Land Bird Conservation Plan Colorado  

Executive Summary
Overview of Colorado
Physiographic Region 36
Physiographic Region 62

  • Alpine Tundra
  • Aspen
  • Cliff/Rock
  • High Elevation Riparian
  • Lowland Riparian
  • Mixed Conifer
  • Mountain Shrubland
  • Ponderosa Pine
  • Sagebrush Shrubland
  • Spruce Fir
  • Wetlands


  • Physiographic Region 87
    Implementation Strategies
    Literature Cited
    Appendices

    Physiographic Region 62: Southern Rocky Mountains

    American Dipper (Cinclus mexicanus)

    Associated Species: Other species that may use habitat in a similar way and/or respond similarly to threats, management, and conservation activities include the Spotted Sandpiper.

    Distribution: American Dippers reside from western Alaska and Canada south to western Panama. In Colorado, they are uncommon summer residents in foothills and mountains from 1800 to 3500 m (6,000-11,500 ft) elevation. In winter, most birds withdraw to lower elevations.

    Habitat Requirements: Dippers reside along clear mountain streams and rivers with sand and rubble on the bottom and little or no aquatic vegetation. Selected streams are usually less than 15 m (50 ft) wide and 2 m (6.5 ft) deep. They require exposed rocks in the stream for perching. Dippers place their nests 2 to 3 m (6-10 ft) above fast or deep water, on cliff ledges, boulders, and bridges (which have replaced natural nesting substrates in some areas).

    Ecology: Dippers move upstream to nesting areas as ice leaves. The beginning of breeding varies from March to May depending upon ice and snow melt, with nestlings sometimes present as late as August. Birds move downstream as freeze-up closes their habitat for the winter. Dippers eat mainly aquatic insects but also occasionally small fish, fish eggs, and tadpoles.

    Management Issues and Conservation Recommendations: American Dippers benefit from some human activities, such as construction of bridges. However, they are hurt by others, such as drawing down streams to supply agricultural or municipal needs, damming and flooding streams, mining (can contribute toxins to streams), and logging (can increase sedimentation); these activities are detrimental to dippers because they eliminate nesting habitat and aquatic insect prey. Reduce or eliminate activities that pollute streams with added sedimentation or mine and chemical waste.

    Dippers exhibit high between-year fidelity to nesting sites. Protect known sites from habitat degradation. Preserve streamside logs and upturned roots, which can serve as cover and as nest substrate.

    Status and Reasons for Concern: Because they rely on aquatic insects, which only flourish in clear, unpolluted streams, American Dippers are excellent indicators of stream quality. They are not adequately monitored by the BBS within Physiographic Area 62, and data are too sparse for meaningful analysis of trends. Dippers were present on an average of 16.63% (SE = 3.19) of BBS routes run in Physiographic Area 62 in Colorado, 1988-1997, at an average abundance of 0.20 (SE = 0.03) individuals per route. The mean number of routes run each year was 21.1 (SE = 3.06). This species is monitored by MCB with point transects.

    Biological Objective: Maintain or increase the species' distribution and abundance, based upon results of BBS and MCB monitoring programs.

    Selected References: Andrews and Righter 1992; Kingery 1996, 1998; Price and Bock 1983.


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