Meeting Abstract
Birds externally exposed to crude oil have impaired flying performance due to crude oil damaging the microstructure of feathers. However, crude oil ingestion can also damage red blood cells (RBCs), which may reduce oxygen delivery to muscles and further limit flying performance. Although RBC damage has been previously described in birds exposed to crude oil, the effects of crude oil ingestion across levels of biological organization (e.g., RBC damage, metabolic scope for activity, and flying performance) remains unclear. In this study, we orally dosed zebra finches (Taeniopygia guttata) with 2 or 6 ml/kg of artificially weathered MC252 crude oil for 28 days and measured RBC integrity using traditional and novel endpoints, basal and maximal metabolic rates using a ‘hop-flutter’ chamber, and vertical flight speed and takeoff acceleration using a high-speed camera. Crude oil ingestion caused a decrease in packed cell volume (PCV) and an increase in reticulocytes, indicating regenerative anemia. Furthermore, we also detected an increase in fluorescent heme-degradation products (HDPs), a novel tool for measuring oxidative damage. Crude oil ingestion caused a reduction in resting metabolic rate, maximum metabolic rate, and aerobic scope. Interestingly, we found that birds exposed to crude oil increased vertical flight speed. Crude oil ingestion also caused a decrease in fat score, which may explain why oiled birds increased flight speed. Our results suggest that RBC damage in birds exposed to crude oil has metabolic consequences, but the metabolic effects do not impair short-range, burst flight.
