This term identifies a swift-flying bird, though exact identification has eluded translators. Jeremiah lists it among migratory birds that instinctively know their appointed times—the stork, turtledove, and crane observe their season, yet God's people fail to recognize their obligations. The word suggests speed and perhaps the darting, erratic flight characteristic of swifts or swallows. Ancient audiences would have watched these birds arrive and depart with seasonal regularity, making their obedience to natural law a sharp contrast to Israel's spiritual waywardness.