Monday, June 30, 2008

Herp of the Day: Varanus [timorensis] auffenbergi

"Roar! I can't believe you caught me!"

Now that Halai is safe and recovered, I can post about his lovely little species. Before I begin - you definitely need to view some of these pictures large and in detail to appreciate them - blogger shrinks them all and loses detail. Just click on each picture to see it full size.

Halai is a Timor monitor, Varanus [timorensis] auffenbergi, a species of dwarf monitor from the island of Timor, north of Australia.

The Timor monitor originally inhabited the monsoon forests of Timor before their extensive clearing, being quite arboreal. Observations have since shown it to be adapting to the deforested landscape and using rocky areas. In captivity, they seem fairly simple to keep, although shy.

This is quite a colorful little Varanus (although it is no prasinus), with pale blue ocelli, orangish coloration underneath, and bold dark-and-yellow patterning on the legs. The species' general shyness, and the fact that this guy escaped for a week and left me bloody over it, prevented me from getting great pictures of the back pattern.

The taxonomic history of this species is very unstable, which is why I leave the name with brackets: Varanus [timorensis] auffenbergi. Part of an Australian radiation of dwarf monitors in the subgenus Odatria, timorensis was originally described as a wide-ranging polytypic species from Indonesia to New Guinea and Australia. Since then, the various subspecies have been elevated to species status, leaving timorensis only on the island of Timor proper. Such elevated species include glauerti, scalaris, and tristis.

Some authors believe there is even more splitting to be done in timorensis. Color pattern is variable between the Timor mainland and the several satellite islands. Sprackland (1999) described the form on Roti island as a separate species, V. auffenbergi. This is the taxon that Halai belongs to, and is separated from timorensis by coloration only, with blue rather than grey ocelli and unmarked creamy-orange color underneath, whereas timorensis is duller with markings underneath.

I strongly contest this split, and it surprises me that it appears to generally be accepted in the years since (it is possible that this acceptance is more from the hobbyist field than the academic, I am not well read in either to know for sure). First - Sprackland describes this species on the basis of two specimens taken from the hobbyist trade, who differ from timorensis only in coloration. There are no fixed differences known between auffenbergi and timorensis in morphology and scalation, at least with a sample size of two. This renders the identification highly suspect - morphology and scalation are heavily used to diagnose reptile species (as opposed to the relatively dominant role of plumage and song in birds) and the lack of any differentiation is very odd. Kirschner (1999) noted that colors in auffenbergi can fade in captivity, rendering them nearly indistinguishable from timorensis. del Canto (2007) reported a timorensis-like monitor on a smaller island near Roti, Pulau Ndao, that was somewhat intermediate in coloration between timorensis and auffenbergi. The diagnosis of a species on something so simple as a variable color difference seems very very weak, at best.

My final disagreement with auffenbergi is the venue of description - the magazine Reptile Hobbyist. Simply put, new species descriptions belong in peer-reviewed scientific literature, not hobbyist magazines. It really makes me wonder if this paper would have even made it through peer review.

So, do we have a case of multiple cryptic species on each of the islands in the Timor complex, or is it simply a case of varying coloration within one species? I believe the splitting of auffenbergi as a species was incredibly premature, although it may well prove valid. The one thing that can be said definitively is that a thorough taxonomic revision of these monitors is needed to sort it out. Pianka and King (2004) mention such a study is in prep - I can't wait to see the results. In any case, I'll continue to recognize Halai as V. [timorensis] auffenbergi, to recognize him as the color form but likely not a separate species. I'll also continue to keep Halai in his cage, safe from making unplanned expeditions to the hidden depths of my kitchen.


Thanks to RG Sprackland for providing a pdf copy of his paper!

Del Canto, R. 2007. Notes on the occurence of Varanus auffenbergi on Roti Island. Biawak. 1(1): 24-25.

Eidenmuller, B. 2007. Monitor Lizards: Natural History, Captive Care, and Breeding. Edition Chimaira.

Kirschner, A. 1999. Bemerkungen zur Pilege und Zucht vom Timorwaran der Insel Roti, Indonesien. Herpetofauna 21(123): 13-18.

Pianka, ER, DR King, and RA King. 2004. Varanoid Lizards of the World. Indiana University Press. [Timorensis chapter]

Sprackland, RG. 1999. New species of monitor (Squamata: Varanidae) from Indonesia. Reptile Hobbyist. February: 20-27.

A happy evening

One week later... monitor found! I hadn't seen or heard a trace of the guy this whole time, so I finally remembered that I have a small nest camera that I could use to get in under the cabinets and look around. I did, and I spotted an opening into the cabinet above. I opened the cabinet, and there he was. He was sitting in with my pots and pans all week - shows how often I cook. Of course, if I had remembered that I had that nest camera when he first escaped, the whole ordeal would've been over in an hour.

I gave the guy a soak just in case he was a bit dehydrated. After which I opened the container to grab him, and he rocketed out and zoomed under the couch. I dove over the couch and grabbed him as he came out the far side, whereupon he latched onto my knuckle. I swear they know grabbing a small amount of skin and twisting is much more painful than just latching onto a finger. It took hitting him with water from the faucet on full to get him to let go. He went straight into his tank after that. I really want better photos, but I don't think I'll take him out again this summer. I'm just glad that the monitor is alive and well, and Eric won't be forced to kill me when he returns from Papua New Guinea.

Thursday, June 26, 2008

Nerodia action

May 26th, 9am

In Lamprey Lust, I recounted the start of a long day (and week) in downtown Ithaca pursuing Northern Rough-winged Swallows nesting in drainpipes along creeks. I began the day in Cascadilla Creek, where it empties out of a gorge into the walled channel that takes it through downtown. In addition to the lamprey sightings in my previous posts, I also made some neat observations on the Northern Watersnakes (Nerodia sipedon) that are abundant along these creeks.

At Cascadilla, the morning started off with a few normal, non-noteworthy encounters with creek-dwelling Nerodia:

While heading back to climb up out of the creek bed, I practically walked right into a tangle of Nerodia on a rock shelf next to the path. I froze, knowing the skittish snakes would almost certainly bolt immediately. They didn't. They had other things on their mind and allowed me to approach within easy camera distance. I bet you can guess what is going on:

I managed to get a few video clips as they allowed me to approach so close (sorry some of them are rotated, fixing them would further reduce the quality, making it unwatchable). In this first one, the two smaller male snakes and the larger female are going at it:

In the next video, the males were being so rambunctious in their movements on the female that they actually pulled the mating ball off the rock ledge. Both males fell but the larger female was able to stay on:

Immediately after falling off the ledge, the two males were so lustly that they completely ignored my immediate presence and went crazy looking for a way back up to the ledge. The female just retreated a little farther into the wall and watched me.

Seeing a mating group of Nerodia like this was a first for me. Late May is just the right time of year I guess, for these guys, lamprey, and other critters in future posts.

I saw many more Nerodia along the creeks over the next few days. At times, while sitting quietly for long periods of time near a rough-wing nest, I could actually watch them cruise around, foraging. I watched one individual swim along the bottom of the creek, surfacing with just the tip of his head to breath and look around. He worked along the far shore, eventually wrapping himself up in a rock crevice in what looked like an ambush posture. Here he came up to breath from his crevice:

Eventually he swam away downstream, passing near enough to the ledge I was on to get some video of him swimming along the stream bottom:

The third cool observation on Nerodia was similarly while I was sitting quietly near the creek. I observed a small Nerodia swimming up close to my shore, dragging something large in his mouth. I snapped a few pictures as I approached, trying to figure out what he had, but I got too close and startled him. He dropped his prey and dashed off into deeper portions of the creek.

The prey item remained where it was, so I walked over to check it out. It was a big Tessellated Darter (Etheostoma olmstedi)! I am a big fan of darters (Percidae), for their bright coloration, bottom-dwelling habits, and especially their extreme diversity centered in the Appalachain Mountains. Relatively few species make it into NY, those that do are generally plain colored, as is the Tessellated. I was still enormously pleased to see this guy, which appeared to be a big, breeding male.

He lay there in the water where the snake dropped him, breathing heavily. There were a few pinpricks of blood from the Nerodia teeth. He didn't appear gravely injured, but he was definitely out of it. I picked him up for a better look and to confirm the ID.

After leaving the darter in the shallows, he stuck around for a while, still breathing hard. Eventually he disappeared, so he must have come around.

I have many more observations on fish, birds, and general creek life from my week in the creek, all coming soon.

Avian Tree of Life

I've recently been pulling together papers to review and post about order- and family- level relationships in birds, in part to help with some revisions of my advisor's Ornithology class. I was surprised and delighted to find Grrlscientist's post about a new paper in Science that reconstructs the avian tree with a whopping 19 loci. This is above and beyond any molecular study yet published at this level of avian systematics. It's a major shakeup, and it is also exactly what needed to be done to resolve the tree. Each molecular locus used adds an independent sample set to the tree, and multiple loci serve to make the analysis more robust. Typical trees often contain just a handful of loci (less than 5, I'd say, my own study contains 4), so this tree is likely the most robust and most accurate that we're going to get for the avian tree. Go see the review at Living the Scientific Life for now, when I incorporate this into my research on avian systematics I'll post as well.

Wednesday, June 25, 2008

Herp of the Day: Glyptemys insculpta

June 7th

While grocery shopping with Shawn downtown, I got a call from Eric who got a call from Sarah who got a call from Fitz... Wood Turtle! Of course we had to rush over to Fitz's house to see this lifer. Last year Eric, Shawn, and I searched the valley behind Fitz's after he reported seeing them nesting, but we had no luck. This year we set up the phone tree above, and it worked, with Eric getting to see his life Glyptemys while I was stuck at work... anyways, long story short Fitz found another one over the weekend that Shawn and I were able to go see.

The Fitzes have Glyptemys insculpta living in the valley behind their house, and they come up to dig nests in their backyard. The valley contains a creek, some swampy areas, and forest, whereas their yard is a north-facing slope with lots of gravel and scrub. They like the open, warm, loose grit for digging nest chambers.

When we got over to Fitz's place, he had this lovely lady waiting for us in his yard:

This turtle is AWESOME. Her carapace is plain, but she is painted with bright orange color on the soft parts hidden around the shell openings that is hard to capture accurately on film. We posed a few photos to express our joy at seeing such a beautiful girl, then took her down the hill back to where Fitz found her.

(Photo by Shawn Billerman)

One interesting thing we noted was her appearance of being ready to pop with eggs, visible as big round bulges between her legs and tail. We suspect that she was responsible for a partial nest dig from the day before.

(Photo by Shawn Billerman)

The coolest thing though was that this individual is previously known. Fitz had marked this girl and several others when he first noticed Glyptemys on his property in 1997, making this girl at least 11 years old, and likely quite a bit older than that as she was adult or near-adult when first marked. Oddly enough, this was the first year Fitz had recaptured any of those handful of marked individuals from the first year. Fitz made some sketches and measurements to compare with his old notes.

Despite our presence hovering over her, this big girl was remarkably calm about it, emerging from her shell and walking about fairly quickly after being set down. This allowed for better photos of the bright coloration. I even noticed that the orange turns into two little yellow marks on her chin, not something I had known about them.

After that last quick round of photos, we let her go her own way. I guess turtles don't have a great turning radius, because she decided the best way back into the forest was straight ahead... through Shawn.

Minor human obstacles aside, she disappeared into the underbrush, hopefully to soon lay a full clutch of future baby Glyptemys.

(Photo by Shawn Billerman)

Tuesday, June 24, 2008

Lamprey Lust

May 26th, 8am

The morning after graduation, I hit the field to look for nesting Northern Rough-winged Swallows for one of my research projects. I had already surveyed the creeks and natural areas surrounding Ithaca, so it was time to turn my focus on the not-so-natural areas in downtown Ithaca itself. There are several main creeks running through Ithaca to empty out into Cayuga Lake. While these creeks run through beautiful gorges on their way downtown, in the city they are channeled by high concrete walls and degrade considerably in quality. Unfortunately, these walls host rough-wings that like to nest in the drainpipes all along their length, so that means I had to go get my feet wet downtown to find them.

My first stop was Cascadilla Creek, where it empties out of a gorge into its walled channel on the edge of downtown. Last week I had scouted a pair of rough-wings using a drainpipe right near the entrance of the walled channel. It's a really pretty area so I was hoping to get a nest here, but the birds present a week ago had vacated the area. While wading across the creek to check the drainpipe just to be sure, a golden serpent-shaped critter went cruising by with the downstream current. I chased after it, initially thinking Nerodia, but the unique wavy dorsal-caudal fins made me quickly realize I was chasing a lamprey... cool! I had only seen one lamprey before, a brook lamprey species in a tributary of the Allegany River last year, but I didn't have my camera to take pictures to identify it later. I really wanted to catch this one and ID it, but I missed it and it carried on downstream.

Minor editorial note: I've been playing with for my videos (the quality seems better than youtube) but the embedded player here allows you to flip through all of my uploaded videos. Feel free to watch them but just don't get confused if it is not the video I intended it to be.

I was a little bummed, and turned to head back upstream, out of the walled portion of creek to climb out and check a few more creeks for rough-wings. On the way though, I climbed up a small (~2 foot) waterfall right at the entrance to the walled portion of the creek... and saw another lamprey, fighting the current and looking to head upstream:

The water is so shallow around this waterfall that I was able to literally stand over them as up to three lamprey of various sizes thrashed around fighting to get upstream. While I wanted to get a picture of the rasping disc to confirm the species by dentition, the large size, golden color, and blotched markings all confirmed these as Sea Lamprey (Petromyzon marinus), an invasive species in the Great Lakes watershed. I knew they had also made it into Cayuga Lake of the Finger Lakes watershed, but I had never even thought that I would ever encounter one. Well, here were three, attempting to make a spawning run.

I made several attempts at grabbing the lamprey to get a picture of the dentition, but these things are slippery and squirmy and they just shoot out of your hand. Two of them swam into the nearby deeper pools to evade me, but one continued to swim in the shallows and even started to spawn. Of course, he was spawning alone so I don't know what good it would do, but it was really neat to see and film. Watch for the rapid vibrations at 0:30:

After a good fifteen+ minutes of intense lamprey-watching, the call of the rough-wing forced me to continue on my searches downtown for a nest. For the next two hours I wandered down the length of Cascadilla Creek before hopping over to Six-Mile Creek, the next creek south, and at least twice the size of Cascadilla. Here I started fairly downstream on its downtown course, a little before it begins to deepen into a channel and enter the Cayuga Lake inlet. I started off walking along a grassy park that borders the creek wall, scanning for more pipes and approaching a pipe I knew has had birds previously. A splash called my attention to a Great Blue Heron (Ardea herodias) just downstream. I froze, because he had something good in his mouth. I very quickly but quietly removed my camera from my pack (I could tell the Heron was aware of me and ready to bolt), and managed to snap this series. I don't think I need to narrate it.

Another lamprey, and a Huge one! This was turning into quite a morning for them. I started looking around in the nearby shallows and saw one, then another lamprey swimming around. I saw one in the distance associating with what could be a nesting depression, so I thought 'this is fantastic' and had to get in the creek with them. I walked upstream to one end of the park, where a ramp allows access into the creek bottom. Right at the base of the ramp, in water just a few inches deep, was an awesome sight - three lampreys going at it in a spawning bed, including a big, golden male. I got my best pictures yet, and a whole bunch of video of the process.

In this first picture, the big golden male is in the center. Males are supposed to attain the brighter colors during spawning, as well as developing a weird ropey ridge along the back, visible in some of the following pictures. I didn't get any video of the actual nest construction, but these guys actually build their depressions by moving stones with their oral discs. The female then attaches herself to a rock, the male wraps around her, and they deposit their future offspring in the silt of the nest.

In this picture, you can see the third, pineal eye on top of the head:

Some video:

After watching these guys for another length of time, I once again had to continue my search for nesting rough-wings. I entered the shallow creek bed here and began walking upstream, where the walls get higher and higher but the creek remains fairly broad and shallow, great for walking and great for spawning lamprey in the shallow rocky riffles. I found several more nests, and several individuals cruising about. One nest even had four lamprey in it.

Over the course of that day and the next week I spent in Six-mile Creek observing rough-wings, I also observed the after-effects of the lamprey spawning rush: death. Like other mass-spawning fish such as salmon, the lamprey die soon after spawning. I saw many individuals cruising around awaiting their fates, and found fresh bodies. They get so much action but at such a cost... it makes me glad humans are iteroparous breeders.