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A Field Key to the Bats of Trinidad

Gerald G. Carter

August 2004

photos by Daniel K. Riskin

All measurements in millimeters.

FA = Forearm

Data taken from:

Goodwin, G. G., and A. M. Greenhall. 1961. A review of the bats of Trinidad and Tobago:

descriptions, rabies infections, and ecology, Bulletin of the American Museum of Natural

History 122:187-342

Goodwin, G. G., and A. M. Greenhall. 1964. New records of bats from Trinidad and comments on

the status of Molossus trinitatus Goodwin, American Museum Novitates 2195:1-23

Reid, F. 1997. A field guide to the mammals of Central America & southeast Mexico. Oxford

University Press, New York.

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Families Unknown- start at 1 Phyllostomidae (Leaf-nosed Bats) - start at 26 (except for vampires (6) and Centurio (5)) Mormoopidae (Leaf-chinned Bats) - start at 10 Vespertilionidae (Plain-nosed Bats) -start at 23 Emballonuridae (Sac-winged Bats) - start at 15 Molossidae (Free-tailed Bats) - start at 18 Noctilionidae (Fishing Bats) – go to 8 Natalidae (Funnel-Eared Bats) – go to 3 Furipteridae (Thumbless Bats) – go to 2 Thyropteridae (Disk-winged Bats) – go to 4 1. Face with conspicuous nose leaf: Phyllostomidae --- 26 1’. No conspicuous nose leaf---2 2. Greatly reduced thumb – almost lacking and mostly contained within wing

membrane: Furipteridae--- Furipterus horrens- Thumbless Bat. FA: 33-37, Fur smoky gray, eyes tiny and hidden in fur

2’. Normal to large thumb---3 3. Tail longer than head and body, ears funnel shaped: Natalidae---

Natalus tumidirostris- Trinidadian Funnel-eared Bat. FA: 39-41.5, small, slender, yellowish bat, long thin threadlike tail extending to tip of thin interfemoral membrane

3’. Tail not longer than head and body, ears not funnel shaped---4 4. Bases of thumbs and feet bearing stalked adhesive discs: Thyropteridae---

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Thyroptera tricolor- Spix’s Disk-winged Bat. FA: 34-38, underparts white or yellowish, triangular face, long, pointed muzzle, tail extends 5-8mm beyond interfemoral membrane

4’. Bases of thumbs and ankles without stalked adhesive discs---5 5. Face conspicuously wrinkled and naked:

Centurio senex- Wrinkle-faced Bat. Unmistakable. White lattice pattern on wing between forearm and digit 4 and digit 5. White spot on each shoulder, FA: 41-45

5’. Face not conspicuously wrinkled and naked---6 6. Very large thumbs, flattened nosepad, upper front teeth prominent, v-shaped,

triangular, with cutting edges razor sharp---7 6’. Upper incisors and canines not blade-like---8 7. Wings with white tips and white leading edges:

Diaemus youngi- White-winged Vampire Bat. FA: 48-54, may make a rattling hiss noise with open mouth display, may emit foul scent from mouth glands, long thumbs with single pad

7’. Wings tips may be pale but not white:

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Desmodus rotundus- Common Vampire Bat. Thumbs very long with two pads, FA: 53-65

8. Upper lip split and drooping; well developed nose pad: Noctilionidae---

Noctilio leporinus- Bulldog Bat. FA: 82-89, hind feet enlarged, large claws

8’. Upper lip not split and drooping---9 9. Thickened flared lips, one or more folds of skin below the lower lip (chin flaps): Mormoopidae---10 9’. Lips not thickened or flared---13 10. Low, rounded ears meet on forehead or snout, several prominent chin flaps:

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Mormoops megalophylla- Ghost-faced Bat. FA: 51-57 upper parts pale yellowish brown to dark brown, underparts paler

10’. Narrow pointed ears, small single chin flap: Pteronotus spp.---11

11. Wings meet on back midline (naked back):

Pteronotus davyi- Naked-backed Bat. FA: 43-49, fur extends onto the back beneath wings

11’. Wings do not meet on back midline (furred back)---12

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12. FA: 55-63:

Pteronotus parnelli- Common Mustached Bat. fur short, pale to dark brown, conspicuous tail tip

12’. FA: 42-48: Pteronotus personatus- Lesser Mustached Bat. fur brown to orange 13. Tail completely enclosed in membrane: Vespertilionidae---23 13’. Tail not completely enclosed in interfemoral membrane---14 14. Tip of tail projecting through dorsal surface of interfemoral membrane, large

eyes, no ornamentation of mouth or nose: Emballonuridae---15 14’. Distal part of tail extends beyond the end of the interfemoral membrane: Molossidae--- 18 15. Fur white:

Diclidurus albus (=virgo)- Northern Ghost Bat. large, FA: 63-69, long fur, with no wing sacs, tiny thumbs

15’. Fur not white, FA < 60---16 16. No wing sacs, distinctive proboscis:

Rhynchonycteris naso- Proboscis Bat. FA: 36-40, pair of wavy lines on back, tufts of fur on forearms, dorsal fur grizzled, grey brown or yellowish center

16’. Wing sacs, naked forearms---18 17. FA: 44-48:

Saccopteryx bilineata- Greater White-lined Bat. pair of wavy lines on back, upper parts blackish, underparts grey, two buffy stripes prominent from neck to rump

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17’. FA: 37-43:

Saccopteryx leptura- Lesser White-lined Bat. pair of wavy lines on back,upper parts dark brown, underparts grey brown, less pronounced back stripes

18. Ears not joined over crown:

Molossops greenhalli- Greenhall’s Dog-faced Bat. ears short and rounded, antitragus square, lips not wrinkled, broad snout, FA: 34-48

18’. Ears joined over crown---19 19. Deep vertical grooves on upper lip:

Tadarida europs- Allen’s Free-tailed Bat. bare spot on lower sides of back; short, thick, black bristles on snout, lips deeply creased and wrinkled

19’. Vertical grooves absent---20 20. Small crest of hair on hair between ears:

Promops centralis- Big Crested Mastiff Bat. FA: 51-57, upperparts dark brown, reddish brown, or blackish, no bristles (long hairs) on rump

20’. No crest of hair on crown: Molossus spp.- snout narrow and angle of snout steeply ridged---21 21. Base of hairs white---22 21’. Base of hairs not white, little contrast between bases and tips:

Molossus ater (=rufus)- Black Mastiff Bat or Greater House Bat. FA: 47-54, upper parts black, dark brown or deep orange fine bristles on rump 22. Fur not extending on to interfemoral membrane:

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Molossus major- Little Free-tailed House Bat. FA: 37-40, similar to M. ater but smaller, fur whitish for first half and then tipped blackish brown or reddish brown

22’. Fur extending on to interfemoral membrane for one third of its length: Molossus trinitatus- Trinidadian Free-tailed Bat. FA: ~49. Skull relatively long and slender for Molossus 23. Dorsal surface of interfemoral densely furred:

Lasiurus spp---24 23’. Dorsal surface of interfemoral membrane not thickly furred--- 25 24. Color reddish:

Lasiurus borealis- Red Bat. FA: 35-45, short rounded ears

24’. Upperparts dull yellow or buffy grey, underparts cream or pale yellow: Lasiurus ega- Southern Yellow Bat. FA: 43-47, pinkish ears and facial skin 25. FA: 25.5-28:

Rhogeessa parvula- Margarita Little Yellow Bat. pale, yellowish; ears small and rounded

25’. FA: 28.5-29.5:

Rhogeessa tumida- Central American Yellow Bat. small, dark reddish brown 25’’. FA: 33-38:

Myotis nigricans- Black Myotis. small dark-colored, underparts not as dark as dorsal side

26. Long, narrow muzzle, small noseleaf, tip of tongue with hair-like papillae

that point backwards: Subfamily Glossophaginae and Lonchophyllinae---41

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26’. Muzzle, not long or extended---27 27. Tail---28 27’. No Tail: Subfamily Stenodermatinae---29 28. Tail extends 1/3 of distance through interfemoral membrane, U-shaped row

of small warts around larger central wart on chin:

Carollia perspicillata- Short-tailed Fruit-eating Bat. FA: 41-45 ears with pointed tips

28’. V shaped groove on chin: Phyllostominae---44 29. White shoulder patches:

Ametrida centurio- FA: 26-34, No dorsal or facial stripes, short muzzle, pug-face, small noseleaf squashed against face

29’. No white shoulder patches, or different colored patches (not white)---30

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30. Almost no tail membrane and stocky hind legs densely furred---31 30’. Tail membrane not greatly reduced and hind legs not densely furred---32 31. FA: 37-42:

Sturnira lilium- Little Yellow-shouldered Bat. shoulder patches on some males are deep yellow, orange, or dark red, Legs well haired over inner edge but sparsely haired over knees and adjoining wing membrane

31’. FA: 45-46:

Sturnira tildae- Trinidadian Yellow-shouldered Bat. pelage tricolored, similar to S. lilium but larger

32. FA: 29-33:

Mesophylla macconnelli- Macconnell’s Bat. small noseleaf behind first, hairs tricolored, pale brown at base, no back stripe. Tragus, base of ear, and upper edges of ears bright yellow

32’. FA: 34-78---33 33. Long tail membrane furred on upper surface but not fringed with hairs, large

eyes, long guard hairs---34

33’. Tail membrane not furred on upper surface---35 34. FA: 38-41:

Chiroderma trinitatum- Little Big-eyed Bat. Interfemoral membrane (13-14 mm) sparsely haired on upper surface , upperparts dark to pale brown with

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indistinct to prominent whitish back stripe extending from between shoulders to rump, upper stripe extends to front of ear, ears and noseleaf edged yellow or whitish at base only

34’. FA: 42-47:

Chiroderma villosum- Hairy Big-eyed Bat. Interfemoral membrane well furred on upper surface, interfemoral membrane long (~19 mm), gray or gray brown, fur tricolor with long prominent guard hairs

35. Back Stripe---36 35’. No Back stripe---38 36. FA: 47-56:

Vampyrodes caraccioli- Great Stripe-faced Bat. FA: 47-56, prominent white back stripe from crown of head to rump. White facial stripes prominent. Tail membrane fairly short (~10mm). Tail membrane fringed along edge.

36’. FA < 45---37 37. Edge of tail membrane fringed with white hairs :

Platyrrhinus helleri- Heller’s Broad-nosed Bat. FA: 37-41, prominent white back stripe present from crown to rump, upper white facial stripe distinct, extends just beyond front of ear. Lower facial stripe less prominent. Tail membrane short (~8mm).

37’. Edge of tail membrane naked:

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Uroderma bilobatum- Common Tent-making Bat. FA: 40-44, upperparts dark grey or grey-brown, hairs bicolored, pale at base. White facial stripes prominent above and below eye. Ears and noseleaf edged with yellow or white.

38. FA: 38-42 (?-from limited data)---39 38’. FA: 55-78---40 39. Inner upper incisors with cutting edges notched:

Artibeus cinereus- Pygmy Fruit Bat. white facial stripes, spaces between each incisor and between incisors and canines

39’. Inner upper incisors with cutting edges entire, not notched:

Enchisthenes (=Artibeus) hartii- Velvety Fruit-eating Bat. FA: 38-42, (rare) similar to A. cinereus, except for cranial details. Horseshoe of noseleaf fused below nostrils, spear short and broad. Upperparts, chin, and throat dark chocolate brown.

40. FA: 69-78:

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Artibeus lituratus- Great Fruit-eating Bat. Upper surface of interfemoral membrane and legs well haired, underparts not frosted, upper facial stripe broader than lower facial stripe

40’. FA: 55-67:

Artibeus jamaicensis- Jamaican Fruit-eating Bat. Upper surface of interfemoral membrane and legs not well haired, almost naked, tips of hairs on belly frosted with white or pale gray. Facial stripes usually narrow and indistinct, but rarely bold.

41. Forearms and legs naked---42 41’. Hairy legs:

Anoura geoffroyi- Hairy-legged Long-nosed Bat. almost no tail membrane, FA: 44-45.

42. Incisors in lower jaw absent:

Choeroniscus intermedius- Trinidadian Long-nosed Bat. (rare) tail half of length of interfemoral membrane, FA: 33- 35.5 (?- from limited data).

42’. 2 tiny pairs of incisors in lower jaw---43

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43. FA: 33-38:

Glossophaga soricina- Common Long-tongued Bat. base of hairs whitish, no gaps between lower incisors

43’. FA: 39-41:

Glossophaga longirostris- Greater Long-tongued Bat. underparts cinnamon brown, paling hair tips

44. FA > 70---45 44’. FA < 70---47 45. FA: 98-100:

Vampyrum spectrum- Great False Vampire Bat. upperparts dark brown or orange, ears large and rounded

45’. FA < 95---46 46. Noseleaf fused to upper lip below nostrils, facial skin pink:

Phylloderma stenops- Pale-faced Bat. FA: 69-93, tips of wings white

46’. Noseleaf not fused to upper lip, facial skin dark:

Phyllostomus hastatus- Greater Spear-nosed Bat. FA: 80-93, fur short and velvety, chin groove bordered by bead-like warts.

47. Noseleaf very long and blade-like, almost as long as pointed ears:

Lonchorhina aurita- Common Sword-nosed Bat. Tail to tip of interfemoral membrane, FA: 49-54.

47’. Noseleaf not long and blade-like---48

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48. Conspicuous, elongated, papilla-like warts around mouth:

Trachops cirrhosus- Fringe-lipped Bat. FA: 57-65. Wings broad.

48’. No conspicuous, elongated, papilla-like warts around mouth---49 49. Chin groove bordered by smooth V-shaped pad---53 49’. Chin groove not bordered by smooth V-shaped pad---50 50. Chin groove bordered by conspicuous bead-like warts, underparts noticeably

paler than upperparts:

Phyllostomus discolor- Pale Spear-nosed Bat. FA: 60-68. Fur short and sleek.

50’. No bead like warts on face---51 51. Ears rounded, noseleaf short and rounded, wings attached to feet near base of

toes---52 51’. Ears pointed, noseleaf long and broad, wings attached at ankles:

Mimon crenulatum- Striped Hairy-nosed Bat. Ear length 21-28. FA: 46-55, prominent white or buff stripe from crown to rump. Sides of noseleaf haired and serrated.

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52. FA: 32-36:

Tonatia minuta (=brasiliense, nicaraguae, or venezuelae)- Lesser Round-eared Bat. horseshoe entirely fused to upper lip. Ears connected across forehead by low band.

52’. FA 54-57:

Tonatia bidens- Greater Round-eared Bat. Ears not connected by band across forehead, tail extending to middle of interfemoral membrane, base of thumb and upper parts of feet hairy

53. Ears connected by a band across forehead---54 53’. Ears not connected by a band across forehead---56 54. Low band across forehead joining ears un-notched:

Micronycteris hirsuta- Hairy Big-eared Bat. FA: 39-46, tail perforating upper surface of interfemoral membrane, externally like M. megalotis but much larger.

54’. High band across forehead joining ears notched---55 55. Connecting band between ears rising to a triangle in center, with shallow notch at apex:

Micronycteris megalotis- Little Big-eared Bat. color of underparts brown, FA: 31-36

55’. Connecting band between ears with center notch deep, dividing band into two triangles:

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Micronycteris minuta- Tiny Big-eared Bat. color of underparts grayish white, FA: 34-38.

metacarpals shown on left 56. Fifth metacarpal longest, ears reaching tip of nose when laid forward:

Micronycteris sylvestris- Tricolored Bat. calcar 6-8, prominently tri-colored fur, dorsal stripe not present. FA: 37-43. Ears moderately large, tips pointed.

56’. Third metacarpal longest, ears falling short of tip of nose when laid forward- --57 57. Fifth metacarpal shortest, underparts yellowish, throat bright orange:

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Micronycteris brachyotis- Orange-throated Bat. FA: 38-42, no dorsal line on back, calcar as long as foot

57’. Fourth metacarpal shortest, underparts olive brown:

Micronycteris nicefori- Niceforo’s Bat. FA: 35-40, faint light gray dorsal line on back, calcar 4-6