For more than six months now, the ceremonial Ohtas, or Doll Being, has been hidden from view after the museum and others nationally took dramatic steps to board up or paper over exhibits in response to new federal rules requiring institutions to return sacred or culturally significant items to tribes — or at least to obtain consent to display or study them.

The doll, also called Nahneetis, is just one of some 1,800 items museum officials say they’re reviewing as they work to comply with the requirements while also eyeing a broader overhaul of the more than half-century-old exhibits.

But some tribal leaders remain skeptical, saying museums have not acted swiftly enough. The new rules, after all, were prompted by years of complaints from tribes that hundreds of thousands of items that should have been returned under the federal Native American Graves Protection and Repatriation Act of 1990 still remain in museum custody.

“If things move slowly, then address that,” said Joe Baker, a Manhattan resident and member of the Delaware Tribe of Indians, descendants of the Lenape peoples European traders encountered more than 400 years ago. “The collections, they’re part of our story, part of our family. We need them home. We need them close.”