An oriented coloring of planar graphs with girth at least five

An oriented k-coloring of an oriented graph G is a homomorphism from G to an oriented graph H of order k. We prove that every oriented graph with maximum average degree strictly less than 10 3 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. [Borodin, O. V. and Kostochka, A. V. and Nešeťril, J. and Raspaud, A. and Sopena, É., On the maximum average degree and the oriented chromatic number of a graph, Discrete Math., 77–89, 206, 1999].