A saddle-billed stork stands in the grassland at the Nairobi National Park near Nairobi, Kenya January 23, 2017. REUTERS/Thomas Mukoya 

Migratory open-billed storks perch on a tree at a wildlife sanctuary in Raiganj, about 195 km (121 miles) south from the northeastern Indian city of Siliguri November 22, 2008. Every year thousands of migratory birds arrive from Siberia and central Asia to many Indian rivers, wetlands and sanctuaries in the winter months. REUTERS/Rupak De Chowdhuri (INDIA) 

Migratory open-billed storks perch on a tree at a wildlife sanctuary in Raiganj, about 195 km (121 miles) south from the northeastern Indian city of Siliguri November 22, 2008. Every year thousands of migratory birds arrive from Siberia and central Asia to many Indian rivers, wetlands and sanctuaries in the winter months. REUTERS/Rupak De Chowdhuri (INDIA) 

A migratory open-billed stork is seen perched on a tree at the Raiganj Kulik bird sanctuary, about 200 km (124 miles) south from the northeastern Indian city of Siliguri July 16, 2007. REUTERS/Rupak De Chowdhuri (INDIA) 

Open-billed storks carry grass back to their nests in Thailand's Ayutthaya Province, nearly 80 km (50 miles) north of Bangkok, January 26, 2007. REUTERS/Sukree Sukplang (THAILAND) 

An open-billed stork carries grass back to its nest in Thailand's Ayutthaya Province, nearly 80 km (50 miles) north of Bangkok, January 26, 2007. REUTERS/Sukree Sukplang (THAILAND) 

Open-billed storks are silhouetted at sunset while standing near their nests in Thailand's Ayutthaya Province, nearly 80 km (50 miles) north of Bangkok, January 25, 2007. REUTERS/Sukree Sukplang (THAILAND) 

Open-billed storks take flight during sunset in Thailand's Ayutthaya Province, nearly 80 km (50 miles) north of Bangkok, January 25, 2007. REUTERS/Adrees Latif (THAILAND) 

An Open-Bill Stork flies over a wild life sanctuary in Raiganj, 195 km (121 miles) south of northeastern Indian city of Siliguri October 23, 2005. Every year thousands of migratory birds arrive from Siberia and central Asia to many Indian rivers, wetlands and sanctuaries in the winter months. REUTERS/Rupak De Chowdhuri 

An open-bill stork looks for a resting place among others in Thailand's Kanchanaburi Province, about 130 km (80 miles) west of [Bangkok], October 22, 2005. [A Thai boy tested positive for bird flu on Friday, but doctors said he was recovering and there was no sign he caught the virus from his infected father who died earlier this week, calming fears of a human pandemic. New cases were reported in Britain, Romania and Croatia, but there was no immediate indication that they involved the lethal H5N1 strain of the virus.] 

An open-bill stork looks for a resting place among others in Thailand's Kanchanaburi Province, about 130 km (80 miles) west of Bangkok, October 22, 2005. A Thai boy tested positive for bird flu on Friday, but doctors said he was recovering and there was no sign he caught the virus from his infected father who died earlier this week, calming fears of a human pandemic. New cases were reported in Britain, Romania and Croatia, but there was no immediate indication that they involved the lethal H5N1 strain of the virus. REUTERS/Adrees Latif 

Open bill storks take flight over rice fields in Thailand's Kanchanaburi Province, about 130 km (80 miles) west of Bangkok, October 22, 2005. A Thai boy tested positive for bird flu on Friday, but doctors said he was recovering and there was no sign he caught the virus from his infected father who died earlier this week, calming fears of a human pandemic. New cases were reported in Britain, Romania and Croatia, but there was no immediate indication that they involved the lethal H5N1 strain of the virus. REUTERS/Adrees Latif 

Open-billed storks take flight from harvested rice fields in Thailand's Suphan Buri province, nearly 150 km ( 90 miles) northwest of Bangkok on July 27, 2004. Migrating birds, including storks, are widely blamed for spreading the H5N1 bird flu strain, which so far has killed millions of chickens and 24 humans, including eight Thais and 16 Vietnamese, earlier this year. Southeast Asian bird flu experts are expected to gather for a three-day meeting in Bangkok, starting tomorrow, to standardize ways of testing for the virulent bird flu strain and encourage governments to tell each other about outbreaks faster. REUTERS/Adrees Latif 

An open-billed stork finds a resting place as night falls in Thailand's Suphan Buri province, nearly 150 km ( 90 miles) northwest of Bangkok on July 27, 2004. Migrating birds, including storks, are widely blamed for spreading the H5N1 bird flu strain, which so far has killed millions of chickens and 24 humans, including eight Thais and 16 Vietnamese, earlier this year. Southeast Asian bird flu experts are expected to gather for a three-day meeting in Bangkok, starting tomorrow, to standardize ways of testing for the virulent bird flu strain and encourage governments to tell each other about outbreaks faster. REUTERS/Adrees Latif 

An open-billed stork lands into a palm tree as night falls in Thailand's Suphan Buri province, nearly 150 km ( 90 miles) northwest of Bangkok on July 27, 2004. Migrating birds, including storks, are widely blamed for spreading the H5N1 bird flu strain, which so far has killed millions of chickens and 24 humans, including eight Thais and 16 Vietnamese, earlier this year. Southeast Asian bird flu experts are expected to gather for a three-day meeting in Bangkok, starting tomorrow, to standardize ways of testing for the virulent bird flu strain and encourage governments to tell each other about outbreaks faster. REUTERS/Adrees Latif 

A migratory Asian Open billed storks sit in a tree in Ayutthaya, 80 km (50 miles) north of Bangkok, July 16, 2004. Thailand is culling wild storks believed to be carrying the bird flu virus. REUTERS/Sukree Sukplang SS/TW 

A migratory Asian Open billed stork sits in a tree in Ayutthaya, 80 km (50 miles) north of Bangkok, July 16, 2004. Thailand is culling wild storks believed to be carrying the bird flu virus. REUTERS/Sukree Sukplang SS/TW 

A migratory Asian Open billed stork flies at sunset in Suphanburi province, 105 km (66 miles) north of the capital Bangkok on January 28, 2004. The Thai government said migratory birds might have brought bird flu to Thailand. REUTERS/Sukree Sukplang SS/TW 

A migratory Asian Open billed stork sits in a tree in Suphanburi province, 105 km (66 miles) north of the capital Bangkok on January 28, 2004. The Thai government said migratory birds might have brought bird flu to Thailand. REUTERS/Sukree Sukplang SS 

An migratory Asian Open billed stork flies at sunset in Suphanburi province, 105 km (66 miles) north of the capital Bangkok on January 28, 2004. The government said migratory birds might have brought bird flu to Thailand. REUTERS/Sukree Sukplang SS/TW