Thursday, June 30, 2011

Toad Arena: The multi-layed approach

So, to continue with my "setup" series, today I'm going to talk about what I do with the toad videos once I get them! That's right folks, I am done with my first set of trials, which means I have about 65 videos that I now need to analyze. Are you keeping up with the math? 10 toads x 7 trials each = 70 trials and 70 videos. So why do I only have 65? Well, I goofed up. Around trial 4, I put a food toad in a control treatment. Sadly, because this is a learning experiment, everything that toad did after the goof could be a repercussion of being put in the wrong trial. This toad was being taught that there was a mealworm in each bowl, every time he went to the arena. Because I accidental gave him a 'control' trial, meaning no mealworms in the bowl, he had conflicting information which would most likely affect his behavior for every trial after that.

Oh, well. Sometimes in life, you make mistakes, but as long as you learn from them, it's OK. I definitely will be triple-checking to make sure that I have the right treatment for each toad from now on!!!

So yeah, back to the original point of this post. I have 65 videos of toads running around arenas, looking for food. Now what am I supposed to do?

Lucky for me, I have this handy program called Ethovision XT that will make a path of where the toad goes and tell me all sorts of things about the path. It can tell me which bowls the toad visits and in what order. It can tell me how long the toad spends in what areas of the arena. It can even tell me how fast the toad is moving (or at least, it's average speed). But just like any computer program, it comes as a blank slate, and I have to tell the program all of the things I want it to record. Ethovision is kind of fun once you get the hang of it because it's all about creating 'zones', or drawing pictures. Here is how I decided what zones to draw in order to get the information I need:

First, I started with a blank arena:

Next, I identified which part of the video is actually the arena (in pink). I also put in circles to identify where the bowls are located (in blue):

Ok, that's it, right? Nope! There's all sorts of other information I might want to know, too. For example, I might want to know how much time the toad is spending around the margin, or wall, of the arena vs. in the middle (frogs and toads have a tendency to hang around walls). I'll draw a circle in the middle of the arena and mark the inside and outside as different zones:

I might also want to know how much time the toad is spending on the bricks and cinder blocks vs. on the ground. When I tested this arena in Texas, the 4 toads I used mostly stayed on the ground. It would be interesting to see if there is a difference between these toads and the toads in the lab. To do this, I can trace the blocks in the arena (in light yellow) and make them different zones that the ground:

I might also want to know if there is a side bias. A side bias could happen if the toads are particularly attracted to one part of the arena or another. Because our arena in Gamboa is outside and there are factors we can't control (like street lights and other frogs calling), it's important to know if the toads are staying in one part of the arena longer than the rest. To do this, I split the arena into 4 equal parts, like quadrants of a graph (in yellow):

The last thing I want to know is how long it takes the toads to first enter the arena (or leave the origin). This can be accomplished by drawing a zone that the toads have to pass through if they want to leave the flower pot (in green above).

And that's it! That's all the information (probably) that I want to know about where the toads go during the trials. Next I 'run' the trials through Ethovision, and it records the path of the toad and tells me things about where it goes.

I'm excited to see what happens - I wonder if the toads will follow the same path every time they visit the arena, or if they will go to different areas each time? What do you think? Do you think your answer depends on if there is food in the bowls or not?

Saturday, June 25, 2011

Will you take the path less traveled?

Well folks, sorry it's been a while since I've written, but I've been diligently crunching numbers and putting toads through trials in the arena. Long days and even longer nights! Let me give you a little breakdown of what a toad trial is like:

Step 1: Set up all of the equipment. This really just requires me to plug everything in and turn it all on. Not too hard. Remember that camera and infrared lights I have set up over the arena? 

The lights get plugged in, and the camera cord runs to a little room just beyond the dryer in the picture. In that room is a DVR box that transcribes the camera feed and plays the picture onto a computer monitor. I don't have a picture of the actual machines, but I'll take one tonight and post it later on. Here is a picture of what the arena looks like in the dark, from the camera's point of view:

Pretty neat, huh?! From here, I can watch the toads as they explore the arena. The video is in black and white, so it's a little hard to see, but I can get an idea of where they are going, what they are doing, and when then visit different areas of the trial arena. 

Step 2: Get the trials ready! Each night I have a schedule of which toads will be tested and in what order. We randomize the order in which toads get tested just in case there is any effect of toads going at the same time each night, or in the same order. What does that mean? Well, instead of toads going in order 1,2,3,4,5, they may go 3,5,2,4,1, or 2,4,3,5,1, etc. etc. There are lots of ways to randomly select what order you will do things, and some great random number generators online. 

I have 10 toads per set of trials, and 2 treatments : 10 toads / 2 treatments = 5 toads per treatment. Just to refresh your memory, my treatments are 'food' for toads that get mealworms in their bowls, and 'control' for toads that get empty bowls during trials. How do I decide which toads get which treatments? You guessed it - it's randomized! 

Note: Even though toads are randomly assigned their treatment group, they keep the same treatment group for the entire experiment. 

Now I look at the schedule, and decide if the next toad is in the food treatment. If so, I put a mealworm in each bowl in the arena. What's a mealworm?

Mealworms are the immature form of a darkling beetle, Tenebrio molitor. They are often used to feed reptiles, amphibians, birds and even fish that are kept in captive situations. We could also feed the cane toads crickets, but those are a little harder to get in Panama, and they have a tendency to escape out of the bowls! :)

Step 3: I press 'record' on the DVR box, and put the toad into the arena. Every toad gets moved in his own little flower pot, and is placed in the same spot to start:

Step 3: I wait for 60 minutes. During this time, the toads are (hopefully) exploring the arena and finding the food in the bowls. The toads that are in the control group will not find any food :(, so I'm not really sure what they do, but we'll find out when we.....

Step 4: Watch the video! Once the trial is done, I put the toad back in his happy home (or holding tank). If the toad was a control toad, then he gets a mealworm since he didn't have a chance to find any during the trial. I can download the video onto my computer and start to analyze it while I run the next trial. 

And voila! This is how it goes every night for 14 nights in a row. Tonight is night 12, so I am almost done with this group. When we're all finished, we'll feed them a nice big meal and send them on their way back to their original homes, like nothing ever happened!

Next time, I'll continue the saga and show you exactly how I analyze the videos. Stay tuned! :)

Monday, June 20, 2011

It rains in Gamboa

Despite the strange dryness of the beginning of the month, it looks like the rainy season is here to stay!

Saturday, June 18, 2011

Trials are a'running!

Hi all!

I've run 4 total nights of trials and here's the breakdown so far:

- I am testing 10 cane toads right now, 5 each night (which is 5 hours total of video recording!)
- Of my 10 toads, 5 have food in their arena bowls ('food' treatment) and 5 do not ('control' treatment)
- Every toad that has the 'food' treatment ate on the first night (YAY!). For those of you who read about my research, this means that each toad only has to go through 6 total trials (equals 12 nights of work).

That doesn't seem like a whole lot, but it is 6 1/2 hours of experiments a night (5 hours of trials + setup, breakdown, and switching between toads), and at least 6 hours of video analysis every day. That's right; 12 days straight of 12+ hours days. Eeeep!

But so far, it's been worth it. Here's a picture of what the arena looks like finished:

I had to extend the walls up about 1.5 feet in order for the toads not to be able to jump out. Lesson learned in the lab - it's always good to try it out first, before you actually get to the field! Here's a picture of the inside:

Note that you can't see any of the leaf litter that we spent hours tearing up. :( oh well, at least the dirt works well. Finally, here's a picture of the PVC contraption at the top that holds the camera and the 4 infrared lights (one at each corner):

Pretty groovy, huh? It's like a giant K'nex set - the whole arena is made up of 1 or 2 foot segments of PVC that all fit together, so it can be broken down and packed up when I'm not using it. 

I don't have enough data yet to show you much, so I'll leave you with a toadily awesome photo shoot:

Me and a large female toad. :)

Large female toad by herself. She was not pleased (I woke her up to take the photos!)

Tuesday, June 14, 2011

My milk frog brings and the (fe)males to the yard...

Tonight we start cane toad trials - so excited! I am hoping that the toads will be hungry enough to visit more than one or two food bowls (which is what they did in Lubbock). We'll see what happens. I'll report back in a few days, when both groups have gone and I have a general idea of what's going on.

Now, however, I'd like to tell you a little story about an unexpected visitor to our house last week:

Who is this little guy? I'll give you a hint - he's about the size of a Gladiator Tree Frog (which is what we thought he was at first). Upon further inspection, we found that he had interesting toad-like bumps all over his skin:

AND he was very, very sticky. Did you guess the milk frog, Trachycephalus venulosus? Then you're right! Este es la rana favorita de Ximena (Ximena's favorite frog), so she was very excited to see it, since it's actually not very common in Gamboa. What luck, he was sitting right under our house at the meeting table, just waiting for us to take pictures of him! As he was being handed around the group so we could all feel his sticky skin, he leaped from my hand onto Ximena's shirt (sadly, no picture), and splashed milky secretion into my eye! At first I thought it was fine, but after a few minutes my eye started to itch and burn really bad. I could still see, so I  said "Ummm, I think I got splashed in the eye....", walked calmly over to the sink, and began flushing my eye out with water. The calm, quick reaction paid off, and as the night progressed my eye stopped burning and was OK. Lesson learned: always watch out for your eyes, mouth, and nose; you never know what might splash off of something!!

Have you every gotten something weird in your eye? What did you do? Did you panic, or react calmly?

Sunday, June 12, 2011

Hoppity hop hop - hop tests!

So I ran into a slight dilemma when I got to Panama. Actually, we (my committee and I) knew this would be a dilemma, but I couldn't do anything about it until I got here. You see, the problem with comparing exploration and learn between two species is that, well, they're two different species! Nothing is really the same for either the Cane toads or the Leaf litter toads; they're different sizes, they eat different things, they live in different habitats... and they move at different rates. So naturally, the testing arena for the smaller leaf litter toads should be smaller than the testing arena for the cane toads. Right? Most people would agree with me, but then the question arises; how much smaller?

At first, I scaled the leaf litter toad arena down by body size. Leaf litter toads are about 1/3 of the size of cane toads (on average), so the arena should be 1/3 the size. Makes sense, right? Well, this is what that would actually mean:

Seems a little...... little. I mean really, 32 inches across? That's less that 3 feet! The leaf litter toads are small, but they aren't that small. So the only thing to do was come down here, catch a few, and see how fast they move. Enter: the idea of the hop test!

To scale the arena accurately, we have to look not just at body size, but at overall range of mobility (i.e. how far can the toads move in a single hop or jump?). To do this, I'll take 5 toads of each species, put them in an empty arena for 10 minutes, and measure their hop and jump length. Sounds tricky, right? Well, it would be, except that we have an A-maze-ing program called Ethovision, which will follow the toads and take all sorts of measurements for us! So far, I've measured 3 cane toads and 2 leaf litter toads so far, and I've got a few more to do before I can make any conclusions. 

Given that the leaf litter toads are 1/3 of the size of the cane toads, what would you predict their range of movement to look like? Would you predict that they would move more or less than the cane toads? Which toad species do you think can hop the farthest? Jump the farthest?

Check back to see if your predictions are right! :)

Thursday, June 9, 2011

Progress: Website is LIVE, arena is coming along!

Hi Folks!

In case you're reading this blog and haven't seen the main show, my website Adventures in Toading is finally up and running! Check it out for more information about my research and about the frogs and toads of Panama.

I've been working on getting my arena set up and moving the toads to our new workspace. Here's a picture of what it looks like right now:

And here are the toads, happy in their new home under the stairs:

 I've still go a lot to do - including rip up a huge pile of leaf littter to put in the arena for substrate:

Ok, back to work - hast lluego!

Monday, June 6, 2011

Website is *almost* done!

Hi folks!

Sorry, I've been fairly absent from my blog - we've been in Panama for 3 days, and I have yet to write anything substantial. We've had a lot of luck, but most of my down time has been invested in getting the rest of the website up and running, so you'll have to forgive me! I'll write about the first few days soon; tomorrow we are going into the city for supplies and mealworms for the toads - yum!

For now, I'll tell you this much: although it hasn't really rained yet (we're at the very beginning of the rainy season here), we've had some great luck catching frogs and toads. I've got 9 out of 10 toads that I need to begin the first set of experiments, and we've seen tons of tree frogs calling. Here are some of my favorite pictures from our first few nights in the field:

Check out the newest section of my site, Frog Calls of Gamboa, and see if you can identify these frogs!

Saturday, June 4, 2011

Scouting for Toads in Panama

We arrived in Panama early Friday morning, around 2am. We decided to stay in the city that night, and drive out to Gamboa (about an hour away) in the afternoon. Friday night we spent time looking for cane toads and other frogs, and introducing Sally, our new field assistant, to Panamanian wildlife. I was able to find 2 toads that were the right size for me - I've got them in plastic containers under the staircase, and am going out to find more tonight!

I'll post pictures tomorrow or the next day, along with the welcome video for the website. For now, I need to go and get ready for more fieldwork! :)

Has it rained where you live lately? Have you heard any frogs calling?