|Wildlife Mortality Information - Avian Botulism
What this map layer shows:
The number of bird deaths due to botulism, when each outbreak occurred,
and the top five species affected, by county.
Avian botulism, or Western duck sickness, is a paralytic disease caused
by ingestion of a toxin produced by the bacteria Clostridium botulinum.
This bacteria is widespread in soil and requires warm temperatures, a
protein source, and an anaerobic (no oxygen) environment in order to
become active and produce toxin. Decomposing vegetation and invertebrates
combined with warm temperatures can provide ideal conditions for the
botulism bacteria to activate and produce toxin. A wide variety of birds
and some species of mammals are susceptible to the disease. This map
layer portrays the incidence of avian botulism in the United States.
It was produced by the U.S.
Geological Survey's National Wildlife Health Center (NWHC), which
was established to address the health and disease issues of free-ranging
wildlife. The center collects information on wildlife mortality events
such as those caused by avian botulism, assesses the impact of disease
on wildlife, identifies the role of various pathogens in contributing
to wildlife losses, and works to develop effective disease prevention
and control strategies. The avian botulism information was extracted
from NWHC's EPIZOO database,
which is a long-term record of more than 25 years of information on epizootics
(epidemics) in wildlife. EPIZOO tracks die-offs throughout the United
States and its territories, primarily in migratory birds and endangered
The Wildlife Mortality Information – Avian Botulism database
shows county-level information on avian botulism events in the
United States, including the dates of each event, the five top
species involved, and the number of deaths. Also available in the
National Atlas are databases describing mortality events due to avian
cholera, avian lead poisoning, and organophosphate/carbamate
poisoning, as well as a database with county-level counts of
wildlife mortality events. More detailed information on avian botulism
and other disease epidemics in wildlife is available from the NWHC Disease
Information page, and from the Field
Manual of Wildlife Diseases.
If you download the data for Wildlife Mortality Information – Avian
Botulism, you may also want to download the Wildlife Mortality Information – Frequency
and the 2001 County Boundaries data. The Wildlife Mortality frequency
information and the County Boundaries map layers can be used together
to create a map of wildlife mortality that is similar to the map in the
Map Maker. The Avian Botulism map layer provides additional information
about specific events.
Download Wildlife Mortality Information
– Frequency Data
2001 County Boundaries