1997-06-13_REPORT - M1981302 (18)

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transport ways and commercial and residential structures during early expansion was also relatively unregulated compared to modem standards. These developments were also relatively small-scale and somewhat reversible compared to modem developments. 2. Existing threats-The location of residential and commercial development and construction are under the jurisdiction of local city and town zoning ordinances. The City of Denver, located in what was once prime habitat for Z. h. preblei, is primarily zoned for commercial and residential development. Similarly, much of the Cities of Boulder, Fort Collins, and Greely are commercially and residentially zoned. Fortunately, the City of Boulder has exercised great foresight through the purchase of extensive parcels of land, placed under the jurisdiction of the Open Space Department, to be used primarily as natural, recreational parks or for ecologically sound agricultural purposes. No such effort has been made to date by the Cities of Fort Collins and Greely. Much of the intervening lands between these major cities is zoned as residential and agricultural. However, the towns of Loveland and Longmont, and dozens of other smaller towns, fragment much of the intervening landscape with both small commercial and generally expanding residential zones. In addition, there are currently no effective zoning ordinances that provide for a buffer zone, or in any other way protect critical meadow and riparian areas from grazing. Without the active participation and commitment of town and city planning committees to establish local zoning ordinances that preserve locations of contiguous, natural habitat, the remaining critical habitat of Z. h. preblei will surely eventually perish. 3. Potential threats- Continued residential, commercial, municipal and agricultural developments could potentially threaten the remaining critical habitat of Z. h. preblei. IL Assessment and Recommendations 1. General assessment of vigor, trends, and status- The assessment of historical trends concerning the vigor and status of Z. h. preblei is a difficult task, due to both the historical and current paucity of demographic data. Historical data in the form of study skins outlines the historical range of the species (see Geographical range). However, the status of the species within its historical range is not well known, as few study skins have been collected (a total of 38, with 14 other records in Colorado, and a total of 6, with 1 additional record in Wyoming). Armstrong (1972) stated that this subspecies, "is poorly known in Colorado, an apparently is nowhere abundant." Long (1965) echoed this idea for Wyoming in stating that this subspecies was rare. These assessments may provide an accurate portrait of the general vigor of this subspecies. It may be that Z. h. preblei has historically maintained a low population density in Colorado and Wyoming,or has at least been isolated in its distribution to refuges of critical moist, lowland habitat. Since there is evidence that this subspecies still exists in locations with appropriate habitat (i.e, Coal Creek in 1989, Rocky Flats in 1991, and VanVleet in 1992), the extinction of the species may not be imminent. However, given the number of reports of this subspecies in recent history (12 individuals in the last 20 years), and the nature of the reports (found in isolated refuges of critical habitat), the current status of the species may be declining, and the preservation of refuges of critical habitat may be essential to maintain this subspecies. Fm.l S1 S u amp Ecs,In. March 24.1993 7d