Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahmanthat Muhammad ibn Ibrahim ibn al-Harith at-Taymi said, "I heard myfather say that the aqiqa was desirable, even if it was only asparrow."
USC-MSA web (English) reference: Book 26, Hadith 5
Arabic reference: Book 26, Hadith 1074