“CBP Agriculture Specialists are the first line of defense to prevent the introduction of animal diseases that have the potential to cause significant damage to the Nation’s agricultural economy,” Troy Miller, Director, Field Operations, New York Field Office said in the statement, which went on to cite the 2015 outbreak of Highly Pathogenic Avian Influenza, also known as bird flu, that caused $850 million in damages.
According to the Washington Post, the passenger wasn't allowed to enter the US this time, but he will be able to reapply to visit in the future. He's been subject to a fine, but beyond that, there were no penalties.
As for the birds, they were turned over to the United States Department of Agriculture Veterinary Services.
h/t Washington Post