Charlotte Douglas International Airport an aviation library with over 9,000 volumes and a very extensive photography collection. Rare aircraft in the collection include one of only two surviving Douglas D-558 Skystreak aircraft and the second (and oldest surviving) U.S.-built Harrier, which was used as the flight-test aircraft and accumulated over 5,000 flight-test hours. In January 2011, the museum acquired N106US, the US Airways Airbus A320 ditched by captain Chesley Sullenberger as US Airways Flight 1549 in the Hudson River on January 15, 2009. This aircraft, which was delivered on June 10, 2011, is about 35 years younger than any other commercial airliner on display
Flock (birds) call of the ground squirrel requires the ability of the animal to first recognize that there is danger present and then to react. This type of behaviour is also seen in some birds. It is important to note that by making an alarm call to signal members of the flock one is providing the predator with an acoustical cue to the location of a possible prey. The benefit here is if the members of the flock are genetically related to one another. If this is true, even if the bird that signalled the flock were to die its fitness would