WESLACO – A record number of ducks is causing concerns at a Rio Grande Valley state park.

A large population of the black-bellied whistling duck recently migrated to the area.

Staff at Estero Llano Grande State Park estimated as many as 5,000 ducks were in their ponds during the peak time earlier this month.

"We're seeing the numbers decrease a little bit so we're seeing the water quality improve just a bit,” says the park’s superintendent, Javier Deleon. "And, we hope to see the water quality continue to improve to encourage a different kind of variety of ducks and other animals in our ponds."

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