(Before we sue, we usually file a “notice of intent to sue” as a warning, which sometimes prompts action on its own.)
If the agency decides the species doesn’t warrant protection — well, if that decision contradicts what science tells us about the species’ imperilment, the Center will probably sue to challenge it. We’ll also probably sue if the agency takes too long to respond to our petition. (Before we sue, we usually file a “notice of intent to sue” as a warning, which sometimes prompts action on its own.)