Dennis Hasch, the webmaster for the Smithsonian's Museum of Natural History in Washington, D.C., sent us this video of a red-tailed hawk that surprised him by landing outside his office window in May 2007.
Not long into the clip, you will notice that a blue jay is unnerved, and a bit unhinged, by the unexpected visitor. If you look closely at the blue jay's legs, at around the 25-second mark, you can see that it is marked with colored leg bands. It had been captured by Smithsonian scientists on May 19, 2004, when it was already at least two years old, as part of a study of the spread of West Nile Virus in the Washington metropolitan area.
Birds are marked with colored leg bands so that they can be identified later. This gives scientists an idea of how long birds live. Blue jays, and their crow relatives, appear to be especially susceptible to West Nile Virus.
With as much fuss as the jay is putting up, you might think that red-tailed hawks are major predators of theirs. This is unlikely as the hawks prefer to catch prey on the ground, such as pigeons, squirrels, and rats. However, they might raid a blue jay nest.