The Green Monster is back!

It’s Red Sox opening day and we’re finally getting some sun and warm temperatures. Baseball fans aren’t the only ones defrosting down in the Fenway; I just got word that an Italian Wall Lizard, our “Green Monster,” poked its head out of one of the compost piles it most likely over-wintered in.

Go Red Sox and Hurrah for the Green Monster!

img_2209

Here’s an Italian Wall Lizard from last Fall in the Gardens. No new pictures yet this spring but stay tuned!

More leads on lizards in CT

This weekend a great article about the Italian Wall Lizards in Greenwich was published in the Greenwich Time. Give it a look here. Thanks to Peregrine Frissell for the interview.

I’m excited because new tips are starting to roll in about lizards in Southern CT and New York. It turns out lizard diversity in the area is higher than expected – we’re getting reports of some other species too:

Here’s a cute little Sceloporus:

image002

(Photo credit: K. Ladd)

And here’s Anolis sagrei, the “festive anole” a long way from home!

image1

(Photo credit: K. Eisley)

Very cool lizards but we’re on the lookout for this guy, Podarcis siculus:

IMG_9876

Here are a bunch more pictures. Email me to let me know if you think you’ve seen one in your backyard!

Lizards eating an orange?!

Many lizard species are known to bolster their diet with vegetation. The practice is particularly common among species that live on islands, given how scarce food resources often are. It was a bit surprising then that Podarcis erhardii, a lizard found plentifully all through the small aegean islands, hadn’t been observed eating plants.

This summer, while in the field, I came upon a farmer’s orange tree. Several of the fruits had fallen on the ground, and I was extremely surprised to see a lizard excitedly digging into the mostly-eaten fruit. As soon as I approached for a picture the lizard ran away, so I took another of the freshly-downed oranges, cut it open, and set it out with my video camera on a tripod watching it. Here’s the video I got (sped up a bit):

Over the next half hour, three lizards visited the orange, and two males even fought over it, suggesting that when it’s available, fruit may be a valuable resource. I mentioned this to a Greek colleague who has spent a great deal of time studying a sister species to erhardii and he related a very similar story, this time with scavenged watermelon and apple cores.

As luck would have it, the same day I saw the lizard eating the orange, Kinsey videotaped a male lizard eating a just-laid lizard egg. This was the first recorded observation of erhardii cannibalism, another trait seen in many other island lizard species.

After all these firsts, we decided we wanted to publish the sightings. In November, our paper “Novel records of frugivory and ovophagy in Podarcis lizards from East Mediterranean Islands” was accepted by the North West Journal of Zoology. I’ll post a PDF once we get proofs, but here’s one of our figures for your enjoyment.

Lizards eating fruit

Lizard sprint speed

As I’ve mentioned before, one of my primary research interests is how these lizards change in different contexts. So far I’ve measured a whole lot of morphological traits like limb length and head width on lizards from islands all over the cyclades. I’ve also measured a whole-organism performance trait, namely bite force, which relies on many of these head-related morphological traits working together in concert to see if that varied from one island to the next. Head measurements have differed significantly, as have bite force measurements. Now I want to determine whether the differing limb lengths also result in differences in performance, specifically sprint speed.

There are many ways in the literature to measure lizard sprint speed. The most common is to use a racetrack or small treadmill, set a lizard down and record how fast it runs across the surface. This works well, to a point, but I’ve never been entirely satisfied with papers discussing the implications of a lizard that runs 4% faster than another over a thick rubber mat. I wanted to test sprint speed in a more realistic context. My first thought was to build a fenced course out in the field, but I soon realized that wasn’t going to be feasible, so I set out to replicate field conditions in the lab.

The two populations I most wanted to test were both from Naxos. One lives in a highly developed valley full of rock walls and terraces and spends almost all of its time on and near the stones. The other lives in an area without any significant human land use – no grazing and certainly no walls, and so spends its time running across loose sand from bush to bush. These two substrates formed the basis of my question – because the lizards in the two areas have different limb lengths, does that mean they have different sprinting capacity over the substrate they’re most used to traversing?

So, I built a 3 meter long plastic-lined chute in the lab. I covered the bottom with sand, set up my video camera, and started recording lizards from both populations running across it. Things got really interesting when, after I absconded with about 15 large stones from an old rock pile, I built a mini rock wall in the chute. I then re-ran all of the lizards across the stones to see if some managed better than others. I now have a few hours of video to go through, frame by frame to calculate the sprint speeds of each individual, but fingers crossed something interesting comes of it! Here are a few pictures of the set up.Sprint Speed SetupSprint Speed Rocks Sprint Speed Sand