Martin Willis / Victoria's Riflebird (Ptiloris victoriae) male in courtship display, Atherton Tableland, Queensland, Australia. Sequence 2 of 3

Bernard Castelein / Yellow-rumped cacique (Cacicus cela) calling, Madidi NP, Bolivia

Marie Read / Red-winged Blackbird (Agelaius phoeniceus) male displaying in cattail marsh, Viera Wetlands, Brevard County, Florida, USA, January.

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

Marie Read / Arctic terns (Sterna paradisaea), two in flight over nesting colony in field of buttercups (Ranunculus sp.), Keflavik, Iceland. Digital canvas expansion.

Marie Read / American avocets (Recurvirostra americana) two during aggressive (territorial) encounter, Bear River Migratory Bird Refuge, Utah, USA, May.

Stefan Christmann / Adelie penguin (Pygoscelis adeliae) calling during courtship, Atka Bay, Queen Maud Land, Antarctica, December.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri), group of three males incubating, one with begging chick. Atka Bay, Antarctica. August.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) male feeding chick aged a few days. Atka Bay, Antarctica. August. Sequence 1/2.

Guy Edwardes / Marsh Frog (Pelophylax ridibundus) vocalising with bokeh effect in the background, Danube Wetlands, Bulgaria

Guy Edwardes / Marsh Frog (Pelophylax ridibundus) vocalising with bokeh effect in the background, Danube Wetlands, Bulgaria

Donald M. Jones / Yellow-headed Blackbird (Xanthocephalus xanthocephalus) male calling, Montana