From 9-foot tall ostriches to albatrosses with gargantuan wingspans, here are some of the biggest birds in the world.

More than 500 species of birds have been spotted in Arizona. An expert birder shares his top 10 list, including a couple you'll likely only see here.

Conservation groups sued the Trump administration today for unconstitutionally waiving dozens of environmental laws to speed ...

Birds that call Arizona's desert ecosystem home — including the state's iconic cactus wren — are in serious decline, according to a sweeping new conservation report. Why it matters: Birds are ...

Arizona’s desert birds are in decline, according to a national conservation report tracking long-term bird populations, prompting one conservation group to ask the federal government to take ...

All confirmed avian flu infections in the species have been found in northern Arizona.

Mount Graham red squirrels live only in the Pinaleño Mountains of southeastern Arizona, where their protected habitat has ...

Environmental groups have filed a lawsuit for allegedly failing to protect the habitat for two endangered species of birds along Gila River.

In one of the largest studies of cancer susceptibility across bird species, researchers describe an intriguing relationship between reproductive rates and cancer susceptibility.

Bird species most at risk of extinction in US About 70 species of birds have lost at least half of their populations in the past 50 years.

In one of the largest studies of cancer susceptibility across bird species, researchers at Arizona State University describe an intriguing relationship between reproductive rates and cancer ...