What a beautiful looking red-tailed hawk, that Rosie is! 
Nest has been made with all kinds of bits of twine and rope, as well as twigs, etc. Sure do hope that the new mama doesn't get caught in any of these bits of twine/rope, as Violet did last season. 
Keep in mind that these are raptors that are capable of tearing apart their prey - rope/twine is an organic product and if the bird couldn't remove it, it will just rot off after a bit of time - that's why falconers use leather, if a bird takes off, their jesses rot off soon enough. If its more of a man-made product, they should be able to work it off in most cases. Getting caught, ie getting their foot snag and not being able to reach their foot that would be of more concern. And of the two bands that birds like ours have on, the FWS band is the one that I've seen removed more often than the coloured band. One of the Regina birds (and a Manitoba bird) back in the late 1990s, was missing its FWS/CWS band when it returned one year - nothing wrong with the bird's foot but no silver band.
And raptors get banged up on their feet - we had a bird with "bumble-foot" (a bacterial infection) and you couldn't believe a bird's foot could swell up that much, it was amazing. Took a long time for the vets to resolve the issue but it worked out in the end. Annoyed the bird though.
