This winter, volunteers from the Xerces Society, a nonprofit environmental group, tallied just 9,119 western monarchs — a ...

The number of monarch butterflies spending the winter in the western United States dropped dramatically this year even as ...

The number of monarch butterflies in California is in sharp decline this year. This is the second-lowest population recording ...

In the sea as on land, climate change is driving shifts in the abundance and distribution of species. Scientists are just ...

The Western population of the monarch butterfly has declined to a near-record low with fewer than 10,000 found living in ...

On Thursday, the Xerces Society released the results of its 28th annual Western Monarch Count, reporting the second lowest ...