Sex-determination explained

Ted ED partnered with Aaron Reedy (of the Lizard Project) to make this great video about the diversity of sex-determining mechanisms.

There is still a lot we don't know about sex-determination as well, which are areas of current and future research.

Food Webs as hypothesis generators

Do you think that a hawk eating a rat could have any influence on the Anoles on our islands?  If you cannot think of a way it could have an influence, take a look at the food web drawn at the right for some ideas.


The student's in Mr. Morris' class have helped me construct a simplified food web for Island M, based on observations we had made on the island or nearby.  Here is a great example of one of the food webs a student constructed based on our observations.  From this drawing, you can see that perhaps the rat population really strongly influences anoles, because they not only directly eat anoles, but compete with them for other food sources.

One thing these webs really help us do is generate hypotheses.  In class tomorrow, students will be coming up with predictions based off of several different scenarios.

A few Lizard Videos

Here are a few last videos from the Lizard Project.  One really clearly shows Dan noosing a lizard, and the other shows how we process (weigh, measure, mark) the lizards.

Lizard Project- Fun with Photography, Thanks to Vincent Musi

Some say that a picture is worth a thousand words.  I think I have never been more in agreement with that statement than after my day yesterday.  Vincent Musi, a world famous photographer, and his family visited us and he took a shot at photographing our lizards.  Vince had wonderful stories about his life as a National Geographic and freelance photographer, and after working with him, it was clear he was a master of his trade. Vince had prepared a wonderful lizard studio, and we spend hours with him working on getting the right lizard poses (which is very hard to do in a very unnatural lizard studio).  After about 6 hours of work, we finally got a lizard to flare his dewlap in just the right place, at just the right time.  Pretty great to see a lizard in such detail, something I could never appreciate with the naked eye!  Many thanks to Vince for coming down to work with the lizards!    Also, Vince's son Hunter is an expert lizard nooser in training!  He had plenty of natural talent!

Lizard Project- Day 10. Lizard Lingo!

We are on the cutting edge of evolutionary biology, but also on the cutting edge of developing new vocabulary.  After spending days and days trying to catch lizards, we have developed some new vocab words.  Let me define a few of these words, and use them in a sentence so you can better understand them. 

“Squirrel” verb To run around to the backside of a tree to avoid danger coming from the front, as squirrels commonly do to avoid predators.

In common lizard speak:  “Hey Dan, did you get that big male?”  “Nah, he squirreled me, can you see him from the other side?”

“The Praying Mantis”  noun The lizard catching technique generally employed to counter squirreling.  When a lizard is unseen, but its location is well known, the lizard-catcher aligns his hands in a prayer position, and then rapidly wraps his fingers around the tree, hoping to capture the lizard on the other side.

In common lizard speak:  “Hey Tim, that lizard is directly on the other side of that branch, use the Praying Mantis!” (Video demonstration to come!)

“The Put-back” noun When one lizard catcher should capture a lizard, but fails at the last moment, but another lizard catcher comes in to capture that same lizard before it escapes.  This word was borrowed from basketball, when a player simultaneously rebounds and scores off a teammates missed shot.  To see a prime example of a putback, see the video:

In common lizard speak:  “I can’t believe that dang lizard got away from me when I was getting it out of the noose!”  “Yeah, Good thing Reedy was there with the Put-Back, Taj Gibson would be sooooo jealous!”

Day 8 & 9: A field day in the life of an evolutionary biologist- repost from Aaron's blog

As a biology teacher it seems to me that many kids who would make really great biologists (Maybe you are one of those kids!), don’t become biologist because they don’t  know any biologists personally and can’t picture exactly what it is they would do as a biologist.  Here at WideWorldScience we love what we do and we want to share it with you.  While it is true that there is a lot of time spent back at the lab, analyzing data, teaching classes, planning experiments and preparing for field expeditions, all of us love to get out and do science in the wild.  We really do love working with our friends outside, paddling kayaks, looking for wildlife, climbing trees and chasing lizards. We live for these field trips!  Here is a typical field day in the life of a biologist:

Dan and Andrew with our rental truck and kayak trailer.

6:30 Wake up- Four of us are packed into the tiny bunkhouse room at the Guano Tolomato Matanzas Estuarine Research Reserve.  It is small, but it has air conditioning, running water, electricity and an internet connection, so we are glad to have it.  Many times we camp in tents while we are working in the field.

6:45 Breakfast- cereal, milk and bananas


8:00 Drive 3 miles to the boat launch- This is where we put the kayaks in the water.  There are lots of fisherman that put their boats in the estuary here.  It is a busy place.7:15 Packing the gear- We pack up all of our gear into the truck for the day.  This includes, lizard nooses, lizard bags, drinking water, dry shoes, sunscreen, cameras, animal coolers, lizard noose repair kit, duct tape (you always need duct tape), life jackets, kayaks, paddles and of course lunch (usually pb&j sandwiches, apples and granola bars).



8:30 Paddle out to the islands- This is one of my favorite parts of the day.  It takes about 10 minutes to paddle to Island M, our closest island, and about 45 minutes to paddle to Island F, the furthest island.  We often have dolphins swim near us while we paddle.

9:00 We land on an island.  This requires us to wade through the shallow water.  Since Tim cut his foot on an oyster shell two days ago, we have to help him keep his feet dry. See this video.

The commute to the office.

9:15- 12:15 We hunt for lizards on the island.  We just walk around carefully looking for lizards in the trees.  When we find one we then try to noose it.  We put numbers on those that we have already caught so we don’t catch them again accidentally.

12:15- 12:45 We take a break to eat our lunch.

1:00- 4:00 We move to a second island and catch lizards there.

Looking for lizards in all the wrong places.

4:15 We paddle the kayaks back to the boat launch and load them back up on the trailer to drive back to the field station.

5:00 Cold Showers-  Sometimes we even stop for ice cream on the way home.


5:00 to 6:30 Blogging, Tweeting, Cooking Dinner and updates data notebooks

















6:30-10:00 Processing Lizards.  This is what we call it when we measure, weigh, mark and take tissue samples from the lizards.

10:30 Sleep time!  We are really tired by this point in the day!

Lizard Project- Day 7

 Each day that we have been working on The Lizard Project has been different, but what all of the days have in common is that we are making progress towards our goal of gathering enough data to make conclusions on whether or not or hypotheses are supported.  All of our data collection brings us closer to being able to say something, supported by evidence, about how sex ratios effect the evolution of animal populations.

Since we caught so many lizards yesterday (135! Wow!) we had a huge backlog of lizard measuring, weighing and marking to do. To get everything done we split up the team.  Dan stayed back at the field station to do the measuring, while Andrew, Tim and I paddled out to Islands M and K. We worked for 6 hours total, but only caught 47 lizards today.  Many of the lizards we spotted today were already marked.  That is a good sign because it means we are already getting close to having all of the animals captured, marked and measured on a couple of our islands. We also had a great Skype conversation  with Erin Nash's Zoology class. The Benton High School students had great questions for us and the whole thing was a lot of fun.

Oyster beds are sharp - ouch!

While we are down hear working the pace can be grueling at times.  The work on the islands is often very hot and we often work late into the night measuring  lizards.  Crawling around in the trees and bushes chasing after lizards leaves us scratched up and bruised.  Yesterday Tim got even more scratched up while getting back into his kayak.  He accidentally stepped on a razor sharp oyster shell and cut his foot.




Throughout all of the work that we do with the lizards, one of the greatest perks of our job is working in such a beautiful setting with so many cool animals all around us.  The insect communities on the islands are amazing and would be worthy of an entire research project on their own.  

Lizard Project Day 6- Lots of Lizards!

 The cool, rainy day we had yesterday made it slow for both lizards and lizard-catchers alike.  When we awoke this morning to clear skies, we knew that the lizards would be eager to be out.  We visited two islands today, and hunted the lizards like mad.  And we did very well.  We caught 135 lizards today, including this one that was eating a grasshopper!  That is A LOT of lizards.  As our goal is to catch as many of the lizards present on each island as we can, we feel very good about days like this.  What we don't look forward to, is processing 135 lizards tonight.  We "process" lizards, be measuring, weighing, photographing, and marking each lizard back in our field station (aka bunkhouse).  It takes about 3 minutes to process each lizard, so you can do the math (and in case you can't do math, that adds up to about 7 hours of solid processing).

We also noticed this pair of Green Anoles mating as we were searching for our study species, the Brown Anole.  So why did these two end up together?  That is part of the question us biologists are interested in.  The were both able to survive this long, so that is a prerequisite to successful mating.  Did this male have fight off other males to keep a high quality territory? Did he attract this female with a flashy dewlap display?  Was it just a chance encounter, and she would have been willing to mate with any male she crossed paths with?  These are all questions we don't know the answers too, but our work with the brown anoles will give us some insights into at least that species. Notice that he is biting the back of her neck during their mating! Interesting.

On a side note, I had the most terrifying moment of my life yesterday. After the rains, I went for a run and then swim in the ocean.  As I was swimming, I noticed two HUGE shark fins cruising towards me.  I turned and swam/ran/stumbled my way back onto the beach.  They came within 10 meters of me. Their dorsal fins were about 18-24 inches tall, and was about 6 feet in front of their tails, which was also breaking the surface.  This means these sharks were probably about 12 feet long.  I never saw the heads, just the fins and tail, so I don't know what species they were,  but based of their size, I  certainly could have been on the menu. Turns out Florida has had the most shark attacks of any state in history, according to the Florida Museum of Natural History...  I won't be swimming anytime soon.