Hi Rob,

These birds are not the nimrods, but probably the most aggressive birds that are capable of "defending" their territory...albeit, to extreme lengths. Birds that are highly aggressive and able to hold off the competition are the most sought after by females. These birds simply have a drive so strong to defend thier territory and their female, that they go to extremes of defense. Unlike us, birds do not have self awareness. Thus, that "other bird" in the mirror is simply one that won't go away and has as much fight as the "real bird".

While out working in the Wenas area last year, I came back to my truck to find a male Western Bluebird fighting its reflection in my side mirror. How it even saw its reflection there is anyone's guess since it is angled towards the truck.

Jeff Kozma
Yakima