In the journal Nature, conservation experts said that Covid-19 also presents a serious threat to the survival of our closest living relatives, the great apes. They urged the suspension of great ape tourism and the reduction of field research (with provisions for lost income) until we know whether the mortality and morbidity of Covid-19 in humans are similar in apes. The transmission of even mild human pathogens has resulted in moderate-to-severe outcomes in these endangered animals in the past.