SGS-LTER Long-Term Monitoring Project: Body weights of rodents captured during SGS-LTER live-trapping on the Central Plains Experimental Range, Nunn, Colorado, USA 1994 -2011, ARS Study Number 118

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/10217/83452. Body size is a fundamental biological
measurement that is known to be related to an
organism's physiology, life-history and ecology.
Estimates of body size are also widely used in
comparative evolutionary and ecological studies,
including food web and diet studies that require
estimates of biomass. Beginning in 1994, small
mammals are live-trapped twice each year on the
three grassland and three shrubland trapping webs.
Individuals are weighed (to nearest 0.5 g using a
Pesola spring scale) when first captured during a
given trapping session but not upon recapture
during the same session. Weights are calculated by
subtracting the weight of an empty capture
(ziploc) bag from the weight of animal in the bag.
Individuals are classified into age classes
(adult, subadult, juvenile) in the field based on
a combination of size and pelage characteristics.
This dataset gives means, standard deviations,
minimum and maximum values for body weight, in
grams, of small mammals captured between September
1994 and September 2008. All sites and sampling
periods were combined. Most individuals (~93%)
were classified as new captures, although a few
individuals that were captured multiple times
across different trapping sessions may appear in
the dataset more than once. Values may differ from
estimates calculated using the entire capture
dataset because age and weight data were screened
more closely to omit obvious errors and
outliers.