Bird strikes ( collisions between birds and aircraft) pose a significant threat to aviation safety. For example , Naval Air Facility El Centro, California, lost an F-18 jet to a bird strike in October 1995. To help combat the bird-strike threat at Naval Air Facility El Centro, I developed a bird-avoidance model as a risk-management tool for the installation. It can be used to schedule flights at NAF El Centro and its two associated practice-bombing ranges during times of low-bird activity. I calculated bird-strike risks and published them in web-page format on both the installation's server and the USGS/Utah State University, College of Natural Resources' server for easy access by flight crews, flight-safety officers, airfield managers, natural resource managers, and other Navy personnel. Bird hazards during daylight hours were quantified using daily bird counts through the year 2000. These were combined with a bird-hazard index for various species, developed using U.S. Air Force bird-strike records. Nocturnal bird hazards were quantified in the fall of 2000 using a bird-radar system to count birds in three relative size classes. Large- and medium-sized birds were scaled to represent a higher risk to aircraft than small birds. Nocturnal bird hazards beyond the fall study were estimated using U.S. Air Force bird-strike records. The main section of the web page allows the user to select the area and time of year, which links to the appropriate color-coded bird-strike-risk graph. The graphs describe the bird-strike risk by time of day and altitude with red for high risk, yellow for moderate risk, and green for low risk. The web page also identifies and describes the most hazardous bird species in the area, recommends methods of hazard management, and provides links to bird-strike-information sources on the web.