Abstract

The Punta San Juan Marine Protected Area (PSJ) (15°22'S, 75°12'W) protects Peru's largest breeding colony of the endangered Humboldt penguin (Spheniscus humboldti), as well as key populations of Peruvian pelicans (Pelecanus thagus) and Guanay cormorants (Phalacrocorax bougainvillii). Cormorant and pelican populations have been protected for over 100 years with their guano harvested for use as fertilizer. Humboldt penguin conservation is intimately linked to these species, as the guano reserves provide protected habitat to the penguins and the guano provides preferred nesting substrate to dig burrows. The high seabird population density and close contact between species could expose penguins to diseases impacting population health. This project's aim was to 1) gather data on the cormorant and pelican populations to define current health, 2) provide a baseline for continued monitoring over time, and 3) allow for a better understanding of potential disease transmission risks to Humboldt penguins when coupled with existing data on penguin population health.

Samples from 110 cormorants and 45 pelicans, including 10 chicks from each species, were collected. Birds received examinations including: weights, measurements, reproductive status, and parasite burden. Samples were collected for complete blood cell counts, plasma biochemistries, plasma protein electrophoresis, gender determination, and diagnostic testing for avian pathogens (paramyxovirus types 1–3, adenovirus types 1–2, reovirus, equine encephalitidities (eastern, western, Venezuelean), West Nile virus, avian influenza, infectious bursal disease, Marek's disease, encephalomyelitis virus, Mycoplasma gallisepticum, Salmonella pullorum, Chlamydophila, and Aspergillus).

Results of this health assessment suggest a relatively low exposure to common avian pathogens. Paramyxoviruses, adenoviruses, and Venezuelan equine encephalitis were identified most frequently. These results highlight the potential susceptibility to disease outbreaks in this population and identify possible future threats that can guide conservation efforts. Continued monitoring of avifauna health at PSJ is vital to protecting this unique ecosystem and the endangered Humboldt penguin.

Acknowledgments

The authors thank all persons involved with this field project, with specific thanks to Susana Cárdenas-Alayza, Michael Macek, Armando Valdes-Velasquez, Daniel Abugattas, Santiago De la Puente, Patty McGill, and Eric Jeltes. Special thanks to Dr. Patricia Majluf for her long-standing commitment to conservation of Punta San Juan's wildlife. Funding for this project was generously provided by the Chicago Zoological Society, the Chicago Board of Trade Endangered Species Fund, the Saint Louis Zoo WildCare Center, and the Saint Louis Zoo Field Research for Conservation Fund.

* Presenting author