I've been listening to an adult male BALTIMORE ORIOLE tap 
away at my kitchen window for a while now.  I imagine he's 
at war with his reflection (we've had robins and 
mockingbirds do that with our car side-view mirrors, but 
this is a first for an oriole!).  We have feeders attached 
to this window, thus providing a perch for his pecking. 
Occasionally he lets off a brief musical chirp.  He doesn't 
appear particularly aggressive, just insistent.  So far, no 
damage to the window, but I'm worried about his beak! 
Should I discourage this behavior or leave him alone?...

Thanks,

D

P.S. Orioles have built a nest in a nearby tree---perhaps 
this is the male of this pair, worried about an intruder?

-- 
Derek C. Richardson, Laurel, PG County, MD
http://www.astro.umd.edu/~dcr/Archives/Photos/birds.html