Next stop, Turks and Caicos!

Frequent visitors to the blog will remember my Redonda adventure earlier this year. If you want to catch up, here are a few posts about my trip to Antigua and Barbuda, and from there to the remote island of Redonda. My goal was to collect baseline data so I could figure out how three endemic lizards adapt following a rat extermination effort.

The group responsible for the rat eradication is at it again, this time in Turks and Caicos.  Next week, I’m headed to Pine Cay to see how lizards, specifically Anolis scriptus, will change following the eradication.

I don’t have pictures to share just yet, but here’s a map of the destination:

(by the way, who could possibly give this place a one-star review?!)

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A quick picture update from the Bahamas

There’s lots going on here in the field. We’ve just wrapped up collecting on Eleuthera and Long Island. I’m back on New Providence swapping out crew. Rob left after Eleuthera. He swapped spots with Geoff. We just lost Jon – a champion lizard catcher on Eleuthera and Long. Raphaël is still here and we’re being joined by Angus and Pavitra tomorrow. The rapidly switching roster is actually the least of the logistics worries but today, with twenty-dozen lizards safely ensconced in a cooler on their way back to Boston, I’m finally taking a few deep breaths.

Here are just a few pictures from the field. I’ll bolster them with a prosier post as soon as I can.

Here’s our quarry, Anolis sagrei, the “festive” anole.

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And here’s one with dewlap unfurled.

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This was Rob’s first time catching Anoles. Here’s his face after his first successful lasso.

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Three days later he was catching like a pro while reposed under thorn bushes.

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We’re catching a lot of lizards for this study – 120 per island. Here are a few in a lizard bag waiting for sorting.

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While we’re catching lizards we’re also gathering data on their behavior and ecology – where they’re piercing and how warm that perch is for example. Here are Raph and Rob typing in some of the data. We’ve got well over 600 observations so far.

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We’ve been doing a bit of driving between sites. Not a problem though with scenery like this. Note, the steering wheel is on the American side but the roads are all reversed (Thanks Great Britain). This causes some consternation trying to get used to the unfamiliar lane position with a familiar vehicle layout. Oddly, 2 of the 3 cars I’ve driven this trip have been reversed in this way. This however was the only car with a helpful red arrow to remind me where to be on the road. Luckily for these dirt paths it’s one car at a time no matter the side.

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We’ve met a few other friends in the field. Here’s Geoff with a racer snake we found in the forest.

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And here’s Anolis angusticeps, the coolest, most secretive anole we’ve seen this trip.

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Here’s the final stage – a giant cooler in the back seat of a small sedan to the airport. Just peeking over the cooler in the back there is Jon, the ringer for lizard catching.

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Bimini is our next stop for tomorrow! One more push on fieldwork, another ten dozen lizards, and then it’s back to Boston.

 

Walking around Redonda

One of our first goals on Redonda was to get a good sense for the density of lizards on the island. This is one of the key metrics that has changed following rat eradications elsewhere in the Lesser Antilles. To do that we used a few different methods, we’re hoping that each will give us a slightly different sense for densities that we can compare one year to the next.

The first was a mark-recapture study in two different locations. We’d survey a fixed area (one of the big fig trees at the north of the island and a boulder field at the south) and catch all the lizards we could find. Every time we caught a lizard we’d write a number on its belly and put a little white dot on its backside (see below). The paint spot will help us see the lizard from a distance without spending lots of time trying to catch a lizard that’d already been caught that day.

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Lizard number 22 getting a number on its belly. Photo credit: Geoffrey Giller

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An anole hanging out on a branch after getting a white spot. Photo credit: Geoffrey Giller

We spent two long days marking all of the lizards we could find in the tree and the rocks. After each site had had a day to rest, we returned. By figuring out which lizards we’d previously caught and how many new lizards had shown up we can get an estimate of just how many lizards are using that area. The lizards in the tree were particularly plentiful – we’re estimating a population of around 50! with unlimited time we’d continue marking, revisiting, and recapturing a few more days but our island time was short so we compromised with a single recapture day at each site. We’ll repeat the survey next year in the same places to see if there are changes in density.

Our next survey method was the tried-and-true walk around, look on both sides of your path, and count ’em up. For this Anthony did a big hike around the perimeter of the island counting all of the lizards he saw. He did this twice and found a lot of lizards! Here’s a page from my notebook showing the track. Unfortunately the map only really makes sense to us, but as you can see, he saw 61 anoles and 65 ameiva that day. The next day he ended up seeing 73 anoles and 118 ameiva! Those are pretty wide margins, but they’ll provide a baseline for next year’s repeat transects.

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Now, I decided to strap a GoPro to Anthony’s head for the second survey. It’s two hours long though so I had to speed the video up. Grab your dramamine, you’re going to need it!

This video is just a short segment of the hike in the vicinity of the “Hanging Gardens.” It’s one of the prettiest parts of the island I think. You can tell too how tricky some of the traversing is. On this section Anthony saw 10 ameiva and 24 anoles. Can you find them? I slowed down the first ameiva so you can get a good look. You’ll also notice a few other surprises along the way.

 

More fieldwork on the horizon

The Redonda posts have trailed off because I’m neck-deep in prepping for the next two trips this field season. I’ve still got a few more Redonda stories in mind to write up though so I’ll try to get them posted before I leave next week. I have to tell you about the next trips though!

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Next Saturday I’m headed to the Bahamas for a quick 2 week and 2 day trip to catch Anolis sagrei, the “festive anole.” This is the last field foray of my first postdoc and the second round of sampling in the Bahamas that I was a part of last fall. You can read the posts Here, here, a little disaster here, and more pretty pictures here.

We’ll be surveying lizards on three islands: Eleuthera, Long Island, and Bimini. In each of those islands we’ll be looking for lizards in two habitats – “primary” undisturbed forest and coastal beach scrub to test for differences in morphology between the populations. We’ll also be taking 360 lizards home with us to breed here in the lizard colony. Whew, sorting out those logistics – permitting, charting flights for the lizards (yes, actually), storing them happily for long periods of time – has been a huge challenge.

To help, I’m going to have 6 people along in the field with me. This is going to be great but means we’ve had to find and sort out 4 train rides, 5 car rentals, and a total of 29 different flights. I’ll be on 8 of those flights over the 16 days! I’ll try to keep posting from the field; you’re going to see some familiar faces. Rob has caught lizards with me in Connecticut before, Geoff was with me in Redonda, and Angus was one of my old field assistants in Greece!

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Rob with his first Podarcis

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(Sorry, Angus, I was looking through old pictures and I just couldn’t resist)

Three days after getting back from the Bahamas I’m hopping on a plane to Greece! Just enough time to do some laundry. Whew!

This Greece trip is another revisit to the island manipulation experiment. The islands are steadily filling up with lizards (I think… Greece did get record snow this year…) and this time around we’ve got a lot of projects going. Anthony and I will be back measuring morphology and bite force, Menelia will be there with her sprint speed setup. Kinsey is back! This time looking at the lizards’ throat color. All in all I’ll have 10 people there running around so, again, coordinating everything has been a huge effort.

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Menelia’s hoping we won’t have this much stuff this year. Shhh… nobody tell her we’re actually gonna have 5 kayaks to haul around!

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Kinsey’s excited to get back to Greece!

I’ll be in Greece until the end of May when I’m headed back to Cambridge for a much quieter summer. Stay tuned for all of the stories from the field!

 

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.

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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.

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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.

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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.

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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:

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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

Living on Redonda

Initially I thought getting to Redonda was going to be a challenge, but the helicopter made that aspect of the trip a delightful adventure. Living on Redonda for a week, though—that was tough. In retrospect, I’d say the challenge was simultaneously harder than anticipated but more comfortable than I’d feared.

Here’s a panorama of our camp:

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There were a total of 10 team members on the island while we were there – the three of us lizard catchers, plus the seven rat eradication team members in charge of deploying and monitoring hundreds of bait stations across the island. As soon as our helicopter landed, heads started popping out from behind boulders, and generous helpers (who, fortunately for me, were in a lot better shape than I was!) helped us haul all of our gear up the hill to basecamp. I’m going to keep emphasizing all of the gear because it was a point of consistent teasing over the week. We kind of had a lot of stuff…

After huffing and puffing our way up the hill, we found the famous casuarina tree (which Geoff is sitting below in the panorama) and two tents already set up for us. (Best helpers ever!) Geoff and I started off sharing the second to last tent on the left. Geoff moved out after only a few days, though, when another tent became available. (And in case you were worried, no, nobody got eaten by rats; one of the people rotating off the island was from the Ministry of the Environment, just doing a one-week stint to help out and see the operation.) I prefer to think Geoff just wanted more room to stretch out and not that my three days (and counting) without a shower was polluting our tent air supply.

Home base wasn’t really our tents, though—it was way too hot for that. The real gathering place, which you can see in the center of the panorama, was “The Manager’s House.” As I mentioned in a previous post, Redonda used to be the site of a large guano mining operation. The manager had a nice, concrete bunker house with a terrific view of Montserrat that has mostly withstood the intervening century. I heard a rumor that it took some very enthusiastic scrubbing to make it livable again, but luckily by the time we arrived it was perfectly habitable. That was where we collected all of our lizard measurements and ate all our meals. It was very much the hub for all things on Redonda.

Speaking of which… here’s a time-lapse video of a typical night in the manager’s house. You may want to watch it on full screen a couple of times, since each time there’s more to notice!

So what was going on? As we did every day, we were entering data, preparing dinner, and sitting around talking and eating. Yes, that’s a projector showing off some of our lizard behavior video from the day. Did you notice the bags on the walls flying up and down in the wind? Or the people scurrying away from the door to avoid the huge rain spot that appears in the foreground?

Wind and rain were two of the less-welcome aspects of life on Redonda. (I know, I know, most of you are laughing by now, wondering what the “welcome” aspects were. Warm weather, fantastic views, some awesome lizard species, and super interesting people, to start.) The wind was ferocious for almost our entire stay. It knocked me off balance repeatedly throughout the day. I would crawl into my tent at night, exhausted, and have to sleep with the nylon walls crashing into me. It was never quiet on Redonda. The wind was almost always howling.

And the rain! Before leaving Boston, I checked the weather for Antigua and saw that it was supposed to be sunny and 80 degrees F plus or minus 1 degree every single day. Great, I thought, no need to pack a raincoat. It turned out that the weather on Redonda was pretty different, despite being only a few miles from Antigua. It rained at least once a day, and some of those rainstorms were torrential. The worst, I think, was the day the rain came out of nowhere, and Anthony, who had climbed into a tree to search for lizards, didn’t even have time to climb back down. The downpour was so blindingly strong that he couldn’t do anything other than cling to a branch to wait out the storm. Geoff and I couldn’t stop laughing on the ground as the rain lashed us and we could just barely make out a stream of curses coming from up in the tree.

Every day, when it finally quit raining, it was HOT. We dried off quickly, and the lizards emerged, and we continued on with business as usual. And then we’d make our way to the manager’s house to get out of the sun, and we’d share some impressively delicious rehydrated meals, and then we’d collapse into our wind-buffeted tents to catch up on sleep before doing it all again the next day.

Describing A. nubilus

 

img_4456-e1487604077456.jpgDr. James “Skip” Lazell Jr. was the first to formally describe Anolis nubilus in a 1972 publication from the Bulletin of the Museum of Comparative Zoology at Harvard. Above are two of his drawings of the species from the publication. He’s a colorful and evocative writer so I’m going to let his description of his 1964 trek to find the species and his subsequent notes on their ecology stand on their own.

From “The Anoles (Sauria, Iguanidae) of the Lesser Antilles” Volume 143, No.1. 1972.

Distribution. Anolis nubilus occurs only on Redonda. This tiny islet is exceedingly steep-to, and rises nearly 1000 feet out of the sea. There is virtually no surrounding bank, and the full swell of the western North Atlantic pounds Redonda’s cliffs. A tiny, nearly vertical gut on the leeward side provides the only access to the top of the islet up the cliffs; great blocks of basalt lie at the foot of this gut, and one’s original entrance to Redonda is made by jumping onto these blocks as the boat goes past them. It is about like jumping from a moving elevator onto a card table, except that elevators give more notice of directional reversals…but getting on is just the beginning.

The islet is a great block of igneous extrusive: strata of basalt and the peculiarly conglomeratelike, porphyritic material so often the result of Antillean vulcanism. The top of Redonda is a rolling wold, and a favorite place of innumerable nesting sea birds; the gut provides a route for their guano to descend the cliffs, and it dries to a thick powder there. Because of its leeward location, a chimney effect is produced in the gut, and the guano dust, mixed with the volcanic sand weathered from the parent rock, tends to rise when disturbed. As one toils up the gut under the tropical sun, one is accompanied by a cloud of this dust, which soon mingles with ones’ own sweat to produce a wondrously aromatic and abrasive, though rather gluey, bath. At the top, jumbles of rocks and clumps of prickly pear rise gently to the old ruins, complete with a hedge of Bougainvillea and the single tree. This is the home of Anolis nubilus.

Population structure and ecology. Anolis nubilus is not abundant, but occurs all over Redonda. Owing to the lack of trees, it seems to dwell mostly in the shade of large rocks close to ground. In the ruins of the old building and on the one tree (a Casuarina, apparently inedible even to goats), A. nubilus climb as high as they can get: about fifteen feet. This species must compete with the large, glossy black ground lizard, Ameiva atrata, for at least some of its food. Surely Redonda once supported more vegetation and presumably Anolis nubilus then had an easier life. The feral goats should be extirpated on this remarkable island, whose only known nonflying vertebrates are species found nowhere else on earth.