Voyageurs National Park has initiated a study of the double-crested cormorant colony in Lake Kabetogama.
Information gained from the study will provide valuable information to the National Park Service and Department of Natural Resources regarding the status of cormorants in the area and their role in aquatic ecosystems, according to Steve Windels, terrestrial ecologists for Voyageurs National Park.
“Cormorants are a really hot topic right now,” said Windels. “This study will allow us and other agencies to make management decisions based on the best scientific evidence available.”
The study has four objectives:
• Determine population and size and other demographic characteristics including numbers of fledged young produced per nest.
• Describe foraging behavior of adult birds using radio telemetry and sightings of color banded individuals.
• Estimate diet composition of adults and chicks.
• Determine prevalence of diseases such as West Nile virus, Newcastle disease, and avian influenza, including the highly pathogenic strain HPAI, in local cormorant populations.
NPS staff and collaborators will visit the colony periodically to outfit cormorants with radio transmitters and color bands and to collect samples. Three other colonies in the Ontario portions of Rainy Lake may also be studied, in part to allow comparisons in cormorant population characteristics and diet composition between Kabetogama and Rainy lakes.
Cormorants are native to Minnesota, and have been in the Voyageurs National Park area since at least 1500 AD, according to archeological evidence and records from early explorers, notes Windels. The colony on Kabetogama was first settled in 1999, peaked at 330 breeding pairs in 2005, and now contains between 100 and 150 pairs. By comparison, Lake of the Woods harbors more than 5,000 breeding pairs.
Double-crested cormorants are a protected species under National Park Service policies.
For more information about the study, contact Windels at 283-6692.