The kidnapping occurred about 0100 local time (midnight GMT) in a village outside the town of Birnin Konni on the Nigerian border, the sources said.
Niger, like much of West Africa's Sahel region, is struggling with a deepening security crisis as groups with links to al Qaeda and Islamic State carry out attacks on the army and civilians, despite help from French and US forces.
Four US soldiers were killed in an ambush there in 2017, sparking a national debate about America's role fighting Islamists in the sparsely populated West African desert that is home to some of the world's poorest countries.
The kidnapped man has been living in the village of Massalata for about a year with his daughter and his brother, and had bought a plot of land and built a house, said Ibrahim Abba Lele, prefect for Birnin Konni.
The man's father has lived there since 2003. They raise camels and often walk them into the surrounding bush, Lele said.
"They were so exposed that he was abducted without anyone knowing," he told Reuters.
The rest of the family was tied up so they could not inform the authorities, and police were not aware that the kidnapping has taken place for about four hours. Authorities believe that he has been taken over the border into Nigeria, Lele said.
US and Nigerien officials did not respond to requests for comment.
Attacks in Niger have generally been restricted to a western zone bordering Mali and Burkina Faso, but there have been signs of encroachment this year.
In August, gunmen on motorcycles killed six French aid workers, a Nigerian guide and a driver in a giraffe reserve just 65 km (40 miles) from the capital Niamey.
Birnin Konni is a few hundred miles to the east of that region. It is also hundreds of miles from a corner of south east Niger that has come under attack from Boko Haram militants based in Nigeria.
Kidnappings in the region are infrequent but not rare. At least six foreign hostages are being held by Islamist insurgents in Mali, Burkina Faso and Niger.
Two of these were taken in Niger, including US aid worker Jeffery Woodke, who has been missing since October 2016, and Joerg Lange, a German aid worker who was taken in April 2018 from a town near the Malian border.Islamists have collected millions of dollars in ransom payments as a result of kidnappings in recent years. The US government has frequently criticized other countries for paying.