Sayyiduna Jabir (may Allah be pleased with him) narrates from Sayyiduna Umar (may Allah be pleased with him) that he ruled a ram for a hyena, a goat for a gazelle, and the young of a goat or sheep for a jerboa.
Abu Ubayd says: «Al-jafr» is "the young of goats that has reached four months of age and been weaned from its mother."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9887
Abu Ubaydah bin Abdullah bin Mas'ud narrates from his father, Sayyiduna Ibn Mas'ud (may Allah be pleased with him), that he ruled a jafr or jafrah (a young goat) for a jerboa.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9888