WASHINGTON - Criticized by a whistle-blower, the Fish and Wildlife Service conceded Monday that it bungled some of the science used in protecting Florida's endangered panthers.

The agency acknowledged three violations of a 2000 law that is intended to ensure the quality of data the government uses. Those involved issuing documents based on faulty assumptions about the habitat of one of the world's rarest animals, agency officials said.

Steve Williams, the agency's outgoing director, reached the conclusions as one of his last actions, based on a review by three senior Interior Department officials.

Dan Ashe, the service's top science adviser and a member of the review panel, said the agency relied too much on data collected only in late morning hours to establish the panthers' home range. Panthers are most active at dawn and dusk. The agency said it now would protect more variety of habitat, but not more acreage.

"I think the service was slow in responding to the changing science," Ashe said. "Those documents did not represent a complete and accurate picture of Florida panther habitat needs." He said the agency will withdraw and reissue several documents on the panthers.

About five years ago, before the complaint was filed, the agency began rethinking its assumptions about panther habitat by convening a study group, said Sam Hamilton, a regional Fish and Wildlife director in Atlanta. He said it's now believed the panther uses "a mosaic of habitats" rather than just primarily forests.

Because of that, said Jay Slack, who supervises Fish and Wildlife's South Florida ecological services office in Vero Beach, the agency will expand protections for more habitat such as prairie, wetlands, pasture and rows of crops where other animals feed.

"It's not just acreage, it's quality," Slack said.

Officials stopped short of saying they had vindicated Andrew Eller, a Fish and Wildlife biologist fired in November who worked in Slack's office. Eller filed a whistle-blower complaint that the agency used faulty science to approve development in panther habitats.

"The word 'vindicate' is one of those words people use when they're trying to make a point," said Ashe, who called the agency's response an "objective and independent review" of Eller's complaints.

Eller and Public Employees for Environmental Responsibility, an advocacy group, jointly challenged Fish and Wildlife in a petition last May under the Data Quality Act.

Jeff Ruch, PEER's director, said his group was "gratified, but constrained in that gratification, in that they're persisting in firing the biologist who they now admit was right."

Ruch said he was concerned that corrections to the data may not be made in time to stop 30 "mega-projects," but Hamilton called that "a gross exaggeration or stretch of the facts" because he said those decisions would be made "using best science."

Agency officials earlier had responded to Eller by saying he was consistently late in completing his work and engaged in unprofessional exchanges with the public. Eller described his office in Vero Beach as understaffed and his firing as politically motivated because he wanted to protect panthers from roads, houses and other developers' projects.

The government created the 26,000-acre Florida Panther National Wildlife Refuge in 1989. That and other measures have helped the panthers' population to roughly quadruple over the last 25 years, but still there are only about 80 to 90 adults and a few dozen kittens, Fish and Wildlife officials estimate.

The breeding population is considered to be below 50, the minimum required to sustain the population. Almost half of the panthers' habitat is on private property spread across several southwestern Florida counties.

ON THE NET

Fish and Wildlife Service: http://endangered.fws.gov/i/A05.html

Florida Panther Net: http://www.panther.state.fl.us

Public Employees for Environmental Responsibility: http://www.peer.org

National Wildlife Federation: http://www.nwf.org