A Field Key to Bats of Lamanai, Belize Elizabeth L. Clare & Nancy B. Simmons © 2019

This key is an attempt to make identification as simple as possible. It is based on external characters and should tell you when you cannot go further at the net. If you catch anything that you cannot identify, PLEASE BRING IT BACK for identification.

Abbreviations: F.A. = forearm length measured from top of wrist to end of elbow with wing folded. Vampires

short nose leaf

Desmodus rotundus long forearms F.A.=53-65 pointed incisors huge thumb two chin pads

Desmodus is the vampire. It will hiss and scream when you touch it.

Vampires lack a tail membrane and have long, powerful hind legs with big feet. Their head can turn most of the way around. Long forearms, huge thumb, two big chin pads, short nose leaf, and pointed front teeth.

We suspect white-winged vampire bats Diaemus youngi may also be in the area. Large Stripe-Faced Leaf-Nosed Bats (bigger than a chicken egg)

Artibeus lituratus Artibeus intermedius Artibeus jamaicensis F.A.=68-78 F.A.=61-69 F.A.=55-67

These bats have a pair of facial stripes on each side of their face, one above the eye and one below. They do not have a stripe on their back and they lack tails.

If the facial stripes are bright it is either Artibeus lituratus or Artibeus intermedius. Forearm length may be use to separate these species most of the time but some individuals may fall in the zone of overlap in size. Upper surface of the tail membrane and legs are well-haired in both species.

If the facial stripes are faint and there is little hair on the upper surface of the tail membrane and legs, it is probably A. jamaicensis. A. jamaicensis is often slightly smaller than the other two species. Small Stripe-Faced Leaf-Nosed Bats I (smaller than a chicken egg – no back stripe)

Vampyressa

Dermanura Dermanura phaeotis Dermanura watsoni Vampyressa thyone F.A.=35-40 F.A.=35-41 F.A.=29-34

Dermanura and Vampyressa lack a stripe on the back. Dermanura species cannot be told apart reliably at the net -- bring back to classroom. The vast majority of what we catch are Dermanura phaeotis, D. watsonii may be present but we have not been able to confirm it.

Vampyressa is very small and fluffy but hard to differentiate from Dermanura without calipers and a hand lens.

Dermanura and Vampyressa can be distinguished based on the front upper teeth. Dermanura has small, bilobed upper incisors while the teeth in Vampyressa are larger and each comes to a single point. Small Stripe-Faced Leaf-Nosed Bats II (smaller than a chicken egg – white back stripe)

Tail fringe

Uroderma convexum Platyrrhinus helleri Platyrrhinus helleri F.A.=40-44 F.A.=37-41 Stripe

Platyrrhinus and Uroderma can be easily distinguished from other stripe-faced bats by the bright white stripe down the middle of the back

Platyrrhinus has a white fringe on the tail. Uroderma has no fringe.

Stripe image from wikipedia – please bring these back for photography. Small Plain-Faced Leaf-Nosed Bats I (smaller than a chicken egg)

Carollia perspicillata Carollia sowellii F.A. = 41-45 F.A. = 37-42 Tibia = 21-23 Tibia = 16-19 Large central bump +U

Carollia can be distinguished from other small leaf nosed bats by their chins, which have a central bump surrounded by many little ones arranged in a U. Carollia species are frequently mixed up with Glossophaga… look for the dot. Both Carollia and Glossophaga have short tails in a broad tail membrane.

Carollia perspicillata is slightly larger than C. sowelli. The only way to tell the Carollia species apart reliably is by measuring the tibia. Colour is highly variable and thus not reliable. Small Plain-Faced Leaf-Nosed Bats II (smaller than a chicken egg) Scent Gland

Chin pads

Yell

Yellow Fur Lampronycteris Sturnira parvidens Hairy Sturnira Legs Glossophaga soricina brachyotis F.A. = 37-42 F.A. = 33-38 F.A. = 40-42

Lampronycteris brachyotis normally has a bright yellow throat and V-shaped pair of chin pads. It has a broad tail membrane and the calcar is as long as the foot.

Sturnira parvidens are yellow to orange all over. Sturnira lack a tail membrane and have very hairy legs. Males have a sent gland on each shoulder that darkens the fur. They have a strong smell.

Glossophaga has a narrow snout and a chin with a central groove flanked by two chin pads with serrated edges (no central bump like Carollia). They have a broad tail membrane but the calcar is shorter than the foot. Large Big-Eared Leaf-Nosed Bats I

Lophostoma evotis Mimon cozumelae Trachops cirrhosus F.A.=47-54 F.A.=53-61 F.A.=57-65 Bumpy chin

Lophostoma used to be Tonatia. One quick “Lophostoma test” is to touch its ears. Lophostoma will probably fold them back against its head.

Mimon cozumelae has a large noseleaf and large ears that are distinctly pointed. Lophostoma evotis has ears that are rounded and not pointed at the tip.

Note that there are other Lophostoma and Mimon at Lamanai see the previous and next page.

Trachops has a very bumpy chin and lips. Large Big-Eared Leaf-Nosed Bats II

Gardnerycteris keenani Phyllostomus discolor F.A.=46-55 F.A.=60-68 Crenulations Dorsal Stripe

Gardnerycteris keenani (formerly Mimon crenulatum) has the longest nose leaf (2cm). The noseleaf is hairy and has ridges or “crenulations” along the edges. The bat has a pale stripe down the middle of its back.

Phyllostomus is hard to identify without practice. It has a pale chest, very rounded mouth a chin with a row of warts along each side but none in the middle, and smallish pointed ears.

Small Big-Eared Leaf-Nosed Bats

Lophostoma brasiliense Micronycteris schmidtorum Micronycteris microtis Centurio senex F.A.=32-36 F.A.=34-38 F.A.=32-37 F.A.=41-45

Lophosotoma and Micronycteris are distinguished by differences in the chin. Lophostoma has a chin with multiple small bumps, while Micronycteris has a v-shaped pair of large chin pads.

Lophostoma used to be Tonatia. One quick “Lophostoma test” is to touch its ears. Lophostoma will probably fold them back against its head.

Micronycteris are extremely hard to identify. Micronyceris schmidtorum and M. microtis are distinguished by the belly fur. In M. microtis it is brown and is the same color as the fur on the back. In M. schmidtorum the belly fur is white or gray, much paler than the brown fur on the back.

Centurio senex – can’t miss it but hasn’t been seen in years.

Extremely Large Leaf-Nose Bats

Chrotopterus auritus Vampyrum spectrum F.A.=101-110 F.A.=77-83

Chrotopterus and Vampyrum are both huge bats with large, rounded ears and a nose leaf that forms a cup underneath the nostrils.

Chrotopterus is the largest bat that we catch routinely. It is about the size of a fist and has woolly gray fur.

Vampyrum has been captured at Lamanai. It is larger than Chrotopterus and has more silky fur that is usually brownish. The face of Vampyrum often has dark splotches of pigmentation on the ”

Mormoopids – bats with frilly lips

Mormoops megalophylla Pteronotus mesoamericanus Pteronotus personatus Pteronotus fulvus F.A.=51-57 F.A.=55-63 F.A.=42-49 F.A.=42-49

These bats lack nose leafs but have complex lips and chins, short silky fur and slim bodies.

Mormoops has the most complicated lips and chin. Its eyes are especially tiny and its head is rounded. Ears are rounded and funnel shaped.

Pteronotus species all have thickened lips and a single chin flap covered with small bumps. They all have long pointed ears.

P.fulvus and P.personatus are both small. P.fulvus has wings that meet on its back making it look “naked backed”. Small Vespertilionids I

Myotis

Rhogeesa

Myotis elegans Myotis keaysi Rhogeesa anaeus F.A.=32-39 F.A.=32-39 F.A.=26-31

These are really hard to tell apart. It is very unlikely you can distinguish them at the net.

Front teeth can be used to tell Myotis from Rhogeesa. In Rhogeesa the canine is straight and needle- like and followed by large premolars (so there is no obvious gap in the toothrow). In Myotis, behind the canine there are two tiny premolars followed by a large last premolar, which makes it look like there is a gap in the toothrow. Rhogeesa anaeus is smaller than the Myotis.

There may be two species of Rhogeesa at Lamanai. We are not sure.

We need to see tail fur to separate Myotis (we think – see next page). Fur colour is highly variable. Small Vespertilionids II

How to distinguish Myotis species:

We think you need to see whether the fur extends below the knee

We think you need to see if it forms a “V” shape.

We think this works….. but we aren’t sure how reliable it is.

Images reproduced from another key – please bring these back for photography. Big Vespertilionids

Eptesicus furinalis Bauerus dubiaquercus Lasiurus ega F.A.=37-41 F.A.=49-56 F.A.=43-47

Eptesicus is often confused with Myotis because it is only a bit bigger (they have slightly overlapping FA measurements). At the net look for the gland on the upper lip. With a hand lens you might see that Eptesicus lacks the reduced premolars seen in Myotis (no gap behind canine in Eptesicus).

Eptesicus and Bauerus both have swellings on their face that are actually a gland. The gland is much larger in Bauerus. Bauerus is also a much larger bat.

Bauerus has long narrow ears and its nostrils are on the tip of the snout and open forward; in Eptesicus the nostrils open more sideways.

Lasiurus has fur over most of the upper surface of the tail membrane; the others don't. Lasiurus is yellow to yellow grey. Captures in recent years are very grey. Noctilio – fishing bat

Noctilio leporinius Male Female F.A.=82-89

Very large bats with giant feet!

Very short orange fur, sometimes brown. Wings are partly transparent – you can read through them. Ears curl back sometimes. Stripe down the back. Enormous calcar.

Males and females are hard to tell apart. Females have a “pseudo-penis” that points up. Males point down. Females often have prominent nipples.

Sac-winged Bats I Two wavy lines

Saccopteryx bilineata Rhynchonycteris naso R. naso Saccopteryx bilineata F.A.=44-48 F.A.=36-40 Tufts of fur Sac

Males of most species have a slit above the elbow that forms a sac. It is missing or rudimentary on females.

All sac-wing bats have pointed noses. Their lips extend over their bottom lips. Their ears are small, pointed backwards, and have prominent internal ridges. They are very delicate bats. Females are slightly smaller than males but the genders are very hard to tell apart.

Saccopteryx and Rhynchonycteris have two stripes down the back. Rhynchonycteris has tufts of white hair on its forearms and lacks sacs. Saccopteryx has black or very dark brown fur, while Rhynchonyteris is distinctly frosted in appearance. Sac-winged Bats II

Peropteryx kappleri Diclidurus albus F.A.=45-52 F.A.=63-69

Peropteryx is the delicate and is plain brown with no stripes and no frosting. Peropteryx has a “butch” haircut with no fur on most of face but fur rises sharply on forehead.

Diclidurus has its sac in the tail membrane and bright white fur.

Molossidae – bats with free tails

Molossus rufus Molossus alvarezi Eumops auripendulus Eumops nanus F.A.=47-54 F.A.=45-52 F.A.=57-63 F.A.=37-49

Molossids all have “dog faces” with curled ears, flat bodies and much of the end of the tail sticks out of the tail membrane in a skin sheath. It is unlikely that any can be identified at the net.

M. rufus and E. auripedulus are very hard to tell apart but Eumops has a broad flat snout while Molossus has a narrow snout with a sharp crest down the middle. You can’t identify these without calipers and a hand lens. Eumops nanus is very small.

M. alvarezi can be identified from the other two by blowing on the fur. The base of the fur is very white.

We suspect that Molossus molossus (F.A.36-40) and a number of other species of Eumops are in the area but we have not caught them in recent years.

Natalids – Funnel Eared Bats

Natalus mexicanus F.A.=36-39

Natalus has been captured only at Ka’Kabish. It is a small, delicate bat that lacks a nose leaf, and has funnel-shaped ears that almost completely wrap around the tiny eye. The hind legs and tail are very long, and it has a long tail membrane. The fur is orange."