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The state of Nebraska contains a wide range of plants, of which, 20 are listed in
The Nebraska Natural Legacy Project as Tier I species (Schneider et al. 2005). Of
the 20 listed as Tier I species in Nebraska, 4 are listed as either Endangered or
Threatened on the Threatened & Endangered Species System (TESS) list (USFWS 2008),
with Gaura neomexicana ssp. coloradensis being one of them. Gaura neomexicana ssp.
coloradensis, also known as the Colorado butterfly plant, is currently listed as
Threatened, state and federally, on the TESS list as it is only found in Kimball
County, along Lodgepole Creek, in the southwest corner of Nebraska. On October 18,
2000, the Colorado butterfly plant was designated as Threatened on the Endangered
Species list (USFWS 2000) and continues to be one of the rarest plant species in
the state.
Nebraska Prairie Partners (NPP), a cooperative between Rocky Mountain Bird Organization
(RMBO) and Nebraska Game and Parks Commission (NGPC), is dedicated to conserving
birds and natural habitats. Our goals were to see if the Colorado butterfly plant
still existed in Nebraska and if it did to what extent, specifically looking at
the current population, health of the plant(s), soil conditions, and if Lodgepole
Creek still contains water in the targeted stretch of the creek where the Colorado
butterfly plant was known to have historically existed. The specific area of Lodgepole
Creek we were interested in was an 8 mile stretch, starting at the eastern Wyoming
line and going east into Nebraska, and Oliver Reservoir SRA, which Lodgepole Creek
flows through a few miles downstream. The Colorado butterfly plant is not known
to exist anywhere else in the state, deeming this area of Lodgepole Creek as critical
for the survival and continuation of this species in Nebraska.
The Colorado butterfly plant is a perennial herb that lives vegetatively, in the
form of a rosette, for most of its life and then flowers once and dies (USFWS 2004).
It occurs on subirrigated, alluvial soil floodplains where it is most commonly found
along creek bends and is typically upslope from the actual creek channel, at elevations
ranging from 1524 to 1951 meters (USFWS 2004). The plant itself can grow up to a
meter in length, given the right conditions, and has a reddish stalk, while the
flower contains white petals that turn pinkish as they start to die off (USFWS).
The anthers and the stigma both stick out from the flower, but the stigma is strongly
exerted and is a key on identifying the Colorado butterfly plant (see Fig. 1). With
the rosettes being small and at ground level, competition for space, water, and
nutrients is critical for this species. Soil moisture and vegetative cover play
an important role in the establishment of Colorado butterfly plant populations,
as Fertig (2001) suggested that the plants are constrained by soil moisture and
dense cover of graminoids and herbaceous plants. Disturbances, like grazing, fire,
and flooding, could be very critical for the continuation of this species as it
would help to reduce vegetative cover and supply the rosettes with the necessary
water requirements it needs. Historically, flooding was probably the main disturbance,
but fire and grazing could prove beneficial for this species as well (USFWS 2004).
Figure 1: Colorado Butterfly Plant with its red-tipped anthers and exerted stigma.
Photo by Travis Wooten.
In total, 3100 to 3200 acres of suitable habitat was searched. All the areas searched
were owned or leased by 2 landowners, except for Oliver Reservoir SRA, which is
owned by the state. What was found was a total of 12 Colorado butterfly plants,
10 flowering and only 2 rosettes. The majority of Lodgepole Creek was dry and has
been for years, according to the landowners, except for about a ¾ mile stretch of
the creek that is stock tank fed by a pipe running to the creek, for the approximately
200 cattle on the land. It was this water-fed part of Lodgepole Creek that contained
2 new populations of the Colorado butterfly plant. The Colorado butterfly plant
was found in a total of 4 areas, with 2 being new sites and 2 being historic sites,
while historically it had been found in 8 areas along Lodgepole Creek and Oliver
Reservoir SRA. While only 2 of 8 historic sites still contained the Colorado butterfly
plant, what might be just as severe is the fact that the 2 historic sites only contained
a total of 5 plants, with only one of those being a rosette.
All plants were found on the north side of Lodgepole Creek, with some occurring
on the creek bank, along bends in the creek, and others occurring up to 100 meters
away from the creek. The plants themselves looked overall healthy, having some predation
by insects and cattle, but most were in great condition with several blooms (Figure
2). The tallest of the plants occurred in a 6 plant colony and measured 20 inches,
while the smallest measured out at 12 inches and was in a 2 plant colony. The soil
conditions for the 2 new sites was completely saturated given these populations
occurred on the side of the water-fed creek. The 2 historic sites were 10 meters
and over 100 meters away from the dry creek and the soil was relatively dry at both
places.
Figure 2: Colorado butterfly plant in bloom. Photo by Travis Wooten.
Going into this study, we were not sure if the Colorado butterfly plant still existed
in Nebraska. After finding it in extremely low numbers, it will not be long before
the Colorado butterfly plant vanishes from Nebraska if management of the habitat
and plants is not implicated very soon. Some management practices that could help
and possibly have an impact in the very near future include: exotic species control,
open spaces in the form of controlled grazing, and flowing water. The spraying of
Canadian thistle (Cirsium arvense) would help, in regards, to less competition for
water, nutrients, and sunlight. The possible spraying of Kochia (Kochia scoparia)
would also help considering it is a tall weedy plant that is very predominant in
most of the surveyed area. While there is cattle and horses already grazing on the
lands, most of the surveyed areas looked to have been grazed fairly hard, possibly
not letting the plants seed out before they are grazed upon. Controlled grazing
could allow time for the plants to seed out and establish themselves. Grazing could
also help keep the Kochia maintain, so spraying for Kochia might not be needed if
grazing is used. Flowing water is probably the most critical need of this species
and probably the hardest to achieve and maintain, but without water it could be
the eventual demise of the Colorado butterfly plant in Nebraska.
Literature Cited
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Fertig, W. 2001. 2000 census of Colorado butterfly plant (Gaura neomexicana ssp.
coloradensis) on F.E. Warren Air Force Base. Report prepared for the U.S. Air Force
by the Wyoming Natural Diversity Database, University of Wyoming, Laramie, WY.
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Schneider, R., M. Humpert, K. Stoner, G. Steinauer. 2005. The Nebraska Natural Legacy
Project: A comprehensive wildlife conservation strategy. Nebraska Game and Parks
Commission, Lincoln, Ne.
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USFWS. 2000. Threatened Status for the Colorado Butterfly Plant (Gaura neomexicana
ssp. coloradensis) From Southeastern Wyoming, North-central Colorado, and Extreme
Western Nebraska. Federal Register. 65, 202: 62302-62310.
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USFWS. 2004. Designation of Critical Habitat for the Colorado Butterfly Plant. Federal
Register. 69, 151: 47834-47862.
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USFWS. 2008. Threatened & Endangered Species System (TESS). http://ecos.fws.gov/tess_public//pub/stateListing.jsp?state=NE&status=listed.
Accessed: 2008.
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Contact:
Bart Bly
Bart.Bly@rmbo.org
State: Nebraska
Funder:
- Nebraska Environmental Trus
- Nebraska Game and Parks Commission
- University of Nebraska - Lincoln
Cooperators:
Materials:
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