HALF MOON BAY -- A necropsy report released late Friday showed two mountain cubs shot to death by California Department of Fish and Game wardens Dec. 1 were much younger and smaller than the agency had previously stated, and Director Charlton Bonham acknowledged the agency needs to do better.

The report, conducted by Fish and Game, found the cubs were about 4 months old and weighed 13-14 pounds, the size of a house cat. Their stomachs were empty and they were in poor condition when they were gunned down while huddling under a porch on the outskirts of downtown Half Moon Bay.

In defending itself against criticism after the shooting that it should have tranquilized the animals, the department initially described them as about twice as big -- 9 months in age and 25-30 pounds. Officials referred to the cubs at the time as "subadults" who had likely been preying on local pets.

"I now realize these animals were smaller than assumed. I regret this unfortunate incident in Half Moon Bay for all involved," Bonham said in a statement. "The department intends to learn from this experience. We take the safety of the public and the welfare of California's wildlife with the utmost seriousness."

Tim Dunbar, executive director of the California-based Mountain Lion Foundation, is one of several experts who had expressed skepticism about Fish and Game's initial reports on the shooting. The foundation is now working with the agency and Assemblyman Jerry Hill, D-San Mateo, to formulate legislation that aims to prevent such incidents in the future.

"This just reinforces our opinion that the actions taken in this situation were incorrect," Dunbar said. "And we're hoping that this will help bring some fundamental changes to the department in how it responds to public safety incidents involving mountain lions."

The legislation would likely put in place protocols to require wardens to give greater consideration to tranquilizing or trapping cougars. Hill said Friday that, if talks go well, he will have an announcement in the next few weeks. Under Proposition 117, which banned mountain lion hunting in 1990, such a change to the law would require a four-fifths vote of the state Legislature.

Bonham said Friday that an internal review was under way before the shooting and will likely wrap up in January.

"Prior to the incident at Half Moon Bay, I directed the department's leadership team to evaluate our guidelines on how we respond to interactions with mountain lions and bears and determine how we can do better," Bonham said.

The necropsy did not note anything abnormal about the cats, other than that they appeared to be starving, with little to no fat deposits. One of the cubs, which wildlife experts presume were orphaned siblings, had congestion in its lungs.

Contact Aaron Kinney at 650-348-4357. Follow him at Twitter.com/kinneytimes.