You left off Parrots, which are just about as intelligent as Corvids. For example, keas have a similar number of pallial neurons to ravens (or maybe slightly more). Parrots and songbirds generally have extremely high neural density but still lower raw neuron counts compared to primates, which makes their competitiveness in many cognitive tasks interesting.

Among parrots, everyone knows African Greys but cockatoos are also highly intelligent, with goffin's cockatoos the standouts in terms of cleverness.