Videos posted to Instagram on Wednesday show the woman capturing what appear to be sparrows as she and a man sit on a bench near Independence Hall.
The man appears to toss food to a cluster of birds as the woman leans down and grabs one and puts it into a small plastic bag, which she ties off as the bird flaps around inside.
Park Service spokeswoman Gina Gilliam says a ranger approached the couple Tuesday over a complaint they were catching birds.
The ranger observed empty plastic bags and told the couple that trapping wildlife in the park is illegal.
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