[This
melanistic (opposite of albino) species of garter snake, as first
recorded by Capt. Lewis in 1804, is regarded as unique to the Townsend,
Montana area.]
Lewis and Clark Expedition
and
the Townsend Black Snake
by
Troy Helmick
President
Thomas Jefferson wrote Meriwether Lewis very lengthy and detailed
instructions1
as the Corps prepared for the Expedition to the Pacific Ocean. Under
the
heading “Other Objects Worthy of Notice,” Jefferson
included:
…the soil
& face of the country,
it’s
growth & vegetable productions …the animals of the
country
generally, &
especially those not known in the U.S., the remains & accounts
of
any which
may be deemed rare or extinct; …times of appearance of
particular birds,
reptiles or insects.2
Tuesday
July 23, 1805: Captain Meriwether Lewis and the main party of the
Expedition proceeded
on their mission up the
Missouri River with eight dugout canoes. As noted on Clark’s
map,3
the
party camped that night on a small island in the river three miles
north of present-day
Townsend in Broadwater County, Montana. Capt.
Lewis recorded in his Journal that day:
I saw a black snake today
about two feet long
the
belly of which was as black as any other part or as jet itself. it had
128
scuta on the belley and 63 on the tail.4
The
following day—July 24, the party continued up the river past
Indian Creek, the
Crimson Bluffs, Yorks Islands, then camped on the west side of the
river six
miles south of Townsend, near Dry Creek. Lewis recorded on that day:
…we observed a great number of
snakes about the
water of
a brown uniform colour, some black and others speckled on the abdomen
and
striped with black and brownish yellow on the back and sides. The first
of
these is the largest being about 4 feet long, the second is of that
kind
mentioned yesterday, and the last is much like the garter snake of our
country
and about its size. None of these species are poisouous I examined
their teeth
and found them innocent. They all appear to be fond of the water, to
which they
fly for shelter immediately on being pursued.5
Capt.
Lewis
evidently found the little black snake to be worthy of notice as he
measured
the length, counted scales and examined the teeth. Worthy of notice it
must be,
as we are still attempting to determine its identity after more than
two
hundred years!
Incorrectly
Identified
In The
Original Journals of the Lewis and Clark Expedition, Vol. II Part II,
Thwaites 1904, a footnote on page 264, Coues misidentified the snake
as, “The
dark variety of the so-called spreading adder or blowing
viper—a
species of Heterodon.”6
In
a
footnote on page 422 of The
Journals of the Lewis & Clark
Expedition,
Volume 4, Gary Moulton, editor., the snake was also misidentified as
the “Western
Hog-nosed snake, Heterodon nasicus,
Burroughs, 276-77;
Cutright
(LCPN), 427-28.”7
In We
Proceeded On, Volume 34, No. 3
August 2008, (page 22) an article by
Kenneth
C. Walcheck, MONTANA ZOOLOGICAL
DISCOVERIES THROUGH THE EYES OF
LEWIS AND
CLARK, the snake was again
misidentified as a “WESTERN
HOG-NOSED SNAKE, Heterodon
nasicus. The snake was described
by Spencer Fullerton Baird and
Charles
Girard (1852). Observation date: July 23, 1805.” 8
All
three
of the editors incorrectly identified the snake. Now, more than 200
years after
Capt. Lewis described the little black snake, we can finally determine
its
proper biological classification.9
In
the
Montana Outdoors magazine publication, IDENTIFICATION
OF
MONTANA’S
AMPHIBIANS AND REPTILES, by Jim
Reichel and Dennis Flath, 1995, two
garter
snakes are listed as native to the Townsend area: the Common Garter
snake,
(Thamnophis sirtalis)
and the Western Terrestrial, (Thamnophis
elegans). Also
noted,
“...all black
individuals are occasionally found.”10
The question then is, does the black snake belong to the T.
sirtalis or to
the T. elegans species?
Searching
for Black Snakes
Larry
Thompson, a Helena, Montana biologist in May of 1983 was searching for
the
black snake in the Townsend area. In an article in The
Townsend Star11
he offered a reward of ten
dollars to the first person to provide a living specimen of the black
snake,
together with information on the exact site and date of capture. We
found no
record of any snakes captured or rewards paid.
The
Crimson
Bluffs Chapter of the Lewis and Clark Trail Heritage Foundation was
chartered
at Townsend, Montana in 1998. The capture and identification of the
Lewis black
snake was one of the objectives shared by several of the new chapter
members.
Progress on the project was very slow until 2003, when a black snake
was
captured in Townsend and another by the Missouri River west of
Townsend. An
interested individual from Kalispell, a college Professor from Bozeman
and a TV
reporter with camera from Helena, all came to see the snakes. We soon
had land
owners, school teachers, students, sheriff’s deputies,
housewives
and others
searching for black snakes along twenty miles of the Missouri River.
The
chapter
contacted Dr. Grant Hokit, Biology Professor at Carroll College in
Helena, MT
and at his invitation we delivered some snakes to him at the college.
He was
immediately and eagerly supportive of our effort. He gave us much
needed advice
on the collecting, care and feeding of garter snakes. We continued to
search
and collect garter snakes and kept in contact with Dr. Hokit about our
progress. We did show live snakes and spoke to students in classrooms
and to
others at outdoor events. Each year as fall weather approached, we
released the
captured snakes so they could return to their communal dens sites
before
winter.
In
spring
2007, Dr. Hokit called us to report that he had students and resources
to proceed
on with a research project to
identify the black snake. We agreed to assist them with hunting and
collecting
snakes and offered to help in any other way that we could.
Species
Identified
Carroll
College students, James T. Van Leuven and Sarah Tomaske came to
Townsend with
the objective to determine if melanistic garter snakes from the
Townsend area
belong to T. elegans, T. sirtalis,
or neither.
In
his
thesis, Survey
of
Melanistic Garter Snakes by Traditional and
Geometric Morphometrics, Van
Leuven explains how a total of 80 T.
elegans, 20 T.
sirtalis and 23 melanistic
individual snakes were captured and
analyzed.12
Five photographs were taken of each specimen, scale count, linear and
geometric
morphometrics and other data were recorded for each specimen.13
A
scale was clipped on each snake to identify and prevent duplication of
data.14
Approximately 2mm of the tip of the tail was clipped and stored for DNA
analysis for a separate study in the future.15
Information collected
with each specimen included time and date of capture, air temperature,
wind
conditions, distance to nearest water source, habitat type, morphotype
and GPS
coordinates.16
All snakes were released near
their capture site.17
Van Leuven completed the research and concluded that melanistic
individuals in
the Townsend area are morphometrically more similar to T.
elegans than
to T. sirtalis.18
DNA
analysis of the specimens clipped from the snakes and stored by Van
Leuven was
completed by Carroll College student Kevyn J. Stroebe in 2009. The
study, Molecular
Genetic Affinities of the Melanistic Western Terrestrial Garter Snake,
Thamnophis elegans
examined the association between phenotype and species of garter snakes
found
along the Missouri River near Townsend, MT by analyzing the cytochrome
b
mitochondrial DNA sequences of Thamnophis
elegans (Western
Terrestrial
Garter Snake), T. sirtalis (Common
Garter Snake) and
melanistic
individuals.19
The results showed that the
melanistic snake
sequences are more similar to sequences of T.
elegans than to
those of T.
sirtalis.20
The
melanistic snakes group with T.
elegans in phylogenetic
analyses.21
The results support the morphological evidence of Van Leuven (2008)
which
showed that the melanistic snakes are morphologically more similar to T.
elegans than to T.
sirtalis.22
The
combined analyses of Kevyn and J.T. is a document in preparation (Melanistic
Phenotype of Thamnophis elegans First Described by Captain Meriwether
Lewis.
Authors: D. Grant Hokit, Jennifer M.O. Geiger, James T. Van Lueven,
Kevyn
Stroebe) that is being submitted to the scientific journal Northwest
Naturalists. The results of
the combined analyses provide strong evidence that the melanistic
garter snakes
reported from Broadwater Co. are morphotypes of T.
elegans.23
Supralabial
counts,
linear morphometrics and molecular phylogenetics all demonstrate the
similarities between T.
elegans and melanistic
individuals
while
simultaneously describing the distinctiveness of T.
sirtalis in
the
area.24
This conclusion was further supported
by the capture of a
specimen exhibiting phenotypic mosaicism (Rakyan et al. 2002) with the
head and
posterior parts in typical color morphology for T.
elegans and
melanism
in other parts.25
Other melanistic
individuals were completely black
with no discernible dorsal or lateral lines.26
Based
on
the results of the analysis of the description by Lewis, and the known
distribution of herpetofauna in Montana, we conclude that it was most
likely a
melanistic individual of T.
elegans that Captain Lewis
encountered on
July 23, 1805 and not
a Western Hog-nosed snake.27
His
location on that date was less than 10 km from our study site, he
described a
snake that is “jet black” [sic]
in
appearance, and his scale counts fit within the range known for T.
elegans (Rossman
et al. 1996).28
Also, on the subsequent day
he mentions a second
black snake (“of that kind mentioned yesterday”)
within the
context of
describing numerous encounters with garter snakes (Lewis et al. 2002).29
Conversely, the Western Hog-nosed snake has not been confirmed in
Broadwater
County.30
For
more
information, contact: Dr. Grant Hokit, Department of Natural Sciences,
Carroll
College, 1601 N. Benton Ave., Helena, MT 59625.
Troy
Helmick is a Charter Member and a Director of the Crimson Bluffs
Chapter of the
Lewis and Clark Trail Heritage Foundation in Townsend, Montana.
NOTES:
1.
Thomas Jefferson, Jefferson’s
Instructions to Meriwether Lewis, Thomas Jefferson Foundation,
Inc. Nov., 2003, accessed May 10, 2014,
http://www.monticello.org/site/jefferson/jeffersons-instructions-to-meriwether-lewis.
2. Ibid.
3. Gary E. Moulton, ed., The
Journals of the Lewis and Clark Expedition, 11 volumes (Lincoln:
University of
Nebraska Press, 1983-2001), Vol. 1, Atlas of the Lewis and Clark
Expedition,
No. 63.
4. Ibid., Vol. 4, p. 421.
5. Ibid., Vol. 4, p. 423.
6. Reuben G. Thwaites, ed.,
Original Journals of the Lewis and Clark Expedition, 1804-1806, 7
volumes and
an atlas (New York, 1904-1905), Vol. II Part II, p. 264.
7. Moulton, Vol. 4, p. 422.
8. Kenneth C. Walcheck,
“Montana
Zoological Discoveries Through the Eyes of Lewis and Clark,”
We Proceeded On,
Vol. 34, No. 3, Aug. 2008, p. 22.
9. The detailed biological data
referred to in this article came from two college theses and an
analysis of the
combined theses—all from the Department of Natural Sciences
at Carroll College,
Helena, MT.
10.
Jim Reichel and Dennis Flath,
“Identification of Montana’s Amphibians
and Reptiles,” Montana Outdoors, 26.3, May/June 1995, p. 30.
11. Larry Thompson,
“Biologist
Looking For Garter Snakes,” The Townsend Star, May 12, 1983,
p. 1.
12. James T. Van Leuven,
“Survey of
Melanistic Garter Snakes by Traditional and Geometric
Morphometrics,” (B.S.
thesis, Carroll College, Helena, MT, April 2008), p. 12.
13. Van Leuven, “Survey
Melanistic
Garter Snakes,” p. 8.
14. Van Leuven, “Survey
Melanistic
Garter Snakes,” p. 8.
15. Van Leuven, “Survey
Melanistic
Garter Snakes,” pp. 8-9.
16. Van Leuven, “Survey
Melanistic
Garter Snakes,” p. 9.
17. Van Leuven, “Survey
Melanistic
Garter Snakes,” p. 9.
18. Van Leuven, “Survey
Melanistic
Garter Snakes,” p. 20.
19. Kevyn J. Stroebe,
“Molecular
Genetic Affinities of the Melanistic Western Terrestrial Garter Snake,
Thamnophis elegans,” (B.S. thesis, Carroll College, Helena,
MT, April 2008), p.
3.
20. Stroebe, “Melanistic
Garter
Snake,” p. 3.
21. Stroebe, “Melanistic
Garter
Snake,” p. 10.
22. Stroebe, “Melanistic
Garter
Snake,” p. 11.
23. D. Grant Hokit, Jennifer M. O.
Geiger, James T. Van Lueven, Kevyn J. Stroebe, “Melanistic
Phenotype of
Thamnophis elegans First Described by Captain Meriwether
Lewis,” (analysis of
two theses in possession of authors, Dept. of Natural Sciences, Carroll
College, Helena, MT, [not dated]), p. 7.
24. Hokit, et al., “First
Described
by Lewis,” p. 7.
25. Hokit, et al., “First
Described
by Lewis,” p. 7.
26. Hokit, et al., “First
Described
by Lewis,” p. 7.
27. Hokit, et al., “First
Described
by Lewis,” p. 8.
28. Hokit, et al., “First
Described
by Lewis,” p. 8.
29. Hokit, et al., “First
Described
by Lewis,” p. 8.
30. Hokit, et al., “First
Described
by Lewis,” p. 8.
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