KhIRS (Ursidae), yak nav hayvoni darrandaro guyand. Bino ba tasnifoti zoologi khirs yak oilai shirkhurhost. Daroziash 1,5—3 m, vaznash az 60 to 700 kg. 7 namudi khirs (aynakdor, labdaroz, malayi, himoloy, malla, safed va baribal) malum ast.
Aksari onho dar nohiyahoi nimkurai shimoli maskun shudaand, faqat khirsi aynakdor dar Amerikai Janubi vomekhurad.
Dar jangalzori Tojikiston khirsi malla (U. agctos) zindagi mekunad. Vaznash ziyoda az 300 kg. Khurokash meva, jalguza, resha, chormagz va inchunin hasharot, kirm, kaltakalos, mohi, qurboqqa, khoyandaho ast. Az tiramoh ba khobi zimistona meravad. Davrai hamlash 7 moh; dar 2 sol yak marotiba (odatan duto) bacha mezoyad.
Xirs 30—40 sol umr dida, dar 3—4- solagi afzoish mekunad. Ravganu talkhaashgro dar tib istifoda mebarand. Sarshumori hamai namudhoi khirs kam shudaast va az in sabab onhoro dar bisyor kishvarho (az jumla dar Tojikiston) muhofizat mekunand.