Explanation:

Bihar is holding a bird festival for the first time as part of its initiative to save migratory birds that arrive in the state in large numbers every year.

• The three-day festival is being organised in Bhagalpur district of Bihar.
• The 60-km stretch of Bihar’s Vikramshila Dolphin Sanctuary between Sultanganj and Kahalgaon had long been a hub of migratory birds.
• The ‘ringing of birds’ involves trapping them in nets and snares.
• Subsequently, they are weighed and their details logged before a metal ring inscribed with a unique number is tied to their tibia bone.
• This helps birdwatchers and professional conservationists log their presence across the globe.

Hence option 1st is correct.