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Zeev Arad - One of the best experts on this subject based on the ideXlab platform.
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reproductive energetics of captive and free ranging egyptian fruit bats Rousettus aegyptiacus
Ecology, 2004Co-Authors: Carmi Korine, John R. Speakman, Zeev AradAbstract:This study explored how a flying frugivorous mammal, the Egyptian fruit bat (Rousettus aegyptiacus), meets the increased energy requirements of reproduction. This bat feeds on low-protein fruit, and females have bimodal polyestrous cycles that are rel atively long for a small mammal. We measured the energy and water balance of captive nonreproductive, pregnant, and lactating females, and of free-ranging lactating females, Our results indicate that females use more than one strategy to cope with the high energy demands of reproduction, These strategies may change according to the availability of food and reproductive status, The primary strategy near the end of pregnancy and at peak lactation was increased food consumption, In the laboratory, mean metabolizable energy intake (MEl) of pregnant and lactating females (271 and 360 kJ/d, respectively) increased by 35% and 80%, respectively, compared to that of nonreproductive females (200 kJ/d), At peak lac tation, energy intake measured by doubly labeled water averaged 350 kJ/d. During late pregnancy, water turnover rate (WTO) increased by 15-23% compared to that of nonre productive females. In the field, WTO at peak lactation was 44% higher than in captive lactating females, and milk production was estimated to be 22 ml.zd, Absolute resting metabolic rate (RMR) in late pregnancy was significantly lower than the RMR of nonre productive females, suggesting that a metabolic depression was used as a compensatory mechanism, Fat deposition was evident during the second pregnancy, when food availability was high, presumably in preparation for a second lactation period, Fetal tissue represented ~ 1,3% of the total energy assimilated during pregnancy, and the gross efficiency oflactation averaged 24%. Both values are lower than the values reported for other eutherian mammals, but similar to estimates for other bat species, and probably reflect the high energy costs associated with flight. A long lactation period may be constrained by flight and the low protein diet of fruits, We conclude that the energy costs of Egyptian fruit bats during reproduction are distributed over a relatively long time, similar to those observed in large mammals.
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REPRODUCTIVE ENERGETICS OF CAPTIVE AND FREE‐RANGING EGYPTIAN FRUIT BATS (Rousettus aegyptiacus)
Ecology, 2004Co-Authors: Carmi Korine, John R. Speakman, Zeev AradAbstract:This study explored how a flying frugivorous mammal, the Egyptian fruit bat (Rousettus aegyptiacus), meets the increased energy requirements of reproduction. This bat feeds on low-protein fruit, and females have bimodal polyestrous cycles that are rel atively long for a small mammal. We measured the energy and water balance of captive nonreproductive, pregnant, and lactating females, and of free-ranging lactating females, Our results indicate that females use more than one strategy to cope with the high energy demands of reproduction, These strategies may change according to the availability of food and reproductive status, The primary strategy near the end of pregnancy and at peak lactation was increased food consumption, In the laboratory, mean metabolizable energy intake (MEl) of pregnant and lactating females (271 and 360 kJ/d, respectively) increased by 35% and 80%, respectively, compared to that of nonreproductive females (200 kJ/d), At peak lac tation, energy intake measured by doubly labeled water averaged 350 kJ/d. During late pregnancy, water turnover rate (WTO) increased by 15-23% compared to that of nonre productive females. In the field, WTO at peak lactation was 44% higher than in captive lactating females, and milk production was estimated to be 22 ml.zd, Absolute resting metabolic rate (RMR) in late pregnancy was significantly lower than the RMR of nonre productive females, suggesting that a metabolic depression was used as a compensatory mechanism, Fat deposition was evident during the second pregnancy, when food availability was high, presumably in preparation for a second lactation period, Fetal tissue represented ~ 1,3% of the total energy assimilated during pregnancy, and the gross efficiency oflactation averaged 24%. Both values are lower than the values reported for other eutherian mammals, but similar to estimates for other bat species, and probably reflect the high energy costs associated with flight. A long lactation period may be constrained by flight and the low protein diet of fruits, We conclude that the energy costs of Egyptian fruit bats during reproduction are distributed over a relatively long time, similar to those observed in large mammals.
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Diurnal and seasonal changes in blood composition of the free-living Egyptian fruit bat (Rousettus aegyptiacus)
Journal of comparative physiology. B Biochemical systemic and environmental physiology, 1999Co-Authors: C. Korine, O. Zinder, Zeev AradAbstract:We studied the blood profile of the free-living fruit bat (Rousettus aegyptiacus) during the beginning of the activity period (around various feeding trees) and upon return to the day roost during 1994–1995. Results of the present study suggest that during winter and early spring bats are characterized by a poor physical and physiological state as reflected in the blood profile, revealing elevated urea and uric acid concentrations. It was found that at the end of the resting phase, R. aegyptiacus was in a mild state of dehydration (increased hematocrit and hemoglobin levels). At the end of activity, upon return to the day roost, both hematocrit and hemoglobin levels decreased but bats still maintained a high plasma osmolality. Several components in the blood are effected by the feeding time and show a cyclic change in concentration. The reverse relationship between glucose and triglyceride levels may indicate that glucose is the energy source during the active phase and that fat is the energy source during the resting period. The low cholesterol level in the blood reflects its absence in the fruit diet.
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Changes in Milk Composition of the Egyptian Fruit Bat, Rousettus aegyptiacus (Pteropodidae), during Lactation
Journal of Mammalogy, 1999Co-Authors: Carmi Korine, Zeev AradAbstract:Composition of milk of the free-ranging Egyptian fruit-bat ( Rousettus aegyptiacus ) was studied from early to peak lactation. Carbohydrates were the main component during early lactation and fats were the main component in milk from mid- to peak lactation. Dry-matter and energy content of the milk increased during mid-lactation and stabilized at peak lactation. Increases were a consequence of increased fat content, but carbohydrate and protein contents remained relatively stable. We conclude that the milk composition of R. aegyptiacus is related to diet and frequent suckling by young. We suggest that the inability of R. aegyptiacus to produce concentrated milk of high fat and energy contents and a low protein content is compensated for by prolonged lactation.
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Is the Egyptian fruit-bat Rousettus aegyptiacus a pest in Israel? An analysis of the bat's diet and implications for its conservation
Biological Conservation, 1999Co-Authors: Carmi Korine, Ido Izhaki, Zeev AradAbstract:The Egyptian fruit-bat Rousettus aegyptiacus is regarded as a pest for agriculture. However, no quantitative data on its diet have been collected in Israel or in other Mediterranean areas, and control measures in the past reduced populations of insectivorous bats in Israel. We therefore studied the relative importance of native versus commercially cultivated fruit plants by analysis of bat faeces. Droppings were collected during 1993‐1995 in two roost-sites in the Carmel National Park. Results show that the bat feeds mainly on fruits but leaves and pollen are also eaten. Leaf eating was observed mainly during winter, when bats may face times of severe decrease in fruit availability and quality. Only four fruit species (15%) of the bat’s diet are commercially grown and only two of these in the research area. Therefore the definition of the fruit-bat as a major agricultural pest should be re-examined. Two eAective methods for controlling damage caused by bats are discussed. # 1999 Published by Elsevier Science Ltd. All rights reserved.
Carmi Korine - One of the best experts on this subject based on the ideXlab platform.
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Finding Your Friends at Densely Populated Roosting Places: Male Egyptian Fruit Bats (Rousettus aegyptiacus) Distinguish between Familiar and Unfamiliar Conspecifics
Acta Chiropterologica, 2011Co-Authors: Ofri Mann, Carmi Korine, Vika Lieberman, Angela Köhler, Helen E. Hedworth, Silke L. Voigt-heuckeAbstract:Individual recognition via olfactory, auditory, or visual cues is crucial for animals to form and maintain stable social groups, particularly in large colonies such as those of Egyptian fruit bats (Rousettus aegyptiacus). We tested whether Egyptian fruit bats are able to distinguish between familiar and unfamiliar conspecifics, using two captive groups of male bats. We recorded the behavioural and auditory responses of focal animals in a binary choice experiment in which they could approach either members of their own social group or unfamiliar individuals. In general, bats preferred to stay close to other bats, familiar or unfamiliar, over resting alone and spent more time in close proximity to members of their own group than to unfamiliar conspecifics. The majority of bats interacted more with the unfamiliar individuals, although this result did not reach significance. We conclude that Egyptian fruit bats are able to distinguish between familiar and unfamiliar conspecifics. Since only one individual emitted social calls and bats never produced echolocation calls during the experiment, we infer that individual recognition was most likely mediated via olfactory and/or visual cues. The ability to identify familiar individuals may indicate that males of Egyptian fruit bats form stable groups within their large colonies.
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ethanol concentration in food and body condition affect foraging behavior in egyptian fruit bats Rousettus aegyptiacus
Naturwissenschaften, 2008Co-Authors: Francisco Sánchez, Carmi Korine, Burt P Kotler, Berry PinshowAbstract:Ethanol occurs in fleshy fruit as a result of sugar fermentation by both microorganisms and the plant itself; its concentration [EtOH] increases as fruit ripens. At low concentrations, ethanol is a nutrient, whereas at high concentrations, it is toxic. We hypothesized that the effects of ethanol on the foraging behavior of frugivorous vertebrates depend on its concentration in food and the body condition of the forager. We predicted that ethanol stimulates food consumption when its concentration is similar to that found in ripe fruit, whereas [EtOH] below or above that of ripe fruit has either no effect, or else deters foragers, respectively. Moreover, we expected that the amount of food ingested on a particular day of feeding influences the toxic effects of ethanol on a forager, and consequently shapes its feeding decisions on the following day. We therefore predicted that for a food-restricted forager, ethanol-rich food is of lower value than ethanol-free food. We used Egyptian fruit bats (Rousettus aegyptiacus) as a model to test our hypotheses, and found that ethanol did not increase the value of food for the bats. High [EtOH] reduced the value of food for well-fed bats. However, for food-restricted bats, there was no difference between the value of ethanol-rich and ethanol-free food. Thus, microorganisms, via their production of ethanol, may affect the patterns of feeding of seed-dispersing frugivores. However, these patterns could be modified by the body condition of the animals because they might trade-off the costs of intoxication against the value of nutrients acquired.
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Absorption of sugars in the Egyptian fruit bat (Rousettus aegyptiacus): a paradox explained.
The Journal of experimental biology, 2007Co-Authors: Christopher R Tracy, Carmi Korine, Berry Pinshow, Todd J Mcwhorter, Michał S Wojciechowski, William H KarasovAbstract:Two decades ago D. J. Keegan reported results on Egyptian fruit bats (Rousettus aegyptiacus, Megachiroptera) that were strangely at odds with the prevailing understanding of how glucose is absorbed in the mammalian intestine. Keegan's in vitro tests for glucose transport against a concentration gradient and with phloridzin inhibition in fruit bat intestine were all negative, although he used several different tissue preparations and had positive control results with laboratory rats. Because glucose absorption by fruit bats is nonetheless efficient, Keegan postulated that the rapid glucose absorption from the fruit bat intestine is not through the enterocytes, but must occur via spaces between the cells. Thus, we hypothesized that absorption of water-soluble compounds that are not actively transported would be extensive in these bats, and would decline with increasing molecular mass in accord with sieve-like paracellular absorption. We did not presume from Keegan's studies that there is no Na(+)-coupled, mediated sugar transport in these bats, and our study was not designed to rule it out, but rather to quantify the level of possible non-mediated absorption. Using a standard pharmacokinetic technique, we fed, or injected intraperitonealy, the metabolically inert carbohydrates L-rhamnose (molecular mass=164 Da) and cellobiose (molecular mass=342 Da), which are absorbed by paracellular uptake, and 3-O-methyl-D-glucose (3OMD-glucose), a D-glucose analog that is absorbed via both mediated (active) and paracellular uptake. As predicted, the bioavailability of paracellular probes declined with increasing molecular mass (rhamnose, 62+/-4%; cellobiose, 22+/-4%) and was significantly higher in bats than has been reported for rats and other mammals. In addition, fractional absorption of 3OMd-glucose was high (91+/-2%). We estimated that Egyptian fruit bats rely on passive, paracellular absorption for the majority of their glucose absorption (at least 55% of 3OMD-glucose absorption), much more than in non-flying mammals.
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The influence of ambient temperature and the energy and protein content of food on nitrogenous excretion in the Egyptian fruit bat (Rousettus aegyptiacus).
Physiological and biochemical zoology : PBZ, 2006Co-Authors: Carmi Korine, Itzick Vatnick, Ian G. Van Tets, Berry PinshowAbstract:Abstract The diets of frugivorous and nectarivorous vertebrates contain much water and generally have high energy but low protein contents. Therefore, we tested the prediction that to save energy under conditions of high energy demands and high water intake, frugivorous Egyptian fruit bats (Rousettus aegyptiacus) will increase both the absolute quantity and the proportion of ammonia in their urine. We also examined whether such changes occur when protein intake is low and water intake is high. We did three feeding trials. In trials 1 and 2, bats were fed one of four liquid diets containing constant soy protein concentrations but varying in sucrose concentration and were kept at ambient temperatures (Ta) of 30°C and 12°C, respectively. In trial 3, bats were kept at \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra}...
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Ethanol and Methanol as Possible Odor Cues for Egyptian Fruit Bats (Rousettus aegyptiacus)
Journal of chemical ecology, 2006Co-Authors: Francisco Sánchez, Carmi Korine, M.m.l. Steeghs, Luc-jan Laarhoven, Simona M. Cristescu, Frans J. M. Harren, Robert Dudley, Berry PinshowAbstract:Frugivorous bats from the Old and New World use odor cues to locate and assess fruit condition. We hypothesized that Egyptian fruit bats (Rousettus aegyptiacus) use as odor cues those volatile compounds that increase in emission rate as fruit ripens. We examined whether the smell of fermentation products may indicate the degree of ripeness to fruit bats. We analyzed volatile compounds in the headspace (the gas space above a fruit in a closed container) of dates (Phoenix dactylifera) and rusty figs (Ficus rubiginosa), both of which are consumed by fruit bats, to elucidate which compounds originate from fermentative pathways and to determine which change in emission rate during ripening. Ethanol, acetaldehyde, and acetic acid were the only volatile compounds detected as products of fermentation in both fruits. In dates, emission rates of these compounds increased during maturation, whereas in rusty figs, they decreased or remained constant. Methanol, although not a fermentation product, increased in emission rate during ripening in both fruits. We found that R. aegyptiacus was neither attracted nor deterred by the smell of methanol at any of the concentrations used. Although the odor of ethanol emanating from food containing concentrations similar to those found in ripe fruit did not attract the bats, at relatively high concentrations (≥1%), the smell of ethanol deterred them. Thus, ethanol at high concentrations may serve as a signal for bats to avoid overripe, unpalatable fruit.
Amy J. Schuh - One of the best experts on this subject based on the ideXlab platform.
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No evidence for the involvement of the argasid tick Ornithodoros faini in the enzootic maintenance of marburgvirus within Egyptian rousette bats Rousettus aegyptiacus
Parasites & Vectors, 2016Co-Authors: Amy J. Schuh, Tara K. Sealy, Dmitry A. Apanaskevich, Brian R Amman, Stuart T. Nichol, Jonathan S TownerAbstract:Background The cave-dwelling Egyptian rousette bat (ERB; Rousettus aegyptiacus ) was recently identified as a natural reservoir host of marburgviruses. However, the mechanisms of transmission for the enzootic maintenance of marburgviruses within ERBs are unclear. Previous ecological investigations of large ERB colonies inhabiting Python Cave and Kitaka Mine, Uganda revealed that argasid ticks ( Ornithodoros faini ) are hematophagous ectoparasites of ERBs. Yet, their potential role as transmission vectors for marburgvirus has not been sufficiently assessed. Findings In the present study, 3,125 O. faini were collected during April 2013 from the rock crevices of Python Cave, Uganda. None of the ticks tested positive for marburgvirus-specific RNA by Q-RT-PCR. The probability of failure to detect marburgvirus at a conservative prevalence of 0.1 % was 0.05. Conclusions The absence of marburgvirus RNA in O. faini suggests they do not play a significant role in the transmission and enzootic maintenance of marburgvirus within their natural reservoir host.
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No evidence for the involvement of the argasid tick Ornithodoros faini in the enzootic maintenance of marburgvirus within Egyptian rousette bats Rousettus aegyptiacus
Parasites & Vectors, 2016Co-Authors: Amy J. Schuh, Tara K. Sealy, Dmitry A. Apanaskevich, Brian R Amman, Stuart T. Nichol, Jonathan S TownerAbstract:Background The cave-dwelling Egyptian rousette bat (ERB; Rousettus aegyptiacus) was recently identified as a natural reservoir host of marburgviruses. However, the mechanisms of transmission for the enzootic maintenance of marburgviruses within ERBs are unclear. Previous ecological investigations of large ERB colonies inhabiting Python Cave and Kitaka Mine, Uganda revealed that argasid ticks (Ornithodoros faini) are hematophagous ectoparasites of ERBs. Yet, their potential role as transmission vectors for marburgvirus has not been sufficiently assessed.
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a recently discovered pathogenic paramyxovirus sosuga virus is present in Rousettus aegyptiacus fruit bats at multiple locations in uganda
Journal of Wildlife Diseases, 2015Co-Authors: Brian R Amman, Amy J. Schuh, Tara K. Sealy, Brian H Bird, Cesar G Albarino, Luke Nyakarahuka, Stephen Balinandi, S Campbell, Ute Stroher, Megan E B JonesAbstract:Abstract In August 2012, a wildlife biologist became ill immediately following a 6-wk field trip to collect bats and rodents in South Sudan and Uganda. After returning to the US, the biologist was admitted to the hospital with multiple symptoms including fever, malaise, headache, generalized myalgia and arthralgia, stiffness in the neck, and sore throat. Soon after admission, the patient developed a maculopapular rash and oropharynx ulcerations. The patient remained hospitalized for 14 d. Several suspect pathogens, including viral hemorrhagic fever viruses such as Ebola viruses and Marburg viruses, were ruled out through standard diagnostic testing. However, deep sequencing and metagenomic analyses identified a novel paramyxovirus, later named Sosuga virus, in the patient's blood. To determine the potential source, bat tissues collected during the 3-wk period just prior to the onset of symptoms were tested for Sosuga virus, and several Egyptian rousette bats (Rousettus aegyptiacus) were found to be positi...
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experimental inoculation of egyptian rousette bats Rousettus aegyptiacus with viruses of the ebolavirus and marburgvirus genera
Viruses, 2015Co-Authors: Mega E Jones, Amy J. Schuh, Tara K. Sealy, Sherif R. Zaki, Ia R Amma, Stua T Nichol, Jonatha S TowneAbstract:The Egyptian rousette bat (Rousettus aegyptiacus) is a natural reservoir for marburgviruses and a consistent source of virus spillover to humans. Cumulative evidence suggests various bat species may also transmit ebolaviruses. We investigated the susceptibility of Egyptian rousettes to each of the five known ebolaviruses (Sudan, Ebola, Bundibugyo, Tai Forest, and Reston), and compared findings with Marburg virus. In a pilot study, groups of four juvenile bats were inoculated with one of the ebolaviruses or Marburg virus. In ebolavirus groups, viral RNA tissue distribution was limited, and no bat became viremic. Sudan viral RNA was slightly more widespread, spurring a second, 15-day Sudan virus serial euthanasia study. Low levels of Sudan viral RNA disseminated to multiple tissues at early time points, but there was no viremia or shedding. In contrast, Marburg virus RNA was widely disseminated, with viremia, oral and rectal shedding, and antigen in spleen and liver. This is the first experimental infection study comparing tissue tropism, viral shedding, and clinical and pathologic effects of six different filoviruses in the Egyptian rousette, a known marburgvirus reservoir. Our results suggest Egyptian rousettes are unlikely sources for ebolaviruses in nature, and support a possible single filovirus—single reservoir host relationship.
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oral shedding of marburg virus in experimentally infected egyptian fruit bats Rousettus aegyptiacus
Journal of Wildlife Diseases, 2015Co-Authors: Brian R Amman, Amy J. Schuh, Tara K. Sealy, Megan E B Jones, Luke S Uebelhoer, Brian H Bird, Joann D Colemanmccray, Brock E MartinAbstract:Abstract Marburg virus (Marburg marburgvirus; MARV) causes sporadic outbreaks of Marburg hemorrhagic fever (MHF) in Africa. The Egyptian fruit bat (Rousettus aegyptiacus) has been identified as a natural reservoir based most-recently on the repeated isolation of MARV directly from bats caught at two locations in southwestern Uganda where miners and tourists separately contracted MHF from 2007–08. Despite learning much about the ecology of MARV through extensive field investigations, there remained unanswered questions such as determining the primary routes of virus shedding and the severity of disease, if any, caused by MARV in infected bats. To answer these questions and others, we experimentally infected captive-bred R. aegyptiacus with MARV under high (biosafety level 4) containment. These experiments have shown infection profiles consistent with R. aegyptiacus being a bona fide natural reservoir host for MARV and demonstrated routes of viral shedding capable of infecting humans and other animals.
Jonathan S Towner - One of the best experts on this subject based on the ideXlab platform.
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No evidence for the involvement of the argasid tick Ornithodoros faini in the enzootic maintenance of marburgvirus within Egyptian rousette bats Rousettus aegyptiacus
Parasites & Vectors, 2016Co-Authors: Amy J. Schuh, Tara K. Sealy, Dmitry A. Apanaskevich, Brian R Amman, Stuart T. Nichol, Jonathan S TownerAbstract:Background The cave-dwelling Egyptian rousette bat (ERB; Rousettus aegyptiacus ) was recently identified as a natural reservoir host of marburgviruses. However, the mechanisms of transmission for the enzootic maintenance of marburgviruses within ERBs are unclear. Previous ecological investigations of large ERB colonies inhabiting Python Cave and Kitaka Mine, Uganda revealed that argasid ticks ( Ornithodoros faini ) are hematophagous ectoparasites of ERBs. Yet, their potential role as transmission vectors for marburgvirus has not been sufficiently assessed. Findings In the present study, 3,125 O. faini were collected during April 2013 from the rock crevices of Python Cave, Uganda. None of the ticks tested positive for marburgvirus-specific RNA by Q-RT-PCR. The probability of failure to detect marburgvirus at a conservative prevalence of 0.1 % was 0.05. Conclusions The absence of marburgvirus RNA in O. faini suggests they do not play a significant role in the transmission and enzootic maintenance of marburgvirus within their natural reservoir host.
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No evidence for the involvement of the argasid tick Ornithodoros faini in the enzootic maintenance of marburgvirus within Egyptian rousette bats Rousettus aegyptiacus
Parasites & Vectors, 2016Co-Authors: Amy J. Schuh, Tara K. Sealy, Dmitry A. Apanaskevich, Brian R Amman, Stuart T. Nichol, Jonathan S TownerAbstract:Background The cave-dwelling Egyptian rousette bat (ERB; Rousettus aegyptiacus) was recently identified as a natural reservoir host of marburgviruses. However, the mechanisms of transmission for the enzootic maintenance of marburgviruses within ERBs are unclear. Previous ecological investigations of large ERB colonies inhabiting Python Cave and Kitaka Mine, Uganda revealed that argasid ticks (Ornithodoros faini) are hematophagous ectoparasites of ERBs. Yet, their potential role as transmission vectors for marburgvirus has not been sufficiently assessed.
Ido Izhaki - One of the best experts on this subject based on the ideXlab platform.
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Is the Egyptian fruit-bat Rousettus aegyptiacus a pest in Israel? An analysis of the bat's diet and implications for its conservation
Biological Conservation, 1999Co-Authors: Carmi Korine, Ido Izhaki, Zeev AradAbstract:The Egyptian fruit-bat Rousettus aegyptiacus is regarded as a pest for agriculture. However, no quantitative data on its diet have been collected in Israel or in other Mediterranean areas, and control measures in the past reduced populations of insectivorous bats in Israel. We therefore studied the relative importance of native versus commercially cultivated fruit plants by analysis of bat faeces. Droppings were collected during 1993‐1995 in two roost-sites in the Carmel National Park. Results show that the bat feeds mainly on fruits but leaves and pollen are also eaten. Leaf eating was observed mainly during winter, when bats may face times of severe decrease in fruit availability and quality. Only four fruit species (15%) of the bat’s diet are commercially grown and only two of these in the research area. Therefore the definition of the fruit-bat as a major agricultural pest should be re-examined. Two eAective methods for controlling damage caused by bats are discussed. # 1999 Published by Elsevier Science Ltd. All rights reserved.
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Comparison of fruit syndromes between the Egyptian fruit-bat (Rousettus aegyptiacus) and birds in East Mediterranean habitats
Acta Oecologica, 1998Co-Authors: Carmi Korine, Ido Izhaki, Zeev AradAbstract:Abstract This study analyses the fruit syndrome of the Egyptian fruit-bat, Rousettus aegyptiacus, the only fruit-bat found in East Mediterranean habitats. Two different sets of bat-fruit syndromes were revealed. One follows the general bat-fruit syndrome and one represents a special case of bat-dispersed fruit syndrome only found in East Mediterranean habitats. The latter syndrome is characterized by dry fruits with a relatively high protein content. Fruit species that belong to this syndrome are available mostly in winter (when the fruit-bat faces a severe shortage in fruit availability and inadequate fruit quality). The fruit syndromes and dietary overlap between frugivorous birds (based on the literature) and the fruit-bat were also studied. Features associated with each set of fruit species generally follow the known bat and bird syndromes. Bird-dispersed fruits tend to be small, with a high seed mass to pulp mass, variable in fat content and characterized by a high ash content. However, when the shared fruit species were included in the analysis, no significant differences were found in fruit features between the bird-dispersed and bat-dispersed fruit syndromes. A limited and asymmetrical dietary overlap was observed between these two taxa, mainly between introduced and cultivated fruits.
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the effect of bat Rousettus aegyptiacus dispersal on seed germination in eastern mediterranean habitats
Oecologia, 1995Co-Authors: Ido Izhaki, Carmi Korine, Zeev AradAbstract:The fruit-bat Rousettus aegyptiacus (Pteropodidae) in Israel consumes a variety of cultivated and wild fruits. The aim of this study was to explore some of its qualities as a dispersal agent for six fruit-bearing plant species. The feeding roosts of the fruit-bat are located an average of 30 m from its feeding trees and thus the bats disperse the seeds away from the shade of the parent canopy. The bat spits out large seeds but may pass some (2%) of the small seeds (<4 mg) through its digestive tract. However, neither the deposited seeds nor the ejected seeds (except in one case) had a significantly higher percentage germinating than intact seeds. Although the fruit-bat did not increase the percentage germinating, seeds of three plant species subject to different feeding behaviors (deposited in feces or spat out as ejecta) had a different temporal pattern of germination from the intact seeds. The combined seed germination distribution generated by these different treatments is more even over time than for each treatment alone. It is sugested that this increases asynchronous germination and therefore enhances plant fitness by spreading the risks encountered during germination, especially in eastern Mediterranean habitats where the pattern of rainfall is unpredictable.
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The effect of bat (Rousettus aegyptiacus) dispersal on seed germination in eastern Mediterranean habitats.
Oecologia, 1995Co-Authors: Ido Izhaki, Carmi Korine, Zeev AradAbstract:The fruit-bat Rousettus aegyptiacus (Pteropodidae) in Israel consumes a variety of cultivated and wild fruits. The aim of this study was to explore some of its qualities as a dispersal agent for six fruit-bearing plant species. The feeding roosts of the fruit-bat are located an average of 30 m from its feeding trees and thus the bats disperse the seeds away from the shade of the parent canopy. The bat spits out large seeds but may pass some (2%) of the small seeds (
