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i
supported only by its tail. The mid-section was visibly swollen
with prey, but this condition did not appear to hinder mobility.
The
snake slowly elevated its body above the overhang. Once
on
top, it crawled higher on the cliff to disappear under a large sotol
plant (Dasylirion texanum).
While the snake was present, the swallows maintained an er-
ratic flight pattern in front
of
the cliff, giving alarm calls. They did
not attempt
to
attack the snake. Only when the snake disappeared
from view did their calls stop.
Evidence
of
similar predatory behavior has been recorded in a
specimen
of
E.
bairdi collected in Brewster County, Texas (Olson
1967. Texas
J.
Sci. 19:99-106). Approximately 33
km
SSW
of
Alpine, Texas, a male
of
the species, ca. 136
cm
long, was ob-
served resting inside two or three cliff swallow nests it had appar-
ently broken open. While this Brewstser County snake was not
observed hunting and preying on the swallows, its stomach con-
tents were examined after it was collected and found to comprise
five adult cliff swallows.
Returning to this Frio River location on the same date in 2001,
I found no active nests and only two or three empty nests from the
previous year. However, ca. 100 m downstream, swallows had
established a new nesting site that contained many nests. This
downstream location had been uninhabited the year prior during
the time the above incident was witnessed.
The Real County snake described here was not collected, so
measurement data are unavailable. However, based on measure-
ments
of
the cliff obtained with an optical laser range calculator,
the length
of
the snake was estimated at well over 132 cm.
While
E.
bairdi is said to be chiefly "day-active" (Werler and
Dixon, op. cit), the incident cited above is unique in my experi-
ence for taking place during the middle
of
a bright, sunny day.
Of
the perhaps two-dozen
E.
bairdi I have observed in the last four
years, all were active after dark, or
just
at dusk.
Submitted by
RODNEY
L.
DEARTH,
San Angelo Nature
Center, 7409 Knickerbocker Road, San Angelo, Texas 76904, USA;
e-mail: sanc@wcc.net.
EPICRATES
SUBFLA
VUS (Jamaican Boa).
FORAGING
BE-
HAVIOR. The endemic Jamaican
Boa
(Epicrates subflavus), lo-
cally known as "Yellowsnakes," are known from three cave sys-
tems: Windsor (Trelawney), Green Grotto (St. Ann), and St. Clair
(St. Catherine) (Prior and Gibson. 1997. Herpetol. Rev.
28:72-
73). Bat predation has only been observed at Windsor Great Cave
(Koenig and Schwartz 2003. Herpetol. Rev. 34:374-375; Vareschi
and Janetzky 1998. Jamaica Nat. 5:34-35). Here we report field
observations
of
E.
subflavus roosting and foraging on bats in two
additional cave systems in Jamaica.
We
surveyed Ratbat Hole (Botany Bay, St. Thomas) on 16 De-
cember
2001and25
March 2002. This cave, known among local
guano collectors, is about 4 km E
of
the satellite dish
of
Jamaican
Communications
on
the main road from Kingston to Morant Bay,
and can be reached after a 20-min steep hike north from Botany
Bay. The main entrance is 5 m wide and about as tall, leading to a
15-20
m vertical passage. This cave is surrounded by karst, inter-
spersed with low secondary dry scrub, and contains at least four
bat species that have sharp seasonal variations in population den-
sity (Davalos and Eriksson 2003. Caribb.
J.
Sci. 39:140-144). On
our
first visit we found an adult
E.
subflavus
on
the cave entrance,
with a bat in its digestive tract. During our second visit
we
found
a
E.
subflavus foraging for bats as they emerged and thereafter,
from 1830 h to 2100 h. The
boa
made numerous unsuccessful
attempts to capture bats identical to those described by Prior and
Gibson (op. cit.).
We
visited Monarva Cave (Revival, Westmoreland)
on
5 De-
cember
2001and21March2002.
Monarva is a locally well-known
dry passage cave in the Negril Hills and is known to harbor popu-
lations
of
at least seven bat species (Davalos and Erickson, op.
cit.). Monarva is surrounded by the hamlet
of
Revival, pasture
fields, and secondary vegetation.
On
our first visit
we
found an
adult
E.
subflavus on the cave wall, 20 m along the steep passage
that funnels thousands
of
bats from the inner chambers to the two-
meter wide cave entrance. This animal remained in the same place
throughout our visit, from 1900-1945
h.
On
our
second visit, ca.
2000 h, we found a juvenile
E.
subflavus 3 m into the cave and
moving out toward the vegetation at the entrance.
These observations confirm the presence
of
this threatened spe-
cies (Hilton-Taylor 2000. IUCN Red List
of
Threatened Species.
IUCN, Gland.
xviii+
61
pp.) in the parishes
of
Westmoreland and
St. Thomas, where previous reports claimed they were abundant
but remained unvouchered (Gibson 1996. Dodo, J. Wildl. Preserv.
Trusts 32: 143-155). We also add two new localities to the handful
of
records
of
E.
subflavus in Jamaican cave systems and confirm
bat predation at Ratbat Hole. The dearth
of
observations
on
the
ecology
of
this boine and the possible threat
of
human interven-
tion in these cave systems warrant further research to determine
the importance
of
the caves for both bats and snakes.
We
thank the Department
of
Mammalogy at the American Mu-
seum
of
Natural History, the Center for Environmental Research
and
Conservation
at
Columbia
University,
and
Elizabeth
R.
Dumont for providing financial support for our field trips.
Submitted
by
LILIANA
M.
DAVALOS
and
REBECKA
ERIKSSON*,
Department
of
Ecology, Evolution and Environ-
mental Biology, Columbia University; and Division
of
Vertebrate
Zoology, American Museum
of
Natural History, Central Park West
at 79th Street New York, New York 10024-5192,
USA
(e-mail:
davalos@amnh.org). *Current address (RE): Sergelsgatan 4E, 416
57 Goteborg, Sweden.
EUNECTES
MURINUS
(Green Anaconda).
SUBDUING
BE-
HAVIOR.
Constricting snakes coil around their prey preventing
the prey from breathing. Additionally, they may cause circulatory
arrest in their prey by applying pressure to the thoracic cavity that
prevents the prey's heart from beating (Hardy 1994. Herpetol. Rev.
25
:45-4
7). Here, I present evidence that when a constrictor handles
potentially dangerous prey, the violence
of
the attack, and method
of
constricting might produce structural damage to the prey that
reduces its ability to defend itself or escape. The following obser-
vations were taken in the Venezuelan llanos, Distrito Mufioz, Apure
State (7°30'N, 69°18'W).
On
26 April 1992, a female anaconda ( 455
cm
total length,
46
kg mass), during the process
of
killing a young capybara (2.5 kg
mass) dislocated the capybara's spine at the cervical level. The
snake did not eat her prey because apparently other capybaras at-
tacked her. The capybara was found floating in the river the next
66 Herpetological Review 35( 1
),
2004
day and examination of the body showed that the capybara had a
dislocated spine and evidence
of
anaconda teeth marks on its skin
matching the size
of
the snake's head. '
On 24 March 1992, I found a female anaconda (413.5 cm TL;
40
kg mass) that
regurgitated
a female
white-tailed
deer
(Odocoileus virginianus) weighing
10
kg.
Upon examination of
the regurgitated deer, I found that it had two broken ribs. I assume
that the constriction process caused the deer's ribs to break.
On
27
January 2001, a female anaconda (460 cm TL) regurgi-
tated a full-grown male white-tailed deer (
0.
virginianus) that had
a disjointed spine at the cervical level.
In May 1999, a large anaconda (ca. 450 cm TL) was observed
constricting a large (ca. 180 cm TL) spectacled caiman (Caiman
crocodilus). During the process of constriction, it was apparent
because
of
the angle between the caiman's tail and body, that the
caiman's spine was broken (Fig.1).
In a recent account, an anaconda constricted a white collared
peccary (Tayassu tajacu) (Valderrama and Thorbjarnarson 2001.
Herpetol.
Rev.
32:46-47) and the authors reported that: "At some
point, a muffled crackling sound was heard, resembling that
of
many bones breaking all at once."
It
is uncertain
ifthe
bones (e.g.,
ribs)
of
the peccary were actually breaking or
if
the sound was
that of vertebrae being dislocated. The following statement by the
authors: "
...
the snake coiled itself round the peccary's torso and
squeezed, visibly stretching the peccary length-wise
...
" suggests
the latter rather than the former.
The evidence presented here demonstrates that constriction by
anacondas can produce structural damage
to
prey in the form
of
broken bones and dislocated vertebrae. Hardy
(op.
cit.) argues that
the violence anq pressure exerted on the prey
is
higher than what
is
needed to cause suffocation and contends that the violence and
excessive pressure serves the purpose of producing circulatory
arrest. While I do not disagree with Hardy's interpretation, I be-
lieve the extra pressure and violence
of
the strike might also serve
the purpose of disjointing the spine or breaking ribs to reduce a
prey's ability to escape or defend itself and to expedite death.
I thank the Wildlife Conservation Society, National Geographic
Society, and Asociaccion para la Conservacion y Recate Ecologico
ACRE, Zoo de Doue la Fontaine-France for financial and logistic
support. I also thank COVEGAN, Estacion Biologica Hato El Frio,
FIG.
I.
Female Green Anaconda (ca. 450
cm
TL) found constricting a
large Spectacled Caiman (ca. 180
cm
TL)
in
the Venezuelan Llanos. It
is
apparent that the spine
of
the caiman has been dislocated.
for permits to work on their properties. I thank Tony Crocceta for
providing photographic material. I am also in debt to
M.
Quero, P
Azuaje, Mirna Quero,
J.
Thorbjarnason,
M,
Munoz for their coop-
eration in the development
of
this research.
Submitted by
JESUS
A.
RIVAS, Department
of
Ecology and
Evolutionary Biology, University
of
Tennessee. Knoxville, Ten-
nessee 37996, USA; e-mail: anaconda@prodigy.net.
FORDON/A
LEUCOBALIA
(Yellow-Bellied Mangrove Snake)
and
MYRON
RICHARDSONII
(Richardson's Mangrove Snake).
DIURNAL
FEEDING
and
PREY
TYPE.
Snakes
of
the
Homolopsinae, a lineage
of
aquatic colubrids, are found through-
out southern Asia and northern Australia. Most species are pis-
civorous and ingest prey head first to assist digestion (Mori 1998.
J.
Herpetol. 32:40--50). All species in Australia are considered to
be nocturnal (Gow 1989. Graeme Gow's Complete Guide to Aus-
tralian Snakes. Angus and Robertson Publishers, North Ryde.
171
pp.). Fordonia leucobalia
is
reported to feed predominantly on
Fiddler Crabs (Uca spp.), and occasionally on the Mud Lobster
(Thalassina anomala) and shrimps (Shine 1991. Copeia 1991:120--
131
).
Very
little is documented regarding the feeding habits
of
Myron richardsonii apart from Shine (1991, op. cit.) who sug-
gested it feeds on a variety
of
fish.
We
report herein several obser-
vations (MN)
of
these two species feeding by day in the man-
groves
of
Ludmilla Creek, Darwin Harbour, Australia (12°25'S,
131°50'E) during 1998, with additional notes on prey consumed
and methods of ingestion.
On 3 March, at ca. 1400
h,
a snake (ca. 40 cm TL), identified
as
F.
leucobalia according
to
Gow (1989, op cit.), was observed within
the mangrove forest. The snake was wrapped around a large male
Fiddler Crab ( U ca flammula
).
The snake did not consume the crab
and left it alive before moving down a nearby crab burrow, per-
haps
as
a result
of
being disturbed by the observer.
On 3April, at ca. 1200
h,
a
F.
leucobalia (brown dorsally and
yellow ventrally) was observed on a creek bank ingesting a
T.
anomala. After ca.
10
min the snake ingested the lobster's tail,
biting firmly down to displace the head, creating a clearly audible
crunching sound. The snake consumed only the tail of the lobster,
leaving the head in the mud.
On
13
April, at ca. 1500 h, a reddish-black
F.
leucobalia was
observed within a channel ingesting a
T.
anomala
as
described
above. On this occasion a second
F.
leucobalia (black and white
morph) approached and began to coil around the first. The first
snake then consumed the tail
of
the mud lobster
as
described above
and moved away from the second snake rapidly.
On 2 March, at ca. 1500
h,
a
M.
richardsonii was sighted on an
exposed track. On close inspection, there appeared to be a black-
colored nudibranch (Gastropoda) in the snake's mouth. The spe-
cies could not be determined because it was almost completely
encased in the snake's mouth.
The above observations report several previously undocumented
phenomena. First, these observations document diurnal feeding in
both
F.
leucobalia and
M.
richardonii. Both species had been re-
garded
as
strictly nocturnal (Gow 1989, op. cit.). Although ob-
served active by day throughout the year (MN, pers. obs.), feed-
ing activities were only observed from March to April, presum-
ably when prey are most abundant (Davis 1985. In Bardsley et al.
Herpetological Review 35( I), 2004
67
