Common use of Other natural or manmade factors affecting its continued existence Clause in Contracts

Other natural or manmade factors affecting its continued existence. Impacts from Drought Drought is considered a universal ecological driver across the Great Plains (Xxxxx 1996). Infrequent, severe drought may cause local extinctions of annual forbs and grasses that have invaded stands of perennial species and recolonization of these areas may be slow (Tilman and El Haddi 1992). In this way, drought may impact LPC through its effect on seasonal growth of vegetation necessary to provide nesting and roosting cover, food, and opportunity for escape from predators (Xxxxxxxx 1982; Xxxxxxxx and Xxxxx 1994; Xxxxxx et al. 1996). The sensitivity of LPC to drought was discussed by Xxxxxxxx (1980) and Xxxxxxxxxx and Xxxxxxxxxx (1961). Precipitation appears to affect LPC adult population trends with a potential lag effect (Xxxxxx 2000). That is, rain in one year promotes more vegetative cover for eggs and chicks in the following year, which enhances their survival. The effects of drought are likely exacerbated by land use practices, but no studies have clearly demonstrated such cumulative impacts on populations (Xxxxx and Xxxxxx 2005). Along with other prairie grouse, LPC have a high reproductive potential in years of adequate conditions. In New Mexico, southern portions of the species range, which on average receive less total precipitation (i.e., Carlsbad area), are impacted more frequently and more severely by drought. LPC populations in these areas may have always been smaller and more variable than those farther to the north, although population data are insufficient to say this with certainty. Thus, drought conditions are unlikely to be the sole causative factor in long-term LPC population declines. The effects of drought on population growth rate may be more significant in small, fragmented populations. Impacts from Collision Mortality Wire fencing is common throughout LPC range as a means of confining livestock to ranches and pastures, or excluding them from areas not intended for grazing such as CRP, agricultural fields, and public roads. Like most grassland wildlife, LPC evolved in open habitats free of vertical features or flight barriers. Fences, power lines, or other wire structures are an unnatural threat to prairie grouse that, until recently, were seldom perceived as significant at the population level (Xxxxx et al. 2007). From 1999 to 2004, researchers recovered 322 carcasses of radio marked LPC in New Mexico, Oklahoma, and portions of the Texas panhandle. In New Mexico, only 14 percent of mortality could be traced to collision. Collision mortality is not unique to LPC, and is increasingly reported in several species of North American grouse. Sage grouse appear to be similarly vulnerable to fence collisions. However, additional investigation is necessary to fully quantify the magnitude of this ongoing threat to LPC rangewide. With 14 percent of adult LPC mortality in New Mexico attributable to collision with man-made structures, the negative effect of fence collisions on long-term population viability for the LPC cannot be understated. Xxxxx (1951) expressed concern that spread of these features in eastern New Mexico might severely limit LPC populations; however, the full extent of collision mortality is unknown and difficult to measure. However, the Xxxxxx Center has developed a low- cost method of marking barbed-wire fences to make them more visible to LPCs. Approximately 96 miles of fence have been marked in Oklahoma and the panhandle of Texas by this method (Xxxxxx Xxxxx, Xxxxxx Avian Research Center, pers. comm. 2008). Initial findings in 2007 indicated a marked drop in bird-fence collisions post-marking. Marking fences in core LPC habitats in New Mexico would be an inexpensive, easily implemented way to minimize one source of LPC mortality. Sand Dune Lizard

Other natural or manmade factors affecting its continued existence. ‌ Impacts from Drought Drought is considered a universal ecological driver across the Great Plains (Xxxxx 1996). Infrequent, severe drought may cause local extinctions of annual forbs and grasses that have invaded stands of perennial species and recolonization of these areas may be slow (Tilman and El Haddi 1992). In this way, drought may impact LPC through its effect on seasonal growth of vegetation necessary to provide nesting and roosting cover, food, and opportunity for escape from predators (Xxxxxxxx 1982; Xxxxxxxx and Xxxxx 1994; Xxxxxx et al. 1996). The sensitivity of LPC to drought was discussed by Xxxxxxxx (1980) and Xxxxxxxxxx and Xxxxxxxxxx (1961). Precipitation appears to affect LPC adult population trends with a potential lag effect (Xxxxxx 2000). That is, rain in one year promotes more vegetative cover for eggs and chicks in the following year, which enhances their survival. The effects of drought are likely exacerbated by land use practices, but no studies have clearly demonstrated such cumulative impacts on populations (Xxxxx and Xxxxxx 2005). Along with other prairie grouse, LPC have a high reproductive potential in years of adequate conditions. In New Mexico, southern portions of the species range, which on average receive less total precipitation (i.e., Carlsbad area), are impacted more frequently and more severely by drought. LPC populations in these areas may have always been smaller and more variable than those farther to the north, although population data are insufficient to say this with certainty. Thus, drought conditions are unlikely to be the sole causative factor in long-term LPC population declines. The effects of drought on population growth rate may be more significant in small, fragmented populations. Impacts from Collision Mortality Wire fencing is common throughout LPC range as a means of confining livestock to ranches and pastures, or excluding them from areas not intended for grazing such as CRP, agricultural fields, and public roads. Like most grassland wildlife, LPC evolved in open habitats free of vertical features or flight barriers. Fences, power lines, or other wire structures are an unnatural threat to prairie grouse that, until recently, were seldom perceived as significant at the population level (Xxxxx et al. 2007). From 1999 to 2004, researchers recovered 322 carcasses of radio marked LPC in New Mexico, Oklahoma, and portions of the Texas panhandle. In New Mexico, only 14 percent of mortality could be traced to collision. Collision mortality is not unique to LPC, and is increasingly reported in several species of North American grouse. Sage grouse appear to be similarly vulnerable to fence collisions. However, additional investigation is necessary to fully quantify the magnitude of this ongoing threat to LPC rangewide. With 14 percent of adult LPC mortality in New Mexico attributable to collision with man-made structures, the negative effect of fence collisions on long-term population viability for the LPC cannot be understated. Xxxxx (1951) expressed concern that spread of these features in eastern New Mexico might severely limit LPC populations; however, the full extent of collision mortality is unknown and difficult to measure. However, the Xxxxxx Center has developed a low- cost method of marking barbed-wire fences to make them more visible to LPCs. Approximately 96 miles of fence have been marked in Oklahoma and the panhandle of Texas by this method (Xxxxxx Xxxxx, Xxxxxx Avian Research Center, pers. comm. 2008). Initial findings in 2007 indicated a marked drop in bird-fence collisions post-marking. Marking fences in core LPC habitats in New Mexico would be an inexpensive, easily implemented way to minimize one source of LPC mortality. Sand Dune LizardLizard‌