Reptilia, Serpentes, Colubridae, Tantilla supracincta: Filling gap, first provincial record, geographic distribution map, and natural history

Abstract

Snakes are among the lesser known terrestrial vertebrates in the Republic of Ecuador. Our knowledge on Ecuadorian snakes is limited at even the most basic levels (taxonomy and distribution), and in the last decade little new information has been published. Several threats are jeopardizing the long-term survival of Ecuadorian flora and fauna, and a lack of biological, ecological, and distributional information about wildlife seriously compromises our ability to evaluate its conservation status and to develop strategies to prevent negative effects such as drastic population declines or extinctions. The taxonomy of the snakes of the genus Tantilla from Ecuador is relatively well known by the

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Reptilia, Serpentes, Colubridae, Tantilla
supracincta: Filling gap, first provincial record,
geographic distribution map, and natural
history
Diego F. Cisneros-Heredia
College of Biological and Environmental Sciences,
Universidad San Francisco de Quito, Casilla Postal
17-12-841, Quito, Ecuador.
E-mail: diegofrancisco_cisneros@yahoo.com
Snakes are among the lesser known terrestrial
vertebrates in the Republic of Ecuador. Our
knowledge on Ecuadorian snakes is limited at even
the most basic levels (taxonomy and distribution),
and in the last decade little new information has
been published. Several threats are jeopardizing
the long-term survival of Ecuadorian flora and
fauna, and a lack of biological, ecological, and
distributional information about wildlife seriously
compromises our ability to evaluate its
conservation status and to develop strategies to
prevent negative effects such as drastic population
declines or extinctions.
The taxonomy of the snakes of the genus Tantilla
from Ecuador is relatively well known by the
efforts of several herpetologists, especially L. D.
Wilson and collaborators (e.g. Wilson et al. 1977,
Wilson 1979, Wilson and Mena 1980, Wilson
1987, Wilson 1999, Greenbaum et al. 2004). With
the exception of T. melanocephala, the Ecuadorian
species of the genus (Tantilla andinista, T.
insulamontana, T. miyatai, T. petersi, T.
supracincta) are represented by very few
specimens and localities.
Tantilla supracincta inhabits the lowlands and
foothills on the Atlantic versant of Central
America from extreme southeastern Nicaragua to
central Panama, and on the Pacific versant from
Costa Rica south to Ecuador (Wilson 1985, Wilson
1987, Wilson 1999, Savage 2002, Köhler 2003).
This species is known in Ecuador from three
widely separated localities (each based on one
specimen): the type locality in the province of
Guayas (Peters 1863, Wilson 1987); and two
localities in the province of Esmeraldas (Wilson et
al. 1977, Wilson 1985, Wilson 1987, Almendáriz
and Carr 1992). The type-locality of T. supracincta
was reported as “Umbegung von Guayaquil” (=
surroundings of Guayaquil) by Peters (1863), and
probably corresponds to some place close to the
Chongón hills (near to Guayaquil), rather to the
city of Guayaquil itself.
Two specimens of Tantilla (adult DFCH-USFQ
S101 and juvenile S102; D. F. Cisneros-Heredia´s
collection, housed at Universidad San Francisco de
Quito), collected on 30 June 2004 by Pablo Caqua
at Cabo Pasado (00º23 S, 80º28W, ca. 100 m
above sea level, Figure 1), province of Manabí,
correspond well with the descriptions of Tantilla
supracincta (Table 1); including the dorsal pattern
(Figures 2 and 3) of black-bordered white
crossbars on a red ground color (Wilson 1987,
Wilson 1999, Savage 2002, Köhler 2003). This
new locality fills the gap between previous
Ecuadorian localities of T. supracincta (Figure 1),
constitute a first provincial record, and represent
the fourth and fifth specimens registered from
South America.
Figure 1. Geographic distribution map of Tantilla
supracincta in Ecuador; close circle corresponds to
locality reported herein, square to the type-locality,
open circles to other literature records, provincial
codes: E = Esmeraldas, M = Manabí, and G =
Guayas.
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Savage (2002) reported that Tantilla supracincta
undergoes an ontogenic change in coloration, with
juveniles being “bicolor black and cream to yellow
with the black bands as long as the combined
extent of the black and red bands in adults”;
Savage (2002) also described “venter and
underside of tail red in adults”, implying that
juveniles have different ventral coloration (not
described). The small juvenile specimen reported
herein (DFCH-USFQ S102) demonstrates a color
pattern very similar to that observed for adults,
with dark pigment not much extended as in the
specimen showed by Savage (2002: Plate 458) and
with a reddish-rose coloration on the venter and
underside of tail (Figures 2 and 3). Therefore, there
is apparently some variation in the degree of dark
pigment covering the red dorsal ground color in
juveniles, with the pattern varying from bicolor
black and pale to black-bordered white crossbars
on a dark red ground color, and with ventral
coloration in juveniles reddish rose (Figures 2 and
3).
Tantilla supracincta inhabits non-seasonal and
seasonal evergreen forests (vegetation
classification sensu Sierra 1999 with modifications
by Anderson and Jarrín 2000) on the Pacific
lowlands of Ecuador from sea level to 225 m
elevation in the provinces of Esmeraldas, Manabí,
and Guayas (Figure 1) (Peters 1863, Wilson et al.
1977, Wilson 1985, Wilson 1987, Almendáriz and
Carr 1992, this paper). This species reaches the
southernmost limit of its geographical range in
Ecuador, along the coastal seasonal forests near the
coastal line and along the Cordillera de la Costa (a
low range parallel to the Andes and along coastal
Ecuador) (Figure 1).
Table 1. Measurements, scalation, and color pattern data of two specimens of Tantilla supracincta (DFCH-
USFQ S101–2) from Cabo Pasado, province of Manabí, Ecuador.
Characters DFCH-USFQ S101 DFCH-USFQ S102
Age Adult Juvenile
Snout-vent length (in mm) 307 149
Tail length (in mm) 85 14 (incomplete)
Tail length/total length ratio 0.22 -
Ventrals 151 155
Subcaudals 63 incomplete
Preocular 1 1
Postoculars 2 2
Supralabials (in contact with eye) 7 (3-4) 7 (3-4)
Infralabials 6 6
Postnasal in contact with preocular Yes Yes
First pair of infralabials separated Yes Yes
Number of crossbands on body 15 13
Percentage of interrupted crossbands on body 66 % 69 %
Number of crossbands on tail 6 -
Percentage of interrupted crossbands on tail 100 % -
Pale nuchal band interrupted medially Yes Yes
Red nape band present No No
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Figure 2. Tantilla supracincta. Dorsal and ventral
views of adult specimen DFCH-USFQ S101, a
few hours after having been euthanized. Cabo
Pasado, province of Manabí, Republic of Ecuador.
Acknowledgments
I am grateful to Pablo Caqua who collected the
specimens and to Vlastimil Zak who donated
them. I thank Josiah H. Townsend and Ricardo J.
Sawaya for their comments on the manuscript.
Maria Elena Heredia and Laura Heredia provided
financial support. Universidad San Francisco de
Quito provided institutional support.
Figure 3. Tantilla supracincta. Dorsal and ventral
views of juvenile specimen DFCH-USFQ S102,
one year after been euthanized; note reddish rose
tint still present. Cabo Pasado, province of
Manabí, Republic of Ecuador.
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Received October 2005
Accepted November 2005
Published online December 2005
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