Table 1. Definitions and measuring tools for biometric variables of Pelecanoides georgicus populations.

Biometric variable	Measuring tool	Definition
Wing length	Wing ruler	Flattened wing chord from carpal joint to longest primary (P10).
Length of T6	Tail ruler	Distance from point of insertion to tip of the outermost tail feather (T6).
Length of T1	Tail ruler	Distance from point of insertion to tip of the innermost tail feather (T1).
Bill length	Dial/vernier callipers	Distance on a horizontal plane from front curve of upper mandible to distalmost crown feathers.
Bill width	Dial/vernier callipers	Width at distalmost crown feathers.
Bill depth	Dial/vernier callipers	Depth (height) of both mandibles at the distalmost crown feathers, including nostrils (nasal tubes).
Arch length	Dial/vernier callipers	Distance from the apex of the lower mandible rami to the distalmost throat feathers.
Head length	Dial/vernier callipers	Distance from the front curve of upper mandible to the supraoccipital.
Tarsus length	Dial/vernier callipers	Distance from the notch between the digits and the tarsometatarsus to the notch between the tarsometatarsus and the tibiotarsus.