U.S. declares 21 endangered species extinct

• The FWS declared one mammal (Guam's Little Mariana fruit bat), eight mussels, two fish and 10 birds extinct. Eight of the birds delisted were endemic to Hawai'i'.

Zoom in: Development and agriculture "razed" the Hawaiian birds' forest habitats and the introduction to the islands of non-native, avian disease-carrying mosquitoes "provided the nail in the coffin" — and climate change is exacerbating threats for other endangered species, per a statement from the Center for Biological Diversity.

• Noah Greenwald, the nonprofit's endangered species director, told Axios in a video interview Monday evening that cold temperatures used to keep mosquitoes to low elevations in Hawai'i', but "now that it's getting warmer, mosquitoes are getting everywhere" due to climate change.

Threat level: Several other native Hawaiian birds are on the brink — notably the akikiki, which were nearly wiped out during Maui's climate change- related catastrophic fires in August as conservationists fought back flames at one sanctuary on the island, Greenwald noted. There are only five of these silver birds left in the wild.

• "Few people realize the extent to which the crises of extinction and climate change are deeply intertwined," Greenwald said in a statement Monday.

• "One silver lining to this sad situation is that protecting and restoring forests, grasslands and other natural habitats will help address both."

Zoom out: Scientists warned in 2019 that 1 million species were at risk of extinction globally, many of which could be lost within decades.

Go deeper: Earth's sixth mass extinction is underway and "rapidly accelerating," study warns