Modeling an Endangered Species—
The Marbled Murrelet

This map illustrates an analytical model to predict suitable habitat for the endangered marbled murrelet of the Queen Charlotte Islands (QCI) on the west coast of Canada. The resulting dataset was used to support the protection of favorable habitat for this red-listed seabird.

The MacClennan model used a weighted score based on forestry and elevation data. Five habitat classes were developed based on the weighted score totals (for each polygon) using forest characteristics of age, height, crown closure, and elevation. The model was also applied to predict habitat for the year 1800 before logging and wildfires modified the local forest. The four smaller maps depict the correlation between the four data inputs used in the model and the QCI topography.

The preferred habitat of the marbled murrelet includes old growth forests at elevations up to 300 meters, tree heights greater than 54 meters, and medium crown closure (approximately 50 percent). These habitat qualities provide the murrelet with protection from predators by tree height while medium crown closure allows ease of access to fishing grounds at sea.

The modeled areas are being considered in an ongoing land-use plan for the islands. This GIS process forms a scientific basis of sound environmental conservation to assist the decision-making process by identifying concealed patterns from the past to the present.