An oriented coloring of planar graphs with girth at least five

An oriented kk-coloring of an oriented graph GG is a homomorphism from GG to an oriented graph HH of order kk. We prove that every oriented graph with a maximum average degree less than 103 and girth at least 5 has an oriented chromatic number at most 16. This implies that every oriented planar graph with girth at least 5 has an oriented chromatic number at most 16, that improves the previous known bound of 19 due to Borodin et al. [O.V. Borodin, A.V. Kostochka, J. Nešetřil, A. Raspaud, É. Sopena, On the maximum average degree and the oriented chromatic number of a graph, Discrete Math. 206 (1999) 77–89].