9 of the Most Dramatic Examples of Sexual Dimorphism

婆罗洲猩猩(猩猩)。(照片:塞吉Uryadnikov /古德科夫ANDREY /存在Shutterstock)
山魈是两性异形的自然界最极端的例子之一。 (Photo: Curioso/Edwin Butter/Shutterstock)

Ever wonder why males and females of the same species can sometimes look radically different from each other? It's all thanks to a condition known as sexual dimorphism, which is generally triggered by the process of sexual selection through competitive mating. Sexual dimorphism can manifest in many fascinating ways — size, coloration, behavior and the presence of secondary sex characteristics liketail feathers, breasts or antlers.

其中的最好的例子是山魈,这被广泛认为是最有性别二态性哺乳类动物。当您检查雌雄山魈以上,你会的第一件事的图像注意到的是,男性表现出对他们的脸和屁股更具活力的色彩。但是,如果你遇到one of these majestic primatesup-close, you'd quickly realize that the most dramatic difference between their sexes is their size. While the average female mandrill weighs about 27 pounds, some male mandrills can weigh up to 82 pounds!

Mandrills have nothing on the triplewart seadevil, though. Living as deep as 6,600 feet below the ocean's surface, these令人毛骨悚然的前瞻性琵琶鱼可以说是世界上最极端的两性异形的彻头彻尾的怪异表现。如下面的图中显示出,该物种的雌性测量关于长的脚,而男性勉强达到半英寸。

Triplewort seadevil (Cryptopsaras couesii). (Photo: Commons sibi/Wikimedia)

This dramatic disparity in size is largely due to the species' parasitic mating practices. (That's right, it's love at first bite!)

由于MNN的布赖恩·纳尔逊explains, "The evolution of the male anglerfish has left them highly reduced. In some species, the males are not even capable of feeding themselves. Instead, they must quickly find a female to attach themselves to, or die. After attaching, their circulatory systems merge and she provides him with sustenance, while he provides her with sperm."

Continue below to learn about more animals that exhibit striking instances of sexual dimorphism.

Pheasants

Ringneck雉(雉鸡)。 (照片:彼得Krzeslak / Szczepan Klejbuk /存在Shutterstock)

除了它们体型较大,雄雉鸡由它们色彩艳丽,装饰羽毛,装饰枝条和超长的尾部特点。雌雉鸡,相反,是在自己的外表相当小。

Elephant seals

Elephant seal (Mirounga leonina). (Photo: David Osborn/jo Crebbin/Shutterstock)

These pinnipeds are named for the males' large proboscises that slightly resemble an elephant's trunk. The reason they've developed this bulbous schnoz has less to do with their appearance and more to do with proboscis' ability to emit incredibly loud roars during mating season.

Orange tip butterflies

Orange tip (Anthocharis cardamines). (Photo: Matthijs Wetterauw/anderMeertinsPhotography/Shutterstock)

对男性的前翅发现橙色提示:这些蝴蝶中,他们表现出特定的两性异形的名字命名。

African lions

African lions. (Photo: Jason Prince/Maggy Meyer/Shutterstock)

The iconic bushy manes of African lions are highly linked to the process of sexual selection, and studies have shown that lionesses are more likely to pick a mate that boasts a dark, thick mane.

鸳鸯

鸳鸯(Aix galericulata). (图片:PANU Ruangjan /超级首席/存在Shutterstock)

而两性的鸳鸯拥有博tiful plumage, the males of this species are especially striking with their red bills, pronounced crests and array of colorful feathers.

Orangutans

婆罗洲猩猩(猩猩)。 (照片:塞吉Uryadnikov /古德科夫ANDREY /存在Shutterstock)

As they reach sexual maturity, male orangutans begin to develop enlarged cheek flaps that are meant to exhibit their dominance. When there is more than one male within a family, the more dominant male will exhibit more exaggerated cheek flaps.

孔雀

孔雀(Pavo cristatus). (Photo: Brigida Soriano/igor.stevanovic/Shutterstock)

Peafowl are among the most well-known and gorgeous examples of sexual dimorphism. While males (peacocks) sport a flamboyant and iridescent "train" of tail feathers that can open up in a grand display, females (peahens) possess a significantly more subdued appearance.