Technical Report

Southwestern Willow Flycatcher Habitat Reconnaissance: Upper Rio Grande from the Colorado State Line to Cochiti Reservoir, New Mexico

URL: https://webapps.usgs.gov/mrgescp/documents/Ahlers_2009_SWFL%20Habitat%20Reconnaissance%20Upper%20Rio%20Grande%20from%20the%20Colorado%20State%20Line%20to%20Cochiti%20Reservoir%2C%20NM.pdf

Date: 2009/03/01

Author(s): Ahlers D.

Publication: U.S. Bureau of Reclamation Report, 7 p.

Abstract:

In the fall of 2008, the Bureau of Reclamation conducted Southwestern Willow Flycatcher (Empidonax trailli extimus, hereafter SWFL) habitat reconnaissance within the mainstem of the Rio Grande from the New Mexico/Colorado State Line downstream to Cochiti Pueblo. The objective of this reconnaissance based survey was to quantify SWFL habitat suitability in a portion of the Rio Grande that has been subject to inconsistent, or non-existent, SWFL presence/absence survey efforts. Approximately 127 miles (205 km) of the Rio Grande were evaluated at elevations ranging from 7200 ft (2200m) to 5200 ft (1600m) (Map 1). A classification system was developed to rank the quality of riparian habitat based on SWFL habitat suitability. The habitat reconnaissance surveys were conducted by experienced SWFL biologists with many years of experience.

Much of the Rio Grande within this reach is confined by steep canyons with high gradient flows and limited riparian vegetation. Land ownership is varied, including Tribal, private, Forest Service, National Park Service, and Bureau of Land Management (BLM). All Tribal Lands were excluded from the study area (Map1).