Eonycteris+spelaea+(Cave+Nectar+Bat)+(Kelly+Tan,+2014)

//Eonycteris spelaea// (Dobson, 1871) (Cave Nectar Bat) =

toc = 1 General Information //Eonycteris spelaea// is the only animal that aids the reproduction of the durian plant, an important source of income for Southeast Asian countries. However, its habitat is quickly being depleted due to human intervention. Their diet consists mainly of pollen and nectar and they are important pollinators when searching for trees and shrubs, travelling many kilometers each night. They are nocturnal animals, only feeding later than dusk.

= 2 Morphology =

2.1 Physical Description
//Eonycteris spelaea// have small, sim­ple ears, big eyes and does not have a **tra­gus** (Figure 2.1). The tongue is long and ex­tend­able with rasp-like protrusions and its muz­zle is nar­row and dog-like (Figure 2).



Dor­sal **pelage** is dark brown (dark grey) and the belly is of a lighter shade. Long scent-dis­pers­ing “**os­met­richia**” hairs cover the necks of males and are darker (tinged yellow brown) than the **pelage** of the head and body. **Mo­lar­i­form** teeth are con­sid­er­ably re­duced and barely ex­tend past the gums. It has a range mass of 35-82g and an average mass of 60g, It has a range length of 8.5-12.5mm, forearm length of up to 7cm and a range wingspan of 60-85mm and an average wingspan of 72.5mm. (Figure 2.2) [1] It has a range basal metabolic rate of 0.881-0.979 cm3 O2/g/hr and an average basal metabolic rate of 0.93 cm3 O2 /g/hr .[2] They are **homiothermic**, **bilaterally symmetrical** and males of the species are larger than females, contributing to the **sexual dimorphism**.[4].

To distinguish // Eonycteris //, look out for the type of tongue, and absence of the index finger claw.[3] Also, note that they do not possess a tragus. Their tails lengths are generally between 12 a nd 33mm as well.



=3 Distribution=



It lives in sea-level to elevated subtropical or tropical forest and caves of northern south Asia. They are native in the following countries: Brunei Darussalam; Cambodia; China; India (Andaman Is., Andhra Pradesh, Assam, Karnataka, Manipur, Meghalaya, Nagaland, Nicobar Is., Sikkim, Tamil Nadu, Uttaranchal); Indonesia; Lao People's Democratic Republic; Malaysia; Myanmar; Philippines; Singapore; Thailand; Timor-Leste; Viet Nam. (Figure 3.2)[5]

3.1 Home Range
Although there is little information about //Eonycteris spelaea// home range, they are known to travel vast distances of 20 to 40 km to forage from their roosts to the trees that flower at night. In family Pteropodidae, it is common to have long flights between roosting and feeding locations.[6]

=4 Population= //E. spelaea// roosts in large, noisy groups from hundreds to thousands of individuals. In the Batu caves in Malaysia, more than 4000 individuals were recorded.[7] In the Philippines, this species is usually found in colonies in thousands of caves and even crop land areas.[8] On Palawan Island itself, two populations were found. One with more than 2000 individuals and another that exceeded 50,000 individuals![9] Despite that, the population size and abundance trends for this species is relatively unknown in South East Asia, but there is a recently discovery of //E. spelaea// in Kalakkad-Mundanthurai Tiger Reserve in Tamil Nadu which suggests a comparatively rare occurrence compared to the //Rousettus leschenaulti//.[10]

=5 Habitat and Ecology=

5.1 Habi­tat
//Eonyc­teris spelaea// dominantly inhabits caves as roosting sites in tropical regions. However, they are also common in other habitats ranging from agricultural types away from forests and different forest types such as secondary lowland, primary lowland and transitional montane-mossy forests.[11] In the caves, // E. spelaea // forms close communities and often cohabits with other bats. // E. spelaea // flies rather slowly, and has adapted to expand its niche to include flowers of many orchard and agricultural crops in its diet.[12] Their range elevation is 50 to 1,250 m and the average elevation is 500 m.[13] In Singapore, their distribution and habitat is not well-researched on, but a population of //E. spelaea// is found under the Bukit Timah Flyover. (per comm. Coleman)

=6 Ecosystem Roles=

The main and most important eco­log­i­cal func­tion of //E. spelaea// is pol­li­na­tion. This species is a pollinator of many forest tree species including Durians. Without them, durian trees will never be able to bear the fruits that we love! The pollination process occurs when the bat feeds on the nectar of the flower. As its face approaches the flower it is dusted with pollen grains, which will then be transferred to the next flower the bat visits.[14] A pos­si­ble sec­ondary ecological role is seed dis­per­sal, but consuming fruit as food is not confirmed.

media type="youtube" key="ax_5mLRT9W0" width="560" height="315" align="center"

Watch the video to see how fast Enoycteris spelaea are in feeding and pollinating a flower! Video with permission from: Baylis and Fletcher.

**7 Reproduction**

7.1 Mating Habits
The age range where an //E. spelaea// male reaches sexual or reproductive maturity is 1 to 2 years. Females reach sexual maturity from 6 months to 1 year. Reports suggest that the females are sole providers of the young before they grow to be independent. After birth, the **altricial** young will suckle on a nipple and remain attached for 4 to 6 weeks while the mother flies around, after which the young can independently fly for short distances. There is provisioning of food from the mother, as well as protection goes on for about 3 months before the young is completely **weaned** off.[15]

7.2 Mating System
//E. spelaea// is polygynous, meaning the males freely mate with other individuals throughout their lifetime. There is con­flict­ing in­for­ma­tion on the cycle or pat­tern of the female phase of being sexually active as well as birth in //E. spelaea// fe­males. One of the study reported that fe­males ex­hibits a pat­tern char­ac­ter­ized by syn­chro­nous births and sea­sonal, bi­modal **polyestry**, the other sources find no syn­chronic­ity be­tween fe­males and no sea­sonal syn­chronic­ity. //E. spelaea// usually have 2 offspring every year, with a ges­ta­tion period of 3 to 4 months; how­ever, some reports sug­gest ges­ta­tion pe­ri­ods that lasts as long as 200 days (be­tween 6 and 7 months). [16]

=8 Behaviour= //Eonycteris spelaea// are **troglophilic** and sociable, especially in their roosts in ceilings of caves with colonies numbering from a dozen to tens of thousands of individuals. Within the colony there is division into sexually segregated groups.[17] The cave nectar bat forage in flocks from 7pm to 2am after their daily torpor.[18] A special be­hav­ior that //E. spelaea// possess is producing of sounds made by wing-clapping when moving in dark environments. This is postulated to b e the rudimentary form of echolocation which helps orientate the bat, and alternatively it may just be due to the slower flight of cave nectar bats which helps reduce the impact should they collide with walls or objects in dark caves.[19] Roost caves of // E. spelaean // are known to be shared with colonies of // Rousettus leschenaultia // and // E. major //.

=9 Communication and Perception=

//Eonycteris spelaean// do not navigate by echolocation, as is its family Pteropodidae, a group of megabats that has well-developed eyes that provides sufficient vision in twilight caves. Moreover, Pteropodidae species have small, simple ears hence visual perception is their dominant way to sense the environment.[20] Other than visual senses, they might use **olfactory** senses, considering the presence of “osmetrichia” hair on the back of males which disperses scent over large distances. It is probably used in mating rituals, and in many species the odour in males are stronger than females which indicates the use of olfaction to attract mates.[21] Lastly, //E. spelaean// might also use sound as they are unique in the production of special wing-clapping sounds, which might either be an earlier form of echolocation.[22] They also use **tactile** senses to interact with their environment. Most Pteropodidae species lo­cate food by smell.[23]

=10 Food Habits=

Their diet con­sists pri­mar­ily of the nec­tar and pollen of plant species that flower at night, hence they are nectarivorous generalists and have been documented to feed over 31 plant species. They are hence also classified as herbivores.[24] Two studies found that pollen is found in their stomach and tongue exclusively. In particular, they prefer the nec­tar and pollen of //Orox­y­lum in­dicum//. //Eonyc­teris spelaea// and //O. in­dicum// are re­ferred to as an ex­am­ple of co­evo­lu­tion be­cause the flow­ers evolved to adapt to the head mor­phol­ogy and feed­ing be­hav­iour of the bat.[25] Other species of plants include //Durio zi­bethi­nus//, //Parkia spe­ciosa//, //Musa acumi­nata//, and //Ficus// species. [26] The cave nectar bat have shown a par­tic­u­lar affin­ity for a spe­cific species of Agave.

=11 Predation=

This species is likely to fall prey to predation by climbing snakes and nocturnal birds such as owls. Like most other bats, their ability to fly, nocturnality and habit of roosting in inaccessible places is a form of protection from predation. However, there is not much information on the specific predators of this species and their adaptations to evade it.

=12 Conservation=

12.1 Threats
Overall, this species is not majorly threatened. According to IUCN, they are in the lower risk/least concern category.[27] However, in some parts of South East Asia, land use change such as deforestation for agriculture and other uses poses a threat locally.[28] The increase popularity of cave tourism and using of headlamps by tourists provides emerging pressure on the species in some caves, for example in Borra Caves, Andhra Pradesh.[29] Bats are nocturnal animals, the intrusion of tourists in the day might disrupt their rest (daily torpor). In countries such as China they are hunted heavily for food.[30]

12.2 Conservation Actions
This species is adaptable, and is present in many protected areas throughout its range. No direct conservation measures are currently needed for the species as a whole. In fact in South Asia, this species, like most other fruit bats in India is considered a vermin. //E. spelaea// has been recorded from protected areas like Kalakkad-Mundunthurai Tiger Reserve in Tamil Nadu.[31] Despite that, this species should still be monitored for the populations to record any changes in abundance and distribution and also taking it out from the vermin category. This is crucial because //E. spelaea// is important in its ecosystem function as a pollinator and labelling it as a vermin is fundamentally wrong as there are no damages to crop.

On top of that, awareness should be raised on the repercussions of disturbing its cave habitats. This comes after pop­u­la­tions in Java and the Lesser Sun­das Is­lands are now en­dan­gered due to hunt­ing, habi­tat de­struc­tion and cave dis­tur­bance. The sub­species //E. spelaea glan­difera// found in In­done­sia, the Philip­pines and Su­lawesi was re­ported as vul­ner­a­ble 1992. Although pop­u­la­tions of //E. spelaea glan­difera// in the Philip­pines seem more resistant to habi­tat changes but are still vulnerable to human disturbances and hunting.[32]

=13 Lifespan/Longevity=

Little information is known about the lifespan of //Eonycteris spelaea// in the wild or even in captivity. When it comes to other Pteropodidae species, the longest known lifespan in captivity is the straw-col­ored fruit bats (//Eidolon helvum//) which live up to 21.8 years; fly­ing foxes Pteropus, 31.4 years; and rousette fruit bats, 22.9 years.[33]

=14 Ecosystem Services=

14.1 Importance to Humans: Benefits
The most significant ecosystem services of //E. spelaea// is the pollination of plants, and by pollinating commercially important species they are very useful to humans.[34] This is es­pe­cially for durian fruits (Durio spp.), which can contribute up to $120 mil­lion (U.S. dol­lars) to the South­east Asian econ­omy every year. They are also hunted for food in some countries. In the Philippines, **bat guano** is collected for use as fertilizer.[35]

14.2 Importance to Humans: Threats
Right now, there are no evidence of any ad­verse ef­fects of E. spelaea on hu­mans.However, bats are known to be [|vectors of many pathogens and viruses].

=15 Taxonomy=

Binomial name: //Eonycteris spelaea// (Dobson, 1871)

15.1Common Names
English-Dawn Bat, Common Dawn Bat, Common Nectar Bat, Lesser Dawn Bat

15.2 Taxonavigation

 * Domain: Eukaryota ||  ||   ||   ||   ||   ||   ||   ||
 * || Kingdom:Animalia ||  ||   ||   ||   ||   ||   ||
 * ||  || Phylum:Chordata ||   ||   ||   ||   ||   ||
 * ||  ||   || Class:Mammalia ||   ||   ||   ||   ||
 * ||  ||   ||   || Order:Chiroptera ||   ||   ||   ||
 * ||  ||   ||   ||   || Family:Pteropodidae ||   ||   ||
 * ||  ||   ||   ||   ||   || Genus://Eonycteris// ||   ||
 * ||  ||   ||   ||   ||   ||   || Species://Eonycteris spelaea// ||

15.3 Synonyms

 * //Eonycteris spelaea//, subspecies //winnyae// || Maharadatunkamsi & Kitchener, 1997 ||
 * //Eonycteris bernsteini// || Tate, 1942 ||
 * //Eonycteris spelaea//, subspecies //glandifera// || Lawrence, 1939 ||
 * //Eonycteris spelaea//, subspecies //rosenbergii// || Jentink, 1889 ||
 * //Macroglossus spelaeus// || Dobson, 1871 ||

15.4 First Description
The first description of //Eonycteris spelaea//, then identified and named as //Macroglossus spelaea//, was in 1871 by Dobson G E and published under Proceedings of Asiatic Society. Following is an abstract of Dobson acknowledging the nomenclatural switch from //Macroglossus spelaea// to //Eonycteris spelaea in// 1973//.//

15.5 Phylogeny
In a phylogenetic study on old world bats by Laura J. Hollar and Mark S. Springer in 1997, the "maximum likelihood, minimum evolution, and **parsimony** (uniform and differential weighting schemes) were used to estimate phylogenetic trees using the three microchiropterans as outgroups. These analyses, including topology-dependent permutation tail probability (T-PTP) tests, bootstrapping, and the Kishino–Hasegawa test, were conducted with PAUP 4.0d49 and 4.0d52 for Power MacIntosh. Bootstrap and T-PTP tests included 500 replications except for the maximum-likelihood analysis with a gamma rate distribution (100 replications)." [36]





=16 Glossary= [|Altricial] - "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born. Bat guano – excrement of bats [|Bilaterally Symmetrical] - having similarity in size, shape, and relative position of corresponding parts [|Homiothermic] – warm blooded Molariform - resembling a molar tooth especially in shape [|Olfactory]- sense of smell [|Parsimony]- favouring trees that suppose the least evolutionary change to explain observed data [|Pelage] - the hairy covering of a mammal Polyestry – more than one breeding season per year [|Tactile] - sense of touch Tragus – the ear of bats [|Troglophilic] – able to spend its whole life in caves [|Weaned] - To accustom (the young of a mammal) to take nourishment other than by suckling.

**17 References**

[1]Kunz, T., M. Fenton. 2003. //Bat Ecology//. University of Chicago Press. [2] Brian K. McNab. 1989. Temperature Regulation and Rate of Metabolism in Three Bornean Bats. //Journal of Mammalogy//, **70**: 153–161 [3] C. Srinivasulu, Paul A. Racey & Shahroukh Mistry. 2010. A key to the bats (Mammalia: Chiroptera) of South Asia. Journal of Threatened Taxa. 2(**7**): 1001–1076 [4]Macdonald, D. 2001. //The Encyclopedia of Mammals//. New York, New York: Barnes & Nobel Books. [5] Francis, C., Rosell-Ambal, G., Tabaranza, B., Carino, P., Helgen, K., Molur, S. & Srinivasulu, C. 2008. //Eonycteris spelaea//. //The IUCN Red List of Threatened Species. Version 2014.3//. Date Accessed: 11th November 2014. [6]Neuweiler, G. 2000. //The Biology of Bats//. New York, New York: Oxford University Press. [7] P. J. J. Bates; D. L. Harrison Jay F. Storz. 1998. Bats of the Indian Subcontinent. //Journal of Mammalogy,// 79(**4**): 1441–1443 [8] P. D. Heideman and L. R. Heaney. Population biology and estimates of abundance of fruit bats (Pteropodidae) in Philippine submontane rainforest. //Journal of Zoology//. 218(**4**): 565–586, [9] Francis, C., Rosell-Ambal, G., Tabaranza, B., Carino, P., Helgen, K., Molur, S. & Srinivasulu, C. 2008. //Eonycteris spelaea//. //The IUCN Red List of Threatened Species. Version 2014.3//. Date Accessed: 11th November 2014. [10] Vanitharani. 2005. Noteworthy representatives of bat species in Agasthiyamalai biosphere reserve, Tamil Nadu, India. //Journal of Theoretical and Experimental Biology//. 2(**2**): 47–59 [11] Findley, J. 1993. //Bats: a community perspective//. New York, New York: Cambridge University Press [12] A. Smith and Y. Xie eds. 2008. A Guide to the Mammals of China. //Princeton University Press//. [13]Reinke, A. 2007. //Eonycteris spelaea, Animal Diversity Web//. Date Accessed: 14th November 2014. [14]Allen, G. 1939. //Bats//. Cambridge, MA: Harvard University Press. [15]Nowak, R. 1999. //Walker’s Mammals of the World//. Baltimore and London, Maryland and England: The Johns Hopkins University Press. [16]Hutchins, M., D. Kleiman, G. Valerius, M. McDade. 2003. //Grzimek's Animal Life Encyclopedia, 2nd edition//. Farmington Hills, MI: Gale Group. [17]Reinke, A. 2007. //Eonycteris spelaea, Animal Diversity Web//. Date Accessed: 14th November 2014. [18]Brian K. McNab. 1989. Temperature Regulation and Rate of Metabolism in Three Bornean Bats. //Journal of Mammalogy//, **70**: 153–161 [19] Edwin Gould, 1988. MammalogistsWing-Clapping Sounds of Eonycteris spelaea (Pteropodidae) in Malaysia. //Journal of Mammalogy,// **69:** 378–379. [20] Macdonald, D. 2001. The Encyclopedia of Mammals. New York, New York: Barnes & Nobel Books. [21]Macdonald, D. 2001. //The Encyclopedia of Mammals//. New York, New York: Barnes & Nobel Books. [22] Edwin Gould, 1988. MammalogistsWing-Clapping Sounds of Eonycteris spelaea (Pteropodidae) in Malaysia. //Journal of Mammalogy,// **69:** 378–379. [23]Kunz, T., M. Fenton. 2003. //Bat Ecology//. University of Chicago Press. [24]Hutchins, M., D. Kleiman, G. Valerius, M. McDade. 2003. Grzimek's Animal Life Encyclopedia. //2nd edition//. Farmington Hills, MI: Gale Group. [25] Neuweiler, G. 2000. The Biology of Bats. New York, New York: Oxford University Press. [26] Edwin Gould. 1978. Foraging Behavior of Malaysian Nectar-Feeding Bats. //Biotropica//, **10**: 184–193 [27] Francis, C., Rosell-Ambal, G., Tabaranza, B., Carino, P., Helgen, K., Molur, S. & Srinivasulu, C. 2008. //Eonycteris spelaea//. //The IUCN Red List of Threatened Species. Version 2014.3//. Date Accessed: 11th November 2014. [28] Molur et al. Status of South Asian Chiroptera. 2002. Date Accessed: 11th November 2014. [29] C. Srinivasulu, Paul A. Racey & Shahroukh Mistry. 2010. A key to the bats (Mammalia: Chiroptera) of South Asia. Journal of Threatened Taxa. 2(**7**): 1001–1076 [30] A. Smith and Y. Xie eds. 2008. A Guide to the Mammals of China. //Princeton University Press//. [31] Francis, C., Rosell-Ambal, G., Tabaranza, B., Carino, P., Helgen, K., Molur, S. & Srinivasulu, C. 2008. Eonycteris spelaea. The IUCN Red List of Threatened Species. Version 2014.3. Date Accessed: 11th November 2014. [32] Francis, C., Rosell-Ambal, G., Tabaranza, B., Carino, P., Helgen, K., Molur, S. & Srinivasulu, C. 2008. //Eonycteris spelaea//. //The IUCN Red List of Threatened Species. Version 2014.3//. Date Accessed: 11th November 2014. [33]Jones, M. 1982. Longevity of captive mammals. //Zoological Garten N. F. Jena//, **52**: 113–128. [34] Robert Hodgkison, Sharon T. Balding, Akbar Zubaid and Thomas H., 2003. Fruit Bats (Chiroptera: Pteropodidae) as Seed Dispersers and Pollinators in a Lowland MalaysianRain Forest. //KunzSource: Biotropica//, **5**: 491–502. [35] Wilson, D. 1997. Bats in Question. //Washington and London: Smithsonian Institution Press.// [36] Laura J Hollar and Mark S. Springer, 1997. Old World fruitbat phylogeny: Evidence for convergent evolution and an endemic African clade. //Proceedings of the National Academy of Sciences of the United States of America//, **94:** 5716 – 5721