
220.31
30
0 – 12
17.33
32.02
96.4 %
3.6 %
HW
15
83 – 1180
517.47
344.87
15
0 – 32
7.53
9.88
98.6 %
1.4 %
_
25
26
TABLE 2. Total number Monophyllus redmani (MR) and Glossophaga
soricina (GS) sampled for H. elatus pollen (N) at three sites in Jamaica.
Sites are Kew Park (KP), Bunker’s Hill (BH) and Holywell (HW). (WP)
is the number of individuals with H. elatus pollen.
MR
GS
Site
Sampling dates
N
WP
N
WP
KP
1/4/12 – 1/7/12
8
6
0
0
BH
12/30/11 – 1/2/12
5
5
8
5
11
3
0
0
HW
1/21/12 – 1/28/12
26
27
TABLE 3. Visit rates (visits flower-1 hour-1) to H. elatus based on videos (V) and visual surveys (S) at three sites in Jamaica.
Sites are Kew Park (KP), Bunker’s Hill (BH), and Holywell (HW). (h) is the total number of hours surveyed. (Fls) is the total
number of flowers surveyed during the night or day at each site.
Nocturnal visit rates
Site
h
Fls (V)
Bats
Hawkmoths
KP
31.50
14
0.35
0.14
BH
29.50
21
0.28
HW
30.00
8
0.15
.
Other moths
Flies
Wasps
0.08
-
0.00
0.05
0.06
0.00
-
-
0.04
0.05
-
Diurnal visits rates
Fls (S)
Apis
11
104
0.02
0.01
-
30.17
11
102
0.09
0.01
30.88
7
49
0.10
0.01
Site
h
Fls (V)
KP
29.23
BH
HW
T. polytmus
M. minima
.
A. mango
Flies
Wasps
-
0.01
0.00
0.01
0.01
0.01
0.01
-
-
0.03
-
27
28
TABLE 4: Percent of time visitors contacted pollen (%P) and/or stigmas (%S) during visits to H. elatus flowers. (Total) is the
total number of visits where pollen and/or stigmas are contacted.
Kew Park
Nocturnal Visitors
Bats
Bunker’s Hill
Holywell
Total
153
%P
89.5
%S
65.4
Total
175
%P
96.6
%S
67.4
Hawkmoths
61
3.3
1.6
33
15.2
0
-
Moths
34
32.4
2.9
38
13.2
0
10
10.0
0
Flies
-
-
-
3
0
0
11
9.1
0
Wasps
1
0
100.0
-
-
-
-
-
-
305
17.4
0
177
29.9
4
0
10
0
0
3.1
-
-
-
0
-
-
-
46
15.2
-
-
Diurnal Visitors
Apis mellifera
54
0.09
0.02
T. polytmus
33
0
0
41
2.4
M. minima
-
-
-
30
16.7
A. mango
-
-
-
20
0
42
7.1
7.1
32
15.6
3.1
0
0
30
13.3
0
Flies
Wasps
1
Total
35
%P
71.4
-
%S
71.4
-
10.9
28
29
TABLE 5. Pollinator Importance (PI) values for visitors to H. elatus flowers are the product of average visit rate
(visits flower-1 hour-1) (± s.d.), and the probability of pollen and stigma contact (Fpollen , Fstigma) during a visit. WPI is the relative
PI value. Values were pooled across sites.
Visitor
visit rate (± s.d.)
Fpollen
Fstigma
PI values (x103) WPI
Bats
0.26 (0.1)
0.86
0.68
152.0
99.67
Hawkmoths
0.09 (0.07)
0.06
0.01
0.1
0.07
Moths
0.06 (0.02)
0.19
0.01
0.1
0.07
Flies (night)
0.02 (0.03)
0.03
0
0
0
Wasps (night)
0 (0)
0
0.33
0
0
Apis mellifera
0.07 (0.04)
0.16
0.01
0.1
0.07
T. polytmus
0.01 (0)
0.01
0
0
0
M. minima
0.01 (0.01)
0.06
0.01
0
0
A. mango
0.01 (0.01)
0
0
0
0
Flies (day)
0.02 (0.01)
0.13
0.07
0.2
0.13
Wasps (day)
0 (0.01)
0.04
0
0
0
29
30
LIST OF FIGURES
Figure
1
Page
Monophyllus redmani with light yellow H. elatus pollen on its belly
(red arrow) and pollen from a different plant on its chest and head..............27
2
Hibiscus elatus. (A) flower showing wide corolla aperture and
position of the stigmas in relation to the anthers. (B) pollen grains
on stigma…………..................................................................................… 28
3
Nectar secretion and concentration at Kew Park and Bunker's Hill.
Nectar secretion (A) and concentration (B) at Kew Park and Bunker's
Hill. Sampling periods correspond to nectar produced during the
first night measured at 4:55-9:55 (Morning), the next day measured
at 15:45 - 20:05 (Evening), and the second night measured at
5:50-11:15 (Second Morning)...................................................................... 29
31
FIGURE 1: Monophyllus redmani with light yellow H. elatus pollen on its belly
(red arrow) and pollen from a different plant on its chest and head
32
A
B
FIGURE 2: Hibiscus elatus. (A) flower showing wide corolla
aperture and position of the stigmas in relation to the anthers.
(B) pollen grains on stigma
A
Kew Park
Bunker's Hill
33
B
FIGURE 3: Nectar secretion and concentration at Kew Park and Bunker's Hill. Nectar secretion (A) and concentration (B) at Kew Park
and Bunker's Hill. Sampling periods correspond to nectar produced during the first night measured at 4:55 9:55 (Morning), the next day
measured at 15:45 - 20:05 (Evening), and the second night measured at 5:50-11:15 (Second Morning)
33