Monday, April 18, 2011

What science did you do down there? (Click on the photo below for a slideshow of the field work.)

Click on the picture in this post to see a slideshow of more pictures from the field.

So as you know we had 3 different hypothesis that we were testing during our time in the field down in Florida. I want to review each of those hypothesis and let you know what we did to collect data to test each one.

#1) The Brown Anole population faces different relative selection pressures in different parts of the environment.
To test this one we put out 50 clay models in 5 locations that were carefully chosen (forest, park, residential area, beach and island) and recorded all bites in the models from predators and lizards. We only got one lizard bite but we got many predator bites. We tried putting out models with and without paper dewlaps. After the first week we moved the models to new but similar locations. We also took careful photos of the shade cover where each model was placed. A computer will analyze these photos and we will check to see if the amount of cover above a model affected how often it was attacked by predators.

#2) Morphological (physical) differences exist in the lizards in different parts of the habitat.
To test this one we planned to measure hundreds of lizards (we measured more than 800) and record careful data about the locations they were spotted in. Unfortunately this part of the project suffered a bit from our high work load. We did not have time to measure carefully the locations of each captured lizard. However, we do have careful measurements for each lizard in our island experiment so when we go back to collect lizards again we will be able to see if physical differences begin to exist on the different experimental islands.

#3 Biased Operational sex ratios will affect population growth and natural selection (evolution).
To test this hypothesis we released 835 lizards on 9 different islands. The islands were not all the same size so we released them in numbers that kept population densities (lizards per square meter) the same. On 4 of the islands we released 66.6% males and 33.3% females. On 5 other islands we did the opposite. We will be going back at the end of the summer to catch babies and record population sizes. We will take DNA samples of all the new hatchlings and compare them to the DNA of the founding populations to see which males and females are having the most reproductive success.

Friday, April 15, 2011

Fine looking female and a handsome dude.

One of the questions that you guys asked was- "How do we tell the differences between male and female lizards?"

Many of you already know if you were part of our class in the first semester because we handled so many lizards in our experiment. However, if you don't know or even if you do know and just like seeing pictures of lizards, here are two photos showing fine looking examples of both a female and a male. The female is the one with the diamond pattern on her back and the male is the larger one with the little yellow spots on his side.

Thanks for all of your interest and support.

Thanks for following along with us as we worked.
Dr. Warner and I had so much fun communicating with all of you and answering your questions as we worked. We are now back home and in need of some much deserved rest. We worked extremely hard and slept very little! However, we love what we do and feel like we really did some great experiments that will give us tons of good data to evaluate our hypothesis and write conclusions to share with the scientific community.

I will continue to answer your questions and post on the blog as long as you guys are still following. This weekend I will get caught up and answer the most popular questions. If you email me a question directly at I will make sure that I answer it. Also look for a slide show with 20-30 pictures of lizards, other animals and our work sites. I will have it all posted by Monday so you won't be bored while you are on spring break. Check back with Wide World Science soon.

Thanks again. Your posts and questions were great. You are the best.

Thursday, April 14, 2011

The island experiment is fully up and running.

Today was our last day in Florida and our busiest yet. We collected all of our clay models and took careful data about their placements. We also released the final 135 lizards on 3 islands in Tomoka State Park. This brings our experiment up to 835 lizards on 9 different islands. That is a truly large scale and should give us great data on how the sex ratio effects the ecology and evolution of populations.

Wednesday, April 13, 2011

Moving in to a new world.

This brown anole was just released into his new home on island H. How will he do? Will he succeed in this habitat? Will he mate and father many offspring? Will his dewlap tattoo give him an advantage? These are the questions we will try to answer when we return to Florida in the summer and fall. We are not quite done yet. We still have to release lizards on 3 more islands. Stay tuned for more updates.

698 lizards now have new homes.

The lizard release was a success. We took the boat out at 7:30 this morning filled with 698 lizards. We dropped them of at our six experimental islands in the Matanzas River. Now for our 4 islands back at Tomoka State Park.

Will this guy (X325) enjoy his new life on island H?

Each lizard is coded with a bag number which can be searched in our computer file to give us the recorded snout to vent length, tail length, mass, dewlap size, limb length and sex.

Release party rescheduled for today.

All experiments have at least some minor challenges. We have had one more to deal with. Yesterday we had more than 500 lizards bagged up and sorted into pillow cases labeled with the letter of the island where we plan to release the animals. We loaded the car and started the drive north to where we would pick up our boat. On the way there the owner of the boat rental called to tell us that storms were on the way and it would not be safe for us to take a boat out. We were disappointed, but since we can't control the weather we rescheduled for this morning. As I write this we are driving north to get our boat. The sun is just coming up over the ocean right outside my window.

Biggest lizard we have seen yet.

One of my favorite parts about working in the field is that we get the chance to see lots of wildlife in addition to our study animals. This is a broad headed skink. They eat invertebrates such as insects and worms and even brown anoles or other small reptiles. We found this one hanging out about 4 meters from one of our clay models.

Monday, April 11, 2011

The big release party is tomorrow.

This is a picture of our field lab that we temporarily set up here at Tomoka State Park. Everyone of those bags on the tables behind Dr. Warner are filled with lizards. Tomorrow we will paddle them out to the islands and release them in their new homes.

We have almost pulled it off.

First things first- thanks for all your posts with great questions. You guys are making this into a very cool educational experience. Dan, Alexis and I are glad to have you following along. We have been working truly insane hours the last couple of days to get the lizards ready to be released on our nine experimental islands. Last night we worked all night and never went to sleep. Today we took a 3 hour nap and are right back at it. There is so much to do. 812 lizards need to be weighed, measured, sorted by size and sex. If you remember from the in class presentation we are creating 9 different island populations where the ratio of males to females will be different. Some will have lots of males and some will have more females. We are doing this to test the hypothesis that the sex ratio will have an effect on which traits get selected for. The idea is that we suspect that on an island with more males, competion for mates will be the greatest selection pressure on the males in the population. On an island with more females, traits like the ability to choose nest sites and get away from predators while carrying eggs might be selected for. We will kayak out to the islands tomorrow with the lizards to release them to their new homes so the experiment can begin. This experiment may last as long as 10 years. Every year the lizards will be collected and we will do dna testing to see which lizards in the origional population had the most reproductive success. Tomorrow is a big day. Now it's time to get some sleep.

Will the color pattern of the dewlap have an effect on the mating success of male brown anoles?

Alexis Harrison is interested in finding out how important the physical appearance (phenotype) of the dewlap is in the reproductive success of the male brown anole. Alexis is testing the hypothesis that males with more red on their dewlaps will father more offspring than males with less red on their dewlaps. To test this question she is changing the dewlaps of some of the males we will be releasing on the islands. When we return to these islands we will take DNA samples of the new hatchlings to find out how many offspring each male has produced by the end of the season. To change the color of the dewlap she give the lizards tattoos that change the amount of red on the dewlap.

Saturday, April 9, 2011

Green anole (Anolis carolinensis)

Many times over the last week on this blog and during the skype calls we have talked about invasive species. Invasive species are a major contributing factor to species extinction around the world. The brown anole is an invasive species and people are worried about the effect it is having on the green anole (Anolis carolinensis). We have seen many green anoles coexisting with the brown anoles on this trip.

Friday, April 8, 2011

Would you call security on this man?

We have discovered that the population density of lizards is very high in areas with artificial landscaping so we spend a lot of time looking for lizards there. We got some weird looks from people and yesterday we were questioned by security guards. However, once we explain that we are scientists, people are usually glad to let us do our work.


One of the classes asked about problems that we have faced so far in our experiments. As many of you know from class there are often problems that come up unexpectedly when doing an experiment. Last night we went to check on some of our clay models that were placed in a picnic area and we found that the state park had cut down dead trees including two that we had placed models on. The picture above shows a wood pile that probably has one of our models burrows in it somewhere. I don't think we are getting that one back. Now we will just change our experiment a bit to work with 48 models instead of 50. Solving unexpected problems is part of working as a scientist.

Thursday, April 7, 2011

Here is a challenge for you students: Help me and Dr. Warner make a list of possible suspects who may have attacked our models.

Here is your assignment: Research the animals (other than brown anoles) that live in central Florida in and around Tomoka State Park. To figure out exactly who has been attacking our models we need to know what other animals are around. See Ms. Flemming for the details and grading criteria and specific detail of this assignment.

Now it's your turn. Students, post a question that you think would make for intelligent conversation.

Wednesday, April 6, 2011

We have fooled the lizards.

One of the biggest worries about our experiments is that our models would not look real enough to fool the lizards. Well, this morning we were successful in recording our first lizard bite. The jaw marks were clearly visible in the model's head.

Time to catch more lizards.

So our projects are going well. Yesterday we weighed, measured and marked more than 200 lizards. It was a long day that started at 6:00am and ended at almost midnight. We have to work hard to get the data while we have the chance. We are now driving north to check out some new lizard collecting sites. We still have 550 animals to go to reach our goal of 850 lizards.

Tuesday, April 5, 2011

When predators attack!

This is a picture of our first clay model we found after a predator attack. Was it a racoon? Was it a bird? Was it a cat? What do you think? Leave a comment below.

Abnormal tail

3rd period zoology asked if we have seen any lizards with deformities. Well, we have caught and measured 304 lizards so far and this one had a really unique tail.

We want to hear from all of you!

We are absolutely loving having you guys be a part of our field work experience. Please leave comments on the blog and follow us on twitter (mr_reedy) to let us know you are paying attention. Come on, what are you waiting for? Click the comment button and drop us a line. We have been measuring lizards for 7 hours straight and we need something to keep us going.

Monday, April 4, 2011

21st century educational outreach.

I loved talking with my former first period students this morning via skype. It was amazing to be standing on an island in the middle of the Halifax River and be showing my students lizards in the field and showing them how science happens in the real world. 2nd period- get your questions ready because your class is next.

Sunday, April 3, 2011

Hard at work.

It is 11:54 pm and we just finished our work for today. We caught around 70 lizards today and checked on lots of clay models. After dinner we started measuring lizards and we are now calling it quits for the night. We'll be back at it early in the morning. Looking forward to the first skype call tomorrow.

Saturday, April 2, 2011

Day 2 - Surveying islands and catching lizards

We had a busy first day of work yesterday. We placed all 50 clay models yesterday in 5 different types of habitat. I can't wait to see if we get any bites. Yesterday we also put out 20 nest boxes full of good moist soil to try to find out where the females are laying their eggs on our islands.
Today we are on our way to meet up with Alexis (from Harvard University) to survey islands at her field site near Marineland, 30 miles north of ours. We will also be hoping to catch and measure a lot of lizards. Check back soon for more.

Friday, April 1, 2011

Fake lizard. Will it fool anyone?

This clay lizard will help us learn what selection pressures the brown anole faces in different environments. It will get attacked and we will identify and count the bite marks to learn about selection pressures.