Effects of traffic noise on auditory surveys of urban White-winged Doves

We investigated the effects of urban noise on auditory surveys of White-winged Doves (Zenaida asiatica) in two major cities in Texas. We conducted auditory point counts throughout the morning in San Antonio (n = 6) and Austin (n = 10) during week days (when traffic noise is higher) and weekends. We categorized survey points as near or far from roads (< 0.8 and > 0.8 km, respectively) for comparison. We documented no difference in density estimates in Austin between week days (46 +/- 10 pairs/ha) and weekends (52 +/- 10 pairs/ha; P = 0.23); however, weekend estimates were consistently higher throughout the morning. Weekend density estimates in San Antonio were higher after 0620 hrs (P < 0.04), the time coinciding with beginning of the morning commute during week days in this city. We documented that weekend estimates (45 +/- 5 pairs/ha) were higher than week day estimates (33 +/- 5 pairs/ha) for points near roads (within 0.8 km; P = 0.02) but not for points far from roads (P = 0.16). Our results indicate that traffic noise can bias auditory surveys. Survey methods that account for probability of detection should be used to correct for potential noise bias.