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SECTIONTHREE whooping Crane <br />reported predation of sandhill cranes by coyotes. Bobcats prey on young whooping cranes in <br />Florida and Texas. <br />Contagious diseases such as avian tuberculosis and avian cholera are threats to whooping cranes <br />(Lewis 1991; FWS 1981). Large concentrations of migrating waterfowl and sandhill cranes (i.e., <br />overcrowding due to habitat loss) likely contribute to the spread of both cholera and tuberculosis. <br />Actions which increase the potential for whooping cranes becoming infected with these diseases <br />represent a threat to the species. <br />Avian cholera is a chronic problem in palustrine wetlands of south - central Nebraska's Rainwater <br />Basin area, often causing die -offs of large numbers of waterfowl. Avian cholera has been <br />confirmed in sandhill cranes in three separate instances on the Platte River, though no population <br />outbreaks along the Platte River have occurred. It is known that whooping cranes also are <br />susceptible to avian cholera (FWS 1981); in January 1985, avian cholera was confirmed in a <br />whooping crane from the Rocky Mountain population (Doughty 1989). The threat of <br />transmission of avian cholera to the Platte River may be reduced if flows sufficient to provide a <br />high rate of flushing and dilution are maintained (FWS 1981). <br />Avian tuberculosis has been diagnosed in 7 of 18 (39 percent) wild whooping cranes necropsied <br />at the National Wildlife Health Research Center during the period of 1982 -1990 (Lewis 1991). <br />One bird from the Aransas -Wood Buffalo population was confirmed to have tuberculosis, and <br />another from that population was a suspect case. Avian tuberculosis likely exists in small <br />numbers of migratory birds and may be transmitted through direct contact with infected birds <br />(FWS 1987a). <br />Oil spills and toxic contaminants are a potential hazard to the wintering area, due to intercoastal <br />navigation. Three spills by nearby navigation traffic occurred in 1995 alone (Lewis 1996) even <br />though no incident directly affecting whooping cranes or their wintering habitats has yet <br />occurred. <br />Other types of catastrophic events that contribute to the species endangerment are exemplified by <br />at least one discrete event of direct mortality. A severe storm that struck the Louisiana coast in <br />August 1940 led to the extinction of the only known nonmigratory flock of whooping cranes. <br />Events that could have severe and possibly catastrophic affects on the species are drought on the <br />nesting area; contagious disease within the flock; storms such as hurricanes, tornadoes, or <br />blizzards; or contaminant spills in essential habitats vital to the species. This vulnerability to <br />catastrophic events has prompted the FWS to undertake experimental efforts to establish <br />additional populations. <br />3.3 BIOLOGY <br />* 3.3.1 Life History <br />Whooping cranes have a maximum longevity of 22 to 24 years in the wild, but 35 to 40 years in <br />captivity (FWS 1994). The average age of first egg production is slightly over 4 years. They <br />mate for life, but will remate following the death of their mate. <br />I= ®rust Wio ftwd <br />Federal Servkes 68FOD97286M /rl.doc 601999(9:52 AM)/URSGWCFS/2 3 -3 <br />