Gray Vireos  Lincoln Fire Study  Purple Martins  Breeding Bird Surveys  Southwestern Willow Flycatchers  Mountain Plovers  Pinyon-Juniper Songbird Surveys in  Estancia Valley  Middle Rio Grande Songbird Study Gray Vireos The Gray Vireo is a small migrant songbird breeding in pinyon-juniper woodland of the southwestern United States. Gray Vireo was listed as threatened in the state of New Mexico by the New Mexico Department of Game and Fish, but relatively little is known about populations in our state. In 2005, Hawks Aloft began annual monitoring of a Gray Vireo (Vireo vicinior) population in southeast New Mexico. We found high rates of Brown-headed Cowbird (Molothrus ater) nest parasitism and low vireo productivity at that site. We added a second site in northwest New Mexico in 2007. Habitat selection, nest success, and trend comparisons between these populations promise to offer insight into the current status and threats for this species. We hope to continue monitoring these populations, and we welcome funding opportunities that would help us expand our vireo research. Our biologist on this project has many years of experience conducting vireo research (including video monitoring) and has published articles on vireo nesting ecology in peer-reviewed ornithological journals. We welcome collaboration with researchers conducting Gray Vireo studies in other regions and invite individuals or organizations to team up with Hawks Aloft.   Lincoln Fire Study In 2000, a wildfire burned portions of the Lincoln National Forest in the Sacramento Mountains of southern New Mexico. In 2001, the Forest Service contracted Hawks Aloft to monitor avian response to the fire. As part of a five-year study, we conducted summer and winter point counts at six sites in the forest to determine songbird use of burned and unburned areas. Burned areas attracted large numbers of House Wrens, Violet-green Swallows, Western Bluebirds, Hairy Woodpeckers, and Green-tailed Towhees, relative to unburned areas. Numerous snags in the burned areas were used as hunting perches or nesting sites for many species. Three-toed Woodpeckers also were seen in small numbers following the fire. Our observations demonstrated how the fire provided short-term benefits for some species, while some coniferous species probably lost habitat, at least temporarily.   Purple Martins During point count surveys following the 2000 wildfire in the Lincoln National Forest, we observed Purple Martins using snags within the approximately 6,500 ha of burned coniferous woodland. Although Purple Martins are widespread in the east and use artificial nesting structures, western populations are local and rely heavily on natural nest cavities. With funding support from the USDA Forest Service (Sacramento Ranger District) and the Purple Martin Conservation Association, we began monitoring Purple Martin colonies in 2006. In a one-week search, we located four colonies and a total of 34 Purple Martins. Among the colonies, we documented 10 active nest trees containing at least 15 active nests. At more than 8,000 ft in elevation, these are among the highest known breeding colonies. Although not nearly as common here as other secondary cavity nesters, such as Western Bluebird and Violet-green Swallow, Purple Martin colonies could continue to appear and grow, at least in the short term, while numerous snags are available for nesting. Annual colony monitoring and area searches will help the USDA Forest Service protect current nest snags and possibly contribute to future post-salvage and snag management plans.     Breeding Bird Surveys Riparian corridors in New Mexico provide critical breeding habitat for a variety of species, including many of conservation concern, such as the Southwestern Willow Flycatcher. Hawks Aloft is working with the Albuquerque and Taos Field Offices of the Bureau of Land Management to monitor breeding bird populations. We survey more than one-dozen riparian sites in central and northern New Mexico each year. Sites include a variety of vegetation types, from native trees and shrubs to exotic salt cedar and Russian olive. Each site also has unique water flow conditions. Annual detection rates for riparian-dependent species and species of conservation concern, associated with local conditions, will help evaluate the health and management potential for some of New Mexico's riparian sites.   Southwestern Willow Flycatchers Each spring and summer, we conduct presence/absence surveys for the federally endangered Southwestern Willow Flycatcher. In New Mexico, annual survey sites include a canyon east of Bluewater Lake in Cibola County, two riparian sites in Sandoval County, the Santa Fe River in Santa Fe County, Rio Truchas in Rio Arriba County, and the Orilla Verde Recreation Area in Taos County. In Colorado, we survey 10-20 sites during some years in the San Luis Valley, including several sites along the Rio Grande. Data on Willow Flycatcher use will help direct management efforts at local sites.   Mountain Plovers A sizeable population of Mountain Plovers resides during the spring and summer on Bureau of Land Management land in northern Taos County, New Mexico. Concern over apparent negative population trends, along with the recent petition to list Mountain Plover as a threatened species, prompted a desire among many researchers to learn more about various populations in the western states. With support from the Bureau of Land Management, we began monitoring the Taos County population in 2001 and initiated a study quantifying plover density and population trends. We conduct annual point count monitoring at 245 survey points and calculate density using a distance sampling and model selection approach. The Taos County Mountain Plover breeding density, as of 2007, is smaller than values reported from other sites in Colorado and Wyoming. However, the large size of the Taos County site (about 50,000 ha) probably renders this population the largest in New Mexico under a single management authority.    Pinyon-Juniper Songbird Surveys in Estancia Valley In 2005, we began conducting songbird point counts in pinyon-juniper and grassland habitat in the Estancia Basin, east of the Sandia Mountains. Both pinyon-juniper and grasslands provide habitat for a unique assemblage of birds; however, pinyon-juniper habitat is widely thinned or cleared for perceived water benefits. Our surveys in treated areas will contribute information on how different types of birds might be affected by management efforts.      Middle Rio Grande Songbird Study This project is the first comprehensive replication of the avian and vegetation portions of the Middle Rio Grande Biological Survey completed in 1984. We are sampling avian abundance and species richness relative to vegetation community and structure (C/S) types within the Middle Rio Grande Bosque. The study area encompasses 79 river miles between the city of Rio Rancho, New Mexico, in the north, and the La Joya State Game Refuge to the south. Within this reach of the Rio Grande, we established 46 transects representing 16 C/S types.  Ultimately, we will provide a twenty-year comparison of (1) overall change in avian abundance and species richness, (2) change in vegetation communities and structure types, and (3) comparison of current avian abundance and species richness relative to C/S types 20 years ago. In addition, we will (4) compare current avian abundance and species richness relative to current C/S types, and (5) compare current avian abundance in relation to landscape context and amount of urbanization surrounding the Bosque.  Finally, given the extensive thinning projects being conducted throughout the Middle Rio Grande relying on the mechanical clearing of introduced, non-native vegetation, we are focusing special attention on comparing avian abundance and species richness in areas subjected to mechanical clearing to areas with a superficially similar, but naturally occurring C/S type.