Mar 25, 2012 By Aaron Reedy, Dan Warner and Tim Mitchell
We are excited to present the very first "Youngzine Live!" series by Aaron Reedy. Aaron and the rest of the team are working on a National Geographic funded Lizard Project and are passionate about bringing science from the field to classrooms. Meet the 3 members of the team here.
From March 28 to April 10, they will be providing field updates from the islands of Florida, and answering questions from Youngzine readers and classrooms. Be sure to check out this page everyday, read the latest blogs and tweets, and ask any questions that come to your mind!
Aaron Reedy will be doing live sessions with interested children/classrooms on his return. If you would like to participate, please send us an email at editor@youngzine.com
Today we had another first for the Lizard Project. While on island H capturing lizards, we found a green anole eating a brown anole. While other people had previously observed this happening, we had not seen this on our islands, until today.
As I was looking for lizards, some rustling on a nearby palm frond got my attention. Expecting it to be a lizard to noose, I crouched down ready to capture it. Thats when I found an adult green anole munching on a hatchling brown anole. The brown anole was still alive and struggling, but looked like the struggle was going to be futile. This was an exciting find for us.
Earlier this week I wrote a post about a nest-site choice study that Aaron and Dan had done in the lab. However, anole nests are notoriously difficult to study in the field- very little is known about anole nesting. However today, we found two anole eggs on one of our islands, which was very exciting for us.
Reptiles have varied reproductive strategies. Some give live birth, which is known as viviparity. Most reptiles, however, are oviparous, which means they lay eggs. And most of these oviparous reptiles lay many eggs in a single clutch. Anoles, however, lay a single egg at a time. We are not certain why anoles lay only one egg, but this is a question some evolutionary biologists have studied. One hypothesis is that the female can escape predators more easily by only carrying one egg at a time. There are many other intriguing hypotheses, however.
Whatever the reason, we were excited to find two anole nests (which consisted of one egg each!). Check it out
Unfortunately, science moves at a fairly slow pace sometimes. We are working on analyzing the data now and doing all of the genetic tests on our tail samples. We hope to have something to share in about 6 months.
Do you think you will find any other animals besides the glass lizard that may have eaten some of the anole lizards on the island? Will you look for any evidence of the lizards being eaten because that may make a difference in the number of lizards, won't it?
Yes, we also found black racer's (a type of snake) and many herons and egrets (birds) that all eat lizards. You can be sure that they are eating the lizards. The evidence we look for is mostly just the general population size. We know that predators can influence the populations, but our experiment is not designed to test the strength of the effect that predators are having on the population.
Hi Arjun,
Great question! Part of the reason we chose the project, is that this experiment is generalizable, and our results may generally apply to many or most sexual animals. Lizards are abundant, short-lived, there is some evidence that they can invest differently in the sexes, and are easy enough to work with. Also, most studies researching these questions don't use vertebrates, so this experiment is more relevant to all sorts of vertebrates.
Hi Diamond,
Great questions. The glass lizard did not evolve from the island lizards, but they do share a common ancestor. You did not evolve from your cousin, but your grandmother is you and your cousin's most recent common ancestor. Anoles and Glass lizards most recent common ancestor was around about 170 Million years ago!
We just caught 135 lizards today. We got about 300 so far this trip, we think, although we didn't do an exact number. We hope to catch every lizard on every island. We mark them, and rerelease them, so when all the lizards we encounter are already marked, we probably have finished this round of data collection,
Hi Zoom,
We caught the lizards from the mainland, and brought them out to the islands. We mostly caught them along landscaping in front of a grocery store, along a bike path, and at a golf course. These lizards are very common here in Florida.
We do take DNA samples from the lizards by clipping of a tiny tip of their tail. However, the tails do grow back pretty quickly.
We also clip certain claws (which don't grow back) to use as an identification mark. It probably does hurt a bit at first, but studies show that it has no effect on their survival and their stress levels.
Good question. The human population is more or less 50/50. There have been times when it has become slightly skewed for certain human groups. Following some wars the sex ratio has been slightly female biased in some countries, but most of the time it remains very close to 50/50.
If your hypothesis is right, how quick would this process be, that is how many generations will it take for the male-female ratio to become equal?
For the "66% male" population, you mentioned that the males will kill each other for the population to become equal. For "66% female" -- how do you think the female population will come down?
The 50/50 sex ratio may be restored as quickly as one generation. However, we are most interested in finding out if this skewed ratio will affect which individual lizards survive and reproduce.
Remember the 66% is really a ratio, not a measure of the overall population. We aren't actually sure if the populations will change much, but we are really concerned with what the ratio of males to females is. Of course we will still monitor population growth, but our experimental question is more focused on the ratio.
We try as hard as we can to not hurt any lizards. We have caught thousands of lizards an released them back into the wild unharmed. However, very rarely a lizard may be hurt while being captured. We try our very best to avoid this. We love lizards too!
Adella: We will be posting daily updates and videos from the biologists, and any questions you ask will be answered by the biologists themselves. It will be as if we are following along virtually! Keep coming back daily.
I love science and i can't wait to follow your experiment from my home! i have a few questions about the experiment...
How do you track the lizards? Do they have a tag or RFID chip on them?
What happens if some lizards die? How will you know?
How will you know how many babies were born and if they survived?
How do you control for variables such as weather, food, etc? Isn't there too many variables to control?
They are too small to use RFID chips (but we do use those with snakes). For lizards we give them a permanent mark by clipping their toes. Since they have four legs with 5 toes on each leg, this gives us a lot of 4 digit clips to use. We also collect a DNA sample from each lizard using a tiny tail clip that will grow back. That way when we find a new baby, we can analyze the DNA to find out who it's parents are.
Many do die, they have lots of predators and conditions can be harsh. We never know for sure if they have died, but if we can't find them again they are most likely dead.
We will never know how many babies were born, but we will be able to tell how many survive, because we will catch them.
We can't control all of the variables, but since all 9 islands are close to each other, they will all experience the same weather. We do loose some control by doing the experiments in the wild, but we also gain a lot of knowledge about how evolution happens in a wild ecosystem.
From Rap:
When you go back to count the lizards, how do you know you have found all of the lizards? Or if you don't find all the lizards won't that skew the results?
@Rap: We try our very best to catch every last lizard on our islands. The lizards are territorial and that works in our favor because we find the same lizards in the same trees quite often and it makes it easier to systematically catch all the lizards. However, as you guessed, it is pretty hard to be sure that we have caught every last lizard.
To some degree you are also right that this can skew our results a bit. We work to get the largest representative sample that we can, and as long as any two particular lizards have an equal chance of getting caught by us, then we can still draw valid conclusions from our data. We work really hard to catch them all and I think we get pretty close. We will probably catch close to a thousand lizards on this trip. We will keep our tally posted.
We are excited to present the very first "Youngzine Live!" series by Aaron Reedy. Aaron and the rest of the team are working on a National Geographic funded Lizard Project and are passionate about bringing science from the field to classrooms. Meet the 3 members of the team here.
sweet
I like and dont like lizards, I like lizards because I think they are very cute and I dont like lizards because I dont like to touch them.
WOW I'm sorry I missed this!!!
OMGN IDK what a brown anole was
sweet
wow, the lizard is soooooooooooooo small!
Good article! I love lizards, we have a lot in our backyard so we catch them and with that I learned to love them!
WOW AARON YOU SURE KNOW A LOT
How do you know if the sharpie marker that you marked the lizards with didn't wash off?
Lizards are cool.
lizards are my favorite creature ever
how far away is the island you are going to visit
aaron i own 2 crested geckos have you found those before? $$
=
What do you use to write the numbers on the lizards?
We use a black sharpie permanent marker. It is one of the most useful tools in field biology!
Where can we learn about the results of your research? Will it be posted here?
See my comments to Zoom. It will still be several months until we can share results with the world.
Unfortunately, science moves at a fairly slow pace sometimes. We are working on analyzing the data now and doing all of the genetic tests on our tail samples. We hope to have something to share in about 6 months.
Are you going to go back to the islands sometime?
We are working to schedule a trip for October to go back to collect babies as this year's eggs will be hatching soon.
Do you think you will find any other animals besides the glass lizard that may have eaten some of the anole lizards on the island? Will you look for any evidence of the lizards being eaten because that may make a difference in the number of lizards, won't it?
Yes, we also found black racer's (a type of snake) and many herons and egrets (birds) that all eat lizards. You can be sure that they are eating the lizards. The evidence we look for is mostly just the general population size. We know that predators can influence the populations, but our experiment is not designed to test the strength of the effect that predators are having on the population.
This seems to be a more generalized experiment and you could use any animals.
So why did you guys choose lizards?
Hi Arjun,
Great question! Part of the reason we chose the project, is that this experiment is generalizable, and our results may generally apply to many or most sexual animals. Lizards are abundant, short-lived, there is some evidence that they can invest differently in the sexes, and are easy enough to work with. Also, most studies researching these questions don't use vertebrates, so this experiment is more relevant to all sorts of vertebrates.
Plus, Lizards are totally awesome!
Tim
i dont like lizards
hey, i think they are cute!
We're crazy about 'em. What is your favorite animal?
Dolphins.
Did the glass lizard evolve from the Anole lizards that you had introduced to the islands? Or if not, which lizard species did it evolve from?
How many lizards have you already caught? How many do you hope to catch and when will you know that you have finished your field data collection?
Hi Diamond,
Great questions. The glass lizard did not evolve from the island lizards, but they do share a common ancestor. You did not evolve from your cousin, but your grandmother is you and your cousin's most recent common ancestor. Anoles and Glass lizards most recent common ancestor was around about 170 Million years ago!
We just caught 135 lizards today. We got about 300 so far this trip, we think, although we didn't do an exact number. We hope to catch every lizard on every island. We mark them, and rerelease them, so when all the lizards we encounter are already marked, we probably have finished this round of data collection,
Tim
glass lizard???
Where did you get the lizards?
Do you name your lizards?
Hi Zoom,
We caught the lizards from the mainland, and brought them out to the islands. We mostly caught them along landscaping in front of a grocery store, along a bike path, and at a golf course. These lizards are very common here in Florida.
Tim
Will these experiments damage any parts of the lizard's bodies? I hope not.
We do take DNA samples from the lizards by clipping of a tiny tip of their tail. However, the tails do grow back pretty quickly.
We also clip certain claws (which don't grow back) to use as an identification mark. It probably does hurt a bit at first, but studies show that it has no effect on their survival and their stress levels.
Also, does the human population follow this 50/50 sex ratio? Are we also balanced?
Good question. The human population is more or less 50/50. There have been times when it has become slightly skewed for certain human groups. Following some wars the sex ratio has been slightly female biased in some countries, but most of the time it remains very close to 50/50.
If your hypothesis is right, how quick would this process be, that is how many generations will it take for the male-female ratio to become equal?
For the "66% male" population, you mentioned that the males will kill each other for the population to become equal. For "66% female" -- how do you think the female population will come down?
The 50/50 sex ratio may be restored as quickly as one generation. However, we are most interested in finding out if this skewed ratio will affect which individual lizards survive and reproduce.
Remember the 66% is really a ratio, not a measure of the overall population. We aren't actually sure if the populations will change much, but we are really concerned with what the ratio of males to females is. Of course we will still monitor population growth, but our experimental question is more focused on the ratio.
Will the experiments hurt the lizards?
We try as hard as we can to not hurt any lizards. We have caught thousands of lizards an released them back into the wild unharmed. However, very rarely a lizard may be hurt while being captured. We try our very best to avoid this. We love lizards too!
do we get to go or just sk questions?
Adella: We will be posting daily updates and videos from the biologists, and any questions you ask will be answered by the biologists themselves. It will be as if we are following along virtually! Keep coming back daily.
Oh! Thanks for explaining to me. I was really confused.
That is so cool. You should do like this more often.
I know this is random, but you seem like a very nice person!!!!!!!! :D
Thankyou! I try to be
i think you are a nice person too.
I love science and i can't wait to follow your experiment from my home! i have a few questions about the experiment...
How do you track the lizards? Do they have a tag or RFID chip on them?
What happens if some lizards die? How will you know?
How will you know how many babies were born and if they survived?
How do you control for variables such as weather, food, etc? Isn't there too many variables to control?
Good questions.
They are too small to use RFID chips (but we do use those with snakes). For lizards we give them a permanent mark by clipping their toes. Since they have four legs with 5 toes on each leg, this gives us a lot of 4 digit clips to use. We also collect a DNA sample from each lizard using a tiny tail clip that will grow back. That way when we find a new baby, we can analyze the DNA to find out who it's parents are.
Many do die, they have lots of predators and conditions can be harsh. We never know for sure if they have died, but if we can't find them again they are most likely dead.
We will never know how many babies were born, but we will be able to tell how many survive, because we will catch them.
We can't control all of the variables, but since all 9 islands are close to each other, they will all experience the same weather. We do loose some control by doing the experiments in the wild, but we also gain a lot of knowledge about how evolution happens in a wild ecosystem.
From Rap:
When you go back to count the lizards, how do you know you have found all of the lizards? Or if you don't find all the lizards won't that skew the results?
@Rap: We try our very best to catch every last lizard on our islands. The lizards are territorial and that works in our favor because we find the same lizards in the same trees quite often and it makes it easier to systematically catch all the lizards. However, as you guessed, it is pretty hard to be sure that we have caught every last lizard.
To some degree you are also right that this can skew our results a bit. We work to get the largest representative sample that we can, and as long as any two particular lizards have an equal chance of getting caught by us, then we can still draw valid conclusions from our data. We work really hard to catch them all and I think we get pretty close. We will probably catch close to a thousand lizards on this trip. We will keep our tally posted.