This data publication contains data files collected as part of a field, laboratory, and modeling effort aimed at uncovering ecological drivers of avian malaria transmission and impacts on Hawaiian honeycreepers across an elevational gradient on the eastern flank of Mauna Loa and Kilauea volcanoes on Hawaii Island. From 2001-2004, mosquito and bird data were collected at nine sites ranging 25 to 1,800 m above sea level. This data publication includes site and sampling coordinate data, mosquito capture data, mosquito avian malaria infection data, and point-transect distance sampling data. Site coordinate data consists of GPS spatial location data of sampling points where mosquitoes were captured and birds were surveyed to estimate abundance, comprising 45 points per site at 100 m intervals along five transects spaced 200 m apart. Mosquito capture data consists of counts of mosquitoes captured per trap night during 4-9 trapping nights per site per month over the study period. Mosquito infection data comprises avian malaria diagnostic data for a subset of captured mosquitoes that were dissected and malaria infection determined by microscopic examination of mosquito midguts and salivary glands. Point-transect distance sampling data consists of quarterly bird survey data in which observers recorded the horizontal distance of each sampling point to birds detected by sight and sound during 8-minute counts.