Puerto Rico has a high diversity of amphibians and reptiles

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A F G
IELD UIDE TO THE
R A
EPTILES AND MPHIBIANS OF
U. S. N S
THE AVAL ECURITY
G A
ROUP CTIVITY
S S , P R
ABANA ECA UERTO ICO

PREPARED FOR U. S. NAVAL SECURITY GROUP ACTIVITY SABANA SECA,
CONTRACT NO. N62470-01-M-3559, ““DISTRIBUTIONS AND INTERACTIONS OF
THE NATIVE AND EXOTIC HERPETOFAUNA IN THE MAJOR HABITATS OF THE
U.S. NAVAL SECURITY GROUP ACTIVITY SABANA SECA””.

BY NEFTALI RIOS-LÓPEZ

REFORESTA, INC.
MAY, 2002

A FIELD GUIDE TO THE REPTILES AND AMPHIBIANS OF THE
U. S. NAVAL SECURITY GROUP ACTIVITY SABANA SECA,
PUERTO RICO
Table of Contents Introduction

Puerto Rico has a high diversity of amphibians and reptiles.
Introduction ………………………………………………………………………………………………2
The native herpetofauna of Puerto Rico includes 10 families of
Land Use History ………………………………………………………………………………..4 amphibians and reptiles. Some of the more conspicuous species
Habitats …………………………………………………………………………………………………………6 include: freshwater turtle, boa, green anole, common coquí, crested
Reptiles and Amphibians toad, and blind snake. Due to the low diversity of large vertebrates
- Lizards in Puerto Rico, many amphibians and reptiles occur at very high
densities and, thus, are
o Ameiva exsul………….…….……………………………………………… 12
an important
o Anolis cristatellus……………….……………………………………. 14
component of the
o Anolis cuvieri………………………………………………………………. 16
animal community.
o Anolis evermanni……………….…….……………….……………… 18
For example, the
o Anolis krugi…………………………………………………………………… 20
densities of lizards and
o Anolis pulchellus………………………………………………………… 22
frogs in the Luquillo
o Anolis stratulus………………………………………………………….. 24
forest are 10 times
o Hemidactylus brooki………………………………..……………… 26
greater than densities in
o Iguana iguana …………………………………………………………... 28
the tropical forests of
- Snakes
Central America.
o Alsophis portoricensis……………………………………………… 30

o Arrhyton exiguum………………………….…………………….…… 32
Although the herpetofauna plays a very important role in
o Epicrates inornatus…….…….…….…………...……………….. 34
the ecology of the different ecosystems in Puerto Rico, the
o Typhlops platycephalus………………………………………….. 36
majority of studies have focused on individual species and most
- Amphibians
studies have been located in the Luquillo Mountains. Furthermore,
o Eleutherodactylus coqui.……………….…….…….………….38
given the increasing number of studies that have demonstrated an
o Eleutherodactylus cochranae……………….………………40
increase in global and local extinctions, and declining populations
o Eleutherodactylus antillensis………………………………. 42
of amphibians and
o Leptodactylus albilabris……..…………..…………………… 44
reptiles, it is critical
o Bufo marinus..……………………………………………………………… 46
that we thoroughly
o Rana grylio..……………………………….………………………………. 48
document the
o Scinax rubber.……………………………….…………………………... 50
distribution and
- Turtle
abundance of this
o Trachemys s. stejnegeri………………………….………………. 52 ecological important
- Photo Credits…………………….…………..……………………………………. 54 group. There is
- Recommended Readings……………….…………………………. 54 increasing evidence
that global climate
change, habitat loss,
and the introduction of
2
Land Use History
exotic species are some of the major factors related with the
increase in extinctions and declining populations.
The U. S. Naval Security Group Activity Sabana Seca
(NSGASS) is a 2,252-acre facility (911.4 hectares) located on the From 1511 to 1935 the main land use in Sabana Seca was
northern coastal plain near Toa Baja, Puerto Rico. agriculture. Initially sugarcane was the principal crop, but by 1776
other crops, such as, coffee, cocoa, citrus, and pineapples were
cultivated in the region. One of the largest fruit 'haciendas' in
Sabana Seca was the Burt E. Stevenson plantation, which was
located in what today is the North Tract and most of the South
Tract of the NSGASS. This plantation operated from 1910 to
1935, and produced pineapples, oranges, and grapefruits, primarily
for export to New York. An additional 220 acres (89 hectares) of
the south tract were part of the farm 'Central Juanita', which also
produced similar crops. By the late 1930's, the importance of
agriculture declines due to a shift in the local Puerto Rican
economy toward small industry.(cid:3)

This facility is divided into two main areas, the North Tract and
South Tract, which include several different habitats. Habitats in
the North Tract include:
herbaceous wetlands,
Pterocarpus forest, mangroves,
canals, and a small coastal
river. Habitats in the South
Tract include: limestone or
karst hills, locally known as
'mogotes', karst valleys, and
herbaceous wetlands. Many
plants and animals, including
some rare or endangered
species, depend on these
In 1941, the NAVY acquired these properties and started a
habitats.
series of constructions and modifications of the land. From 1943

to 1951, the NAVY converted areas of abandoned agricultural
As part of the commitment to the conservation of natural
lands into military facilities, communication installations, and a
resources, the NSGASS has sponsored many research projects. In
residential district. Smaller areas, including abandoned valleys,
this project, we document the amphibian and reptile community in
were either left to reforest naturally or maintained as lawns. In
six major habitat types.
1962, the NSGASS became the tenant organization, and, in 1971,

they assumed the responsibility of protecting the natural resources.
3 4
Habitats
< 1937

North Although the area of the NSGASS is relatively small, it has a
Tract high diversity of habitats, and each habitat supports a different
community of amphibians and reptiles, resulting in a high diversity
1995 > of species. The North Tract is mainly coastal wetland, and the most
important habitats are: herbaceous wetlands, Pterocarpus
officinalis forest, mangroves, and the Rio Cocal. The most notable
In the North Tract (1937) sugar cane plantations dominated this habitats in the South Tract are the limestone (karst) hills and
area until the late 1930's. Originally this area was covered with valleys. Within each habitat, transects were established to
wetland forest, most likely dominated by Pterocarpus officinalis. characterize the vegetation and herpetofauna diversity.
This area was deforested and canals were constructed to drain the
area for planting. After sugar cane activities were abandoned,
these areas have converted to grassland and herbaceous wetlands, North Tract
and the forest has only recovered along canals (1995).

Herbaceous Wetlands –– Approximately two third of the North
Tract is herbaceous wetlands. There are two major types of
< 1937
herbaceous wetlands: areas that are drier and are used for cattle

ranching and wetter areas that are dominated by Typha
South
domingensis (cattail). This habitat is dominated by amphibians
Tract
because of the abundance of freshwater. The most abundant

amphibians are Scinax ruber (no common name), the coquíes, and
1995 >
the white-lipped frog Leptodactylus albilabris. The most abundant
reptile is Anolis
pulchellus (grassland

anole). Other species
Agricultural activities, even within the narrow valleys, are
that have been
evident in the 1937 photograph of the South Tract. Karst hills
frequently observed
were not used for agriculture due to the severe topography and
in this habitat include
poor soils, but they were deforested for timber and firewood. In
Bufo marinus (marine
contrast, karst valleys were used for cultivation. Soil and nutrients
cane toad), Rana
from the surround hills were washed downhill by rainfall and
grylio (pig frog), and
deposited in these valleys. This results in fertile soils appropriate
Trachemys s.
for agriculture. In the 1995 photograph, the land use of the same
stejnegeri (fresh
area has changed dramatically. Homes have replaced the
water turtle or
cultivated areas, and vegetation has recovered on the karst hills and
‘‘jicotea’’).
valleys. Although urban areas have increased between 1937 and

1995, the area covered by forest has also increased.
5 6
Pterocarpus officinalis Forest –– The common name of Mangrove Forest ––
Pterocarpus officinalis Jacq. is blood wood, because it has red The white mangrove,
sap. In Puerto Rico, this species is known at ‘‘Palo de pollo’’ or Laguncularia racemosa
chicken tree, because the shape of its buttresses resembles the foot (L.) is the dominant
of a chicken. Even though this species is not in danger of species in the study
extinction, the site. However, a few
forest type is individuals of the black
threatened by mangrove, Avicenia
agricultural and germinans (L.) occur in
urban development. the forest. This forest
In general, this remains flooded during
forest occurs along most of the year, and
lowland rivers, soil and water salinity are higher than in the Pterocarpus officinalis
behind mangroves Forest. The lack of freshwater and little or no understory
in less saline areas vegetation, might explain the low herpetofauna species richness.
(like the one in the Two anole species, Anolis cristatellus and A. stratulus, are the only
North Tract), and in residents. The marine cane toad, Bufo marinus, can be seen
small flooded occasionally on the forest floor, especially during the dryer
valleys in upland areas. It is a vital component of fresh to brackish months.
water wetlands throughout the Caribbean, Central and northern
South America, and in western Africa. The forest retains nutrients Rio Cocal –– The Rio Cocal is the largest body of water within the
and sediments eroded by area, and extends eastward along the north coast. It is surrounded
rain from upland areas, by red mangrove, Rhizophora mangle (L.). Red mangrove also
and protects coral reefs occurs along the banks of several small canals, which flow into the
and other marine habitats Rio Cocal. Four species of reptiles have been observed in this
from excessive habitat. The lizards
sedimentation. In this Anolis cristatellus
forest, we have observed and A. stratulus, and
three species of reptiles the introduced green
(Anolis cristatellus iguana, Iguana
[crested anole], A. iguana, are
pulchellus, and A. permanent residents.
stratulus [spotted anole]) The ‘‘jicotea’’,
and four species of Trachemys s.
amphibians (E. coqui stejnegeri,
[common coquí], L. occasionally has been
albilabris, R. grylio, and observed basking on
B. marinus). drifting logs.
7 8
South Tract Karst Valleys –– The karst
valleys are more humid and

have richer soils in
Karst Hills –– Millions of years ago, these karst hills formed in a
comparison with the karst
marine environment by deposition, fusion, and solidification of
hills. For these reasons,
high calcium carbonate
they were deforested for
materials. When these areas
agricultural activities.
became exposed,
Many agricultural areas
approximately 35 million
have been abandoned, and
years ago, the combined
reforestation has occurred
effect of water, wind, and
naturally or has changed to
solar radiation began to
other uses. V1
reshape these hills. The
In this study, we
weathering of the limestone
compared the herpetofauna
rocks and the deposition of
diversity among three karst
soil have produced two
valleys. One valley has
distinct microhabitats: hilltops and hillsides.
been maintained with cut
The hilltops are characterized by large areas of exposed
grass (V1). A second
rock and pockets of brownish loose soil in crevices and fissures.
valley (V2) was maintained
The scarcity of soil and rapid water percolation results in trees of
with cut grass until 2000,
small diameter and
when it was reforested with
stature. Erosion by
more than 500 individuals
wind and water moves
of native trees. A third
nutrients and soil from V2
valley (V3) was abandoned
the hilltops to the
approximately 40 years ago, and has recovered naturally.
hillsides and valleys.
The species that have been
The karst hillsides are
observed in the karst valleys include
characterized by dense
Anolis pulchellus, A. cristatellus, A.
reddish soils, rich in
stratulus, A. cuvieri, A. krugi,
clay and debris,
Ameiva exsul, E. inornatus, A.
resulting in trees of
portoricensis, A. exiguum, E. coqui,
larger diameter and
E. cochranae, E. antillensis, B.
stature.
marinus, and L. albilabris.
The species that have been frequently observed in the karst

hills include Anolis cristatellus, A. stratulus, A. cuvieri (giant

anole), Ameiva exsul (‘‘siguana’’, not a true iguana), Epicrates

inornatus (boa), Alsophis portoricensis (racer snake), Arrhyton

exiguum (garden snake), E. coqui, E. cochranae (whistling coquí),

and E. antillensis (Antillean coquí).
V3
9 10
Species

Ameiva exsul

Lizards

Natural History and Ecology –– This is the larger of the two
‘‘siguanas’’ or ground lizards from the main island of Puerto Rico.
It is also the most
abundant and
widespread 'siguana'.
Snakes Individuals of this
species can often be
heard foraging in the
litter, which makes it
easy to spot and
identify. When
disturbed, they do not
climb trees, but run
Amphibians quickly for a short
distance and then
continue foraging. It is a diurnal active forager and has a diet
which includes insect larvae and adults, small amphibians (e.g.
Eleutherodactylus antillensis), eggs, and fruits.

Size and Coloration –– Adults grow up to 7.9”” (20 cm) in snout-
vent length. They are
brown or olive-brown
dorsally, with scattered
Turtle cream-white spots on
the flanks and hind
legs. Some males
exhibit a dull bluish tan
on the head and flanks,
and this coloration
pattern can extend to
the tail.

11 12
Similar species –– Although a second ‘‘siguana’’ (Ameiva wetmorei)
also exists on the main island of Puerto Rico, it is 1/2 to 1/3 the Anolis cristatellus
size of A. exsul. In addition, A. wetmorei has several longitudinal
mid- and dorso-lateral cream stripes on a black background, a
bright scarlet colored tail, and a distribution limited to the driest
areas in southern and southwestern Puerto Rico.

Natural History and Ecology –– This is the common anole or
'lagartijo común' of Puerto Rico. It is also known as the Puerto
Rican crested anole, because many males have a conspicuous crest
and tail fin. The species has an extensive distribution, and
although it is most
abundant in
forested areas, it is
also common in
urban habitats.
Introduced
populations exist
in southeastern
Dominican
Republic and
south Florida. It
is diurnal and The large dorsal crest gives the species its common name, the crested anole.
Distribution –– Ameiva exsul is limited to the forest floor. It mainly arboreal. Juveniles and adults sleep on twigs and leaves of
prefers areas with dry soils in the karst region. It was most shrubs and trees, but juveniles usually occur closer to the ground.
frequently found foraging in closed canopy forest and forest Its’’ diet includes invertebrates, amphibians, and other anoles.
margins. When basking (e.g. sunbathing) it was found most
frequently along margins of trails and roads. Size and Coloration –– Adults grow to 3.0”” (7.5 cm) in snout-vent
length. The species
is mainly brown or
grayish brown
although it can
occur in many
shades of brown,
turning darker or
lighter when
basking under the
sun. Some
specimens have a
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