Delineating and identifying long-term changes in the whooping crane (Grus americana) migration corridor

Area of Science:

• Ornithology
• Conservation Biology
• Ecology

Background:

• Effective conservation of migratory species requires defining and identifying changes to their seasonal ranges.
• Historic sightings have been the primary data source for delineating the whooping crane migration corridor in the Great Plains.
• Understanding shifts in this corridor is crucial for the recovery of this endangered species.

Purpose of the Study:

• To update the delineation of whooping crane migration corridors using historical and recent telemetry data.
• To identify and quantify changes in the migration corridor's location and width over time.
• To inform conservation and recovery strategies for whooping cranes.

Main Methods:

• Combined opportunistic sightings (1942-2016) with telemetry data (2010-2016) from 58 whooping cranes.
• Delineated 50%, 75%, and 95% core migration corridors.
• Analyzed spatial shifts and changes in corridor width using statistical methods.

Main Results:

• Migration corridors were well-defined, with the 95% core averaging 294 km wide.
• Detected an average easterly shift of 1.2 km/year in the corridor from Oklahoma to Saskatchewan.
• Observed a modest narrowing of the migration corridor, averaging -0.7 km/year.

Conclusions:

• Whooping crane migration corridors have shown plasticity and shifted eastward over eight decades.
• Conservation and recovery actions may need to be adjusted to reflect these observed changes.
• Behavioral flexibility is key for whooping crane persistence amidst changing environmental conditions.