Reporting on the Reptiles of Redonda

This post is reposted from www.anoleannals.com and so might be a little familiar in its start to readers here.

IMG_4616I’m back from Redonda and the expedition was a great success! I’m happy to report there were many Anolis nubilus boulder-hopping out of the way of the black rats and even blacker ground lizards on the island. In many ways the trip was even more challenging than expected but we came out with quite a lot of data so we have a great sense of the current status of the reptiles on the island and a baseline for comparisons into the future.

redonda

To refresh your memories, Redonda is an island of Antigua and Barbuda and was completely denuded by rats and goats over the last century. Despite the dearth of vegetation, three endemic reptiles had been hanging on: Anolis nubilusAmeiva (Pholidoscelis) atrata, and an as-yet unnamed Sphaerodactylus dwarf gecko. The government of Antigua and Barbuda, in collaboration with Fauna & Flora International and local NGO the Environmental Awareness Group, has decided to undertake a massive restoration effort by eradicating the rats and relocating the goats. My job was to get some baseline data on the current lizard populations so we can figure out how they change into the future.

Helicopter inside

Helicoptering to the island was every bit as exciting as I’d hoped. The Jurassic Park theme was playing through my head the whole way down. See that grassy patch with slightly fewer large rocks – that was the little tiny helipad, but our pilot was a pro and set us down perfectly. Almost as soon as we were out of the helicopter, we deposited our bags by our tents and set about catching Anoles.

nubilus

Anolis nubilus is at first blush a relatively innocuous member of the genus. They’re perfectly camouflaged in this environment, which is to say they’re drab gray and brown. Their dewlaps are cream-colored (which is really just my nice way to say drab gray-yellow) and the most elaborate of the females sport faint dorsal stripes. Males did fairly regularly display impressive crests behind their heads, but nonetheless, the species at first and second glance is considerably less flashy than many of their cousins on nearby islands.

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Photo: Geoffrey Giller

All that said, there’s still a lot of cool stuff going on with nubilus. As Skip mentioned in his article 45 years ago, there’s a casuarina tree right next to the remains of the mine manager’s house that hosts an abundance of the few Redonda tree lizards living up to their name. The tree is still there and the lizards are still eagerly defending their precious few branches (see above).

There are actually quite a few trees still on Redonda, some of which are native Ficus trees. For the most part they’re in fairly inaccessible areas, but that really just means you need to bring a longer noose pole and don’t look down. I caught a lizard on this tree below with a perch height of approximately 350 meters (that’s really going to mess with the averages). Truth be told, after catching the lizard my knees were so wobbly I had to go find a nice big boulder and just had Geoff and Anthony shout me data for a while.

fig cliff

After a week on the island and many many Anoles, we got morphometric and performance data, diet data, extended focal-animal behavior videos, two mark-recapture density studies and two permanent transects established, thermal ecology data, habitat use data, and flight behavior data. We even exhaustively determined whether nubilus likes Chuckles! (But that’s a story for another post).

I know this is an Anole blog, but there were some pretty cool things going on with the other reptiles on the island, too. The ground lizards were jet black and really big. Here’s a picture of Anthony Herrel trying to get a tail measurement:

atrata tail

Photo: Geoffrey Giller

The atrata spent their days cruising around scavenging. We saw one eating a hermit crab, and we heard rumor of another that managed to get a sardine away from one of the crew working on the eradication effort! Analyzing the stomach contents of these guys is going to take quite a lot of detective work.

We also were able to gather the first natural history data on this unnamed dwarf gecko species. They’re strangely beautiful with an unlovely shovel-face and semi-transparent, too-squishy, gelatinous body. You wouldn’t guess it but they’re quick! 1D4_1226editlarge

In all, the reptiles of Redonda were fascinating and getting to explore the island was a unique privilege. I can hardly wait to return next year, and many years after, to see how the lizards change with the island.

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“What about us?” Technically these guys are reptiles too, but c’mon, the lizards are so much cooler. Photo: Geoffrey Giller

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Working on Redonda

As I said in the previous Redonda post, I’m headed to the island in search of the three endemic species of lizards living there. My goal is to gather as much baseline data as possible on the natural history of these lizards so we can come back in a year, or in 10 years and see how they’ve changed without killer rats chasing them and hungry goats munching all of the vegetation.

That’s easier said than done though.

First, here’s a picture of Redonda taken by Dr. Jenny Daltry, the FFI scientist coordinating these efforts (and featured in that video I posted).

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Photo: Dr. Jenny Daltry, FFI via news.mongobay.com

The first, fairly unmissable thing to notice is that Redonda is surrounded by cliffs straight into the sea. This picture actually shows the pleasant, accessible side of the island! Here’s the other:

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Photo from toptenz.net.

So getting onto the island is going to be a bit of a trick. In 1964, the herpetologist that first described Anolis nubilis, Skip Lazell, described making a harrowing jump from boat to shore and scrabbling up a guano-coated sluiceway in order to get to the lizards. Another researcher I talked with tried to swim from boat to island twice and never managed to clamber up those slopes. So, if not by sea, then by air. We’ll be helicoptering into Redonda (!) and, if I have my way, we’ll be blaring the Jurassic Park theme.

In order to get as much of this one-shot data as possible I’m taking along two team members to help out. Geoff Giller is a friend from Yale and a terrific photographer and science journalist. Anthony Herrel, will also be coming along. He’s popped up more than a few times on my blog; we’ve been working together in Greece for the last several years.

We’re going to be on Redonda for 8 days. Yup. Eight days dodging rats and chasing lizards. That should be challenge enough, but to make things more interesting, there’s no fresh water anywhere on the island. We’re going to have to bring all of our food and water to the island via helicopter. Of course, it’s going to be in the 80s the whole time we’re there and with only 1 tree on the whole island, shade is going to be scarce, so I’m thinking we’re going to go through that water pretty fast.

Of course, since there aren’t any people living on the island, there’s no electricity. Normally I’d be kind of excited to be “unplugged” and off the grid for a week but alas, some of my research equipment needs power. Lots of power. So I’ve got a solar array coming along to keep computers and spectrophotometers running. Then there are the cameras. So many cameras. We’re bringing 3 GoPros, 2 DSLR digital cameras, 1 handheld video camera for behavior analyses, and a drone. Power consumption is definitely going to be problematic – I’ve been trying to calculate energy consumption rates for all these things over and over to figure out if we’re going to make it. Then there’s memory storage for all those devices… in all Geoff and I are bringing almost a terabyte of flash cards. Egads.

All of that equipment is going to be worth it though! We’re going to get the first ever comprehensive data on what these lizards look like, how they behave, and how they fit into their current ecological community. The next question is when the community shifts to no longer include these invasive pests, how are the lizards going to adapt? Stay tuned!

 

 

Field expeditions at their best.

It doesn’t get much better than this NPR account of field biology, exploration, rare species and biodiversity conservation.

Short story: (but really you should read the whole NPR article) there’s a spire of rock called Ball’s Pyramid in the Pacific Ocean, west of Australia. Hundreds of years ago, explorers landed, finding massive stick insects up to 12 centimeters long. They called them tree lobsters.

In 1918 a supply ship accidentally released rats (scourge of native fauna the world-over) which gobbled up the stick insects, driving them, we thought, to extinction. But that changed in 2001 when, following up on a rumor, David Priddel and Nicholas Carlile went looking for these “tree lobsters” and found 24 hiding out in a bush in a particularly remote cliff face. Four of these insects were taken back to the mainland where two promptly died, but “Adam” and “Eve” survived and began breeding in the Melbourne Zoo. There are now some 700 individuals of Dryococelus australis (likely more) alive and breeding, giving the species a second lease on life. Now to keep them away from rats!

(please note, all of these photos were taken from the NPR site sourced above)