A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

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)

During his time in Ethiopia, New York-based art director and photographer Diego Arroyo spent time with the Hamar, Mursi, Dassanech, and Arbore Tribes. They, along with several others tribes, make up the 200,000 people situated in Africa’s Great Rift Valley. The people of the Omo Valley are still primarily herders and farmers, living an isolated and simple life. While they have yet to be truly touched by globalization, they could soon disappear. Their way of life is being threatened by a massive hydroelectric dam. (Photo by Diego Arroyo)

Wednesday March 8 marks International Women's Day, with festivals, concerts and exhibitions among the numerous events planned around the world to celebrate the achievements of women in society. The annual event has been held since the early 1900s and traditionally promotes a different theme each year, with this year's edition calling on people to #BeBoldForChange and push for a more gender-inclusive working world. Reuters photographers have been speaking with women in a range of professions around the world about their experiences of gender inequality. Here: Yolaina Chavez Talavera, 31, a firefighter, poses for a photograph in front of a truck at a fire station in Managua, Nicaragua, February 22, 2017. (Photo by Oswaldo Rivas/Reuters)

1st prize in the People Observed Portraits Stories category. Carla Kogelman, the Netherlands. The photo shows Hannah and Alena, two sisters living in the rural village of Merkenbrechts, Austria. (Photo by Carla Kogelman/World Press Photo)

A jogger runs along Bregagh Road at Dark Hedges, Armoy, Northern Ireland, Wednesday, February 10, 2016. Road markings have been painted by mistake on the world famous road that features the Dark Hedges tree lined road which was made famous by the Game of Thrones and is now a massive tourist attraction. (Photo by Peter Morrison/AP Photo)

British holidaymaker Sean Chinn captures a crocodile on camera during a dive at the Jardines de la Reina marine park in Caribbean Sea, Cuba. (Photo by Sean Chinn/Caters News Agency)

Revellers take part in an annual block party known as “Cordao de Prata Preta”, one of the many carnival parties to take place in the neighbourhoods of Rio de Janeiro, February 6, 2016. (Photo by Pilar Olivares/Reuters)