WASHINGTON (AP) — House Republicans complain the Obama administration is refusing to turn over documents related to enforcing environmental laws at wind farms where dozens of eagles and other protected birds have been killed.

Rep. Doc Hastings of Washington says the Fish and Wildlife Service has engaged in a “deliberate slow rolling of documents and answers” for nearly a year. Hastings is the chairman of the House Natural Resources Committee.

The agency’s director, Dan Ashe, said Wednesday that he and his staff have made “super-human efforts” to fulfill the committee’s request, but that the volume of documents sought and timeframe for producing them were “completely unreasonable.”

An Associated Press investigation last year revealed that the administration was not prosecuting wind energy companies for killing eagles and other protected birds.

Construction is expected to begin later this year on a wind farm in northwest Missouri. Element Power officials say the operation near Oregon in Holt County will be the largest wind farm in the state.