Secondary Sexual Characteristics are elements of a creature's physiology that result from it being male or female. It is one step removed from "primary sexual characteristics" (which describes the actual reproductive organs). For example, everyone knows that only male lions have that iconic mane of fur around their neck, and that only male mallard ducks have a green head; it is one of their species' Secondary Sexual Characteristics.
Many times, fictional creatures are based on some manner of Real Life inspiration, and whether or not they have noticeable sexual dimorphism corresponds to whatever inspired them — if one author decides to call a lion a Smeerp, it makes sense that male Smeerps might have thick manes while female Smeerps do not, right?
Secondary Sexual Characteristic Gender Clues
- Animal Facial Hair: Male individuals with moustaches and/or beards.
- Bizarre Sexual Dimorphism: Sexual dimorphism played to such extremes that males and females are scarcely recognizable as members of the same species at all. (Can be the result of Bizarre Alien Biology.)
- Furry Baldness: Older male individuals who are bald or balding.
- Furry Female Mane: Female individuals posessing a head of long, humanlike hair that the corresponding males do not. (A common occurence with anthropomorphic animals.)
- Hartman Hips: Female individuals possessing wide hips and a narrow waist, but a small bust. (Also common with anthropomorphism.)
- Humanoid Female Animal: Species where members of one sex (typically, the females) are more anthropomorphized than their counterparts.
- Impossible Hourglass Figure: Female individuals possessing wide hips, a narrow waist, and a large bust. (Also common with anthropomorphism.)
- Messy Male, Fancy Female: Female individuals appear smooth-furred or feathered or elaborately groomed, whereas male individuals appear scruffy or messy.
- Non-Mammal Mammaries: Species whose female members have humanlike breasts, regardless of whether or not their species has any need for such things (and, frequently, they don't).
- Masculine Lines, Feminine Curves: Females have curvaceous bodies while males have squarer, more angular or straighter bodies.
- Pale Females, Dark Males: Females are lighter colored than males.
Other Gender Clue Tropes
- Pink Girl, Blue Boy: A special case of Color-Coded for Your Convenience.
- Tertiary Sexual Characteristics: Gender clues supplied by means other than the individual's inherent physiology.
Tropes That Get the Secondary Sexual Characteristics of Animals Wrong
No Real Life examples, please. Please only list fictional examples that aren't listed in any of the tropes listed here. Anything that fits in any of the tropes listed should be listed in that trope.
- Green Lantern: The people of Graxos IV essentially look like golden-skinned elves, but the females like Arisia Rrab have much more human looking feet. Males like her uncle Blish Rrab have only two toes which are widely spaced and more pointed.
- In Animorphs, it's noted that male Hork-Bajir have three horns, while females only have two. Also, female Andalites have smaller tail blades than males.
- Starting in Pokémon Diamond and Pearl, the Pokémon series had introduced secondary sexual characteristics for certain Pokémon. Some, like the Frillish family and possibly the Gible family, fall into a subtrope, but others, such as Pokémon like Rhydon having larger horns when male, female Pikachu having heart-shaped tails, or female Combee having a red mark on one of their heads, are just this trope.