Hi Michael,

I have no doubt that Northren Harriers can, and do, stand up against other predators. With hunger, all things are possible. However, more often than not, I see them robbed of prey by Red-tailed Hawks, Bald Eagles, and occasionally Peregrine Falcons. Generally, they seem very quck to drop their prey and flee, rather than scrapping with other raptors. Having witnessed a Peregrine Falcon prey on a Northern Harrier, I understand why! Check the link for some photos (somewhat gruesome) of an interaction that we recorded during raptor migration surveys in the McKenzie area of northern, BC, that did not work out so well for the Harrier.

http://www.flickr.com/photos/guylmonty/244539679/in/set-72057594118625124/

http://www.flickr.com/photos/guylmonty/244542729/in/set-72057594118625124/

thanks,

Guy L. Monty
Currently in Mount Vernon, WA