The eggs come from various species, but the most ‘domesticated’ is a ground-dwelling lizard that favors river banks, and over-lays like mad. So long as the lizards are well-fed, they produce eggs. Lots of eggs, the over-do strategy of some species that would have you hip-deep in lizards (or geese) if they were always successful. Overlaying is the strategy they practice (biologically speaking) rather than development of brain power. And the atevi have long had a supply of eggs. So have parid’ji. In the gradually loosening requirements of seasonality (since the egglaying in moderate climes goes on almost non-stop so long as the lizards get a good diet) enterprising people both feed the lizards to be sure they keep laying, the lizards hang around where there’s food, and the parid’ji can be bribed to trade eggs for sweets, so the entrepreneurs can parlay that arrangement into the parid’ji locating the egg stashes, the humans digging up the nest and taking most, the parid’ji getting their rewards, and the whole operation going on and on and on. Atevi protect and feed both the lizards and the parid’ji, so the system works with minimal effort and all species thrive.