Purpose and Objective

Implementation of restoration measures at the demonstration project was expected to improve wildlife habitat. A wildlife study was conducted to determine the response of wildlife populations and to examine the extent of habitat enhancement.

Methods

The California Department of Water Resources (DWR) conducted wildlife surveys from March 1988 to November 1991 (Bogener 1993). Based on CDFG recommendations, the surveys targeted small mammals, deer, rabbits, nongame birds, and waterfowl as the most appropriate wildlife groups to monitor. Wildlife abundance in the study area was compared to a similar, but unmanipulated, control area immediately downstream of the study area.

Four transects were established in the project area and four in the control area. These transects crossed the stream at approximately 300-foot intervals in the 65-acre fenced project area and in the control area (Figures 11-1 and 11-2). For the study, the control area was assumed to accurately reflect pre-project habitat conditions in the study area. Vegetation data collected by PG&E in a separate study indicated the areas were statistically similar to a 95% confidence level (see Section 8).

Surveys of small mammals and deer and rabbits were conducted each year during April and October. Small mammals were trapped, sexed, aged, and keyed to species. Deer and rabbit use was determined by counting fecal pellet groups on each of 80 one-milliacre (4.84 square yards) plots. Pellets were removed from each plot after being counted so that the counts would represent approximately six months of accumulation. Deer use was expressed as deer days use per acre, determined by an average deer fecal rate of 13 pellet groups per day. Rabbit use data were recorded as pellet groups per acre.

Monthly avifauna sampling was conducted using line transects each year from April through October. Each transect was walked slowly and the species, number, and location of birds sighted were recorded following the methods of Balph, Stoddart, and Balph (1977). Direct counts of waterfowl were recorded along approximately 2.1 miles of the stream, including the length within the 65-acre study area and approximately one mile of stream in the control area.

• The demonstration project clearly improved wildlife habitat for most species. Of the species observed, only rabbits and three species of birds seemed to prefer the drier habitat of the control area. The project created high-quality wetland riparian habitat within an area where these types of habitats were generally limited in quantity and degraded in quality. The combination of check dam structures to raise the groundwater table and fencing to exclude grazing resulted in a more rapid vegetative response than could have occurred had either stream restoration technique been implemented individually. Wildlife species responded rapidly to the changes in vegetative community and will continue to do so as the vegetation structure develops in the project area.
• The average density and richness (number of species) of birds was significantly greater in the project area. Ninety-four avian species were observed during the study. Species richness was 21% greater and total density 96% greater in the project area compared to the control area. Three species (American robin, northern flicker, and yellow warbler) occurred at significantly greater densities in the control area, whereas 16 species (American coot, barn swallow, Brewer’s blackbird, cinnamon teal, cliff swallow, common nighthawk, gadwall, green-winged teal, horned lark, mallard, marsh wren, northern harrier, pied-billed grebe, red-winged blackbird, violet-green swallow, and Wilson’s phalarope) were observed at statistically significant greater density in the project area.
• Total waterfowl densities, richness, and production were significantly greater in the project area: 17 species were observed in the project area compared to 9 species in the control area (Figure 11-3). All waterfowl species except snow geese had greater densities in the project area. Overall waterfowl use was 700% greater in the project area. Nine species used the project area for reproduction, compared to 3 species in the control area. During the four-year study period, 588 waterfowl were produced in the project area compared to 23 in the control area, a ratio of 25:1. These differences could be even greater because attraction of waterfowl to the study area may have also increased use of the adjacent control area.
• The project has provided a refuge for avian species considered at risk. There were statistically significant increases in the numbers of neotropical migrants (a group considered at risk) using the project area. The short-eared owl, a state-listed species of special concern, successfully reproduced at the site. A state-listed threatened species, the sandhill crane, attempted nesting at the project area in 1991, but was unsuccessful. As the willows at the site develop, habitat will be provided for the willow flycatcher, listed by the state as a species of special concern and by the U.S. Forest Service as a sensitive species.
• Deer use in the project area averaged 1.9 days per acre in the winter season (mid-October to mid-April) and 3.1 days per acre in the summer (mid-April to mid-October); sampling did not detect deer use in the control area. Developing vegetation in the project area also provided enhanced fawning habitat. Three doe with fawns were observed bedding in the project area.
• Rabbit use in the control area was significantly greater (4.5 times) than in the project area. The presence of preferred rock outcrop habitat in the control area, which was not available in the project area, may have been a factor.

• No significant differences were noted for small mammals using the control and project areas except for montane vole, which was captured more frequently in the project area. The higher water table in the project area produced a greater density of grasses and sedges, which this species requires for cover, food, and reproduction. The small mammals were predominantly deer mice, representing 88% of the animals trapped.
• The continued success of the project as an improved wildlife habitat depends on long-term maintenance of the check dams and continued control of grazing in the project area. Some light to moderate short-term grazing in late July, which would allow time for regrowth of vegetation before fall, could be allowed with minimal impact to nesting waterfowl.

Section 12

Photographic Monitoring

Purpose and Objective

Restoration projects may take many years to show statistically viable results because of the time required to achieve geomorphic stability, for plants to establish and grow, and for plant and animal species to colonize new habitats. Wide variability in weather and land management practices from year to year may mask long-term trends. The objective of this effort was to test the effectiveness of photographic monitoring in providing a visual, low-cost means to qualitatively assess how resources change over time in response to enhancement measures. Photographs often show effects before they are evident in statistical data.

Methods

Photographic monitoring was initiated in 1985, before the check dams and other treatments were installed. Photographs were taken annually in August to maintain a consistent comparison. Thirteen permanent photographic monitoring stations were established along the stream channel in the demonstration exclosure. Stations were spaced at 50-foot intervals from the downstream fence crossing (below Check Dam #1) to upstream of Check Dam #4. Three photos were taken at each station (views upstream, downstream, and across the channel). The labeled slides were mounted in a binder for later use in analysis. Unusual changes, improvements, or problems observed were documented in field notes.

Key Findings

• Plant establishment, significant improvement in vegetation cover, stabilization of streambanks, sediment deposition, and narrowing of channels are substantiated by comparing photographs taken over time at the same station (Figure 12-1).
• One individual should be responsible for ensuring consistency of the photographs and for maintaining a central project photo file. Other project personnel who take photos should send copies (dated and identified) to the central file to ensure that the project’s photo record is complete.
• Photos are a valuable tool for maintaining a visual record of changes over time and for training project personnel. They can be used to document implementation procedures (e.g., planting methods, dam construction, bio-geotechnical revetment techniques, and fencing details) and failed methods. Photo records of site visits may be useful in obtaining political support for the projects.
• Some resources are not easily photographed. Although formal photographic monitoring may not be economically justified, a few good photographs of deer, waterfowl, fish, and other wildlife using the project area are important for maintaining public support and promoting funds for project maintenance and other watershed projects.
• The use of historical and current low-altitude aerial photographs provides a valuable means to determine the source of erosion problems and identify long-term trends. Aerial photographs complement qualitative documentation from ground-based photo points. As more low-cost, finer-resolution satellite imagery becomes available, remote sensing will be yet another source of good information to monitor trends and conduct analysis.
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