A federal agency is sifting through thousands of comments regarding a Texas hunter’s application for a permit to import the carcass of an endangered black rhinoceros that he hopes to kill.

Since publishing the application request in November, the US Fish and Wildlife Service has received more than 15,000 comments about the hunter’s request, as well as petitions with about 135,000 signatures demanding that it be denied.

Although other agency measures have drawn more comments, “I’m not sure we’ve ever received a petition quite like this one before,” said service spokesman Gavin Shire, adding that the permit department normally receives no more than eight comments per application.

Shire said the agency will examine the public comments “for substantive information” as it weighs whether the hunt in Namibia – where 1,800 of the remaining 4,880 black rhinos live – is a form of conservation.

The hunter, Corey Knowlton, bid $350,000 at an auction last January that the Dallas Safari Club billed as a fundraising effort to save the species.

The club said the hunt is postponed until Knowlton gets permission to import the trophy of one of five black rhinos approved by the Namibian government for culling.

Namibia sold another hunting permit directly to Michael Luzich, a Las Vegas investment manager who is also seeking a permit to bring the trophy into the US.

But Luzich has received far less scrutiny than Knowlton, who said in January he had hired full-time security because he received death threats after his name was leaked on the internet.

The agency granted a permit to import a sport-hunted black rhino taken in Namibia in 2009, but has said it is applying extra scrutiny to Knowlton’s request because of the rise in poaching.

Environmentalists say the animals are already under the gun for their prized horns, and that allowing them to be hunted is wrong.

“Kill it to save it is counterintuitive and flawed logic,” said Jeff Flocken, the North American regional director for the International Fund for Animal Welfare. “The fact that some Americans are showing they will pay any price to kill one of the last black rhinos is not going to help the species in the long run but only continue to put a price on its head.”