While 'out back' looking for Red Tailed Hawks to photograph a number of Turkey Vultures were observed circling over a grove of trees ... watching them for a while I noticed a couple disappear into the trees ... however they didn't re-emerge. Making use of the terrain to stalk them it was possible to get quite close whereupon they were discovered feasting upon carrion; in particular, a rabbit carcass. Upon noticing me, all but one alighted. While keeping an intense eye upon my movements it continued tearing at the rabbit carcass as I shot photos and slowly, ever so slowly got closer and closer until I eventually crossed that magic line whereupon with great effort it lifted off and into blue above.