On today's First Up pod - We get the latest on California's spate of mass shootings; Novac Djokovic defies the hecklers to march on in the Australian Open; we talk with Green Party co-leader Marama Davidson ahead of the swearing in of Chris Hipkins as Prime Minister - what will it mean for the coalition's smaller member? And we meet the Auckland postie who's written a children's book about some of the 160 dogs he's met on his route. First Up - Voice of the Nathan!