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2014 Southeastern Naturalist Notes Vol. 13, No. 4
J.P. Flaherty and J. Friers
Predation on the Brown Basilisk (Basiliscus vittatus) in South
Florida
James P. Flaherty1 and Joshua Friers2,*
Abstract - Although native to Central and South American, Basiliscus vittatus (Brown Basilisk) is
now firmly established in South Florida. Birds, lizards, and large crustaceans prey upon the Brown
Basilisk throughout its native range, but snakes had been the only documented predators of this species
in Florida. Here we document predation on Florida Brown Basilisks by the wading bird Ardea
alba (Great Egret) and two different species of large, predatory fish—Micropterus salmoides (Largemouth
Bass) and Centropomus undecimalis (Common Snook).
Non-native reptiles and amphibians have become diverse and numerous in Florida—for
example, 38 lizard species had become established as of 2011 (Meshaka 2011). Currently,
however, Basiliscus vittatus Wiegmann (Brown Basilisk) is the sole member of the family
Corytophanidae established in Florida. The Brown Basilisk is a medium-sized lizard with
the unique ability to run on the water’s surface (Laerm 1974). In its native range of Central
America and northeastern South America (Savage 2002), Brown Basilisk is typically associated
with forested riparian habitat, although adults are frequently observed far from water
(Hirth 1963, Maturana 1962). The Brown Basilisk was first documented in Dade County (now
Miami-Dade), FL in 1976, where its introduction was likely the result of escape and/or intentional
releases from pet owners and dealers (Wilson and Porras 1983). Populations have since
been found in 6 other counties throughout southern Florida (Krysko et al. 2011). In Florida,
Brown Basilisks are usually found near thick vegetation at the edge of canals or borrow pits
and can often be observed basking on branches overhanging water (Krysko et al. 2006, Meshaka
et al. 2004). Dietary preferences are not well known in Florida, but individuals have
been documented eating insects (Coleoptera, Dictyoptera, Hymenoptera), true bugs (Hemiptera),
arachnids, Ficus spp. (figs), and lizards (Krysko et al. 2006, Meshaka et al. 2004).
In its native range, Brown Basilisk is preyed upon by a wide variety of species (Savage
2002). Hirth (1963) mentioned that snakes were likely the major predators of Brown
Basilisks, but also observed a juvenile being consumed by an Ocypode quadrata Fabricius
(Atlantic Ghost Crab). Birds of prey are also significant predators, and Brown Basilisks
make up a substantial portion of the overall diet in certain species (Gerhardt et al. 1993). In
Florida, snakes had been the only documented predator of Brown Basilisks. Known snake
predators include Pantherophis guttatus L. (Red Cornsnake), Coluber constrictor L. (North
American Racer), and Drymarchon couperi Holbrook (Eastern Indigo Snake) (Meshaka et
al. 2004). Here we document 3 novel instances of predation events involving the Brown
Basilisk in Florida.
On 19 September 2012, at approximately 15:00, we observed an Ardea alba L. (Great
Egret) foraging along a heavily vegetated canal bank, dominated by Neyraudia reynaudiana
(Kunth) Keng ex Hitchc. (Burma Reed) at Homestead Air Reserve Base (ARB) in
Miami-Dade County, FL (25°29'20.83"N, 80°22'16.46"W; datum WGS 84). After 5 minutes
of observation, we saw the Great Egret spear an adult male Brown Basilisk of ~38 cm
total length (TL). Following a brief struggle, the bird proceeded to manipulate the Brown
1Center of Excellence for Field Biology and Department of Biology, Austin Peay State University,
Clarksville, TN 37040. 2US Department of Agriculture Wildlife Services, Homestead, FL 33030.
*Corresponding author - joshfriers@yahoo.com.
Manuscript Editor: John Placyk
Notes of the Southeastern Naturalist, Issue 13/4, 2014
2014 Southeastern Naturalist Notes Vol. 13, No. 4
N58
J.P. Flaherty and J. Friers
Basilisk and swallow it headfirst. After quickly swallowing the prey, the Great Egret resumed
foraging along the canal bank and we saw it spear and consume several small fish
and Lithobates spp. (frogs).
In July 2011, during a routine canal survey at Homestead ARB (25°29'21.60"N,
80°22'18.87"W; datum WGS 84), we flushed a medium-sized Brown Basilisk (~20 cm TL)
out of the vegetation along the canal edge, and it proceeded to run across open water. When
the lizard was ~1.5 m from shore, a Micropterus salmoides Lacépède (Largemouth Bass),
quickly swam from under a nearby mat of aquatic vegetation and grasped the Brown Basilisk
in its mouth. As the Largemouth Bass swam away, the lizard’s legs and tail were visibly
protruding out of the fish’s mouth. On 27 June 2013, we witnessed a second predatory event
involving large fish. During another canal survey at Homestead ARB (25°29'20.82"N,
80°22'19.20"W; datum WGS 84), a large Brown Basilisk (~30 cm TL) dropped from a
low-hanging Chrysobalanus icaco L. (Cocoplum) branch into the canal and began running
across the water. Almost immediately, we observed a Centropomus undecimalis Bloch
(Common Snook) grasp the Brown Basilisk in its mouth and swallo w it whole.
To the best of our knowledge, these are the first documented cases of Brown Basilisks
being consumed by Great Egrets, Largemouth Bass, or Common Snook. It is likely that in
southern Florida, Brown Basilisks are frequently preyed upon by wading birds, due to their
mutual association with riparian areas. The Brown Basilisk’s unique behavior of running
on the water’s surface may also render them especially vulnerable to large predatory fish,
which are known to feed upon other vertebrates moving across the top of the water column
(Hodgson and Hansen 2005).
Acknowledgments. We thank Michael C. Fulbright and Dr. Michael Andrejko for reviewing
the manuscript. We would also like to thank Dr. Glenn Johnson for advice regarding the
biota of South Florida.
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