Kali Holder, a veterinary pathologist at the National Zoo, is motivated by problem-solving and a passionate curiosity about nature. Image: courtesy of Kali Holder When an animal becomes endangered, it ...

Nomad Scythian herders roamed vast areas spanning the Central Asian steppes during the Iron Age, approximately from the 9th to the 1st century BCE (Before Common Era). These livestock pastoralists, ...

Sixty-five percent of households in the U.S.—almost 80 million families—own a pet today, according to a survey by the American Pet Products Association. In addition to offering unconditional love and ...