Search

Coastal bird species are often affected by oil spills and can suffer damage to the kidneys, adrenal glands, salt glands, and gastrointestinal tract. Although hypothermia is often touted as the proximate cause of avian death in oil spill events, birds can ultimately succumb to these petroleum product-related injuries based on blood electrolyte and acid-base abnormalities caused by multiple organ dysfunction. However detection and treatment of these analyte abnormalities remains challenging because we know little of the nature of analytes in the healthy water bird. Blood samples were obtained from free living and rehabilitated healthy Mottled ducks (Anas fulvigula), Black-bellied whistling ducks (Dendrocygna autumnalis), Yellow-Crowned Night Herons (Nyctanassa violacea) and Brown Pelicans (Pelecanus occidentalis) from 2008–2012. Blood gas, electrolyte, and select biochemical and hematological parameters were determined in the field with a patient side analyzer while complete blood counts, packed cell volumes and osmolalities were determined by standard laboratory methods. Reference intervals and 95% confidence intervals were determined and the effect of age, sex, body condition, time and date of sampling were also assessed for all analytes. Species, lifestyle, environment, and diet all appear to have an effect on “normal” electrolyte and acid base analytes in coastal birds. An increased plasticity of and tolerance to change in blood analytes may be a normal finding in these species which may facilitate care in the response setting. The reference intervals of apparently healthy coastal birds differed from mammalian values in some instances, however these intervals will assist in the appropriate diagnosis and treatment of these species in rehabilitation and oil spill response. These values can be used to assist biologists, rehabilitators and veterinarians in assessment, management and treatment of avian species in the event of environmental disturbance, such as oil spill, draught, or tropical storm as well as to assess overall ecosystem health via coastal birds as indicator species.