Any species when the female is larger than the male?

I have a bet with my girlfriend, and I figure there must be, but cannot find an adequate cite or proof. Any biologists out there know of any?


The deepsea anglerfish. The male is miniscule compared to the female and lives as a parasite on her body.

Quite a few male spiders are smaller than the female of the same species.

A queen bee is much larger than the male drones.

I believe females are larger than males in a number of bird species. Owls, for one. Female spiders are often larger than males. I know I’ve heard of others, too, so I’m sure other people will chime in.

In the insect and arachnid world, it is very common for the female to be several times larger than the male.

Here is a cheerful sequence of photos showing a female mantis enjoying a nutritious post-coital snack–her mate. Chock full of the vitamins and minerals that other mantises need!

Birds of prey, with the exception of the Burrowing Owl (Athene cunicularia). Most females are a couple of inches taller than the males, and usually outweigh the males by about 1/3.

In most other non-raptor species, the males are larger than the females.

There are a lot of fish species where the female is larger than the male; in fact I’d say the majority. That’s partly because the bigger the girl, the more eggs she can lay - but all the males need is a few drops of sperm, so they are more often than not the runts. Just off the top of my head, moutan whitefish, corydorus catfish, northern pike, burbout, guppies, well - the list goes on. I know hyenas have females as the dominant ones, and they might be bigger than the males too (or at least the same size).

Hyenas are female dominate…in fact, not only are the females larger than the males, the also have false penises and often mount the males…

Darwin himself discovered that in some barnacles the males are nthing more than little parasites, many times smaller than the female, that can only attach themselves to the female, draw nutrients from her and manufacture sperm.

Hmm sounds like some guys I know!

I’ve heard this about several birds of prey. One explanation I’ve heard is that the male is very aggressive, so the female is larger as a sort of protection. My thoughts: 1.) Does that explain why the girls are taller in high school? 2.) This explanation sounds like a guy came up with it.

Female rorquals (baleen whales) are larger than the males.

In many, maybe even most, species of frog, the female is larger than the male. Here’s a site that even has a picture!

I’ve heard two theories on why raptors exhibit reverse sexual dimorphism** (- 1) two different-sized sexes allows a wider range of food, so they are not competing with each other; and 2) it has something to do with the nesting - the fact that egg production pulls lots of nutrients from the female’s body, so a larger female can handle the loss better than one that would be smaller.

As far as the males being more aggressive, from experience, I’ve seen some really aggressive female raptors, almost to the point of killing their own mate during the non-breeding season (from my understanding, Cooper’s Hawks are notorious for this behavior).

On average, girls tend to mature faster than boys, but the boys later “catch up”, although I have read a recent study where boys are also starting to mature well before 13, possibly due to exposure to excessive hormones in food products (sorry, can’t find the cite, and this ain’t GD).
**The fancy term for what we’re talking about here (take away the reverse, and the male is larger than the female). Don’t say the Teeming Millions[sup]TM[/sup] never taught you something.

So the short answer we’re seeing here is that for many animal species, probably a sizable majority, females are larger than males.

It’s not a question of finding a needle in a haystack. There are thousands of examples of varying degrees. Why, I’ve seen the silverback humps of male mountain gorillas described as “extreme” dimorphism. That’s nothing compared to some species, including a type of sea cucumber and a weird crustacean called a rhizocephala , where the males are basically reduced to sperm-sacs within the females.

In Michael Crichton’s The Lost World, he talks about the Tyrannosaurs as having that reverse sexual dimorphism, because the females were so much larger than their male counterparts. I don’t know if that’s true, but it’s the first thing that popped into my head.

what is a false penis? Someone talked about hyenas, and I’m curious what it is. Is it just a really big clitoris? Is it some new appendage altogether? Is it like the udder on a cow, which could be six false penises?

This gets really ugly!
IIRC, Hyena’s have an excess of testosterone prenatally, which caused the external female genitalia to enlarge and extend tubularly. The rough part comes in giving birth through this, where it’s not unknown for the whole unlikely apparatus to rupture. At best it’s more painful than a ordinary birth. Does anyone here know if all mammal births are painful or just big headed humans?

I don’t recall the nature show saying whether male hyena’s are seriously hung.

Anal; it’s pretty much the real deal but it isn’t functional and doesn’t have all the same plumbing hook-ups; they aren’t meant to. Female hyenas have a lot of testosterone in them to keep them on-par and nastier than the males. When they are in the womb, they are exposed to a lot of male hormones even when develloping as females, and these extra male hormones have a side-effect of producing some of the male characteristics even though they are not in the female DNA blueprint.

Human residents of Azilda, Ontario.