Matutinal

matutinal \ˌma-chu-ˈtī-nəl; mə-ˈtüt-nəl\ adjective: 1. of, relating to, or occurring in the morning, 2. of an organism, active in the pre-dawn hours or early morning

Etymology: Late Latin matutinalis, from Latin matutinus, from Matuta goddess of morning

January 7th's post on crepuscular gave its meaning as “active during twilight”. Since twilight can refer to dawn or dusk, we need matutinal to specify dawn at the exclusion of dusk.