Wildlife Specialist report
Wildlife Specialist report
Wildlife Specialist report
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and collisions (Gaines et al. 2003). Knight and Cole (1991) indicate that birds may<br />
respond to human activity by altering their behavior, spatial distribution, and habitat use.<br />
Corridors created by roads can fragment songbird habitat, and human activity within<br />
these areas may displace or disrupt breeding activity for songbirds and other avian<br />
species (Hamann et al. 1999). Increased nest parasitism by Brown-headed Cowbirds and<br />
increased access by nest predators is also a major source of disturbance in fragmented<br />
riparian ecosystems. Fragmentation of limited, high value habitats such as riparian<br />
corridors may result in some of the most severe impacts to songbirds (Hamann et al.<br />
1999). Hutto (1995) indicates that many songbird species are largely or exclusively<br />
restricted to riparian habitats. Therefore, it can be inferred that songbirds occupying these<br />
specific habitats will be more affected by riparian corridor fragmentation via roads and<br />
trails, than fragmentation of adjacent forests (Hamann et al. 1999). A recommended<br />
corridor buffer of 100 meters or greater was suggested as the minimum width within<br />
fragmented riparian habitat necessary to minimize effects to songbirds (Vander Hagen<br />
and Degraaf 1996). Other researchers have suggested managers buffer minimum corridor<br />
widths from 75–175 meters to include at least 90 percent of all songbird species that may<br />
be impacted by road fragmentation of habitat. This analysis used a buffer of 100 meters<br />
on each side of the road to analyze the effects of roads to riparian bird species. Road<br />
miles and densities in riparian corridors were the analytical tool by which direct effects to<br />
riparian bird species were measured.<br />
Southwestern Willow Flycatcher [(SWWF) Federally “Endangered” Species with<br />
Designated Critical Habitat, and NM PIF High Priority Species with Known<br />
Territories on the GNF] - The Southwestern Willow Flycatcher (SWWF)/ breeds in<br />
dense riparian habitats in southwestern North America, and winters in southern Mexico,<br />
Central America, and northern South America (USFWS, 2002). The subspecies was<br />
listed as endangered effective March 29, 1995 (USFWS, 2002). The SWFL breeds in<br />
relatively dense riparian tree and shrub communities associated with rivers, swamps, and<br />
other wetlands, including lakes (e.g., reservoirs) (USFWS, 2002). The size of the New<br />
Mexico population in 2007 was estimated at 800-900 birds, based on the documentation<br />
of approximately 514 territories and 403 nests (NMPIF 2010). The total species<br />
population is estimated at 1,200 territories or approximately 2,400 individuals (Durst et<br />
al. 2008). About 32% of the global population is thought to occur in New Mexico<br />
(NMPIF, 2010). On the Gila National Forest we have had two sites that have been<br />
consistently occupied for over 10 years along the Gila River. These two areas are in<br />
locations known as the Gila Bird Management Area (GBMA) and the Fort West ditch<br />
site. In 2008 seven territories were found at the GBMA and four territories at the Forest<br />
West ditch site (Shook 2009). In 2007 a new breeding site was discovered on the Forest<br />
along the San Francisco River (Keller Canyon site). The Keller Canyon site, located on<br />
the reach between Deep Creek and Alma Highway 180, had three flycatcher territories in<br />
2007, 2008, and 2009.<br />
The Ubar Ranch, found in the Cliff/Gila Valley on private land, is located near the two<br />
sites on the Gila River on the Forest, and is one of the largest sites known throughout the<br />
subspecies range. In 2008, 140 territories were detected on the Ubar Ranch (Durst et al<br />
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