Hi, I'm Craig, I don't have a mating season, and this is Mental Floss on YouTube. Today, I'm going to answer pianotrumpet's big question - why don't humans have a mating season like most animals?

So, a mating season is a period of time in which breeding primarily occurs. This is often related to the female estrous cycle. A female animal in heat changes both physiologically and behaviorally, making her more sexually active during that time, and pianotrumpet is right that many animals have this, including wolves, snakes, bears, hobbits, and so on. 

Quick warning, if it wasn't already obvious, we're going to be talking a little bit about sex in this video. Let's get started - if you're allowed. 

(0:34) Theme Song!

(0:42) Women don't have an estrous cycle, though, they have a menstrual cycle. During the estrous cycle, if a mammal doesn't conceive, she re-absorbs the endometrial lining, a mucus membrane in the uterus.

On the other hand, women shed a lot of endometrial lining during the menstrual cycle. The other main difference between the menstrual cycle and the estrous cycle is that women are sexually active throughout their menstrual cycle, and as I mentioned at the beginning of this video, mammals who have an estrous cycle tend to only be sexually active when they're in heat. I've never said "estrous cycle" so much in my life.

So why do humans have a menstrual cycle rather than an estrous cycle? Well, we don't really know. One theory is that women evolved to shed their endometrial lining to protect the uterus from dangerous pathogens.

As we all know, there is more endometrial lining in humans than other mammals. So, another theory is that the thick lining has evolved to protect the mother from the embryo that's stealing too many of the mother's resources, or making its way too deep into the uterine wall. We're just not sure.

All that said, humans in general have seasonal sexual habits. Peak sex times for humans are in June and December. How do we know? Well, a few things make it clear. More children are conceived during summer and winter, more condoms are bought during those times, and more STD's are diagnosed during that time.

Google searches also confirm this. People tend to Google sexual words, dating sites, and pornography domains more during the winter and summer. There's a slight drop off of those types of searches during the spring and fall - so they don't spring up. They kind of fall off. We could have wrote that in - those puns in to this.

Some experts believe that we are affected by a mating season or sex cycles. Others suggest that these times just coincide with vacations and holidays so people are more likely to have sex during those times. I think it's because television is in reruns during those times, so they're bored. 

Thanks for watching Mental Floss on YouTube, made with the help of these lovely mammals. If you have a question of your own, leave it below in the comments. See you next week.