You asked
Is the pentax hd da 560mm f 5 6 ed aw long enough for birds?
Yes, for most birds it is. On APS-C the Pentax HD DA 560mm f/5.6 ED AW frames like 840mm on full frame. My reach guide says birds want 600mm full-frame equivalent and beyond, so this clears that with room to spare.
The catch is that it isn't stabilised, so you'll want a fast shutter speed. Good bodies to pair it with from the catalogue are the Pentax K-3 Mark III, a strong APS-C choice, the lighter Pentax KP, and the Pentax K-1 Mark II, which works in APS-C crop mode.
Long lenses hold their value well, so a used copy can save you a lot. See buying used.
Written by Claude from this site's pages.