"I Study Snake Sex"

One of the best parts of science is the community of talented scientists I am lucky to know and from whom I am constantly learning. Meet Cat, a fellow PhD Candidate in Biology at Portland State University. Cat is a master of radioimmunoassays, western blots, and witty conversations. I do not know anyone more ready to make a positive impact by wielding science through the world of policy.

Cat is also my go-to editing buddy: we swap papers and grants, hold each other accountable and give raw, honest feedback. If you do not have someone that can do this for you, I recommend you find one. As a plant biologist, the hormone pathways in stressed out snakes are foreign to me. Giving feedback through this lens, the edited versions of Cat's writing powerfully help me understand the complicated interacting pathways. Enjoy! -ALG

"Create the community you love, love the community you create"


“Sometimes snakes feel like having sex, sometimes not. Why is that?”

I’ve tweeted exactly that under the hashtag #tweetyourthesis,

Let me unpack what I actually study and connect it to the real world.

Certain hormones are associated with reproduction. For instance, young men have a ton of testosterone in their blood when puberty hits. They (mostly) do not ask every person they meet out on a date, so we can infer that having loads of circulating testosterone makes you somewhat more interested in mating than you might otherwise be, but it does not actually make you have sex with this or that person. We do not yet understand what goes on in the brain and body to decide that right now is the appropriate time, place, and life stage to mate.

I study how females in particular make high-stakes decisions about reproduction. As a wild animal, all reproductive decisions come with substantial risk because having babies when you lack sufficient resources to reproduce (body fat, good habitat, etc), you and your babies could die, but if you wait, you may never pass on your genes. A female’s body “decides” to reproduce by getting geared up (or not) to be receptive to a male’s sexual advances. That’s the sex part.

Now the snake part: Why study snakes? There are a whole lot of animals on earth, and scientists have studied a tiny fraction of them in any detail. We know very little about how non-human, non-mammal, non-rodent critters work. For intellectual reasons, studying snakes allows me to find out if their bodies work similarly to the animals we know more about. Snakes use many of the identical hormones that all other vertebrates use (creatures with a spine: mammals, birds, reptiles, amphibians, fish), so what I learn about snake hormones and behavior can be applied to many other creatures.

I also study snakes for purely practical reasons. The wild red-sided garter snakes I study form “mating balls” of dozens of male snakes courting a single attractive female snake. So focused are they on convincing the female to mate that I can walk right up and pick up the whole mating ball. I can collect a lot of free living animals easily which makes finishing my PhD research in a timely manner possible.

Finally, I ask what goes on in a female’s brain and body to determine if she will mate at a certain time, which male she will mate with, and how many babies she will (or won’t) have.

If you consider all the animals, in all the habitats, all over the world, billions of reproductive decisions are happening all around us, all the time. These decisions impact whether or not a species will go extinct, if a fishery is sustainable and when a hunting season will open, but we are still learning about how reproductive decision-making. This is why I study why and when snakes feel like having sex.

-Catherine A. Dayger | cdayger@pdx.edu | @ScienceSquall

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