My wife, my daughter, my son in law and I were walking the Lake Shore Trail at Elk Island, expecting to see some birds. I was rigged with the K10 + FA 1.7X AF + M 400/5.6, my daugher was sporting her new K200 with my A 70-210/4 on it, and my wife was expecting scenics with the MZ-S and FA 24-90/.
We met this handsome specimen on the trail. We did not complete the walk as he was coming our way. I was having quite a bit of difficulty moving backwards with only a walking stick monopod for lens support on the shady trail. August and September are the rutting season for bison here. It is not recommended to be closer than 100 meters (330 feet) to the bison. When we met him coming around a corner he was maybe 70 meters away. He weighs nearly a ton (900 kg) and stands about 6 feet (1.8m) at the shoulder.
This head shot was taken with the 1.7X on the lens. The light was from behind the bison, and I was probably about 40m from him. He just kept on walking in my direction. This shot is not cropped. f/11 (f/18.7 effective) at 1/60, ISO 400.
This full shot was taken after he took a drink from the lake. 1/500, f/8, ISO 400. He is not threatening, just turning after taking his drink, despite the appearance of an "evil eye".