1997-06-13_REPORT - M1981302 ‎(18)‎

• Permit No: M1981302
• IBM Index Class Name: Report
• Doc Date: 6/13/1997
• Doc Name: EXHIBIT A STATUS REPORT ON ZAPUS HUDSONIUS PREBLEI A CANDIDATE ENDANGERED SUBSPECIES
• Media Type: D
• Archive: No

7. Demography
1. Known populations- The status of extant populations of Z. h.preblei is
poorly known in Colorado, and unknown in Wyoming. A live-trapping
effort was conducted in areas of suitable habitat in Colorado, and in areas
of most recent known locations of subspecies capture. Areas of most
recent capture were trapped in an effort to confirm the presence of extant
populations. No Z. h.preblei were captured in these locations. A single
individual was captured in a new location south of Boulder, Colorado.
All known captures and observations of the subspecies since 1972 are
listed below in chronological order.
2. Demographic details (Number and geographic spacing of known
populations)
a. Particular Population:
1. Area of the population-Three individuals captured,one
each in 1972, 1976 and 1977, at the Fort St. Vrain
Nuclear Generating Station by Dr. Bruce Wunder,
University of Colorado, as a subcontractor to Fred Glover
at Thome Ecological Institute in Boulder for a study
entitled Ecological Monitoring-Fort St. Vrain Generating
Station from 1972-79. To date, we have not obtained
this report. However, Bruce Wunder (pers. comm.)
stated that all captures were located northeast of the
Nuclear Generating Station along an irrigation canal
which flowed to the S. Platte River.
2. Number, and age (or size) classes of individuals-
Specific details may be available in the above report.
3. Density (number of individuals per unit area)- It is
doubtful that a population estimate during the 1970s
would be available in the above report; with only one
capture in any year, any population density estimate
would be very low.
4. Presence- Pioneer Environmental Consulting Services,
Inc. conducted live-napping at four different locations
(Sections 27 and 34, T 4N, R 67 W) at Fort St. Vrain
from August 5-9, 1992, including heaviest trapping at the
location of the three captures in the 1970s. Over 920
trap-nights, no Z. h. preblei were captured.
5. Evidence of reproduction-The population was evidently
viable during the mid-1970s, given the chronological
spacing of the captures. However, there is no evidence
of current reproduction.
6. Evidence of expansion/contraction- The presence of
any population at Fort St. Vrain is highly questionable
given the results of the recent live-trapping survey. The
live-trapping results may indicate a contraction or
extirpation of the population.
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