A Field Guide to the

of Sri LankaBATSWipula Bandara Yapa

Dilmah Conservation was initiated in 2007 by Dilmah to incorporate environmental conservation efforts into the MJF Charitable Foundation, which focuses on social justice. Dilmah Conservation works towards the sustainable use of the environment in partnership with various governmental and non-governmental organisations. The pledge made by Dilmah founder Merrill J. Fernando to make business a matter of human service is deeply ingrained in the work carried out by Dilmah Conservation. For additional information visit our website at:

www.dilmahconservation.org77671 00L

Prof. Wipula Yapa started studies on Sri Lankan bats over 30 years ago. After graduating from the University of Kelaniya in 1985, he carried out an ecological study on cave dwelling bats in Sri Lanka. He proceeded to Germany in 1990 for his doctoral studies and received his PhD from the Ludwig Maximillians University of Munich. He returned to Sri Lanka in 1995 and joined the Department of

Wipula Bandara Yapa

A Field G

uide to the Bats of Sri Lanka

Zoology, University of Colombo. In 1995, he initiated an ecological survey on the distribution of bats in Sri Lanka, which was one of the detailed surveys carried out in Sri Lanka in recent times. His research expands to many areas such as breeding habits, roosting ecology, migration, social behavior and pathogens of bats. He is currently serving as a Professor in Zoology and is the Head of the Department of Zoology & Environment Sciences of the University of Colombo.

Bats of Sri Lanka

Wipula Yapa

A Field Guide to the

A Field Guide to the Bats of Sri Lanka 13

Contents

Foreword 08Preface 09Acknowledgements 101. Introduction and Evolution 15 1.1. Bats 15 1.2. Evolution 16 1.3. Classification 18 Classical 18 Modern 192. Diversity Habits and Habitats 21 2.1. Morphological Diversity 21 2.2. Reproduction and Social life 24 2.3. Roosting Habits and Habitats 25 2.4. Activity Patterns 30 2.5. Diet 31 2.6. Echolocation 343. Conservation and Importance of Bats 37 3.1. Humans and Bats 37 3.2. Economic Importance 38 3.3. Bats and Diseases 40 3.4. Conservation Issues 41 3.5. How Can We Help? 434. Bats of Sri Lanka 44 4.1 Country 44 4.2 How to use this book 46 4.3 Family and Species profiles 48 Pteropodidae 48 Rhinolophidae 60 Hipposideridae 66 Megadermatidae 78 Vespertilionidae 84 Embalonuridae 110 Molossidae 1185. Key 1246. Glossary 1287. Bibliography and Resources for further study 1368. Index 141 8.1. Scientific Names 141 8.2. Common Names 141

52 A Field Guide to the Bats of Sri Lanka

Lesser false vampire bat Megaderma spasma (GR)

A Field Guide to the Bats of Sri Lanka 15

1. Introduction 1.1. Bats - (Order: Chiroptera)

Bats are mammals; and just like humans they give birth to live young, nurse them with milk and sometimes even carry them when they go in search of food. They are also a fascinating group of animals. In fact almost everything about bats is so extraordinary and unique, setting them well apart from all other mammals. For example, they are the only group of mammals capable of sustaining powered flight. For this, their forelimbs are modified to form a wing, which is so different from that of birds. The bat wing is a membrane which covers the hand and also sides of the body (Figure 1). Bats have also developed an effective orientation system which involves the use of sound signals for perceiving the environment, the process which is known as echolocation. Although some other groups of vertebrates such as oil birds, whales and certain species of shrews are known to echolocate, echolocation in bats is far more superior and advanced than the rest. These two specialisations, namely the evolution of flight and echolocation in bats, are most probably the main parameters in the diversification of feeding and roosting habits, reproductive strategies and social behaviour of bats. Thus, bats have been able to exploit many ecological niches that were inaccessible to other group of mammals, making them a very successful group of mammals. So far, over 1200 species of bats have been recorded, amounting to roughly ¼th of the total number of mammals recorded at present. Thereby, they are the second largest mammalian order (next to rodents) in number of species and probably exceed all other such groups in overall abundance. They have successfully colonised almost every continental region on the earth (except Antarctica), as well as many oceanic islands and archipelagos. Their widespread distribution and the unique specialisation in morphology, physiology and behaviours have led to a variety of feeding habits which include feeding on fruits, nectar, leaves, flowers, pollen, insects, fish, other smaller vertebrates and even blood.

16 A Field Guide to the Bats of Sri Lanka

1.2. Evolution

Bats are believed to have evolved before early Eocene, 50 million years ago, as a complete skeleton of a bat, Icaronycteris index was found from an early Eocene site. This is the earliest known fossil record of a bat. The skeleton was assigned to the suborder Microchiroptera based on the structure of the forelimb and the morphology of the upper molars. The first true Megachiropteran with dentition adapted to a fruit eating diet was found much later, in the early/middle Miocene epoch about 20 million years ago.

Figure 1 General body plan of a bat

Tail

Knee

Wrist

Elbow

Propatagium

Ear

Tragus

Upper arm (humerus)

Forearm (radius)

Thumb

Second finger

Third finger

Fourth finger

Calcar

Uropatagium

Foot with 5 toes

Plagiopatagium

Fifth finger

Dactylopatagium

A Field Guide to the Bats of Sri Lanka 17

Until the 1980s most workers agreed that the common ancestor of all extant bats was a flying mammal, a hypothesis which implies that bats are monophyletic and powered flight evolved only once in mammals (Fig 2). This classical view that Megachiroptera and Microchiroptera are the closest relatives of each other has much supporting evidence from biochemical and molecular studies and from some morphological characteristics such as the vascular system of the skull, foetal membranes and the nervous system.

However, there is also evidence to support the view that bats are diphyletic, which means that flapping flight evolved twice in mammals. The first event is believed to have taken place in the Cretaceous period when an insectivorous mammal lineage evolved from leaping to full flight in pursuit of flying insects, thus giving rise to Microchiroptera. The second event would have probably occurred in the Tertiary period when an early primate began to glide in search of fruits. Some of these gliders are believed to have given rise to Megachiroptera. This flying primate hypothesis arose from the unexpected finding that Megachiroptera shares a number of advanced visual pathway characteristics with primates that were not found in any other mammalian order, nor significantly in Microchiroptera. This hypothesis has found increasing support from other sources of evidence such

Fossil of a bat

18 A Field Guide to the Bats of Sri Lanka

as brain features, immunological studies of serum proteins with monoclonal antibodies and analysis of restriction sites and protein sequences, globin and a-crystallin. These alternatives and different hypotheses concerning the relative phylogenetic positions of non-volant and gliding taxa relative to bats – have significantly different implications in relation to the origin of powered flight in mammals.

1.3. Classification

1.3.1. Classical Classification

Bats belong to the Order Chiroptera and they are the sole members of this Order. According to classical classification, it is divided into two suborders; Microchiroptera and Megachiroptera. The Megachiroptera are represented by only one family, the Pteropodidae, which are restricted to the Old World tropics of Africa and Asia. There are over 170 species of Megachiropterans. The modern Microchiroptera are divided into four super families, Emballonuroidea, Rhinolophoidea, Phyllostomoidea and Vespertilionoidea, which indicate evolutionary affinities among 17 families. There are three families in the super family Emballnuroidea: Rhinopomatidae (Mouse-tailed bats), Emballonuridae (Sheath-tailed bats) and Craseonycteridae (Bumble bee bat). Rhinolophoidea includes four families: Nycteridae (Hollow-faced or Slit-faced bats), Megadermatidae (False Vampire bats), Rhinolophidae (Horseshoe bats) and Hipposideridae (Leaf-nosed bats). Superfamily Phyllostomoidea includes: Noctilionidae (Fisherman bats), Mormoopidae (Moustached bats) and Phyllostomidae (New World Leaf-nosed bats). The remaining superfamily Vespertilionoidea includes families: Natalidae (Funnel-eared bats), Furipteridae (Smoky bats), Thyropteridae (Disc-winged bats), Myzopodidae (Old world Sucker-footed bats), Vespertilionidae (Evening bats), Mystacinidae (New zealand Short-tailed bats) and Molossidae (Free-tailed bats). Finally there is a fifth Superfamily, the Palaeochiropterygoidea, which includes three families of fossil

Figure 2 Phylogenatic tree

Flying Primates Bat Monophyly

A Field Guide to the Bats of Sri Lanka 19

Order Chiroptera

Suborder Megachiroptera Family Pteropodidae (Fruit bats)

Suborder Microchiroptera

Superfamily Emballonuroidea Family Emballonuridae (Sheath tailed bats)

Family Craseonycteridae (Bumble bee bat)

Family Rhinopomatidae (Mouse-tailed bats)

Superfamily Rhinolophoidea Family Rhinolophidae (Horseshoe bats)

Family Hipposideridae (Old world Leaf nosed bats)

Family Megadermatidae (False Vampire bats)

Family Nycteridae (Slit faced bats)

Superfamily Phyllostomoidea Family Phyllostomidae (New world Leaf-nosed bats)

Family Mormoopidae (Moustached bats)

Family Noctilionidae (Fisherman bats)

Superfamily Vespertilionoidea Family Thyropteridae (Disc-winged bats)

Family Furipteridae (Smoky bats)

Family Mystacinidae (New Zealand Short-tailed bats)

Family Myzopodidae (Old world sucker-footed bats)

Family Vespertilionidae (Evening bats)

Family Molossidae (Free tailed bats)

Family Natalidae (Funnel-eared bats)

1.3.2. Modern Classification

Recently, in studies based on molecular phylogeny, some researchers (for details refer Teeling et al., 2002) made a drastic change in the classical classification of Order Chiroptera by introducing two new suborders; Suborder - Yinpterochiroptera and Sub order - Yangochiroptera. All the Megachiropterans (fruit bats) and the members of the superfamily Rhinolophoidea (which were Microchiropterans in the traditional classification), were grouped together in the Suborder Yinpterochiroptera while the remaining families of Microchiropterans were included in the suborder Yangochiroptera. Thus, the traditional division of the two Chiropteran suborders, (the Megachiroptera which included non-

Microchiropterans (all extinct): the Palaechiropterygidae, Archaeonycteridae and Icaronycteridae.

Table 1. 1. Classical classification of bats

20 A Field Guide to the Bats of Sri Lanka

Order Chiroptera

Suborder YinpterochiropteraSuperfamily Pteropodoidea Family Pteropodidae (Fruit bats)

Superfamily Rhinolophoidea Family Rhinopomatidae (Mouse-tailed bats)

Family Megadermatidae (False Vampire bats)

Family Craseonycteridae (Hog Nosed bat)

Family Rhinolophidae Subfamily Rhinolophinae (Horseshoe bats)

Subfamily Hipposiderinae (Old world Leaf nosed bats)

Suborder YangochiropteraSuperfamily Emballonuroidea Family Emballonuridae (Sheath tailed bats)

Family Nycteridae (Slit faced bats)

Superfamily Noctilionoidea Family Phyllostomidae (American Leaf nosed bats)

Family Mormoopidae (Moustached bats)

echolocating bats and Microchiroptera (echolocating bats) have been changed. The suborder Yinpterochiroptera comprises five families: Pteropodidae (all fruit bats or megachiropterans), Rhinopomatidae (mouse-tailed bats), Megadermatidae (false vampire bats), Craseonycteridae (hog-nosed bat or bumble bee bat) and Rhinolophidae. The family Rhinolophidae consists of two sub families: Rhinolophinae and Hipposiderinae. In the classical classification, Family Rhinolophidae consisted of only horse-shoe bats, containing a single genus, Rhinolophus, and Family Hipposideridae with old world leaf-nosed bats. However, in the new classification horseshoe bats or rhinolophids were included in subfamily, Rhinolophinae and, all old world leaf-nosed bats were included in the subfamily Hipposiderinae. Family Craseonycteridae contains a single species Craseonycteris thonglongyai. Suborder Yangochiroptera comprises 12 families; Nycteridae, Emballonuridae, Phyllostomidae, Mormoopidae, Noctilionidae, Furipteridae, Thyropteridae, Mystacinidae, Myzopodidae, Vespertilionidae, Natalidae and Molossidae.

This sister-taxon relationship between the rhinolophoid microbats and the megachiropterans suggest that laryngeal echolocation within bats evolved more than once. Or alternatively, if echolocation evolved only once, then this ability was lost subsequently in Megachiropterans. There remains considerable uncertainty in both subordinal and superfamilial classifications within bats, where both morphological and molecular data conflict and different molecular data sets provide varying support. Thus, phylogeny of Chiroptera is not yet fully resolved and further studies may one day clear the taxonomic ambiguity of bats.

A Field Guide to the Bats of Sri Lanka 21

Table 1. 2. Modern classification of bats

Family Noctilionidae (Fisherman bats)

Family Furipteridae (Smoky bats)

Family Thyropteridae (Disk-winged bats)

Family Mystacinidae (New Zealand Short-tailed bats)

Family Myzopodidae (Old world sucker-footed bats)

Superfamily Vespertilionoidea Family Vespertilionidae (Evening Bats)

Family Molossidae (Free tailed bats)

Family Natalidae (Funnel-eared bats)

2. Diversity, Habits and Habitats2.1. Morphological Diversity

In general Megachiropterans are larger than the Microchiroptera. However, there is a considerable overlap in body size. The weight of the Megachiropterans varies from 10g to 1.5 kg and the forearm length (i.e. the length of the radius and ulna, which is generally used to indicate the size of a bat) ranges from 35-230mm. The wingspan or spread of the wings of the largest fruit bat, Pteropus vampyrus is about 170cm. Yet the majority of Megachiropetrans are relatively small. There are 42 genera of Megachiropterans and the maximum forearm length is less than 70mm in about 50% (24 genera). The maximum Fore Arm Length (FAL) exceeds 1 meter only in 7 genera, which include the genus Pteropus.

The largest bat, Golden-crowned Flying Fox (Acerodon jubatus)

22 A Field Guide to the Bats of Sri Lanka

The smallest bat, Kitti’s Hog-nosed Bat (Craseonycteris thonglongyai)

Rufous horseshoe bat (Rhinolophus rouxii) colour variations- Left Dull brown form (HS), Right yellow to bright orange form (TP)

The largest Microchiropteran as measured by forearm length is the false vampire bat, Vampyrum spectrum, which attains a wingspan of 60 - 100cm and body mass of 145–190g. This is also the largest carnivorous bat in the world. The smallest bat, Kitti’s Hog-nosed bat found in Thailand, Craseonycteris thonglongyai, (probably the smallest mammal in the world as well) has a body weight of just 2g.

In the eyes of many people, bats are not colourful animals and the general notion is that bats are dark coloured. Although this is true in most cases, there are some brightly coloured bats, such as the painted bat (Kerivoula picta), which typically haunts banana plantations and is found in several parts of Sri Lanka. Its entire body, apart from parts of the wing, is bright orange or tawny red in colour, whereas the middle parts of the wing are conspicuously black. The colour may even vary among individuals and even though the typical fur colour of the Rufous horseshoe bat (Rhinolophus rouxii) is dull brown, the colour of some individuals may vary from yellow to bright orange. Albinism in bats is rather rare, but albino bats have been seen on rare occasion.

A Field Guide to the Bats of Sri Lanka 23

Figure 3 - Above Left and Right Microchiroptera bat Below Right Megachiroptera bat

Figure 4 - Left Different types of bat tailsA. Free tail, B. Mouse tail, C. Full membrane,

D. Sheath tail, E. Short tail, F. tail lacking

Figure 5 - Above Different types of noseleafs - A. Triangular, B. Truncate, C. Heart shape, D. Square shape, Below Different types of ears - A. Large

rounded, B. Pointed, C. Broad, D. Rounded, E. Triangular

A

A

A

B

B

C

C

D

D E

B

DC

E F

24 A Field Guide to the Bats of Sri Lanka

2.2. Reproduction and Social Life

Bats are a group of highly social animals. Generally bats are gregarious, which means they live in large congregations and in fact they form the largest known mammalian congregations, some of which exceed several millions of individuals (e.g. Davis cave in Mexico: 20 million bats). However, all bats do not live in such groups and many species live in smaller groups. In species that are considered “solitary”, the mother raises her young alone. Thus, the mother and her dependant young (generally a single pup) is the basic social unit of bats, and depending on the species, this may range in size from dozens of individuals to millions.

Bats exhibit numerous specialisations in female reproductive morphology and cyclicity. Nearly all temperate bat species show a single peak of reproduction to avoid harsh weather conditions such as winter. Early mating prior to hibernation occurs in almost all species of temperate bats regardless of taxonomic affiliation. Thus, in most species that live in temperate countries, some form of sperm storage has evolved and the young are born after the winter when weather conditions are more favourable. Seasonal peaks of reproduction are also common in tropical bat species, even though the fluctuation of weather conditions is not as severe as in temperate regions. For tropical insectivorous species, rainfall is the most important environmental determinant in reproductive seasonality. The reproduction of these species is often synchronised with prominent peaks in rainfall, as insects are more abundant in rainy seasons.

Generally many species of bats give birth to a single pup in one breeding season, although twinning is also occasionally seen at least in some species. In Sri Lanka, twining has been observed in a few species such as: Pipistrellus tenuis, P. ceylonicus and Scotophilus heathii.

Nursery colony of Hipposideros lankadiva, Sri Lanka (DR)

A Field Guide to the Bats of Sri Lanka 141

Chaerephon plicatus 122Cynopterus brachyotis 58Cynopterus sphinx 56Falsistrellus affinis 92Hesperoptenus tickelli 94Hipposideros ater 74Hipposideros fulvus 76Hipposideros galeritus 72Hipposideros lankadiva 68Hipposideros speoris 70Kerivoula hardwicki 106Kerivoula picta 104Megaderma lyra 82Megaderma spasma 80Miniopterus fuliginosus 108Murina cyclotis 102Myotis hasseltii 100Pipistrellus ceylonicus 90Pipistrellus coromandra 88Pipistrellus tenuis 86Pteropus giganteus 50Rhinolophus beddomei 62Rhinolophus rouxii 64Rousettus leschenaulti 54Saccolaimus saccolaimus 116Scotophilus heathi 96Scotophilus kuhlii 98Tadarida aegyptiaca 120Taphozous longimanus 112Taphozous melanopogon 114

Index Scientific Names Common Names

Black-Beared Tomb bat 114Cantor’s Leaf-nosed bat 72 Chocolate bat 92 Common flying fox 50Dusky Leaf-nosed bat 74Egyptian Free-tailed bat 120Fulvous fruit bat 54Fulvous Leaf-nosed bat 76Great Yellow bat 96Greater False Vampire bat 82Hardwicke’s forest bat 106Indian Pipistrelle 88Indian Pygmy bat 86Kelaart’s Pipistrelle 90Large Leaf-nosed bat 68Lesser Dog-faced fruit bat 58Lesser False Vampire bat 80Lesser Woolly Horseshoe bat 62Lesser Yellow bat 98Long-Winged Tomb bat 112Painted bat 104Pouch-bearing Tomb bat 116Round-eared Tube-nosed bat 102Rufous Horseshoe bat 64Schneider’s Leaf-nosed bat 70Schreiber’s Long-fingered bat 108Short-nosed fruit bat 56Tickell’s bat 94Van Hasselt’s mouse-eared bat 100Wrinkled-lipped Free-tailed bat 122