Dietary
energy estimate inferred from fruit preferences of Cynopterus sphinx (Mammalia: Chiroptera: Pteropodidae) in a flight
cage in tropical China
Aeshita Mukherjee 1,
Burkhard Wilske 2 & Jin Chen 3
1,3Plant–Animal Interaction
Group, 2 Plant Physiological Ecology,
Xishuangbanna
Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla 666303,
Yunnan, P.R. China
Email: 1 aesh2003@yahoo.com
Date
of publication (online): 26 June 2010
Date
of publication (print): 26 June 2010
ISSN
0974-7907 (online) | 0974-7893 (print)
Editor:H. Raghuram
Manuscript
details:
Ms # o2326
Received 06 October 2009
Final revised received 04 April 2010
Finally accepted 24 April 2010
Citation:Mukherjee, A., B. Wilske & J. Chen (2010). Dietary energy estimate inferred
from fruit preferences of Cynopterus
sphinx (Mammalia: Chiroptera: Pteropodidae) in a flight cage
in tropical China. Journal
of Threatened Taxa 2(6): 908-918.
Copyright: ©
Aeshita Mukherjee, Burkhard Wilske & Jin Chen 2010. Creative Commons
Attribution 3.0 Unported License. JoTT allows unrestricted use of this article
in any medium for non-profit purposes, reproduction and distribution by
providing adequate credit to the authors and the source of publication.
Author
Details: Dr. Aeshita
Mukherjee is an ecologist and was a Postdoctoral
Fellow with the Plant-Animal Interaction Group, Xishuangbanna Tropical
Botanical Garden, Chinese Academy of Sciences, P.R. China. Dr. Burkhard Wilske is an
ecophysiologist, Botanist having expertise in VOC and Carbon budgeting. He is presently a Postdoctoral Fellow
at the Bio-Geosciences Institute, University of Calgary, Canada. Prof.
Chen Jin is the Director of Xishuangbanna Tropical Botanical Garden,
Chinese Academy of Sciences, P.R. China.
Author
Contribution: The first author AM designed the
research plan, data collection, analysis and wrote this manuscript, while
the second author BW’s input was interpretation of result, literature search
and helping in analysis. The third author JC provided guidance and was
the over all project in-charge.
Acknowledgements:
The findings are an outcome of a postdoctoral study supported by the XTBG,
Chinese Academy of Sciences. We are thankful to the Chinese Academy of Sciences
for the technical and financial support during the study. We also thank the
Forest Department, Yunnan Prefecture, and the XTBG officials for allowing us to
perform both wild and captive studies on fruit bats. We are grateful to Mr. Shao Li, and Mr. Swat Sanjitan, Plant
animal Interaction Group, XTBG, CAS, for ready help, field assistance and in
smooth conduct of these experiments.
Abstract:From a conservation standpoint, inferences about
dietary intake are much more robust when placed within a demographic, temporal
and nutritional context. We
investigated the dietary cornerstones of fruit preference and the dietary
energy gained in the Short-nosed Fruit Bat Cynopterus sphinx. Feeding trials were conducted with 15 wild-caught bats kept
in a large flight cage in Xishuangbanna, Yunnan, China, over nine weeks. The goal was to estimate the amount of
food required for the sustenance of C.
sphinx in captivity and calculate the food amount in terms of
energy. Of the fruits (apple,
banana, pear, papaya and guava) offered, apple (89%) and banana (93%) were
found to be preferred. The
relative consumption of fruit species tended to be positively correlated with
the energy value per gram fruit. Banana (93%) was the most preferred and papaya (47%) the least preferred
of the offered fruits. The results
suggest that the minimum recommended dietary intake is 214–267 kJ per day
for an individual of C.
sphinx in captivity with conditions allowing flight. From this, we can assume that the same energy
requirements may represent the minimum intake for bats in the wild. Both body mass and food consumption
decreased significantly when bats were kept in a small cage.
Keywords: Body mass,
captivity, Cynopterus
sphinx, energy intake, fruit preference.
For Figures & Tables – click here
Introduction
Fruit
bats play a crucial role in maintaining diversity in plant communities via regeneration
and genetic flow of dominant forest trees (Banack 1996, 1998). Food resources like flowering and
fruiting plants exert different selective forces on the foraging behaviour and
energetic budgets of pollinators and the seed dispersers (Voigt et al.
2006). Fruit bats are important
pollinators and seed dispersers in various ecosystems (Crome & Irvine 1986;
Eby 1991; Cox et al. 1991, 1992; Elmqvist et al. 1992; Findley 1993; Rainey et
al. 1995; Banack 1996, 1998). Fruit bats may feed on a large number of different fruit species and
substantial dietary information is available for some Pteropus species
(Dobat & Peikert-Holle 1985; Marshall 1985; Mickleburgh et al. 1992; Wiles &
Fujita 1992). However, few studies
offer a thorough investigation of the energetics of fruit bats in a single
area. Theories concerning diet
breadth, diet selection and the evolution of feeding strategies in frugivorous
bats have been based primarily on studies of neotropical fruit-eating bats
(Phyllostomidae) along with support from African fruit-eating bats
(Pteropodidae) (Fleming 1982, 1986). Fleming (1986) concluded that frugivorous bats eat a taxonomically
nonrandom subset of fruits and seasonal availability of fruit is a key
characteristic of the fruit taxa, which has allowed bats to specialize on
them. A number of different
physiological and behavioural strategies have been identified in mammals
helping them to accommodate increased energy demands at various stages of their
life cycle. These strategies
include increases in energy intake (Brody 1945; Randolph et al. 1977; Millar
1978; Hickling et al. 1991) or mobilization of fat reserves to fuel the
increased demands (Fedak & Anderson 1982). Alternatively, the increased requirements at different
stages can be offset by reduced physical activity (Randolph et al. 1977) or
reduced maintenance energy expenditure of the mother during pregnancy (Speakman
& Racey 1987). It has been
shown that lactating bats Myotis
lucifugus and Eptesicus
fuscus) and fruit-eating megachiropteran Rousettus aegyptiacusincreases their field metabolic rate (Korine et al. 2004; Kurta et al. 1989a)
where as the Plecotus auritususes the compensatory strategies to offset increase energy demands (McLean
& Speakman 1999; Voigt 2000a). Daily activity is energetically costly, and may be the reason why during
resting phase S. australisand other blossom-bats readily enter daily torpor to reduce metabolic rate (MR)
even under mild environmental conditions (Bartholomew et al. 1970; Kulzer &
Storf 1980; Geiser et al. 1996; Coburn & Geiser 1996, 1998; Bonaccorso
& McNab 1997; Bartels et al. 1998; Geiser 1998). Energy expenditure in the field can differ substantially
from that predicted from basal metabolic rate (BMR) measurements in the
laboratory (Geiser & Coburn 1999).
As
a group, bats have several characteristics unique among mammals with respect to
their energy allocation and life histories. They are typified by having long life spans for their body
sizes, and most species give birth to a single offspring followed by an
extended parental care period (Kunz & Pierson 1994). Moreover, pups do not begin foraging
independently until they have nearly achieved adult size, possibly due to the
constraints of flight (Barclay 1994).
Energy
consumption and expenditure have been studied mainly in insectivorous
free-ranging microchiropterans (Kunz 1974; Speakman & Racey 1987; Kurta et
al. 1989a,b, 1990; Kunz et al. 1995; Stern et al. 1997; McLean & Speakman
1999; Reynolds & Kunz 2000) and a few on fruit eating bats (Thomas 1984;
Korine et al. 2004; Voigt et al.2006). One may
expect significant differences between the insectivorous microchiropterans and
the frugivorous megachiropterans because of the latter’s generally larger size
and fruit-based diet. Proteins
have sometimes been considered a limiting nutrient for frugivorous bats, as
fruits are generally low in nitrogen (Thomas 1984; Courts 1998, Elangovan &
Marimuthu 2001). Thomas (1984)
hypothesized that many frugivorous bat species over-ingest fruits to obtain sufficient
protein with their diets. This may
be the reason why many species of flying foxes also use flowers and leaves
(Marshall 1985), as both flowers and leaves can contain substantial amounts of
protein (Law 1992; Kunz & Diaz 1995; Ruby et al. 2000). A number of dietary studies provide
lists or tabulations of dietary items used by flying foxes, but quantifications
of the amount of food intake are missing (e.g., Ratcliffe 1932; Funmilayo 1979;
Dobat & Peikert-Holle 1985; Marshall 1985; Richards 1990; Fujita 1991;
Mickleburgh et al. 1992; Widmann 1996; Entwistle & Corp 1997; Eby
1998). However, Elangovan &
Marimuthu (2001) reported the dietary intake and specifically the nitrogen
content in the diet of C.
sphinx. From a
conservation standpoint, inferences about dietary intake are much more robust
when placed within a demographic, temporal, and nutritional context.
We
investigated the dietary cornerstones of (i) the food preference, and (ii) the
respective energy gained based on results obtained with 15 wild-caught
specimens of the Indian Short-nosed Fruit Bat (C. sphinx). C. sphinxfeeds mainly on fleshy-pulpy fruits growing in and around the tropical
rainforest, and also visits fruit orchards and exploit seasonally available
fruits. This study aimed at (i)
estimating the amount of food required for the sustenance of C. sphinx in
captivity, and (ii) to calculate the food amount in terms of energy
intake. In addition, we tested the
hypothesis that of the above-mentioned three main strategies used by small
mammals to cope with the energetic demands, C. sphinx would rather decrease food consumption
in proportion to cage size. While
the study estimates the food requirements to conserve or keep bats in
captivity, the average dietary intake in captivity may also mark the minimum
requirement of the species in the wild.
Methods
Bat collection and maintenance in
captivity
Eleven
male and four female Indian Short-nosed Fruit Bats were mist netted in their natural
habitats in and around Xishuangbanna Tropical Botanical Garden (21055.60’N
& 101015.94’E), in southern Yunnan Province, southwestern China.
The bats (n = 15) were accommodated and kept in a newly set up flight cage for
nine weeks. Thereafter the bats (n
= 6) were individually housed for four weeks in small wire mesh cages, where
their flights were confined to the cage. All bats were released at the end of the investigation.
Enclosure
design and the captive environment govern a variety of behaviours that captive
bats display (Heard 1998; Wilson 1988). Since bats are the only group of mammals that can truly fly, they need
special attention as flight is severely limited in captivity (Wilson 1988). Greenhall (1976) suggested for
experiments that cage sizes should be such that the bat can fly freely or not
at all. For our study we used both a flight cage and subsequently a set of
flight-restricting cages. The flight cage had a dimension of 10 x 5 x 2.5 m,
which allowed the bats to fly and dispose extra fat. The flight cage was set up under the canopy of a 50 year old
rubber tree plantation to provide a mild climate and avoid extreme day and
night temperatures. For the second
set of feeding experiments, the bats were transferred to smaller wire-mesh cages
(52 x 26 x 30 cm), which absolutely limited the flight option and made the bats
more sedentary.
Feeding trials
To
evaluate the food requirements, bats were kept in two different captive
conditions and feeding trials were conducted over a period of two months in the
flight cage and for one month in the flight restricted cage. The whole experiment was based on a
natural fruit diet and the feeding trials were based on five different fruits. Of the five species of fruit, randomly
three fruit species were display in 12 hanging food cups in different
combination each day. To ensure
fruit preference was unbiased, all possible combinations were tested for the five fruit species. Each fruit type was weighed separately
using a digital balance (ScoutTM Pro-balance, Ohaus Corporation,
USA; precision of 0.5g) before given to the bats. The following evening the remaining fruits were collected
separately by species in plastic bags, and weighed. Approximately 100g fruit
per bat were provided each day prior to sunset. Water was given ad libitum. Prior to the experiment, the fruits were cut into similar
size and displayed to account for the water loss due to evaporation. We found negligible water loss due to
very high humidity and tropical climate of the study area. The food preference was inferred from
the difference between the amount of fruit offered and consumed. In order to verify a possible change in
consumption, the amount of fruit displaced remained the same in both the
captive conditions. The bats were
re-trapped and weighed to record the change in the body mass each weekend,
which indirectly infers the estimated fat accumulation. Conversion from fruit intake to energy
content and nutritional values were derived based on Smolin & Grosvenor
(1994) and compared with FAO (1995) as
well as Centre for Food Safety Hong Kong (2006), The standard energy values per
gram of fruits were taken and multiplied by the actual amount of food intake by
the bats in our experiment. Following Duncan & Young (2002) the selectivity index (S.I.) for
each fruit type was calculated as
(1/3-Pi)2 + (1/3-Pj) 2 + (1/3-Pk) 2
S.I.
=
2/3
where
Pi, Pj and Pk are the proportions of the foods
consumed per day.
Results
Fruit preference
Three
combinations of fruit offers including three to four different fruits were
tested to examine food preferences in C. sphinx. Three Combined offers included both tropical fruits, which were
available in abundance for the local bat population such as banana (B), guava
(G), and papaya (PA), and fruits like apple (A) and pear (PE), which are not
native and only available from few orchards within the region. From the combined offers of apple,
banana, pear, and guava, the bats preferred apple and banana (χ2 =
15.08, df = 3, p < 0.05) (and reconfirmed performing Wilcoxon signed ranks
test, z = 2.275, p = 0.028). The
selectivity index for apple was 0.43, banana 0.39, pear 0.13, guava 0.11 and
papaya 0.07 (Fig. 1). The same
fruits were preferred when combined with papaya, and the preference for apple
also dominated over guava and pear (two-tailed Mann–Whitney U-test,U = 0, N1 = N2= 6, p < 0.03). The offer of banana, apple and papaya in a percentage
proportion of roughly 40:20:40 resulted in a predominant consumption of banana
(two-tailed Wilcoxon signed-ranks test, t = 0, N =
10, p < 0.03). Papayas yield the lowest preference (sign test; χ = 1, N = 10, p< 0.04) amongst both the native and uncommon fruits. The relative
consumption of fruit species, i.e., (fruit X consumed / fruit X offered)*100,
tended to be positively correlated (r = 0.82) with the caloric value per gram
fruit (Fig. 2) based on averages derived from three independent sources (Smolin
& Grosvenor 1994; FAO 1995; Center for Food Safety Hong Kong 2006). Mainly apple escaped the trend. Contrasting, both the calcium content
and the calcium-to-phosphorus ratio were rather negatively correlated with the
food preference of the bats during the experimental period (cold season).
Fruit consumption
The
fruit consumption was significantly lower during the first two days compared to
the rest of captive period (χ2= 21.5, df = 4, p < 0.05; Fig. 3). The consumption was steady
(73–74%) and did not differ significantly during the initial five weeks
(two-tailed Wilcoxon signed-ranked tests; p > 0.3). The
consumption showed an increment by 77% and reached up to 81% in the following
weeks. We also found significant increase in food consumption per bat in
relation to time between the two captive conditions (least square regression
analysis: p < 0.01; and p < 0.001, respectively). Papaya (53%) made the maximum portion
of the left fruit.
Consumption
of apple and banana ranked at par with 89% and 93%, respectively. The consumption of fruits decreased
significantly in the small cage (χ2= 32.8, df = 1, p < 0.05 and confirmed performing
two-tailed Wilcoxon signed-ranks test, t = 0, n = 8, p< 0.02). Compared to the
flight cage where the consumption ranged from 70–80 % of the offered
fruit, the same got reduced to 30–45 % in the small cage. There was significant difference in
fruit consumption when compared between flight cage and in the small cage (two
way ANOVA, F = 5.43, df = 2, p < 0.01). The papaya made the bulk (75%) of left out fruit. Unlike in the flight cage, where the
consumption percentage increased over the period of captivity, in the small
cage the consumption percentage showed a decreasing trend over a period of four
weeks (45.6, 41.9, 44.8, 38.1 & 30.3 %, respectively) (Fig. 3). Daily dietary intake and nutritional values. The average daily
consumption of fruit per 15 bats was 400.18g apple, 547.81g banana, 83.72g
guava, 194.42g pear, and 111.46g papaya. Thus, the daily food consumption of food per bat was 36.52g banana,
26.68g apple, 7.43g pear, 5.58g guava, and 12.96g papaya in the flight
cage. The conversion and deduction
of the total weekly fruit consumption of 15 bats to an individual bat per day
equates to 269.03kJ of energy that is required while in captivity based on the
nutritional values obtained from Centre for Food Safety Hong Kong (2006), the
same consumption deduced to only 214.27kJ based on FAO 1995 values.
The
water content of papaya (0.88g g-1) is higher than for all the other
fruits. Banana provides twice the amount of carbohydrate (0.24g g-1)
as compared to papaya (0.1 g g-1). The comparison of fruits displaced in terms of energy gain,
showed that banana and papaya provide the highest (0.72–1.09 Kcal g-1)
and the least (0.39–0.27 Kcal g-1) amount of energy,
respectively note that the lower and higher values were from FAO (1995) and
Centre for Food Safety Hong Kong (2006), respectively.
To
assimilate 69.03kJ, a bat needs to consume 200–238 g of papaya but only
59–89 g of banana. Conversely, 200g of papaya means that an average male
bat would be required to consume more than four times its body weight per
night. The amount of fruit
consumed and the respective nutritional contents are given in Table 1.
Comparisons
of body mass changes
The initial average body mass on
catch was 48.4g and 53.0g for male and female, respectively. The average body mass decreased within
the first two weeks after catch but later regained the weight of the original
body mass. The female bats showed
comparatively higher gain in body mass than the males (sign test; x =
1, n = 10, p < 0.03). The overall body mass did not differ significantly over the captive
period of nine weeks (Fig. 4a). The average body mass of bats in the small cage showed a declining trend
but was not significant (ANOVA {time/body mass}): p > 0.05 over the
four-week experiment (Fig 4b). With an average reduction from 55g to 46g and from 50g to 46g the
females lost more weight than the males, respectively.
Discussion
Cynopterus sphinxgenerally ate all fruits that were offered. However, large differences existed in the consumption
relative to fruit species. Banana
was the most preferred fruit followed by apple. Neither guava nor pear was consumed in the same amounts, and
papaya was the least preferred of the fruits. While banana, papaya and guava are abundantly available
throughout the area, both apple and pear represent introduced fruit. With caloric values of 0.27, 0.41,
0.43, 0.58 and 1.09 Kcal g-1, the five fruits papaya, guava, pear,
apple and banana lined up along a positive trend of consumption increasing with
the caloric value based on the nutritional values obtained from the Centre for
Food Safety Hong Kong (2006). Even
with deviating values for apple and pear, the nutritional contents published by
Smolin & Grosvenor (1994) corroborate the overall trend. FAO (1995) presented significantly
lower (0.72 Kcal g-1) and higher (0.69 Kcal g-1) caloric
values for Chinese banana and guava, respectively, which was reflected by
giving a broader range of minimum energy requirement.
Still,
a single fruit-related character such as energy content, abundance of resources
or its exoticness may not fully explain the food preference of the bats. Few reports on food preference in bats
include similar fruit. However,
lowest preference for papaya was also reported for flying foxes (Banack 1998),
which fed on papaya mainly during periods when alternative fruits where not
available or not ripe. Contradictorily, the C. sphinx consumed/ preferred papaya over other
fruits and banana was the least preferred fruits (Elangovan & Marimuthu
2001).
The
daily energy expenditure of the bats in captivity can be divided between the
long roosting phase and a shorter activity phase when they fly around the food
resources. It seems important to
estimate the amount of energy bats need while in confinement. From the present study it appears that
the daily intake of food varied according to their demand of energy expenditure
for movement and during resting. The total consumption of fruit was significantly lower (roughly
30–40 %) for animals in flight-restrictive cages, reflecting less
activity and hence lower energy requirements. Banack (1996, 1998) reported bats in the wild being
extremely selective in choosing fruit within a tree, smelling and occasionally
biting 10–15 fruits before choosing one in situ or flying to another
tree to continue the search. Such
hyper-selective searching requires much higher energy input and may probably be
less frequent under conditions of food scarcity.
In
the flight cage, where the bats had to fly to get food, the individual bat
consumed on average an energy equivalent to about 269kJ (FAO 214.27kJ) per
day. The validity of this value
may underly some restrictions, because factors such as the environment and
variations in both (seasonal) climate, handling-time efficiencies and
physiological or morphological state can alter requirements in nutrients and
secondary compounds (Rosenzweig & Sterner 1970; Willson & Harmeson
1973; Ellis et al. 1976; Pierson et al. 1996). The daily energy expenditure by blossom-bats in the
laboratory is relatively high in winter, because they have long activity
periods at night and undergo only short and shallow periods of torpor during
the day (Coburn & Geiser 1996, 1998). According to (Voigt 2000b, 2004; Voigt & Winter 1999) the power
requirements of horizontal forward flight are known to increase with body mass
and thus mass-dependent costs of locomotion could substantially contribute to
the overall higher energy expenditure of large individuals. Again, it is important to mention that
the main phase of experiments was conducted during the month with lower
temperatures, and hence in order to maintain homeostasis the bats may have used
a higher proportion of energy even during resting. Furthermore, the daily energy intake averaged over both male
and female and different ages, but did not reflect increased requirements due
to pregnancy or lactation of female bats, which breed in area throughout the
year (Mukherjee et al. 2006).
Despite
differences in diet and feeding strategy among mammals, most species that have
been studied appear to have similar qualitative nutrient needs for normal
tissue metabolism. These
similarities may also be true for fruit bats. Fruit bats presumably have no difficulty meeting energy
needs during periods of food abundance because they consume large amounts of
high carbohydrate fruits, both in captivity and in the wild. Analyses of most cultivated fruits
indicate that the concentrations of many nutrients are quite low. Compared to established nutrient
requirements of other mammals and the foods needed to provide them, fruit, when
consumed alone, would seem to constitute an inadequate diet regarding their low
protein content. However, several
studies concluded that fruit bats could meet their protein requirements
exclusively with fruits (Thomas 1984; Herbst 1986; Stellar 1986;
Conklin-Brittain et al. 1999; Delorme & Thomas 1999).
Occasional
observations also revealed that some bats feed on leaves of some ficus species
(A. Mukherjee pers. obs.; Korine et al. 1999; Nelson 2000). Pierson et al. (1996) reported that
leaf resources may represent a regular part of the diet following major
disturbances and during the breeding season.
Bats
are one of the only other mammals besides humans that have problems with
calcium deficiency, and reproduction by female bats may be limited by their
intake of calcium. Nelson (2000)
found that 83% of the captive bats engaged in leaf eating, and that 70% of
female bats ate leaves, a particularly important calcium source. Bats may prefer high sugar containing
and succulent fruits to relieve hypoglycaemia and dehydration. At least during the low-temperature
months of our experiments the bats showed no particular preference for a
special calcium-rich or a special Ca/P-ratio containing diet. However, such particular preferences
may develop during other seasons and particularly during pregnancy. Furthermore, the way fruit bats eat,
i.e., ingesting mostly juices and rejecting the fibrous portion of fruits, may
result in higher bio-availability of the consumed calcium.
C. sphinxin our flight cage experiment behaved similar to wild-caught Short-tailed Fruit
Bats (Carollia perspicillata),
which reportedly rested for approximately 30min between foraging bouts when the
bats were kept in an outdoor enclosure (Bonaccorso & Gush 1987). Short-tailed Fruit Bats have an
extremely sensitive sense of smell (Laska 1990a) and are proficient at
discriminating between similar odours (Laska 1990b) and olfaction is more important
than either vision (Laska & Schmidt 1986; Mikich et al. 2003) or
echolocation (Theis et al. 1998) for the detection and gross location of food. C. sphinx appears to
follow the same cue to locate food resources (Mukherjee et al. 2006). Again similar to the Short-tailed Fruit
Bat, which showed the most diverse diet among several frugivorous bat species
in Costa Rica (Fleming et al. 1977; Fleming 1988), C. sphinx showed preferences but otherwise
consumed all the offered species of fruit. Based on our occasional observation over a period of three
years while working in the rain forest, our study also suggests that C. sphinx is a
dietary generalist (Table 2). Therefore, we have to assume that it must either use familiar food
resources, which may be of low quality or ephemeral, or sample unknown and
possibly toxic foods (Day et al. 2003; Ratcliffe et al. 2003) and might be
operating on an overall tight energy budget (Delorme & Thomas 1996).
Specific
nutrient requirements for frugivorous bats remain virtually unknown, however,
information exists providing practical guidelines to formulate diets for
certain bat species in captivity. Research opportunities in bat nutrition proliferate, and regarding the
bat species diversity, the information derived from a detailed diet plan for a
large species would improve not only dietary husbandry of this species, but our
understanding of the potential nutrient requirements of other species with
similar dietary habits and feeding strategies.
Our
study provides important information on food preferences and energy
requirements for C. sphinxin captivity, and it may contribute to succesful captive breeding and
conservation of the species. To
improve diet formulas for fruit bats in long-term captivity, future research
may put more focus on identifying the food combinations appropriate for meeting
needs in micro-nutrients. It seems
obvious that energy requirements for resting and for flight in captivity can be
met by offering ad libitum quantities
of nutritionally appropriate food, especially because fruit eating bats readily
accept cultivated fruits. However,
more detailed understanding of diets from bats in captivity also contributes to
our understanding of bats in the wild.
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