Colin Donihue

So here’s just a bit of background to get you caught up before we dive into the new stuff. I’ve several posts from last May and June about the island introduction experiment (you can get to them from the archives) but I’ll give you the broad overview just so we’re on the same page.

Islands are unique and fascinating laboratories for studying what makes a species “tick.” The limited food, shelter, access to mates, and good nesting sites, makes islands challenging places for lizards. Nonetheless, numerous species do great on small islands in the Mediterranean – indeed all over the world. To do so, small-island lizard populations often adopt a suite of physical, behavioral and/or physiological adaptations.

In P. erhardii, I’ve found a lot of interesting differences between lizards living on Naxos (a very large island) and on the near-by small islets. Small-island lizards are larger, have proportionally larger heads, and a proportionally stronger bite force. The manuscript detailing these results is currently in review, so I can’t elaborate here just yet, but suffice it to say, small-island P. erhardii look and behave differently than their large island kin.

The process by which this transpires, the order and drivers of of these adaptations, and the consequences for the ecological community are largely unknown. That is the question I set out to test, but that’s quite a handful. It’s large-scale and long-term, and necessitates fundamentally changing the ecology of five small islands that don’t currently have lizards on them. After a great deal of scouting, (again see the archives) I found 10 small islets that don’t have Podarcis. After an even greater amount of outreach and discussion, my team gained permission from local stakeholders, and just about every Greek Ministry, to choose five islands for introduction.

Here’s Kambana with a beautiful little church on it. This is a lovely little island – great for lizards.Here’s a picture of Petalida all in spring bloom. Petalida is the Greek word for “limpet,” and indeed, the island looks just like a limpet shell rising out of the sea.

Here’s Mavronissi – much rockier with interspersed shrubs. It means the “Black” island. In the background there you can just make out the town of Naoussa, our home base on Paros.

Here’s a picture of Agios Artemios – our big producer this year! This island’s huge advantage is seabird nests bringing lots of marine nutrients to bolster the plant and insect community on the island. So much delicious lizard food!

Finally, Galiatsos. This island is flat as a pancake, and frankly was my chief concern for the lizards. Those little lizards pulled through though, even here!

So, after extensive baseline quantification of everything we could count, measure, or photograph, 20 marked lizards were released. Here’s the video from Kambana:

In total, I put 20 lizards on each island: 12 females (8 of whom were gravid) and 8 males. All of the lizards originated from the same large-island population on Naxos. After that, it was a nail-biting 10 months to return and find who had made it. Stay tuned!

*A note to those of you reading these updates on email: these videos don’t come through so check out the website to watch the video footage.