Common use of Disease or predation Clause in Contracts

Disease or predation. Xxxxxx (1998) reported no available information on ectoparasites or infectious diseases in LPCs, although several endoparasites, including nematodes and cestodes are known to infect the species. The Lesser Prairie-Chicken Interstate Working Group (1997) concluded that, while density-dependent transmission of disease was unlikely to have a significant effect on LPC populations, a disease that was transmitted independently of density could have drastic effects. The avian reticuloendotheliosis virus (REV) is a viral disease documented in poultry, which has been found to cause considerable mortality in captive Attwater’s prairie-chickens (Tympanuchus cupido attwateri) and greater prairie-chickens (X. xxxxxx). In 1999 and 2000, researchers surveyed blood samples from 184 LPCs from three states to determine if REV was present in the species. However, all samples were negative, suggesting that REV may not be a serious problem for most wild populations of LPC (Xxxxxxxxxx et al. 2002). The impact of West Nile Virus (WNV) on the LPC is unknown. Ruffed grouse have been documented to harbor WNV infection rates similar to some corvids. For 130 ruffed grouse tested in 2000, all distant from known WNV epicenters, 21 percent tested positive. This was remarkably similar to American crows and blue jays (23 percent for each species), species with known susceptibility to WNV (Xxxxxxx et al. 2001). Recent analysis of the degree of threat to prairie grouse from parasites and infectious disease concluded that microparasitic infections that cause high mortality across a broad range of galliform hosts have the potential to extirpate small, isolated prairie grouse populations (Xxxxxxxx 2004). Currently, CEHMM is conducting a regional assessment of WNV within the indigenous populations of Chihuahuan ravens (Corvus cryptoleucus). Ravens were chosen as environmental sentinels for this study due to their omnivorous/scavenging nature and susceptibility to avian pathogens such as the WNV. Many of the nesting areas currently being investigated overlap with the known occupied range of the LPC. Data collected during this investigation will be made available in the event that WNV becomes a suspect in any suspicious LPC population decline. Prairie falcon (Falco mexicanus), northern harrier (Circus cyaneus), great-horned owl (Bubo virginianus), other unspecified raptors, and coyote (Canis latrans) have been identified as predators of LPC adults and chicks (Xxxxx et al. 1979; Merchant 1982; Haukos and Xxxxx 1989; Xxxxxx 1994a). Predators of nests and eggs also include Chihuahuan raven, striped skunk (Mephitis mephitis), ground squirrels (Spermophilus spp), and bullsnakes (Pituophis melanoleucus), as well as coyotes and badgers (Taxidea taxus) (Xxxxx et al. 1979; Xxxxxx 1998). LPC predation varies in both form and frequency throughout the year, with raptor predation increasing during lek attendance (Xxxxx et al. 2007). Although the FWS has found no information on disease in LPCs and impacts of predators on LPCs at various life stages, there is no indication that either of these factors have risen to the level that they threaten the continuing existence of the species.

Disease or predation. Xxxxxx (1998) reported no available information on ectoparasites or infectious diseases in LPCs, although several endoparasites, including nematodes and cestodes are known to infect the species. The Lesser Prairie-Chicken Interstate Working Group (1997) concluded that, while density-dependent transmission of disease was unlikely to have a significant effect on LPC populations, a disease that was transmitted independently of density could have drastic effects. The avian reticuloendotheliosis virus (REV) is a viral disease documented in poultry, which has been found to cause considerable mortality in captive Attwater’s prairie-chickens (Tympanuchus cupido attwateri) and greater prairie-chickens (X. xxxxxx). In 1999 and 2000, researchers surveyed blood samples from 184 LPCs from three states to determine if REV was present in the species. However, all samples were negative, suggesting that REV may not be a serious problem for most wild populations of LPC (Xxxxxxxxxx et al. 2002). The impact of West Nile Virus (WNV) on the LPC is unknown. Ruffed grouse have been documented to harbor WNV infection rates similar to some corvids. For 130 ruffed grouse tested in 2000, all distant from known WNV epicenters, 21 percent tested positive. This was remarkably similar to American crows and blue jays (23 percent for each species), species with known susceptibility to WNV (Xxxxxxx et al. 2001). Recent analysis of the degree of threat to prairie grouse from parasites and infectious disease concluded that microparasitic infections that cause high mortality across a broad range of galliform hosts have the potential to extirpate small, isolated prairie grouse populations (Xxxxxxxx 2004). Currently, CEHMM is conducting a regional assessment of WNV within the indigenous populations of Chihuahuan ravens (Corvus cryptoleucus). Ravens were chosen as environmental sentinels for this study due to their omnivorous/scavenging nature and susceptibility to avian pathogens such as the WNV. Many of the nesting areas currently being investigated overlap with the known occupied range of the LPC. Data collected during this investigation will be made available in the event that WNV becomes a suspect in any suspicious LPC population decline. Prairie falcon (Falco mexicanus), northern harrier (Circus cyaneus), great-horned owl (Bubo virginianus), other unspecified raptors, and coyote (Canis latrans) have been identified as predators of LPC adults and chicks (Xxxxx et al. 1979; Merchant 1982; Haukos and Xxxxx 1989; Xxxxxx 1994a). Predators of nests and eggs also include Chihuahuan raven, striped skunk (Mephitis mephitis), ground squirrels (Spermophilus spp), and bullsnakes (Pituophis melanoleucus), as well as coyotes and badgers (Taxidea taxus) (Xxxxx et al. 1979; Xxxxxx 1998). LPC predation varies in both form and frequency throughout the year, with raptor predation increasing during lek attendance (Xxxxx et al. 2007). Although the FWS has found no information on disease in LPCs and impacts of predators on LPCs at various life stages, there is no now indication that either of these factors have risen to the level that they threaten the continuing existence of the species.