SGS-LTER Long-term Monitoring Project: Spotlight Rabbit Count on the Central Plains Experimental Range, Nunn, Colorado, USA 1994-2006, ARS Study Number 98 (Reformatted to the ecocomDP Design Pattern)

This data package is formatted as an ecocomDP (Ecological Community
Data Pattern). For more information on ecocomDP see
https://github.com/EDIorg/ecocomDP. This Level 1 data package was
derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/knb-lter-sgs/136/17.
The abstract below was extracted from the Level 0 data package and
is included for context: This data package was produced by researchers
working on the Shortgrass Steppe Long Term
Ecological Research (SGS-LTER) Project,
administered at Colorado State University.
Long-term datasets and background information
(proposals, reports, photographs, etc.) on the
SGS-LTER project are contained in a comprehensive
project collection within the Digital Collections
of Colorado
(http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429).
The data table and associated metadata document,
which is generated in Ecological Metadata
Language, may be available through other
repositories serving the ecological research
community and represent components of the larger
SGS-LTER project collection. Additional information and referenced materials can be found:
http://hdl.handle.net/10217/83448. Rabbits are the most important small-mammal
herbivores in shortgrass steppe, and may
significant influence the physiognomy and
population dynamics of herbaceous plants and woody
shrubs. Rabbits also are the most important prey
of mammalian carnivores such as coyotes and large
raptors such as golden eagles and great horned
owls. Two hares (Lepus californicus, L.
townsendii) and one cottontail rabbit (Sylvilagus
audubonii) occur in shortgrass steppe. In 1994, we
initiated long-term studies to track changes in
relative abundance of rabbits on the Central
Plains Experimental Range (CPER). On four nights
each year (one night each season, usually on new
moon nights in January, April, July, October), we
drove a 32-km route consisting of pasture
two-track and gravel roads on the CPER. This was
the same route as that driven for carnivore scat
counts. Surveys began at twilight. Observers with
two spotlights sat in the back of a 4WD pick-up
driven at <15 mph. We recorded the
perpendicular distance (in m) to each rabbit using
a meter tape or range finder; the direction of the
rabbit relative to the road; and noted if
individuals were solitary or in clusters. We also
recorded any carnivores or other animals seen
during spotlight surveys. Beginning in Spring
1998, we recorded the vegetation type (habitat)
and topographic position of each rabbit seen, as
well as position relative to human features, eg
windmills, cattle guards, on the landscape. We
used the number of rabbits of each species spotted
per km of route as an index of relative abundance.
We used line-transect approaches in DISTANCE to
estimate population densities from perpendicular
distance data. The Shortgrass Steppe Long Term Ecological
Research (SGS-LTER) project was funded by National
Science Foundation as one of the first sites in
the US LTER Network in 1982. This collaborative,
interdisciplinary research project was established
in the Natural Resource Ecology Lab at Colorado
State University by ecosystem scientists who
learned novel approaches to study grassland
ecosystems during the International Biome Program
(IBP) (1968-1974). The SGS-LTER project was built
upon the foundation of data and information
obtained during IBP, as scientists sought to
identify and follow, and often manipulate in
experiments, important ecosystem processes over
the long-term. The objectives of the SGS-LTER
project were to investigate what mechanisms
regulate processes in the shortgrass steppe.
Research questions focused on how biotic and
abiotic components of the ecosystem are coupled,
where and when ecosystem components are most
vulnerable to perturbations, disseminating
information that would be helpful for rangeland
management and assessing impacts of climate
change. Scientists explored variations in the
structure and function of the ecosystem over space
and time and sought to understand how these
aspects are governed by climate, natural
disturbance, biota, physiography, and human use.
Scientists at the SGS-LTER integrated long-term
monitoring data, designed experimental studies,
performed and advanced modeling techniques, and
synthesized data to conduct innovative research,
education, and outreach. The core SGS-LTER
research site was established on the Central
Plains Experimental Range (CPER) in Nunn,
Colorado, part of the United States Department of
Agriculture’s Agricultural Research Service. The
research site sits in the rain shadow of the Rocky
Mountains at the western edge of the shortgrass
steppe of North America. The shortgrass steppe
ecosystem evolved with grazing by the American
bison, which has now been replaced by cattle.
Grazing by domestic livestock is the primary land
use of native grassland, which occupies about 60%
of the land area of the shortgrass steppe. Short
grasses dominate the vegetation community, which
have adapted to grazing and less than 400 mm of
annual rainfall. The topography is characterized
by gently rolling hills, broad ephemeral stream
courses and low flat-topped terraces. Aspects of
physiography regulate the shortgrass steppe
ecosystem, including landscape position, soil age,
water holding capacity, soil depth and surface
texture which, in turn, determine such properties
as soil moisture storage, net primary productivity
and the distribution of small mammals such as
prairie dogs and pocket gophers. SGS-LTER
scientists have expanded their research studies
beyond the CPER to identify similar or different
patterns in ecosystem structure and function in
North American grasslands; across the Great Plains
region and along the latitudinal gradient from
Wyoming to Mexico. They also conducted cross-site
collaborative research and compared their results
and tested theories in grasslands located in South
America, Asia and Africa. Funding from NSF for the
SGS-LTER project ends in 2014, but over thirty
years of research has resulted in a scientific
team with diverse expertise, which produced over
1200 journal publications, almost 400 book
chapters and over 200 theses. Data, products and
other information produced from the SGS-LTER are
available through the LTER Network Information
System, Digital Collections of Colorado at CSU or
upon request through [e-mail].