Very small particles visible only with an electronic microscope. Considered to be complex molecules and not living organisms, these are often causes of disease in plants, animals, and bacteria.
Manual listing field procedures for bird specimen collecting, bacterial, fungal, parasitic, and viral diseases, biotoxins, chemical toxins, common and scientific names of birds, and glossary. Manual can be downloaded or viewed in PDF format.
National Wildlife Health Center studies the West Nile Virus to learn the current geographic extent, to understand how the virus moves between birds, mosquitoes, and humans, and to predict future movements of the virus.