Thursday, October 4, 2012

Anole eating anole!

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.

Wednesday, October 3, 2012

We found eggs!

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

Lots of Lizards, big and small

We have been catching lizards for four days now, and we have nearly eclipsed the 500 lizard mark!!!  That is a ton of lizards, even for us!  There are several reasons we are having such lizard catching success.  Overall, the populations have established very well and are growing.  But another important factor is the time of year. 

Last time we came in April just before the reproductive season.  Many of the babies from the previous summer had died and the surviving ones were relatively large.  This time, we are coming in October, at the end of the long reproductive season.  The eggs that were laid between April and August have now hatched and there are baby lizards everywhere.  Many lizards don’t survive to adulthood, but by monitoring the lizards right after they hatch, we are very likely to catch the babies. Thus, this time of year has more lizards than any other time on the islands.

Another cool thing about our project is we are getting "recaptures".  When we capture a lizard, we will mark its toes and release it back on the island.  When we come back on a trip 6 months or a year later, we will be able to figure out if we had caught that lizard before and then learn about how much its grown and what traits may have helped it survive.  On this trip, we have already recaptured two "Founders" or the original lizard we released in April 2011. They have been out on these islands for 1.5 years, which is very old for an Anole lizard in the wild.  And very cool for us!

Anole lizards have no parental care, so the baby lizards pop out of eggs as miniature versions of mom and dad.  They are feeding on really small insects and evading predators from day 1.  They only thing that the youngsters aren’t worried about that the adults are is mating, but that will wait for now. These lizards grow very fast and as you can see in the video, a baby lizard might grow up to 70 times its size as a baby.