The first global inventory of flu strains in birds has identified 116 avian flu strains in wild birds. The inventory is based on a review of over 50 published studies. The number of strains found in wild birds is twice the number of strains in domestic birds. The study shows that the diversity of bird flu strains is more in some regions of the world. Understanding global bird flu strain diversity would help in devising strategies to control the outbreak of the virus in humans which is becoming increasingly common. PLoS ONE, March 5