Differences between Scaly-sided Merganser (Mergus squamatus) and Common Merganser (M. merganser) feather...

Area of Science:

• Ornithology
• Microscopy
• Morphology

Background:

• Feather microstructures are crucial for avian species identification.
• Understanding these structures aids in differentiating closely related species.

Purpose of the Study:

• To investigate inter-species microstructural differences in contour, rectrices, and down feathers between Scaly-sided Merganser (Mergus squamatus) and Common Merganser (Mergus merganser).
• To evaluate the potential of feather microstructural characteristics as reliable indicators for species identification.

Main Methods:

• Scanning electron microscopy (SEM) was utilized to examine feather microstructures.
• Stepwise discriminant analysis and leave-one-out cross-validation were employed to assess discriminatory power.

Main Results:

• Significant variations were found in specific microstructural features of rectrices (e.g., hooklet number, prong length) and down feathers (e.g., barbule length, node number, distance between nodes).
• Discriminant analysis achieved high correct classification rates: 56.9% for contour feathers, 91.3% for rectrices, and a perfect 100% for down feathers.
• Down feather characteristics (barbule length, node number, distance between nodes) proved to be the most effective discriminators.

Conclusions:

• Feather microstructural characteristics, particularly those of down feathers, serve as highly reliable morphological markers for distinguishing Scaly-sided Merganser from Common Merganser.
• SEM-based analysis of feather morphology offers a robust method for avian species identification.