Cooperative breeding is defined as when more than two individuals contribute to the care of young in a single brood. For crows this means that, in addition to the mated pair, there can be up to 10 additional birds helping to raise this year’s brood. Generally, these are young males that are related to the male breeder. The motive behind cooperative breeding is somewhat mysterious since there are costs to both breeders and helpers. Costs to parents including diversion of food provisioning towards helpers and, for males, threat of paternity loss to helpers. Costs to helpers are more straight forward; they’re delaying their own breeding efforts to rear offspring which only share some of their genetic identity. So why do crows bother?
The brothers quarreled. The younger brother proposed that the speck was bringing food or that it was food, while the elder argued it was bringing lice or that it was lice. The elder flew to the chair back and perched there, croaking down at his brother, who crouched submissively yet croaked back before retreating to the merlon on the north side of the tower. When the elder brother followed him there, he took flight again.
When the elder brother was in his first year, his song dreams were sometimes overwhelming. Several times he woke himself. This waking was always preceded by a graduating panic as he formed the pattern of the song with his beak in silence. As he struggled from the ringing depth, his wings engaged, too, in the restlessness. The pattern deepened as he ascended. The pressure from above dissipated. In a gasp he broke the surface and, flapping and cawing in a singular pattern, startled his older sister awake.
In his adolescence, he would wander above the fields, sinking and climbing in a rhythm that seemed to emerge from the weight of the air itself, as if some pressure in it, graduating as he descended, pulsed back at back him at a certain altitude. He came to know it, and this knowing informed other categories of foresight.
And as he winged after his younger brother, he saw waves crashing against a rocky coast.
Flapping above the pasture that sloped away from the tower. Squeezing out the pattern. Flapping is not discrete motions. It is one exertion, and corvids are more adapted to doing it than humans are to walking. For a juvenile, flying is still exhilarating and dangerous. As the younger pressed his ascent, the elder quickly overtook him, climbing above him. The younger knew what this meant from watching a kestrel do the same thing to a young jackdaw. Overcome with fear and exposure, the younger abandoned his ascent and dove. It was ungraceful, in part a fall. He landed hard and cried out before recovering, then hugged his chest to the grass and soil again as his brother alighted next to him. And they held this attitude towards one another for what must have seemed a long time. The elder pecked at a mote in the soil, and the younger regained his legs. In the deepening shadow of the tower, they stepped in their patterns and cocked their heads alertly.