Tanikawa, L., S. Kunta, M. Lee, S. Sirivella, D. Grubb, and J.C. Rorabaugh. 2016. Predation of a Thornscrub Hook-nosed Snake (Gyalopion quadrangulare) by a Forrer’s Leopard Frog (Lithobates forreri).

Abstract

First documentation of predation of Gyalopion quadrangulare by Rana forreri

Full text

SONORAN HERPETOLOGIST 29 (2) 2016 24
In 2015, stu-
dents in a
science class
at Deereld
Elementary
School, Irvine,
California,
extracted a
102 mm SVL,
1 gram Thorn-
scrub Hook-
nosed Snake
(Fig. 1) from
the stomach of
an adult female
Forrer’s Leopard
Frog (also 102
mm SVL, 87
grams, Fig. 2).
The frog was
purchased with
others from
Fischer Science
Education,
Pittsburgh,
Pennsylvania.
Predation of a Thornscrub Hook-nosed Snake (Gyalopion quadrangulare)
by a Forrer’s Leopard Frog (Lithobates forreri)
Lucas Tanikawa1, Srijan Kunta1, Mimi Lee1, Sudeep Sirivella1, Dan Grubb2, and James C. Rorabaugh3
1Students, Deereld Elementary School, Irvine, California, 92604
2Science Specialist, Deereld Elementary School, Irvine, California, 92604, DanGrubb@iusd.org
3P.O. Box 31, Saint David, Arizona 85630, jrorabaugh@hotmail.com
NATURAL HISTORY NOTE
The Thornscrub Hook-nosed Snake (Gyalopion
quadrangulare) is a small (< 354 mm TL) colubrid that
occurs in Sonoran desertscrub, thornscrub, tropical
deciduous forest, and marginally into oak-mesquite
savanna from extreme south-central Arizona south to
Nayarit (Hardy and McDiarmid 1969, Ernst and Ernst
2003). The only record of predation was a speci-
men found in the stomach of a Sonoran Coralsnake
(Micruroides euryxanthus) from Ruby Road, Santa Cruz,
County, Arizona (Rossi and Rossi 2003).
Forrer’s Leopard Frog (Lithobates forreri) is a large
(to at least 120 mm SVL) spotted frog known from the
lowlands of southern Sonora south to Costa Rica. It
occurs in wetlands within thornscrub and various trop-
ical forest types, but also occupies agricultural ditches
and canals (Savage 2002, Rorabaugh 2008). Nothing
is known of the diet of this species, but it presumably
feeds upon a variety of invertebrates (Lemos-Espinal
et al. 2013) and possibly small vertebrates, as do other
large leopard frogs. Many Forrer’s Leopard Frogs are
harvested from agricultural areas of southern Sonora
and northern Sinaloa for scientic study and dissection
in classrooms.
In 2015, students in a science class at Deereld
Elementary School, Irvine, California, extracted a 102
mm SVL, 1 gram Thornscrub Hook-nosed Snake (Fig.
1) from the stomach of an adult female Forrer’s Leop-
ard Frog (also 102 mm SVL, 87 grams, Fig. 2). The
frog was purchased with others from Fischer Science
Education, Pittsburgh, Pennsylvania. The label that ac-
companied the specimens said the locality was “Mex-
ico”. An email message from Fisher to JCR stated the
supplier was Ranaco Corporation, Tucson, Arizona.
JCR called Peter Rhinethall of Ranaco who said the
frogs were collected from agricultural ditches between
Ciudad Obregón, Sonora and Culiacan, Sinaloa, but
most come from Sinaloa. The majority of collecting
occurs in September and October. No further details
of the collection date or locality are known.
Finding a Thornscrub Hook-nosed Snake in an
agricultural area is unexpected, but it could have been
captured by the Forrer’s Leopard Frog in an adjacent
thornscrub or other natural community type. Agricul-
ture in southwestern Sonora and northwestern Sinaloa
is in places fairly continuous, but in others (such as
along the trace of the Río Yaqui, Sonora) it interdigi-
tates with more natural vegetation communities. There
are no records of the Thornscrub Hook-nosed Snake
from the coastal plain of southwestern Sonora that are
denitively from agriculture, although collections from
the vicinity of Navojoa and Ciudad Obregón (e.g.,
LACM 67269, CAS 94261, UIMNH 50971) could have
been in agriculture, and are at least close to croplands
as they exist today. Similarly, Hardy and McDiarmid
(1969) show several records of Thornscrub Hook-
nosed Snake from the coastal plain of northwestern
Sinaloa that are in or close to agricultural areas today.
These lowland records are at elevations of about nine
to 45 m.
Fig. 1. Thornscrub Hook-nosed Snake (Gyalopion quadrangulare)
from the stomach of the Forrer’s Leopard Frog (Lithobates
forreri) in Fig. 2.
Fig. 2. Adult female Forrer’s Leopard Frog (Lithobates forreri)
from which the Thornscrub Hook-nosed Snake (Gyalopion
quadrangulare) was extracted.

SONORAN HERPETOLOGIST 29 (2) 2016 25
The study of
extinction is
known as dirol-
ogy. Species are
facing extinc-
tion at an accel-
erated rate and
conservation
eorts to save
imperiled spe-
cies may be too
little too late -
but it’s our duty
as stewards of
the earth to do
what we can to
conserve and
preserve what’s
left before it’s
too late.
Literature Cited
Ernst, C.H., and E.M. Ernst. 2003. Snakes of the
United States and Canada. Smithsonian Books,
Washington, D.C.
Hardy, L.M., and R.W. McDiarmid. 1969. The amphib-
ians and reptiles of Sinaloa, Mexico. University of
Kansas Publications, Museum of Natural History
18:39-252.
Lemos-Espinal, J.A., H.M. Smith, and A. Cruz. 2013.
Amphibians and Reptiles of the Sierra Tarahumara
of Chihuahua, Mexico. ECO Herpetological Pub-
lishing, Rodeo, New Mexico.
NATURAL HISTORY NOTE CONT.
Rorabaugh, J.C. 2008. An introduction to the herpeto-
fauna of mainland Sonora, México, with comments
on conservation and management. Journal of the
Arizona-Nevada Academy of Science 40:20-65.
Rossi, J.V., and R. Rossi. 2003. Snakes of the United
States and Canada; Natural History and Care in
Captivity. Krieger Publishing Company, Malabar,
Florida.
Savage, J.M. 2002. The Amphibians and Reptiles of
Costa Rica. University of Chicago Press, Chicago,
Illinois.
ANNOUNCEMENT
Publication of Dirology: Seminar Proceedings
The study of extinction is known as dirology. Species
are facing extinction at an accelerated rate and con-
servation efforts to save imperiled species may be too
little too late - but it’s our duty as stewards of the earth
to do what we can to conserve and preserve what’s left
before it’s too late. Our very own Associate Editor, Dr.
Suman Pratihar, is doing all he can to conserve rare
and endangered amphibian species.
On February 27, 2016, Dr. Pratihar hosted a
seminar on the national level held in Sukumar Sen-
gupta Mahavidalaya funded by SERB, Department of
Science and technology, New Delhi, India. Dr. Pratihar
reached out to the world’s experts on species extinc-
tion and collected short articles for the proceedings
of this important seminar. The editor of the Sonoran
Herpetologist, Howard Clark, published a short article
(Clark 2016) on the rare and endangered Blunt-nosed
Leopard Lizard (Gambelia sila)—only found in the Cen-
tral Valley of California, and adjacent grassland valleys.
Figure 1 (below) is the cover of the proceedings.
For a copy of the proceedings please click on this link:
http://bit.ly/1VAkxtB
Literature Cited
Clark, H.O., Jr. 2016. The possible extinction of the
Blunt-nosed Leopard Lizard (Gambelia sila) of the
San Joaquin Valley, California, USA. Pages 28-30 in:
Suman Pratihar (Editor). Dirology: The Science of
Extinction. Seminar Proceedings. Publication result-
ing from one day National level seminar held in
Sukumar Sengupta Mahavidalaya on 27 Feb., 2016
funded by SERB, Department of Science and tech-
nology, New Delhi, India. ISBN 978-93-85248-64-1.
Fig. 1. Purple Frog (Nasikabatrachus sahyadrensis) or Pig-nosed Frog. As the sole member of a family, which predates all other known
frogs in the subcontinent by 50 to 100 million years, it has great signicance for the understanding of evolution of amphibians in
the region. In July 1997, Krushnamegh Kunte (then a post graduate student of the Wildlife Institute of Dehradun) was the rst to
photograph it. The discovery was nally published in Nature on 16 October 2003: Biju, S.D., and F. Bossuyt. 2003. New frog family
from India reveals an ancient biogeographical link with the Seychelles. Nature 425:711-714.