A common kingfisher sits on a branch of a tree after catching an insect in Allahabad, India, Sunday, July 9, 2017. The common kingfisher is a highly territorial bird that has to eat nearly sixty percent of its bodyweight every day. (Photo by Rajesh Kumar Singh/AP Photo)

Three elephant seals put on a show in Roie Galitz's “Three Tanors”, taken on January 7, 2016 in South Georgia Island. The Comedy Wildlife Photography Awards are in full swing, so check out some of the fierce competitors jostling for the top prize this year. Photographers Paul Joynson-Hicks MBE and Tom Sullam founded the awards to spotlight wildlife conservation efforts and to inject some humour into the world of wildlife photography. (Photo by Roie Galitz/CWPA/Barcroft Images)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Over the years a large population of grey herons have made an unlikely home in urban Amsterdam. Julie Hrudova documents how the birds integrate into city life. Here: Hundreds of herons come to the city during winter to find food and shelter. (Photo by by Julie Hrudova/The Guardian)

A stork-billed kingfisher (Pelargopsis capensis) is seen perched on a tree during monsoon rain on July 25, 2016 in Bintan, Indonesia. The stork-billed kingfisher is a tree species which is widely but sparsely distributed in the tropical Indian subcontinent and Southeast Asia, from India to Indonesia. This kingfisher is resident throughout its range. It is very large, measuring 35 to 38 cm (14 to 15 in) in length. The adult has a green back, blue wings and tail, and grey head. (Photo by Sijori Images/Barcroft Images)

Martin Herrera, 58, who has had a love for roosters since his childhood, and has spent the last 20 years domesticating and training them, walks with his favorite rooster “Paquito” in San Jose, Costa Rica April 27, 2017. (Photo by Juan Carlos Ulate/Reuters)

Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)

A golden eagle grabs a flying drone during a military training exercise at Mont-de-Marsan French Air Force base, Southwestern France, February 10, 2017. (Photo by Regis Duvignau/Reuters)