Habitat loss and hunting are among the primary threat factors for the animals on the list.
The 41-year-old female known as Nola saw her health take a quick turn for the worse.
The critter had held the dire designation since 1967.
Life just got better for some 3,000 species of plants and animals that gained protection after a 3.3-million-acre park was approved.
These often solitary great apes with soulful eyes can look like philosopher-kings.
Scientists say they've figured out at least 13 different vocalizations used by the animals to express various emotions.
Although it may look like a whimsical cartoon character, the axolotl is in serious trouble.
Yellowstone's grizzly bears have made a remarkable recovery, but some worry the bears could lose their Endangered Species Act status.
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