Loser Lizards and Motherly Winners (March 23, 2014)

Our most recent program was on the Sunday after Spring Break. In hindsight, not the best date for a program! We had two kids show up, and their parents. So, a small group, but we had a great time anyway, and asked lots of good questions.

In preparation for this program I visited my guest, Jess Magaña, at the OSU Zoology Department where she does her research. I took some pretty good photos of lizards in their cages...

Brown anole lizards in their cages at the OSU Zoology Department

Jess holding one of her subjects.

This is just one section of one wall of the lizard room!

I kicked the program off with a new song, "My Lizard Brain," which is basically about how mysterious it is the way we humans make decisions, and maybe that it has a lot to do with the way other animals make decisions, since we've retained a lot of ancient circuitry in our brains through the process of evolution. I expressed all that in the form of a love song, which my wife, Lisa, finds intriguing - it's the second lizard love song I've written. I don't know if that's a coincidence or a "thing." Maybe a lizard love CD is in the works.

I kicked us off with a brand new song.

Jess's research was inspired by thinking about how lizards make decisions about allocating their energy. In particular, how does a female lizard decide (and we use the word "decide" loosely here, since it probably isn't a conscious decision being made) how much energy to put into making eggs and babies? I asked everyone to think like a lizard and allocate some energy to various lizard activities such as finding food, defending territory, and reproduction.

Giving some thought to how much energy a lizard should allocate to various lizard activities such as finding food, defending territory, and reproduction.

Collecting data from our imaginary lizards.

Just like in real life, we got lots of different answers for our imaginary lizards. We talked about different kinds of things that might effect a lizard's choices. The thing that Jess was most interested in is what's called "the experience effect." Lots of animals' behaviors are known to be effected by things they've experienced in the past. Jess wanted to know whether a female lizard would put more or less energy into her eggs and offspring according to whether she has won or lost fights for territory in the past.

Answering questions.

To find out, she paired female lizards in conflict situations by putting one lizard into another's territory. After ten minutes she removed the interloping lizard, effectively making it the loser. Then she followed the winners and losers over time to see how they did with their eggs and offspring.

During our program tried putting two males together in a cage, so we could observe some of the aggressive behaviors. We saw the lizards move toward one another and bob their heads. We didn't see them display their dewlaps, though, as they often will.

Lizard fight! We introduced the light brown lizard on the right into the cage to see if the darker lizard on the left would defend his territory.

The lighter lizard made aggressive moves up the stick.

The darker lizard finally turned to face the interloper. They never got too energetic about the confrontation, though. Maybe they felt too cold or too "on display" for an energetic fight.

Jess found in her study that the lizards who lost territorial fights put less energy into their offspring and more energy into their own upkeep. Those who had won the fights gained less weight and hatched heavier babies. Moreover, the effect was increased with the number of fights. The heaviest babies came from the lizards who had won two or three fights instead of just one.

One of our attendees suggested that the lizards who win fights can get the best territory with the most food, and therefore it makes sense that they would spawn larger offspring. That's probably true of lizards in the wild.

However, Jess went to a lot of trouble to make sure the lizards in her study got the same amount of food, and lived in very similar "territories." The only difference between the winning group and the losing group was that the winning group won their fight and the losing group lost theirs. I think it's really interesting that just losing a fight or two triggers the lizard to put less energy into her eggs.

Next time we'll be delving into the teeny tiny world of proteins and trying to figure out how those micro-machines that run our bodies do what they do! 

April 13, 2:00 at the library. I hope to see you then!!

Imperiled Bats of Tar Creek (March 9, 2014)

Whew, it's been a while, but we did it - another Born to Do Science program for the books!

My guests were Dr. Karen McBee and her student, Rachel Eguren, whose study we talked about.

Rachel, who did the bat study, Karen, her advisor, Monty (me) the host, Elizabeth the children's librarian

I performed a brand new song based on Rachel's research. She wanted to find out whether the bats at the Tar Creek superfund site are affected by toxins in the area. She had to come up with a really clever way to answer that question, since you can't just ask a bat how it's feeling. The song, "Figure It Out" takes the form of a few journal entries where the researcher is trying to feel her way through the process. Scientists don't get to follow directions in a lab book - they're figuring out how to do things as they go!

Me singing a brand new song, "Figure It Out," inspired by Rachel's research project. 

What Rachel ended up doing is flying bats through an obstacle course made of strings that would drop when hit by a bat's wing. She charted the time each bat spent in the air against the number of strings dropped. As you would expect, for the control group (bats from a healthy habitat), the longer the bats flew the more strings they knocked down. However the Tar Creek bats showed almost no such correlation!

To get us in the question asking mood, we ran the kids through their own obstacle course, made from sections of carpet tubes. In hindsight, we should have placed the tubes closer together, or maybe had the kids stick their elbows out like bat wings, because even when we spun them with their eyes closed to simulate bats whose brains are addled with lead, hardly a tube got knocked over. Rachel had more time than we did to design her obstacle course. She made sure the strings were placed so that the bats could get through without knocking strings, but it was a challenging for them.

We timed each kid's run through the obstacle course, just like Rachel did with the bats.

After our activity we discussed lots of details about Rachel's study, including how she video taped the bats using a night-vision (infra-red) camera. She needed a marker in the bat cage to show depth so she could tell on the video whether the bats were flying through the obstacles. The marker had to be warm, to show up on camera, it had to stay warm for a long time, it couldn't require an electric outlet since she did her trials outdoors where the bats live, and it had to be relatively inexpensive. See the photo caption to find out what she used...

Karen passing around a "hot hands" - this is what Rachel used as a marker in her night vision (infra-red) video.

Rachel is still compiling results from the lab so she can correlate each bat's performance in the obstacle course with the levels of toxins found in their body tissues. But judging from the bats' performance in the obstacle course, the is definitely something different going on with the Tar Creek bats. The heavy metals in the area, including lead, may be affecting the bats' brain function, which could interfere with their ability to maneuver. This would make it more difficult for them to hunt at night.

The heavy metals in the soil and water around Tar Creek were left there by mining operations started over 100 years ago. In 2009 the town of Pitcher was completely evacuated due to the toxins. Dr. McBee and her students are studying many different aspects of how wildlife in the Tar Creek area has been affected.

Bats from the OSU Zoology Department collection.

Looking through the night vision camera!

Bat skeleton.

Thanks to Rachel, Karen, and the Stillwater Public Library for making this program possible, and for support from the National Science Foundation.

See you next time for "Loser Lizards and Motherly Winners!"