Preble's Mouse
Preble's Mouse

Preble's Jumping Mouse Habitat

As the City states in its South Boulder Creek:
The Management Area has the most concentrated population of Preble's meadow jumping mice (Zapus hudsonius preblei) in Boulder County.
In the City's South Boulder Creek Citizen's Guide they state:
For instance, the third largest known population of the Preble's meadow jumping mouse instance can be found here.
The City goes on to say in its South Boulder Creek Plan:
In addition to affecting orchids and birds, irrigation may play an important role in the preferred habitat of Preble's meadow jumping mouse. The Preble's meadow jumping mouse is found in wet meadow and willow/shrub habitat. This type of habitat is common along irrigation ditches in the riparian, floodplain, and terrace vegetation associations in the area. Preble's have been captured at several locations within the southern end of the Management Area. Presently, little is known about how management, in particular agricultural operations, affect this mouse.
And finally, in the South Boulder Creek Plan the City describes the importance of irrigation ditch corridors:
The ditches that deliver water often support riparian zone vegetation such as cottonwood trees and coyote willows that provide important habitat for raptors and the Preble's meadow jumping mouse.
This is backed up by a report commissioned by the City that states:
Irrigation ditches in the area are intensely used by the Preble's Mouse.
The map below shows one of the main trapping sites (blue circle) along South Boulder Creek. This site is 500 feet from the edge of the Hogan/Pancost property.

Preble's Trapping Sites

Note, the myriad irrigation ditches in the area (shown in green). The Superphostical ditch, which runs northwest from the creek, is a major irrigation ditch with consistent flow throughout the summer that leads directly from this study area and adjoins the Hogan/Pancost property for a length of 1800 feet. Clearly, if there is a large population of Preble's Mouse at the trapping site then there will probably be Preble's west of the site as well. As the City's reports have noted the Preble's makes intense use of the irrigation ditches in the area.

It is unknown whether the Hogan/Pancost property itself harbors any populations of the Preble's Mouse. In August 2003, the developer petitioned the United States Fish and Wildlife Service to exempt this property from any trapping survey. Their rationale was that this property does not contain sufficient habitat to support the Preble's. This opinion seems to run counter to what the City's reports have stated as to Preble's habitat.

Even if this property does not harbor the Preble's Mouse what will be the impacts of this development have on the adjacent habitat? One of the rationales for moving the Lemons property into Area II was the impacts that that development would have on the adjacent habitats to the east. Shouldn't the same criteria be used for the Hogan/Pancost property?

The Developer's Study

In the developer's report to the county was a report of a wildlife investigation from 1996. This report makes such a sweeping claim it behooves us to quote them at length.
The Pancost Hogan property does not contain any wildlife habitat of importance. With regard to the potential of the site to support a population of the Preble's jumping mouse, there is no habitat on the property suitable for this species, or for any threatened or endangered wildlife species.

Habitat for the Preble's jumping mouse consists of mesic (adapted to a moderately moist habitat - ed) herbaceous vegetation, usually undisturbed, and often in association with willow shrub. The habitat on the property is highly disturbed (i.e., modified from original pristine conditions), and the mesic vegetation is limited. Also, the site is closely bordered by development, which acts as a partial barrier to wildlife movements.

The initial statement is pretty sweeping. No "wildlife habitat of importance"? Humm, tell that to the raptors, coyote, prairie dogs, etc., that make use of this land. What about the City's studies that describe the importance of irrigation ditches to this species?

The characterization of the land as not containing Preble's habitat and the later description of said habitat as mesic, herbaceous, vegetation associated with willow scrub implies that this property does not contain these types of plants. Well, we're not botanists but, again, if it quacks like a duck it probably is a duck. If it looks like cattails/sedges/willows/rushes ...

As we have shown this land contains much mesic, herbaceous, vegetation associated with willow scrub. As to the "modified from original pristine conditions" characterization, yes, this land is not pristine, none of the land in the entire Boulder Valley is in its pristine condition. That does not render it unsuitable for wildlife habitat.

City 3rd Party Review

Two years ago the City hired a external 3rd reviewer for the environmental studies submitted by the developer. At the January 2011 Planning Board meeting this reviewer spoke before the Board and said (I paraphrase):
Look, I don't know anything about Preble's. I'm just telling you what the developer's biologist told me
This 3rd party review doesn't sound like much of a review.




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