I don't think endangered species listing is enough to keep President Obama from signing or congress from voting on the must pass spending bill.
Politico has a pretty good in depth write up.
Sec. 122. None of the funds made available by this or any other Act may be used by the Secretary of the Interior to write or issue pursuant to section 4 of the Endangered Species Act of 1973 (16 U.S. C. 1533) --
a proposed rule for greater sage-grouse (Centrocerus urophasianus);
a proposed rule for the Columbia basin distinct population segment of greater sage-grouse;
a final rule for the bi-state distinct population segment of greater sage-grouse; or
a final rule for Gunnison sage-grouse (Centrocerus minimus).
So what's the big deal? This is congress making decisions on endangered species. The important part is what listing might do and who does and doesn't want it listed.
Big Oil. Big Enviro.
Listing could impede or stop every access road to do anything at all in the oil fields of most western states. Environmentalists have looked upon sage grouse as the holy grail of endangered species, the species occurs just about everywhere there is sage brush. Listing the sage grouse could justify lawsuits to stop everything from oil to ranching to condos to any sort of building at all. All the states have robust sage grouse conservation programs as do many private landowners etc. They are making every effort to appear to be trying like hell to save the prairie chickens (yes I know technically they aren't exactly the same bird, gimmee a break) The problem is populations have crashed already and no one is sure why or how to increase them or if it is even possible.
The sage grouse is a spotted owl on steroids. It would allow litigation over most BLM land. This rider only addresses a few distinct population segments, and only for a year. I strongly suspect that the new congress will make changes to the Endangered Species Act itself. The Oil lobby has been pumping an unusual amount of money and effort into old large powerful Sportsmen's Groups, something they hadn't done before. I doubt all this forethought and effort is simply over sage grouse which is a barely hunted species.
I'd look for many more riders to come.
I figured this is an appropriate song, Garden of Eden is an anthem to a sullied environment and it's by the New Riders of the Purple Sage.