Mammals of Costa Rica: Outline
INTRO SLIDE: Introduce yourself, mention that this is just an Introduction to the mammals of
Costa Rica; it is just a sampling—not all-inclusive. Ice breaker questions…have you seen any
mammals? What, exactly, is a mammal?
WHAT IS A MAMMAL? :
 Taxonomy as classification system: Kingdom Phylum Class Order Family Genus Species
 Mammals are a class of animals that have these characteristics in common:
 They breathe air
 They’re warm blooded/endothermic (produce and maintain body temperature
internally)
 They have body hair
 Produce milk to feed their young. Produced from special glands in the breast (modified
sweat glands) called mammary glands
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ALSO MENTION:
MOST give birth to live young (not all!)
Mammals are set apart from other vertebrates by a unique jaw arrangement (two jaw
bones from reptilian ancestors became the two middle ear bones in mammals)
CLASS MAMMALIA:
 There are about 4,000 species of mammals worldwide.
 Divided into egg-laying mammals (Only 5 species- include platypus and echidnas) and
those who give birth to live young
 Of the mammals who give birth to live young, 3,800, are placental mammals (have fully
developed young), and 270 are marsupials (young considered “larvae”- underdeveloped
and continue development in pouch)
MAMMALS OF COSTA RICA:
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There are about 240 species of mammals in Costa Rica. That represents 6% of the
world’s mammals!
About half of these are bats, incredibly important to the ecosystem, although we won’t
cover them in this talk. This diagram represents all of the different orders of mammals
found in Costa Rica. In this talk, we are focusing on 5 groups of terrestrial mammals that
you are likely to see or have heard about in Costa Rica.
OPTIONAL: Might want to mention some mammals we won’t talk about, but which
guests might see in San Luis: peccaries/deer, gray foxes (in the dog family) , and tayra (in
the weasel family)
HOW DID THEY GET HERE? :
 One of the reasons Costa Rica is so diverse is that it formed part of what is known as
the Panamanian land bridge (from the Galapagos Hotspot), which connected North and
South America between 2-7 million years ago. Mammals were able to migrate down
from the North, up from the South, and there was speciation in between.
 Rodents were in both areas (Caviomorph rodents like agouti/paca came from South
America)
 Members of Carnivora (dogs, cats, raccoons, bears, weasels, etc) were in the North
 In the South, there were Opossums, anteaters, monkeys, sloths, armadillos, etc.
OPPOSUMS:
 8 species in Costa Rica: Common and Virginia opposums; central american wooly
opossum; water opossum; and mouse opossums.
 Didelphidae means double-wombed. That means opossums have two uteri and two
vaginas.(Birth canal forms temporarily between them) Males, likewise, have a twopronged penis!
GENERAL CHARACTERISTICS:
 Opossums are marsupials. There are 270 species of marsupials in the world, most in
Australia/New Zealand. This means they give birth to underdeveloped young (larvae),
who continue to develop in pouches and remain attached to the teat.
 Most opossums are more arboreal (wooly), some are more terrestrial (virginia). Naked,
prehensile tails and opposable thumbs on the hind feet help them be good climbers.
 Eat: insects, small vertebrates, snails, fruit, flowers, nectar, eggs, carrion.
PICTURES SLIDE:
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Body weight ranges from 4.5 lbs (Virginia opossum) to 3oz (the mouse opossums)
Zorro pelón (pelón=bald) is the Spanish name for opossums. Not to be confused with
zorro gris (gray fox) or zorro hediondo (skunk/”smelly zorro”!)
ANTEATERS, SLOTHS, AND ARMADILLOS:
GENERAL CHARACTERISTICS:
 Found ONLY in New World (the Americas). (Old world is Africa/Asia/Europe)
 This order is named after Xenarthrales, sharp vertebrae in the lower back; a
characteristic that all members of this order share. It may contribute to digging ability in
offering lower back support
 They have 2 or 3 enlarged claws on forefeet, used for digging, hanging from trees,
ripping into ant nests, etc.
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Members of this order have low body temperatures and, accordingly, lower metabolic
rates, so they burn less energy. This compensates for their low energy diets, i.e. ants and
leaves. However, it also leaves them vulnerable to the cold; many Xenarthrans found
dead in wet season
Their thick, shaggy fur offers insulation from the cold. Armadillos have shells (poor
insulation) and very little fur, but compensate by digging burrows to sleep in.
Reportedly have poor sense of vision and hearing. Anteaters and armadillos thought to
locate food almost completely by smell
ANTEATERS:
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Anteaters are solitary, are both nocturnal and diurnal, and can also can be arboreal or
terrestrial
They eat ants, termites, and occasionally bees! Up to 9,000 a day! Myrmecophagous.
(Means ant eating) They feed for about a minute at each nest AND forage in a straight
line so they don’t accidentally encounter nests they have already disturbed (helps avoid
bites and stings by aggravated soldiers). Also, by causing little damage, they can return
periodically to feed from the same set of nests.
Anteaters have no teeth (Xenarthra was formerly named Edenata- lack of teeth). Their
mouth is a hole from which tongue is extended. Tongue has backward-facing hair and
sticky saliva.
The common name “Tamandua” comes from Tupi language (an indigenous Brazilian
tribe): Taa (ant) and mandeu (to trap)
SLOTHS:
 Eat leaves of many varieties. Chew with peg-like, constantly growing teeth. Lack canines
have grinding cheek teeth
 Break down cellulose through bacterial fermentation (much like cow or other large
herbivore). Have to plan well because if not, could starve with a full stomach!! Can take
up to 4 weeks to digest leaves (older leaves take longer than young leaves to digest
because they have more fiber). Stomach represents 1/3 of body- so they can stay light
enough to be in trees
 Along with that, they have less muscle mass compared to other mammals-allows them
to be light enough to stay hanging
 These textured grooves in hair appear to encourage growth of algae (may be symbiotic if
sloth can use algae for camouflage and absorb nutrients through its hair follicles)
 Sloths can lose up to 1/3 their body weight when they do this! Three main theories: 1)
To recycle nutrients give back to their modal tree in which they spend up to 20% of their
time (Problem: roots are often spread out far from the base of the tree) 2)Historical
predators (Harpy eagles) may discern location if they defecate from the tree OR even
terrestrial predators could locate sloth from pattern of defecation on ground 3) the
moths and other insects go through egg and larval stages in sloth dung- if there were
some symbiotic benefit??!
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Moths, beetles, mites. One sloth can host 100 moths and 1,000 beetles!
TWO-TOED SLOTH:
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Has the lowest AND most variable body temp of any mammal (77 to 96 F)
The more aggressive of the two species of sloth in costa rica
Can live up to 32 years, gestation period almost a year! (11.5 months)—females seem to
be more abundant than males, which may explain this. (If two toed sloths mate
infrequently, few males needed to “get the job done”)
Mostly nocturnal
THREE-TOED SLOTH:
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Diet is less diverse than that of a two-toed sloth– tastes learned from mother’s diet
(leaves licked off lips)
Longer arms lets them get choice leaves: (younger leaves gen have less fiber, fewer
toxins, more protein)—length of limbs may allow them to be pickier
This is a picture of one with a baby…exhibiting typical behavior hanging on branch.
Gestation period 6 months for this species.
Fur color varies from “blonde” to dark brown
PICTURE SLIDE:
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Funny that the sloth is pictured in a Cecropia tree. NOT true that sloths eats exclusively
Cecropia—they are just easier to see in those trees because of their open canopy.
Actually one captive sloth died when fed a diet of only Cepcropia)
MONKEYS:
GENERAL CHARACTERISTICS:
 Unspecialized teeth allow them to eat a variety of foods. MOST EAT FRUITS, INSECTS,
AND LEAVES. Different species don’t outcompete each other because each has a slightly
different diet/focus
 Eyes positioned in front of head; lots of overlap in visual range (more so than any other
mammal) allows for good depth perception for jumping on branches but it gives less
overall field of vision. This makes them more vulnerable to predators (i.e. compare with
a rabbit’s lateral vision- good for detecting predators- but poor depth perception) BUT
monkeys do travel in troops, which is good for protection/alerting to predators.
 Active during the day, sleep in nests made in trees at night
 Some families of primates have claws…Cebids have nails
 Cebids have different warning calls for different types of predators. Can be loud, raucous
at times. Scent also very important in communication.
MANTLED HOWLER MONKEY:
Most common monkey in Costa Rica. You can see them often on highways and sides of main
roads
 2/3 of diet is young leaves, also process in hindgut like sloth. Challenging food source!
Toxins and cellulose. To avoid buildup of toxins, don’t eat all individuals in a given treemove on after a while. 1/3 of diet: flowers and fruit. So technically they are “mostly”
folivorous, not exclusively
 Howler troops will rarely move more than 2km a day- more lethargic b/c of low energy
diet. Has earned the nickname “The laziest monkey in Costa Rica”
 Namesake is their loud call. They use it for territorial displays/in response to other
troops, also at dusk, dawn, and usually before rains. Hyoid bone is a hollow bone next to
vocal chords that serves as an amplification chamber for sound– call can be heard
kilometers away. *This bone is 25X larger than that of similar sized monkeys*
CENTRAL AMERICAN SPIDER MONKEY:
 Eat mostly fruit, which is seasonally and patchily distributed– need to move around
often, and quickly, at times across great distances; fruit is protein-poor, they supplement
with young leaves and decaying bark. Fruit is a high energy food source, therefore it
makes sense that they are:
 The most active AND agile of the Costa Rican Cebids. They have longer forelimbs and
fingers than the other monkeys. They even have a reduced/vestigial thumb: it just gets
in the way of swinging!
 Part of their agility is not only longer limbs, but higher dependence on their prehensile
tail– see photos (mother holding herself with tail while she helps teach offspring to
forage; youngster on right photo already hanging solely off tail). There is a naked pad of
exposed skin on underside of tail used for grip .(Howlers also have a prehensile tail but
it is not as strong or dexterous)
WHITE-FACED CAPUCHIN MONKEY:
Most commonly seen species in San Luis/at UGA. Gets its name from its white hood: looks like
that of capuchin monks
 Diet consists of fruit, new leaf shoots, and insects, and can include vertebrates like
nestlings, eggs, small mammals, birds, lizards, frogs, crabs, oysters (so good at raiding
coati nests in Guanacaste that they almost prevent from successfully raising young!)
Have been seen teaming up to chase squirrels.
 Most aggressive of the four species– have been seen taking bites out of a silky anteater
and a large iguana. More carnivorous, so this makes sense.
 Tool use: Fur-rubbing: Certain plants rubbed on fur seem to serve medicinal properties:
citrus peels are bit and banged on tree, or juice/pulp is squeezed over fur (insect
repellant properties); certain vines are masticated and made into a paste that is rubbed
into fur (contain insecticides, antiseptics, fungicides). Until recently thought that only old
world monkeys used tools. Anecdotally, have been seen dropping sticks on a boa
constrictor attacking a young capuchin, using a branch to club a fer-de-lance (to death!).
Use tools to get food in captivity.
PICTURE SLIDE:
 White faced capuchin monkey eating the remains of a variegated squirrel. March 2012,
Santa Rosa National Park
RODENTS:
 In Latin, rodere means :”to gnaw”. Rodents include squirrels, mice, porcupines, agoutis,
etc.
GENERAL CHARACTERISTICS:
 Rodents make up about half of all the worlds mammals. There are about 50 species in
Costa Rica and 2,000 worldwide.
 Four incisor teeth grow constantly, as quickly as several millimeters per week, and only
front edge has enamel. Back edge softer, wears down faster (designs ensures they stay
sharp like a chisel!)
 This design helps them eat mostly hard foods, like seeds and nuts. Rodent forefeet are
varied and help with foraging: some have sharp claws for climbing, some long claws for
digging; others have hoof-like claws, webbed feet in some cases.
 The smaller rodents have BOTH short gestation periods AND take little time to reach
sexual maturity, so they reproduce very quickly. *An exception to this: the Caviomorph
rodents like agouti and paca– they have about 2 or 3 litters a year, with 1-4 offspring per
litter.
 Rodents are the staple food of many carnivores. Important seed dispersers: i.e. Studies
have found that fungi spores can germinate after passing through mice. Yearly damage
in crops lost to rodents is in the millions- they’re important seed predators as well.
Rodents have caused more human deaths in the past 5,000 years than all wars
combined (disease spreaders)
SQUIRRELS:
 Squirrels spend most of their time in trees (only occasionally go to ground). Usually
solitary.
 Diet includes fruit, seeds, bark, and even insects
 Squirrels forage at all levels of the forest. The pictures depict the two most common
species in San Luis. When found together, variegated squirrel eat more soft foods like
fruit; red tailed squirrel eats more hard material like nuts. Classic case of potential
competitors using slightly different niches– can live harmoniously without outcompeting each other.
AGOUTI:
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Agoutis are active during the day and are always on the ground. Tend to leap forward
when they move, swinging back legs to the front.
Monogamous pairs share territory but forage and sleep alone, coming together for
breeding
Important seed disperser: agoutis cache seeds for when fruit is largely unavailable (they
use large, hard seeds that are unlikely to rot—like Mucuna seeds and Cucaracho seeds).
They are unlikely to retrieve all buried seeds (either because they can’t find them or
because they die). Interesting study that appeared in Scientific American demonstrated
that agouti will actually dig up the caches of other individuals and re-bury the seeds,
further dispersing them.
Ecologically important as food source for larger predators. Agouti can live up to 17 years
in captivity, but usually only live 2 to 3 years in the wild before they are eaten.
Young get their own small den (made in hollow trees or dense brush) first morning after
birth– mother can’t fit inside. Mother calls out to nurse and licks pup to stimulate
defecation, then eats it. (This prevents filth, and can help diminish predation)
PACA:
 Unlike diurnal agouti, pacas are exclusively noctural.
 They are the largest rodent in Costa Rica, and white have spots. They can also produce
loud sounds to fend off rivals and predators.
 Diet overlaps with agoutis EXCEPT for during fruit shortages: agoutis stand on hind legs
to feed, so they can eat hard seeds, manipulating with paws. Paca eat on all four legs, so
they can’t manipulate seeds. Instead, they eat young seedlings, roots, leaves.
 COPROPHAGOUS: Pacas eat their own feces to extract nutrients they didn’t absorb the
first time around.
 Paca are endangered and much more rare than agouti, in part because they the #1
most-sought-after game meat of hunters in Costa Rica.
CARNIVORES:
Includes wild cats, coyotes, raccoons, olingos, kinkajous, cacomistle (bears too!)
GENERAL CHARACTERISTICS:
 All members eat at least SOME meat, although many are omnivorous, and some are
mostly Frugivorous.
 MOST have carnassials: blade-like teeth that work against each other like scissors,
allowing carnivores to slice off meat with the side of the mouth after a kill
 Also have sharp canine teeth that give them a powerful bite; can do a lot of damage.
 Some species in the Carnivora have no collar bones; flexible shoulder blades permit a
longer stride and more power/flexibility for running.
 Fused wrist bones gives more power and stability for jumping from trees, climbing, and
running.
 Costa Rica hosts 22 species in this order. Of these, 10 are endangered.
RACOON FAMILY:
 Within this family, which includes coatis, kinkajous, olingos, 2 types of raccoons, and a
cacomistle, the ONLY species with carnassial teeth is the cacomistle. They eat much less
meat than other families in this order.
 Members of this family (most notably, raccoons and coatis) probe around with feet to
detect and assess food.
 They have good night vision but little to no color vision
 Because they eat such a variety of things, members of this family are very important
ecologically. They are important seed dispersers because of the fruit they eat and also
they seeds they carry in their fur when foraging at all levels of the forest canopy and
floor. AND
 Since they also eat meat, help control insect and rodent populations
Pictured here, Coati are both nocturnal/diurnal and terrestrial/arboreal. Males solitary.
Females and young travel in groups of 25 or more
PICTURE SLIDE:
 LEFT: Olingo hanging from a hummingbird feeder at the Monteverde Cloud Forest
Reserve. Mostly nocturnal, solitary. (But more likely to be found during the day than a
kinkajou) NO prehensile tail (easiest way to tell apart from kinkajou)
 BOTTOM RIGHT: Kinkajous are typically redder. Kinkajous have especially long tongues
(as you can see!) for eating nectar (in some countries, called “honey bear”). Eat very few
insects (may be incidental to eating fruit/flowers/nectar)
CATS: FAMILY FELIDAE:
Jaguarundi pictured here: often confused with tayra, which is in the weasel family
 The smaller cats are mostly nocturnal; jaguarundi is mostly diurnal
 The felines are top predators and thus need greater ranges. Since they are so large and
need more space, they are also more scarce.
 When hunting, felines stalk, then ambush prey. Their diet can vary from grass to sea
turtles (Green and Olive Ridley) to tapirs, paca, monkeys, fish, boas, etc. Often drag prey
away to special feeding sites that they may revisit.
 Forward-facing eyes combined with a short muzzle affords them good depth perception
and stereoscopic vision--- important for hunting! And jumping from heights.
 Felines can hear sounds at frequencies up to 3X higher than the human upper
limit…rotating ears help amplify ultrasonic sounds made by rodents, a staple prey item.
They use hearing and vision to find food. (Not smell—that is used for communication.)
 Jaguar, Puma, Ocelot, Jaguarundi, Margay, Oncilla
PICTURE SLIDE:
 Puma has a huge range (From Canada to lower limit of South America). Known as
Mountain lion, cougar, Florida panther, etc. depending on where it is found.
 What is a (black)panther? A melanistic color variant of a jaguar or leopard
PICTURE SLIDE II:
 Tigrillo or caucel is the common name for both of these species in Spanish—very hard to
tell apart! Margay is slightly bigger.
TAPIRS:
 Horses, rhinoceroses, tapirs in this order (just 16 species worldwide!)
GENERAL CHARACTERISTICS:
 Word UNGULATE is Latin for “hooved ones” – they have an odd number of toes that
they walk on (see photo). Horses and Rhinos also in this order.
 Only 4 species of Tapir in the world
 3 species in the Americans, thought to have migrated South from North America
 Smell the air constantly when nervous, also important in communication (“marking
spots” where they urinate on trees)
BAIRD’S TAPIR:
Only species in CR
 Most active around 6-7pm and again around 3-4 am
 Eat seeds, plants (huge variety-over 150), stems, some fruit. Can exert 300-500lbs of
pressure when biting a hard seed. Important plant predators and seed dispersers.
 Have 1.25 inch think hide- they can forage through dense brush without being bothered
by spines, etc. Name “tapir” is in reference to Brazilian indigenous word “tapy” meaning
“thick”
 Always on the ground, solitary
 Tapirs need clean, clear water for resting and defecating. (They usually rest in or near
water, and almost all Tapir dung has been found floating in water) They also flee into
water when predators near --they are strong swimmers and can dive for 15-30 seconds
at a time. They also use water for insect relief.
 Cellulose can’t be digested by stomach enzymes- Tapirs have a microorganism in
stomach to break down cellulose. (takes less time to digest the tough plant fibers, but
then again less carbohydrates are absorbed). Tapirs may make better use of fruit than
other large grazers.(In even-toed ungulates, fruit will not have fermented before it
reaches the stomach and the nutrition would be lost) Tapirs digest more quickly, so they
would absorb the fruit’s nutrients.