The Denver Zoo is welcoming two of its newest residents and a brand new species to the zoo -- two critically endangered Somali wild asses, Kalifa and Kamowa, half-brothers who just arrived from the San Diego Wild Animal Park.

Kalifa was born in San Diego in July 2008, followed by Kamowa in February of 2009. The two wild asses share the same father, according to a Denver Zoo press release.

At about four feet tall at the shoulder and weighing about 600 pounds, Somali wild asses are smaller than most of the other members of the equid family, which also includes horses and zebras. This species is usually found in the arid grasslands and semi-deserts of Ethiopia and Somalia.

The International Union for Conservation of Nature (IUCN) classifies the Somali wild ass as critically endangered with a wild population of less than 1,000 individuals.

Look at photos of The Denver Zoo's new Somali wild asses below, watch video above.

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  • Kalifa and Kamowa, The Denver Zoo's new Somali wild asses. (photo via The Denver Zoo)

  • One of The Denver Zoo's new Somali wild asses. (photo via The Denver Zoo)

  • One of The Denver Zoo's new Somali wild asses. (photo via The Denver Zoo)

  • One of The Denver Zoo's new Somali wild asses. (photo via The Denver Zoo)

  • Israela, a month old Somali wild ass stands in the enclosure at the Ramat Gan safari park near Tel Aviv, Israel, Wednesday, May 30, 2012. According to the International Union for Conservation of Nature, the Somali wild ass is a critically endangered species, facing a high risk of extinction in the wild. (AP Photo/Ariel Schalit)