White-throated magpie-jays are large, brightly colored birds with long tails and crest feathers. Body weight typically ranges from 205 and 213 g and body length from 46 to 56 cm. Sexual dimorphism is evident in tail length, with females having much shorter tails (267 to 314 mm) than males (284 to 334 mm). Most other male and female body measurements are similar. Wingspan typically ranges from 178 mm to 193 mm. Tarsus length ranges from 39 to 46 mm and bill length from 29 to 34 mm.
Adult white-throated magpie-jays have mostly white face and ventral coloration with rich blue dorsal feathers. Both sexes have a black ring that runs across their breast, beginning behind the eye. Males and females can be distiguished by coloration, with a thinner and often incomplete black ring in males. Males also have partially white crests and very little black coloration above the eye. In contrast, females tend to have almost entirely black crests, and much black or black-and-white mottled coloration above the eye. The auricular patch (patch around the internal ear), is black in both sexes, but much more pronounced in females, often blending into the breast ring.
Range mass: 205 to 213 g.
Average length: 50.8 cm.
Range wingspan: 17.8 to 19.3 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently