**** = cessation date not available.

(e) = estimate, *** = mortality estimate not available.

Suspect = diagnosis is not finalized or completed tests were unable to confirm the diagnosis, but field signs and historic patterns indicate the disease; Open = diagnosis is not finalized and tests are on-going; Undetermined = testing is complete or was not pursued and no cause of death was evident; NOS = not otherwise specified.

Arizona Veterinary Diagnostic Laboratory (AZV), California Animal Health and Food Safety Laboratory Network (CAF), California Fish & Game Disease Laboratory (CFG), Cornell University (COR), Maryland Department of Agriculture (MDA), No diagnostics pursued (NON), USGS National Wildlife Health Center (NW), Other (OT), Southeastern Cooperative Wildlife Disease Study (SCW).

Written and compiled by the U.S. Geological Survey National Wildlife Health Center Field Investigations Team members: Anne Ballmann, LeAnn White, Barb Bodenstein, and Jennifer (Buckner) Buckner.

To report mortality or receive information about this report, please contact the USGS National Wildlife Health Center, 6006 Schroeder Road, Madison , WI 53711

Quarterly Mortality Reports

Avian Cholera in California
Pasteurella multocida (avian cholera) epizootics were reported in various locations within nine California counties (Alameda, Butte, Colusa, Glenn, Sacramento, San Joaquin, Siskiyou, Sutter and Yolo) during the first quarter of 2012 (January � March). Cases were investigated and reported by the California Department of Fish and Game in partnership with USGS National Wildlife Health Center. The smallest event involved an estimated 75 dead wood ducks on a pond in Butte County. State waterfowl areas such as Woodbridge Ecological Reserve, Upper Butte Basin, North Grasslands, and Yolo Bypass Wildlife Areas estimated losses ranging from 200 to 1,500 birds including ducks, geese, and shorebirds. Sutter, Stone Lake and Klamath Basin National Wildlife Refuge Complexes, which serve as wintering areas for an estimated 2 million migratory birds, estimated final mortalities ranging from 100 to over 10,000 waterfowl, shorebirds and gulls, respectively. Refuge staff and volunteers at Tule Lake/Lower Klamath Lake NWR (Klamath Basin NWR Complex) retrieved 3,908 dead birds between mid-February and late April. The staff estimates this is approximately one-third of the birds that died during the event. The species most affected were the snow goose, American coot, American wigeon, white-fronted goose and northern pintail. This was the largest outbreak of avian cholera the Klamath Basin NWR staff has seen since 2008 when an estimated 10,000 birds died due to avian cholera.

Avian Cholera in the Midwest United States
Avian cholera was the second leading cause of avian mortality events (after trematodiasis), reported to the USGS National Wildlife Health Center, in the Central and Mississippi flyways during the first quarter of 2012. Greater and lesser snow geese and Ross�s geese were the primary species involved in all four mortality events in the Midwest. The first 2012 cholera event in the Midwest occurred in Pike County, Missouri at the beginning of February and involved less than ten geese. The other three events in the Midwest were reported shortly thereafter, first in northwestern Missouri (Holt County) followed by Iowa and Nebraska. The event in Iowa involved an estimated 150 geese in Fremont County on a wildlife management area. The last avian cholera event on that area was reported in 2003. The largest event in the Midwest in 2012 occurred in Nebraska across multiple Waterfowl Production Areas in Clay, Phelps, and Kearney Counties and involved almost 1,300 birds, primarily snow geese and Ross�s geese, as well as a few other species of waterfowl - such as Northern pintails and mallards. The avian cholera mortality in 2012 in Nebraska was the highest for the state since 1999 when an estimated 1,400 died from this disease.

North America White-nose syndrome Update for Winter 2011/2012
Geomyces destructans, the fungus that often causes fatal skin infections of hibernating bats in eastern and central North America, continued to spread this past winter season. Most notably, characteristic skin lesions of white-nose syndrome (WNS) were confirmed on little brown bats at a hibernaculum west of the Mississippi River for the first time in Lincoln County, Missouri and the southern Appalachians of northern Alabama (Jackson County). While no mortality was detected at either location and mortality remains low along the western disease front, an estimated 5.5 million bats are believed to have died from WNS since it was first recognized five years ago near Albany, New York. Winter bat populations have been reduced more than 80% in the northeast and mid-Atlantic United States although there are some early indications that bat populations may have stabilized at some of the original affected sites in New York. White-nose syndrome was also confirmed at the only known bat hibernaculum in Delaware for the first time this past winter although G. destructans had been previously detected on bats returning early to known maternity roosts from this hibernaculum. WNS has now been confirmed in 18 states and 4 Canadian provinces, and it continues to expand into new counties and districts within the affected area. Iowa recently announced the detection of low levels of G. destructans DNA on a single big brown bat showing no clinical signs in Jackson County. The viability of the fungus at the Iowa site is still unknown. In addition to range expansion of WNS, the federally-listed endangered gray bat (Myotis grisescens) was also added to the list of North American hibernating bats confirmed with the disease which includes little brown bats (M. lucifugus), Northern long-eared bats (M. septentrionalis), Eastern small-footed bats (M. leibeii), endangered Indiana bats (M. sodalis), tricolored bats (Perimyotis subflavus), and big brown bats (Eptesicus fuscus).