Jack Dykinga / Rainbow over Long Canyon with fall coloured Cottonwood (Populus) trees against canyon walls, Burr Trail, Grand Staircase-Escalante National Monument, Utah, USA, October 2018.

Nick Hawkins / Chum salmon (Oncorhynchus keta) migrate up a small river near Bella Bella, British Columbia, Canada. September

Marie Read / Wood Ducks (Aix sponsa), females behave aggressively toward a male (second from right) that is trying to join them on a floating log, autumn, New York, USA, October.

Marie Read / Snow buntings (Plectrophenax nivalis) flock in flight during a snowstorm, New York, USA, January.

Marie Read / Blue jay (Cyanocitta cristata) holding an acorn in its bill whilst perched on tree stump, with autumn foliage, New York, USA, October.

Jeff Foott / Cottonwood (Populus sp) trees in autumn, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Mountains and river after autumn snowfall, Sunwapta River, Jasper National Park, Alberta, Canada

Jeff Foott / Mixed coniferous and deciduous forest after snowfall in autumn, Wells Gray Provincial Park, British Columbia, Canada

Jeff Foott / Waterfall after autumn snowfall, Tangle Creek Falls, Jasper National Park, Alberta, Canada

Jeff Foott / Waterfall after autumn snowfall, Tangle Creek Falls, Jasper National Park, Alberta, Canada

Jeff Foott / Fremont Cottonwood (Populus fremontii) trees in autumn, Bentonite Hills, Capitol Reef National Park, Utah

Jeff Foott / Hiker near waterfall and rainbow, Nevada Fall, Yosemite National Park, California