Quantifying the Responses of Songbirds and Woodpeckers to Changes in Habitat at the Stand and Landscape Scales: Testing for Thresholds and Setting Management Targets

How do species respond to changes in habitat, and can their responses be used to set reliable management targets? The intern’s research is focused on determining whether forest birds respond non-linearly to the loss of forest habitat due to logging. For example, theoretical models show that the probability of finding forest birds within a given patch of forest declines sharply when less than 30% of forest cover remains in the patch. A point of sharp decline in a graph of a particular response to habitat loss is referred to as a 'critical threshold' or 'habitat threshold'. Thresholds indicate the point at which species become highly affected by habitat loss, and thus, can be used as a guide to set quantitative management targets - such as the amount of forest that should be not be logged. The intern proposes to quantify changes in bird abundance and reproduction in response to changes in habitat at the stand and landscape scales using an intensive survey method. She will statistically test for non-linearity and thresholds in these relationships, and then she will compare the results to a related study that will estimate responses using a standard, less intensive survey method.

Kelly Squires
Faculty Supervisor: 
Dr. Kenneth Lertzman
British Columbia