Chapter 11Gen. 16:11 describes how, at the Covenant between the Pieces, when Abram laid out his sacrifices, birds of prey came down on the carcases, but Abram drove them away. Jubilees leads up to this by an extended piece of foreshadowing, the reasons for which I do not understand:
The prince Mastema sent ravens and birds to devour the seed which was sown in the land, in order to destroy the land, and rob the children of men of their labours. Before they could plough in the seed, the ravens picked (it) from the surface of the ground. For this reason [Nahor] called [his son's] name Terah because the ravens and the birds reduced them to destitution and devoured their seed. And the years began to be barren, owing to the birds, and they devoured all the fruit of the trees from the trees: it was only with great effort that they could save a little of all the fruit of the earth in their days.A few paragraphs later:
The seed time came for the sowing of seed upon the land, and they all went forth together to protect their seed against the ravens, and Abram went forth with those that went, when the child was a lad of fourteen years. A cloud of ravens came to devour the seed, and Abram ran to meet them before they settled on the ground, and cried to them before they settled on the ground to devour the seed, and said, 'Do not descend: return to the place whence you came!' and they proceeded to turn back.
He caused the clouds of ravens to turn back that day seventy times, and of all the ravens throughout all the land where Abram was there settled there not so much as one. All who were with him throughout all the land saw him cry out, and all the ravens turn back, and his name became great in all the land of the Chaldees. There came to him this year all those that wished to sow, and he went with them until the time of sowing ceased: and they sowed their land, and that year they brought enough grain home and eat and were satisfied
In the first year of the fifth week Abram taught those who made implements for oxen, the artificers in wood, and they made a vessel above the ground, facing the frame of the plough, in order to put the seed on it, and the seed fell down from it onto the share of the plough, and was hidden in the earth, and they no longer feared the ravens. And after this manner they made (vessels) above the ground on all the frames of the ploughs, and they sowed and tilled all the land, according as Abram commanded them, and they no longer feared the birds.