Health Assessment of the Humboldt Penguin Population

Dr. Mike Adkesson, one of the Saint Louis Zoo's veterinarians, recently returned from a field project at Punta San Juan, Peru. Dr. Adkesson was working on a project investigating the health of the Humboldt penguin population at the reserve. Punta San Juan has the largest population of penguins in Peru and is a very important breeding site. A thorough understanding of the current health of this population is important for conservation efforts. Veterinary examination of individual birds provides important information on the health of individual penguins, which can then be used to construct an image of the health of the entire population. Knowledge of what diseases are currently present in the colony gives us the ability to monitor for changes over time. Introduced or emerging diseases that are not currently present in the region could represent potential threats to the population at Punta San Juan. The recent emergence of new threats such as West Nile virus and highly pathogenic avian influenza are good illustrations of diseases that could have severe population effects. Dr. Adkesson's fieldwork also encompasses collaborative toxicological work and nutritional studies, which provide valuable data on the health of the population. Comparative data from wild penguins will further help our understanding of normal parameters for this species and allow us to provide the best care possible in captivity.

During a two week stay in Peru, Dr. Adkesson and his team were able to examine and collect samples from 80 adult penguins and 20 chicks. All the birds were given a complete veterinary examination, weighed, and measured. Blood collected from the penguins was assessed for routine indicators of health. Serologic testing of the blood is being performed to check for evidence of 19 different diseases in the population. Plasma will also be used to assess vitamin, mineral, amino acids, and fatty acids levels as indicators of nutritional health and diet composition in the wild. Blood samples from the chicks are also being used to assess calcium and calcium hormone levels to provide important comparative data to samples from captive chicks as a method to prevent bone diseases in young penguins. External parasites were collected for identification, and fecal samples were examined for intestinal parasites. All the penguins were implanted with a small microchip (similar to the type used in a pet dog or cat) to allow for future identification. The veterinarians also trained local field biologists in Peru on how to collect tissue samples from any deceased penguins they encounter. The tissue samples will be able to provide additional toxicological data to determine exposure to environmental pollutants.

The project has been designed as part of a long-term effort to monitor the health of the population. The data gathered this year, combined with data from additional samples collected next year, will provide a fairly complete baseline set of data off of which future studies will be based, aiding in the conservation of the Humboldt penguin at Punta San Juan.

Saint Louis Zoo
June 2007