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Wetlands support a disproportionate segment of our wildlife, including birds; one
estimate is that 75 percent of the wildlife of Colorado use wetlands, yet these
wetlands account for less than 2 percent of the state’s area. Despite the importance
of wetlands, the US Fish and Wildlife Service estimates that approximately half
of our nation’s wetlands have been lost. Threats to wetlands and rivers persist
today – including development pressure, pollution, sedimentation, agricultural and
municipal water needs, and invasive species of plants and animals.
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Surveying birds at an enhanced wetland in the CWP
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To protect and restore Colorado’s wetlands, the Colorado Division of Wildlife created
the Colorado Wetlands Partnership (CWP), a voluntary, incentive-based program for
restoring, enhancing, creating, managing, and protecting biologically significant
wetlands and associated uplands in the state. Since the inception of the CDOW Wetlands
Program in 1997 and with the cooperation of several major partners, including Ducks
Unlimited, The Nature Conservancy and USFWS Partners for Fish and Wildlife, Intermountain
West Joint Venture, and Playa Lakes Joint Venture, over $20 million has been spent
on wetlands protection projects (acquisition, restoration, enhancement) within the
state. However, conservation project sites had not been evaluated systematically
for biological contributions; in other words, the accomplishments of these projects
in protecting wildlife habitat and populations have not yet been documented. To
address these information needs, RMBO created the Wetlands Monitoring and Evaluation
Project (WMEP) to assess ecological outcomes from wetland conservation projects
in the CWP.
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Northern Shoveler
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We were particularly interested in knowing the types of wetlands protected, the
types of restoration, enhancement, or protection practices applied, how birds used
restored wetlands, and the success of various conservation projects in providing
critical bird habitat.
RMBO began implementing the WMEP in 2002. Initial years of the project involved
protocol development, establishment of four intensive monitoring efforts to
document avian and plant community response to wetland conservation projects,
and completion of 165 site assessments in 11 Wetlands Focus Areas (see map).
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We also developed a database, Evaluwet, which contains five database modules with
47,627 data records. Through different phases of the project we focused on projects
providing waterfowl nesting habitat in the San Luis Valley and songbird responses
to riparian habitat restoration statewide (please see 2006 report for detailed results).
Most recently we investigated how restored shallow wetlands are providing migratory
shorebird and waterfowl habitat along the South Platte River (2007 report). We conducted
257 surveys of 16 wetlands at 11 sites. We observed 16,527 birds representing 60
species, including 33 species of conservation priority under one of the North American
bird conservation iniatives. We also conducted 210 weekly surveys of water depths
and extent of surface area flooding on 26 wetlands at 18 sites. At the conclusion
of the migration season, we sampled wetland vegetation, documenting 132 species
of plants.
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Monitoring water depths in relation to migratory shorebird and waterfowl use
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The abundance of wetland-dependent birds as well as species richness varied greatly
among sites. Sites that hosted high numbers of birds also hosted high numbers of
species. Hydrologic conditions also varied greatly among sites, with some sites
never providing wetland conditions throughout the study season and others being
wet the entire season. Dry sites rarely hosted wetland-dependent birds. We found
strong temporal trends in the abundance of waterfowl and shorebirds through the
study season, in part driven by the migration chronologies of various species. Waterfowl
and shorebird densities were most highly related to wetland size and percent of
unvegetated area flooded in shallow water depth classes. We found no relationships
between bird use and specific vegetation characteristics or percent of wetlands
in the area surrounding wetland sites.
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Riparian habitat along Conejos River on BLM’s Simpson Property, San Luis Valley;
note multiple habitat layers, presence of snags, and tall whitetop
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We calculated avian use-days for the study area and estimated over 75,000 use days
on these study areas alone. Because our sites were selected randomly, they should
be representative of all restoration sites within the South Platte River WFA. Thus,
we can project that restoration projects within this Focus Area collectively support
a minimal estimate of 410,760 avian use days per spring migration season.
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Identifying vegetative response and bird habitat characteristics on a restored wetland
New channel construction at Fourmile Creek in South Park, August 26, 2004
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A number of management implications may be drawn from this work. First, management
of surface water levels drives the use of sites by both waterfowl and shorebirds.
Sites that hosted high numbers of waterfowl also were used by high numbers of migrating
shorebirds, demonstrating the compatibility of managing for both bird groups on
the same sites. In March and April when waterfowl are most abundant, flooding of
depths less than 40 cm is related to high waterfowl use, while during late April
and May flooding of less than 20 cm and especially less than 4 cm will most benefit
shorebirds. For both groups, the maintenance of open areas free of vegetation is
also related to high bird use. Finally, we found that some sites with augmentation
water rights provided high quality habitat, indicating a compatibility of use between
augmentation water rights and wildlife habitat conservation.
The Wetlands Monitoring and Evaluation Project is a model program for evaluating
the outcomes of wetland conservation projects and has been instrumental in supporting
the wetlands protection efforts ongoing in Colorado and the Rocky Mountain region.
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The project provides land and project managers feedback on the efficacy of
their restoration practices and helps them to design adaptive management practices.
Program administrators are provided information about the breadth and successes
of their program. In addition, because wetland ecosystems continue to undergo threats
and available funds cannot meet all conservation opportunities, WMEP information
can help determine the most effective strategies for preserving Colorado’s wetlands.
Finally, evaluation and monitoring are extremely important for documenting the success
of programs to their funding sources and supporters, including Congress. This project
was active from 2002-2007; is it no longer funded.
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CWP wetland project to restore and enhance shallowly flooded wetlands through the
use of contour levees and grazing exclusion on private land; San Luis Valley Focus
Area.
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CWP riparian restoration project; private land in the Southwest Wetlands Focus Area.
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Contact:
Alison Cariveau
Alison.Cariveau@rmbo.org
State: Colorado
Funders:
- Colorado Division of Wildlife
- US Environmental Protection Agency
- Colorado Governor’s Office of Energy Management
- Intermountain West Joint Venture
- Playa Lakes Joint Venture
- USFWS Partners for Fish and Wildlife
Cooperators:
- Colorado Natural Heritage Program
Materials:
Teal Nest
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