Sunday, October 16, 2011

Rodents, Snake Evolution, and Dates

South America was isolated during most of the Cenozoic and evolved a terrestrial vertebrate fauna that included many mammals, including caviomorph rodent. Antoine and colleagues (2011) have now describe South America's oldest known rodents, based on a new diverse caviomorph assemblage from the late Middle Eocene, about 41 million years ago (MYA) of Peru, including five small rodents with three stem caviomorphs. This means rodent dispersal is not linked to the Eocene/Oligocene global cooling and drying episode (about 34 MYA), as previously thought, instead rodents arrived in South America during the much warmer and wetter conditions of the Mid-Eocene Climatic Optimum. Thus, rodents evolved in China about 55 MYA (early Eocene), reached India, Southeast Asia, and Africa by about 46 MYA, and were in South America by 43 MYA. The authors phylogenetic results reaffirm the African origin of South American rodents and support a trans-Atlantic dispersal of these mammals during Middle Eocene times. This discovery further extends the gap of 15 million years between first appearances of rodents and primates in South America. But perhaps of more interest to people, who read this blog, is what impact did it have on snakes? Click on the table to enlarge it.

Rodents are snake food - many species feed on rodents today - and it has been long thought that snakes evolved their macrostomate lineage (snakes with the ability to gape their mouths to swallow excessively large prey) to feed on mammals. Could this prey have been rodents? Rodríguez-Robles et al. (1999) thought rodents were the reason the erycine boas evolved a large gape. Recently Pyron and Burbrink (2011) published a revised list of dates for the appearance of the different lineages of snakes based upon the DNA clock, these dates are shown in the attached table, and the snake clades are shown in their order of appearance. A quick look at the table shows the first mammal eating snakes alive today were the pythons which appeared a mere 40 MYA. Given that pythons probably evolved in Australasia and rodents were not present in Gondwanan it seem probably that pythons evolved there large gape to eat something else - marsupial mammals seem more likely. The earliest snakes with the macro-gape that appear in the list are the acrochordids, completely aquatic snakes, snakes that feed on fish - they were around 84.66 MYA according to this data. Given that boines were in South America 45 MYA, and rodents did not arrive until 43 MYA, it is unlikely they evolved their huge gape to consume the mammals they do today- see video. Therefore, it appears macro-gape snakes may have first evolved their big, elastic mouths to eat big fish. 

Literature
Pierre-Olivier Antoine, Laurent Marivaux, Darin A. Croft, Guillaume Billet, Morgan Ganerød, Carlos Jaramillo, Thomas Martin, Maëva J. Orliac, Julia Tejada, Ali J. Altamirano, Francis Duranthon, Grégory Fanjat, Sonia Rousse, and Rodolfo Salas Gismondi. 2011. Middle Eocene rodents from Peruvian Amazonia reveal the pattern and timing of caviomorph origins and biogeography. Proceedings of the Royal Society B published online before print October 12, 2011, doi:10.1098/rspb.2011.1732. 

Pyron, R. A. and Burbrink, F. T. (2011), EXTINCTION, ECOLOGICAL OPPORTUNITY, AND THE ORIGINS OF GLOBAL SNAKE DIVERSITY. Evolution. doi: 10.1111/j.1558-5646.2011.01437.x 

Rodríguez-Robles, J. A., Bell, C. J. and Greene, H. W. (1999), Gape size and evolution of diet in snakes: feeding ecology of erycine boas. Journal of Zoology, 248: 49–58. doi: 10.1111/j.1469-7998.1999.tb01021.x

Friday, October 14, 2011

Coloborhynchus capito, A Huge Pterosaur


Coloborhynchus capito.  Image courtesy of  
Mark Witton,University of Portsmouth
:www.markwitton.com 

New research from the Universities of Portsmouth and Leicester has identified a small fossil fragment at the Natural History Museum, London as being part of a giant pterosaur – setting a new upper limit for the size of winged and toothed animals.

Dr David Martill from the University of Portsmouth and Dr David Unwin from the University of Leicester examined the fossil - which consisted of the tip of a pterosaur snout that had been in the Museum collections since 1884.

Their identification of the fossil as being part of the world's largest toothed pterosaur has been published in Cretaceous Research.

Dr Unwin, from the School of Museum Studies at the University of Leicester, said: "Our study showed that the fossil represented a huge individual with a wingspan that might have reached 7 metres. This is far larger than, for example, any modern bird, although some extinct birds may have reached 6 metres in wingspan.

"What this research shows is that some toothed pterosaurs reached truly spectacular sizes and, for now, it allows us to put a likely upper limit on that size – around 7 metres in wingspan."

Dr Martill, from the University of Portsmouth, added: "It's an ugly looking specimen, but with a bit of skill you can work out just exactly what it was. All we have is the tip of the upper jaws - bones called the premaxillae, and a broken tooth preserved in one socket.

"Although the crown of the tooth has broken off, its diameter is 13mm. This is huge for a pterosaur. Once you do the calculations you realise that the scrap in your hand is a very exciting discovery.

"The specimen was placed in the collections of London's Natural History Museum by Sir Richard Owen, perhaps the world's greatest vertebrate palaeontologist. In his day, Owen reconstructed a giant New Zealand Moa from a single bone. We might never achieve Owen's calibre, but it is nice to think that we are following in his footsteps."

Pterosaurs are flying reptiles, famously seen in Jurassic Park, that lived in the Mesozoic Era alongside dinosaurs between 210 and 65 million years ago.

There are six or seven major groups of toothed pterosaurs, but in this study the researchers focused on just one: the ornithocheirids. Unlike other toothed groups, all of which were of relatively modest size (wingspans at most of 2 or 3 metres), they are known to have achieved very large and possibly even giant sizes with wingspans of 6 meters or more. Ornithocheirids were specialised fish-feeding pterosaurs that used a fiercesome set of teeth in the tips of the jaws, to grab their prey as they flew low and slow over the surface of the water.

Dr Unwin said: "We found that, generally speaking, large ornithocheirids reached wingspans of 5 or 6 metres which was consistent with previous ideas about this group. However, we also came across one fossil, collected in the mid-19th century from a deposit in Cambridgeshire called the Cambridge Greensand that seemed to be unusually large.

"This fossil, now in the collections of the Natural History Museum, London, consisted of the tip of a pterosaur snout. The shape of the snout and the broken-off tooth that it contained allowed us to identify the new find as belonging to Coloborhynchus capito, a very rare ornithocheirid represented only by a few fossil fragments from the Cambridge Greensand. Calculating the original size of the animal based on just a fragment is difficult, but we were able to take advantage of some recent finds in Brazil of almost complete skeletons of ornithocheirids that are closely related to the Cambridge Greensand jaw fragment."

"Our study showed that the fossil did indeed represent a very large individual with a wingspan that might have reached 7 metres."

Significantly, though, this is still far short of the giant size achieved by some toothless pterosaurs. Several species of a group called azhdarchids achieved wingspans of around 10 metres.

The challenge for the researchers now is to try to understand why some groups, such as azhdarchids, reached these giant sizes, while toothed forms, such as the ornithocheirids, did not. Teeth are heavy, so part of the explanation may lie in weight reduction by losing these.

Dr Unwin said: "This research is important because it helps us to better understand patterns of evolution over millions of years, and in groups that are now extinct. At a more general level, it feeds into TV documentaries such as the current series 'Dinosaur Planet' on BBC, ensuring that they have the 'ring of authenticity' that ensures successful reception, by experts and the lay public alike. Indeed, these programs are enormously popular, as viewing figures show, allowing us to comfort ourselves with the thought that the research we carry out is helping to satisfy the interests of a not insignificant portion of the viewing public.

"For Dave Martill and I, this was to some extent the 'bread and butter' stuff that we do everyday. But it's this slow piling up of data and, critically, its connection into our general understanding, that leads to the really big discoveries. Dave likes to refer to the fossil as the ugliest fossil he ever studied, and I can see his point, but as I did my PhD on Cambridge Greensand pterosaurs they have a special place in my affections and, no matter how ugly, I still love them."

Citation
Martill, D. M. and Unwin, D. M. 2011. The world's largest toothed pterosaur, NHMUK R481, an incomplete rostrum of Coloborhynchus capito (Seeley 1870) from the Cambridge Greensand of England. Cretaceous Research 10.1016/j.cretres.2011.09.003. http://dx.doi.org/10.1016/j.cretres.2011.09.003

Answers to Where's Waldo

Howdy Herpers,

First off, I hope you all know that I've sworn off sending impossible
puzzles. I did that once, it won't happen again.

I solved both of these myself before sending them off to you.
The second one took me two guesses to get right--but I didn't
know what type of herp was in the second one initially.

That's another thing that I will do from now on: tell you whether it
is a snake, turtle, or lizard etc that you are looking for.

Without further adieu, all 9 responses for the first image found
the snake. But only Jeff M. and Marty F. got the species right.
As Jeff M. is close to the action, his correct guess didn't surprise
me. Marty getting it right did. Good show!

My initial guess when I first saw Steve's photo was that it
was a cottonmouth. But knowing that Steve has a good place
for eastern hognose snakes led me to the correct guess. Yes,
the snake in image one is a hognose.
Way the hell over in the UK, Peter Lawrence was the first to get the second
image correct. Dave Barker came right in behind him with the circle that you
see on answer number 2.
As one who sometimes steps on obvious snakes to look in escarpments under boulders
or trees, this one was duck soup for me. But it isn't very clear in the image, deliberately so.
The snake is a black-tailed rattlesnake, from the Ruby Road area of Southern Arizona.
I had originally guessed this molossus to be from the Huachucas, as did a few of you. But
Paul Condon's labeling on the attached third image makes it clear that it was not
a WOWchuca animal.
Next week, I'll introduce you to the full crop of Suizo animals we are tracking.

I have a few Waldos ready for the next game as well. Feel free to send me anything
along these lines that you have. If you stump me, I most likely won't send it out. So, make
it hard if you like, but make it possible. I enjoy looking for Waldo as much as you guys do.

Best to all, roger

Reproductive Modes of Frogs - Recent Discoveries

A male Oreophryne guarding 
eggs glued to a leaf, a rarely 
observed behavior amongst 
microhylids. Photo credit: 
S. J. Richards.
Reproductive modes in amphibians encompasses a combination of morphological, physiological and behavioral traits that include where the anaimal lays its eggs,  egg size and number, development time, stage and size of hatchling, and the type of parental care, if it occurs at all. Most of us in North America are familar with frogs depositing their eggs in water, the tadpoles develop into froglets, and then into adults, but go to the tropics or other regions of the world and frog reproductive modes become remarably diverese. The number of papers reporting advances in knowledge on reproductive modes in frogs is ever increasing, and some species have evolved remarkably complex and diverse mechanisms for protecting their offspring. Here are just a few that have been reported in the last year.

Within the genus Hypsiboas (family Hylidae) two reproductive modes are known: some species deposit their eggs in stagnant water and others deposite eggs in natural or constructed basins, with subsequent flooding that releases tadpoles into ponds or streams. Apparently, individuals within a species can be somewhat flexible in their reproductive modes. Ribeiro de Moura and colleagues (2011) described Hypsiboas pardalis depositing its eggs in a terrestrial bromeliad. Bromeliads are relatively safe habitat for tadpoles and spawns compared to puddles and streams, where competitors and predators are more abundant. Similarly, Touchona and colleagues (2011) recently reported that the neotropical treefrog Dendropsophus ebraccatus (Hylidae) lays eggs both above water on leaves and directly in water, this exposes embryos to different abiotic conditions and predator communities and undoubtedly increases the chances of survival for some of the eggs.

 Rodriguesa and colleagues (2011)  report observations on the reproduction of three shoaling/maternal-caring leptodactylids  (Leptodactylus latrans, Leptodactylus podicipinus and Leptodactylus  leptodactyloides), that suggest female presence to tadpoles is important. Females of the three species connected water bodies by digging channels to their tadpoles so that the larvae would not be stranded in drying pools and could find additional food. Females of one species,  Leptodactylus latrans, drove off predatory snakes, as well as conspecific males that approached tadpoles to prey upon tadpoles. In water bodies containing predatory fish, tadpoles of L. latrans only reached metamorphosis despite the presence of guardian females.

Direct development in frogs is where the embryos bypass the aquatic tadpole stage and hatch from the egg as froglets - miniatures of the adults. It is perhaps the most extreme evolutionary modifications of amphibian life histories. The direct development strategy has evolved independently at least 10 times in frogs and resulted in many hundreds of direct-developing species that are mostly tropical. The family Microhylidae (sometimes called narrow-mouth frogs) has a global distribution in the tropics and subtropics with members of the family exhibiting  a diversity of reproductive strategies, however direct development has been documented in only one microhylid subfamily, the Australasian Asterophryinae. This subfamily reaches its greatest diversity in New Guinea, where it is represented by 23 genera. Anstis and colleagues (2011) examined embryonic development in some members of three genera Cophixalus,  Austrochaperina, and Oreophryne and found direct development during which the embryo develops to a minute froglet within the jelly capsule. They compared the development of these Australasian frogs with the neotrpical Eleutherodactylus and foun the New Guinea frogs have a different scenario for development - so not all direct developing frogs are the same.

Gramapurohit and colleagues (2011) studied another direct developing frog in India's Western Ghats, Nyctibatrachus humayuni (family Nyctibatrachidae). Nyctibatrachus frogs exhibit a unique reproductive behavior  completely lacking or having an abbreviated amplexus. They deposit terrestrial eggs and have male paternal care. The authors studied the courtship and spawning behaviour of Nyctibatrachus humayuni from Matheran in the northern region of the Western Ghats. The breeding season coincides with the onset of south-west monsoon; and adult males vocalize from wet rocks or dead logs that often contain egg clutches. Females approach the calling males, resulting in a loose cephalic amplexus that lasts less than 10 minutes. The male dismounts, sits on the side, while the female deposits the eggs and moves away from the spawning site. Once the female moves off the spawn, the male slowly moves on to the eggs and fertilizes them. The males appear to be territorial and attend the eggs only at night, and presumably reduces the risk of predation by nocturnal predators.

Literature
Anstis, M., F. Parker, T. Hawkes, I. Morris, and S. J. Richards. 2011.  Direct development in some Australopapuan microhylid frogs of the genera Aus­trochaperina, Cophixalus and Oreophryne (Anura: Microhylidae) from northern Australia and Papua New Guinea. Zootaxa 3052: 1–50.

Gramapurohit, N. P., M. S. Gosavi, and S. K. Phuge. 2011. Unique courtship and spawning behaviour in the wrinkled frog, Nyctibatrachus humayuni.  Amphibia-Reptilia, 32: 333-339

Ribeiro de Moura, M., A. P. Motta, and R. Neves Feio. 2011. An unusual reproductive mode in Hypsiboas (Anura: Hylidae).Zoologia (Curitiba, Impr.) 28(1) http://dx.doi.org/10.1590/S1984-46702011000100021.

 Rodriguesa, A. P., A A. Giarettab, D. R. da Silvab and K. G. Facureb. 2011.Reproductive features of three maternal-caring species of Leptodactylus (Anura: Leptodactylidae) with a report on alloparental care in frogs.Journal of Natural History 45 (33-34):2037-2047.

Touchona, J.C., J. Urbinac and K. M. Warkentina, 2011. Habitat-specific constraints on induced hatching in a treefrog with reproductive mode plasticity. Behavioral Ecology (2011) 22 (1): 169-175.

New Game -- Where's Waldo?

Howdy Herpers,

In both cases, it's a snake. Find and identify if you can.

Image 1: by Steve Barten

Image 2: by Paul Condon

1-2-3 GO!

Thursday, October 13, 2011

Airborne Pheromones Detected by Reproducing Snakes

Photo Credit: Veer
Throughout history snake tongues have been hypothesized to be a venom delivery mechanism, a prey capture device, and a way to lubricate prey with saliva before swallowing. By the end of the 19th century the hypotheses turned more toward sensory functions, such as tactile and smell. Ever since George K. Noble's work in the 1930's it has been known that snakes used their tongues to detect molecules released by other other snakes - pheromones. Serpent tongues have been known as molecule collectors for the 70 years and have been experimentally demonstrated to be part of the vomero-nasal system. Now, new experiments demonstrate snake's don't have to pick-up pheromones with their tongue.

Rick Shine at the University of Sydney and Robert Mason at the Oregon State University have found snakes not only able to sense molecular communications through direct contact of their tongue, but are also able to 'smell' airborne molecules.

"Snakes usually depend on large fat molecules to tell them about another snake's sex and reproductive condition. Because these molecules are large, they don't float through the air - and so, a snake picks them up by tongue-flicking the body of another snake directly, or by tongue-flicking a trail that the other snake has left on the ground," said lead author Shine.

"Our work shows that snakes are more flexible that we had realised - they are quite capable of using airborne cues as well, involving different kinds of molecules, so long as these provide useful information."

Males snakes can detect that a female has mated - and will stop courtship- from the airborne scent of the fluids produced during copulation. Using red-sided gartersnakes (Thamnophis sirtalis parietalis) the authors exposed courting males to odors released by female snakes, male snakes, and two mating snakes, and recorded changes in behavior.

"We took an empty margarine container, and cut two holes (one on each side) through which we could pass hollow flexible plastic tubes. One tube ran to a portable aquarium pump, so that when we switched on the pump it pushed air through the margarine tub and out the tube on the other side," said Shine.

"We placed our 'stimulus' (say, a female snake) inside the margarine tub, and held the outlet opening close to the heads of courting male snakes at the den. That way, we could expose them to specific smells, but without giving them access to the large surface-bound molecules that snakes generally use as sex pheromones."

As predicted, when courting snakes were exposed to smells issued by the mating pair of snakes in the margarine container, the courting stopped.

The research suggests that snakes are able to adjust their behaviour to take advantage of certain cues in their environment to maximise their chances of reproductive success.

"Previous studies by these authors have shown that the presence of sperm plugs plays a significant role in the prevention of re-mating by females. The pheromonal evidence described here shows that sperm plugs are not the only deterrent employed by males to maximise their reproductive success," commented Warren Booth from North Carolina State University in the U.S., who was not involved with the study.

"Thus, we have evidence that males have evolved multiple strategies, both physical and chemical, to prevent females re-mating, and therefore to maximise their reproductive success," Booth added.

"In many species, courtship is an energetically expensive behaviour that can reduce or even eliminate a male's reproductive success if he is unable to find a responsive female. In instances where visual confirmation is not available olfactory cues in the form of airborne sex pheromones, as described here, provide the only information available to a male."

Literature

Noble, G. K. 1937. The sense organs involved in the courtship of Storeria, Thamnophis, and other snakes. Bulletin of the American Museum of Natural History, 73, 673–725.

Shine, R. and T. Mason. 2011. An airborne sex pheromone in snakes. Biology Letters October 12, 2011, doi: 10.1098/rsbl.2011.0802

Monday, October 10, 2011

147 Years of Invasive Herps

Living in the Chicago suburbs, between a metropolitan concrete desert and a vast agroecosystems, you don't expect to find an exotic herpetofauna. However, over the years people have brought me a variety of released pets. The occasional boa or iguana is to be expected, but perhaps the most unusual was an acquaintance that pulled his pickup into my driveway and said, "...are there lizards in Illinois," of course I replied in the affirmative. He removed a shovel from the back of the truck, on the blade was a very large, road killed Tokay Gecko. He had found the lizard on a road that runs through miles of cornfield, and the nearest human dwelling was at least a mile away.

In a recently published paper Kenneth Krysto and colleagues confirm three intercepted and 137 introduced amphibian and reptile taxa that have been found in the state of Florida. Remarkably only two (1.34%) were the result of biological controls, four (2.68%) came from zoo escapes; 18 (12.08%) came from cargo; and totally unsurprising, 125 (83.89%) came courtesy of the pet trade.

Florida holds the record for having the largest (56 taxa) established non-indigenous herpetofauna in world, Hawaii is a distant second (31 taxa).The origins of the non-native species spanning span the globe, and includes species from Australia, Oceania and Indonesia, Asia, the Mediterranean, Africa, Madagascar, South America, the Caribbean, as well as other states.

The literature suggests that about 10% of non-indigenous species that are transported to a new area actually become introduced, and 10% of those become established, and 10% of those become pests. This model was developed for British plants and animals, but exceptions to the rule are introduced birds in Hawaii, where more than half of the introduced species became established. The number (43 species) of non-indigenous lizards in Florida is spectacular, considering Florida has only 16 native lizards. This may be due to a combination of their popularity in the pet trade, but also the climate and microhabitats available in Florida.

This report is likely to have consequences for the pet trade and exotic animal business. It also raises the issue of ignoring non-native species or trying to do something about them. The flora and fauna at any given location is the result of co-evolved species, species that have adapted to each other over geological time. Humans have altered those communities in the blink of an eye, with little regard for the consequences. Ignorance is an enemy and released pets that become established can also become pests, and some are capable of causing serious damage to ecosystems. This paper makes for fascinating reading.

The African Clawed Frog was intentionally
introduced into Florida in 1964 by an animal
dealer. JCM
Citation
Krysko, K. L. et al. 2011. Verified non-indigenous amphibians and reptiles in Florida from 1863 through 2010: Outlining the invasion process and identifying invasion pathways and stages. Zootaxa 3028: 1–64.

Friday, October 7, 2011

Alligators, Pseudomonas, & Human Welfare

Alligator (above) JCM, Pseudomonas
(Below)
Human welfare may very much depend upon biodiversity. No matter how you feel about the environment, no matter how greedy you are, you will get sick at some point and your health problem will more than likely be treated with a product that its molecular origin in an organism. Stories about superbugs, pathogens that have evolved resistance to known antibiotics, are a regular feature on the nightly news. Getting a superbug is frequently associated with a visit to a hospital, a place with lots of germs and where people are treated with many antibiotics.  Solutions to antibiotic resistance will likely be solved with more molecules from organisms. Linking human welfare to biodiversity provides a window of opportunity to educate the ignorant masses unable to find value in protecting the biosphere and changing their attitudes toward nature. More than 60% of all pharmaceuticals originate from  molecules found in organisms. Loss of biodiversity is a loss of potential future medicines. Venkata Machha and colleagues (2011) report the results of testing bacteria resistance to antibiotics with a refined leukocyte extract from the American Alligator. The alligator blood extract exhibited the strongest antibacterial effect on Pseudomonas aeruginosa followed by Enterococcus faecium and then Klebsiella pneumonia. The antibacterial activities were acid-soluble, heat-stable at 70oC for one hour, sensitive to protease treatment, and did not require divalent metal ions for antibacterial activity. Taken together their data suggest that the molecule(s) responsible for the observed antibacterial activities are small, cationic antimicrobial peptides. Why is it that alligator blood is so effective against antibiotic resistant bacteria. Think about where alligators live - dirty water and add to this the fact that they frequently get injured taking prey or fighting with other gators. Those injuries are exposed to all of those nasty bacteria and alligator immune systems have evolved the means to overcome the pathogens. The article is available on-line.

Citation
Machha, V., P. Spencer and M. Merchant 2011. Effects of Leukocyte Extract from the American Alligator (Alligator mississippiensis) on Antibiotic-Resistant Bacteria. The Open Zoology Journal 4:9-13 [DOI: 10.2174/1874336601104010009]

Where's Waldo - Chelonian Answers

Howdy All,

There were some very creative answers to yesterdays puzzle.
But Jeff Moorbeck, Marty Feldner, and Craig Ivanyi (in that order) came smoking
in within minutes of each other with the correct answers.


Marty and Craig even went so far as to correctly identify the region of Arizona in which
the snake was found. I will pass along only a hint: "T.A."

Are we right, Chip? (I also guessed it to be from there).

It is a Speckled Rattlesnake (Crotalus mitchellii). See Jeff's circle on the Chip Cochran attached image.

Two honorable mentions for this image are a spiny lizard (Al Muth) and a horny toad
(John Sullivan). While I'm not seeing them in the image, that doesn't mean
that they aren't there.

The answer of three with the tortoises was mostly unanimous, and probably correct.
If you all care look at the image again, three are certainly obvious. Look
behind the head of the rear-most tortoise. Is that the rear end of yet another
tortoise carapace, or a rock?

My own answer was 3, maybe 4.

The one incorrect answer came from one of the hawk-eyed turtle
folk from Chicago:
*************
"I keep scanning in the sticks and twigs in the foreground and I don't see
any tortoises anywhere. Is this another unrealistic waldo pic? Maybe if the
resolution was increased a little bit. There is kind of a pebble thing in
the foreground, is that a tortoise?"
************
Enough with the BS. You all have a great weekend.

roger

Another Where's Waldo - Chelonians

Howdy Herpers,

Image 1 (Photo by Chip Cochran): Where is it, and what is it?


Image 2 (Photo by Young Cage): This one is for all of who had trouble with the mud turtle.


Question 1: Do you see a tortoise in the picture?

Question 2: Do you see more than one tortoise in the picture?

Question 3: How many tortoises are there in the picture?

One, two, three --- GO!

roger

Schuett/Repp Suizo Mountain - Crotalus scutulatus

Howdy Herpers, 5 October 2011

I got off to a bad start on the evening of 27 August. I hopped out of my truck, and prepared to open a data sheet by placing a thermometer in a nearby palo-verde tree. The fact that moments later, I forgot which palo-verde tree I thrust said thermometer into was the beginning of the bad start. Anybody who works after nightfall with various instruments of science scattered about knows the danger of not paying rapt attention to placement. The darkness that is often associated with nightfall can make even the simplest chore a nightmare in flandickery if full focus is not applied at all times.

As an amused Blake Thomason looked on, I walked in circles around the various pieces of surrounding shrubbery, muttering curses and bitch slapping myself incessantly. After about ten minutes of this, Blake took pity on me, and began to scour the area around our parking lot as well. About two minutes later, he called me over and said: "Hey Amigo--look what I found!"

Image 1: "Hey Amigos--look what Blake found!" It's a Mojave Rattlesnake (Crotalus scutulatus), only the second one ever found in the 10.5 year duration of the Schuett/Repp Suizo Mountain study. This is an in situ image of the snake as Blake found it--less than 20 feet from our parking spot!

The previous Mojave Rattlesnake was found 22 July 2009. At that point in time, we didn't have the means or desire to radiotrack a "scut." We were fearful that since they don't normally occur on our plot, we might have a wayward snakethat would wander well off plot and be lost.

Image 2: However, with the scut found on 27 August, we decided we'd try our hand at tracking him--regardless of any would-be wandering. This is obviously a posed image, taken the day following the capture.


In no time flat, we had a transmitter in him, and began tracking.

Image 3: In the early going, tracking good old Blake the snake went slicker than greased owl scat. On 7 September, he was found behaving very atrox-ish, coiled in prickly pear next to a pack rat midden. His total move was ~100 meters to the southeast of his capture spot. He had wrapped around to the south side of our hill. I expected him to move southward, out to the creosote flats by Park Link Drive.


Image 4: Knowing that this snake might just boogie right off the plot, staying with him became imperative. The next tracking session was on 11 September. He had shifted westward about 100 meters, and had actually crossed Main Street.

Image 5: I tracked him again on 13 September. He had shifted about 200 meters to the northwest. Thus far, there was nothing to indicate that there was trouble ahead. 

On 17 September, I could not get his signal from our normal parking spot. Blake the person and I took a drive to the top of Iron Mine Hill, and picked up a very faint series of blips. They were coming in from the north, and the weak blips indicated he was a LONG way out there. We drove back down the hill, (encountering my shadow, tortoise number 505 on the way down), and headed across Suizo Wash. We got the signal from the other side. At that point, as we had three other people waiting for us at the parking spot, we drove back and formed a two truck caravan to work the back roads that occur haphazardly around the countryside. We drove around for over an hour, the results being akin to the sound of one hand clapping. My companions were still gung ho to keep trying, but I pulled the plug on the effort. We were out there to find new snakes, (which we did-but that is another story), and I wasn't about to waste five pairs of eyeballs by driving around all night in no mans land looking for a lost child. (The thought of putting his image on a milk carton occurred to me. "Have you seen this child?")

On 24 September, the same scenario repeated itself. I drove to the top of the hill, once again freaking out poor old tortoise number 505, who was peacefully munching on some grass at the edge of the road. The signals came in ever-so-faintly, and I drove to the edge of the earth with zero luck again.

Great feats of deep thinking began. How did I do this back in the day when we had big male Black-tailed Rattlesnakes that would take off? Then it hit me. The next time I got the signal, I would make cock sure of which direction it was coming from, and hike him out. None of this driving wildly around on back roads hoping for a convenient parking place. Hiking them out is what I used to do with lost children in the past, before I got fat and lazy.

Thus it came to pass that on 28 September, I drove to the top of Iron Mine Hill. Once again, poor old 505 was choking down some dry grass at the edge of the road. This time, he paused long enough to give me a dirty look, and then continued to browse. Once again, a faint signal came in, this time from the northwest. I aligned my compass in the direction, and noted that I could get about 100 meters closer to him by driving to a place that was in direct line with the compass/signal.

I started the hike at 1715. I told myself that I would walk until 1810 before I threw up the white flag. At precisely 1800, the first faint blips appeared again. The crowd went wild!

Image 6: By 1815, I had tracked him down. He had moved an astounding 1,885 meters from his point of capture. As good fortune would have it, he followed the one road that leads in that direction. I could have driven and parked right beside him that night.

 
On 1 October, another drive to the top of our hill yielded no tortoise 505, and no signal. Off we went on a wild drive to try to find the signal, with no luck.

On 2 October, John Slone joined me for another attempt. At the last possible second, we caught a faint glimmer of a signal. It wound up being nearly an hour later, but we finally we tracked him down.
Image 7: He was now 4,280 meters northwest of his capture spot. That is over 2.6 miles!


Image 8: And of course, when we found him, he was traveling in that same northwest direction he has been heading since we first found him. Just after this image was taken, he exploded into a defensive posture, rattling and loudly hissing. He was not glad too see us! 

 

The paved road gradient that leads to our plot takes one through some changes in the landscape that in turn leads to changes in the herpetofauna that inhabit the region. To the west end of the road, Sidewinders, Mojave Rattlesnakes, and Desert Iguanas can be found. These all peter out together about one wile west of our plot. We knew when we installed the transmitter that we might be in for a difficult subject to track.

Blake the Snake is probably one of those rare individuals that cut loose from a smaller home range to check out the world around him. He found us at the eastern edge of his journey, and that was likely not a good experience for him. I speculate that he is now heading back to his home range. As one who has herped the whole length of the area, I have only once encountered a Mojave Rattlesnake once in November.
That means Blake the Snake is going to hibernate soon. If I can stay on top of him until that point, we probably will have him at the point where he is back home again.

Image 9, By Royce Ballinger. View from Iron Mine Hill looking northwest. To the left background, local herpers will recognize Picacho Peak. To the right, the Picaho Mountains. Smack dab in the middle of the two mountain ranges is the lone hill that is called "Huerfono" (The Orphan in Spanish). Blake the Snake is slightly past Huefono, and about 1/2 mile to the north. 


This here is Roger Repp, signing off from Southern Arizona, where the SNAKES are strong.......................

Tuesday, October 4, 2011

The Mekong Mud Snake

The Mekong Mud Snake, Enhydris subtaeniata. JCM
From the mid-19th century to the mid-20th century it was popular to lump species, placing names in synonymies of older names if there was reason to suspect they might be the same species. With snakes, characters like similar scale rows at mid-body, similar color patterns, combined with similar distributions resulted in species named by one person being placed in the synonymy of another species by somebody else. The result, zoologists in the early 20th century greatly underestimated animal diversity. Such was the case of the Mekong Mud Snake, Enhydris subtaeniata. Rene Bourret described Hypsirhina enhydris subtaeniata in an obscure French colonial journal (Bulletin General de l'Instruction Publique) in French Indochina (Vietnam), in 1943 Malcolm Smith placed the name in the synonymy of Enhydris jagorii. However, it was recognized by Murphy (2007) as a valid species of the genus Enhydris, and established as a member of the enhydris clade based on molecular work (Karns et. al. 2010).

As its name suggests, the Mekong Mud Snake is endemic to the middle and lower Mekong drainage, but also occurs at Bung Boraphet in central Thailand. It is a highly aquatic, fishing eating snake they reaches high population densities at some locations.  In a new paper Vimoksalehi Lukoschek and colleagues (2011) report high genetic diversity in Enhydris subtaeniata between seven sampled localities, while genetic diversity was low within each sampled locality. The authors suggest the diversity is the result of genetic isolation of populations by changes in the Quaternary landscapes of Indochina and that the snake was able to colonize central Thailand using corridors of ancient, now drowned river valleys.

Literature
Karns, D. R., Lukoschek, V., Osterhage, J., Murphy, J, C., and Voris, H. K. (2010) Phylogeny and biogeography of the Enhydris clade (Serpentes: Homalopsidae). Zootaxa, 2452. pp. 18-30. ISSN 1175-5334.

Lukoschek, V., Osterhage, J. L., Karns, D. R., Murphy, J. C. and Voris, H. K. (2011), Phylogeography of the Mekong mud snake (Enhydris subtaeniata): the biogeographic importance of dynamic river drainages and fluctuating sea levels for semiaquatic taxa in Indochina. Ecology and Evolution. doi: 10.1002/ece3.29

Murphy, J. C. 2007. Homalopsid Snakes, Evolution in the Mud. Krieger Publishing, Malabar, FL.

Sunday, October 2, 2011

More on The Golf Course & its Endangered Herpetofauna

Rana draytonii, WEI
An article on the San Francisco Examiners web site by Carole Groom and Adrienne J. Tissier (both members of the San Mateo County Board of Supervisors) is reporting that San Mateo County and Pacifica have a framework for a plan to make Sharp Park a place where golfers from all socioeconomic strata successfully co-exist with sensitive coastal species. They suggest the golf course can be reconfigured to support the endangered snakes and threatened frogs, while recapturing some of Dr. Alister MacKenzie (the desinger of the golf course in the 1920's) original layouts. Additionally they report that San Mateo County has already identified private sources willing to underwrite most (maybe all) of this proposed peaceful co-existence.You can find the entire article on-line.

Sharp Park Golf Course contains two threatened species the California Red-legged Frog, Rana draytonii, a species that has lost much of its habitat to development and a species that is often referred to as “Twain’s frog” because it was the central character in Mark Twain’s short story “The Celebrated Jumping Frog of Calaveras County,” it was a favorite competitor in jumping frog competitions—until the California red-legged frog was displaced by species imported from other parts of the world. Rana draytonii became a staple of the diet of the forty-niners during the California Gold Rush, and eventually became an item on the menu of San Francisco’s finest dining establishments. The golf course operation has been killing California red-legged frogs for many years. Every year when normal winter rains occur frogs begin to breed at Laguna Salada and Horse Stable Pond, laying egg-masses that attach to aquatic vegetation. Because of the golf course’s poor design and unfortunate placement, these same winter rains cause several of the golf course’s fairways to flood. For many years, the golf course would simply pump the water through the sea wall and drain the water off the course: and in the process strand frog egg masses that would desiccate and die, losing entire generations of this threatened species.
Thamnophis sirtalis tetrataenia. WEI

Sharp Park has also provided excellent habitat for the San Francisco Garter Snake, Thamnophis sirtalis tetrataenia. The snakes used Laguna Salada, a lagoon for feeding and the surrounding upland refuge areas and basking habitats. In the 1940s, herpetologist Wade Fox surveyed Sharp Park for the first time, and found the species abundant, suggesting the population was present long-before the recently constructed golf course altered the species’ habitats.

However, Fox also discovered that the golf course was having detrimental impacts on this endemic snake. He found a snake killed by golfers in 1946, and noted that the species probably was frequently killed in this manner. Over the next few decades the snake’s population crashed, and in 2006 the U.S. Fish and Wildlife Service concluded a dead snake found on the property was killed by the course’s lawn mowers. The population crash and the on-going take of the species is particularly worrisome because the survival of the Sharp Park population is key to the success of the species’ overall recovery plan. When the plan was written, Sharp Park had one of only six known potentially viable populations of the species. The plan states that at least four more would need to be established if the species is to have any chance of recovering. Unfortunately, the population at Sharp Park Golf Course has crashed since that time: there may be fewer than 10-20 individuals left on the property.

The San Francisco garter snake was protected by federal law by 1967, and was listed as an endangered species under the Federal Endangered Species Act when the Act was passed in 1973. It is also protected as a Fully Protected Species under California law, and therefore killing the species is not only illegal, but it is also impossible to get a permit to kill the San Francisco garter snake except for restoration projects and scientific research.

Since the garter snake was protected great effort has gone into conserving the species, including the creation of a recovery plan and controlling developments to ensure that the species’ habitats aren’t adversely modified. However, many obstacles still remain to the snake’s survival. Indeed, it is even starting to lose its favored prey, the California red-legged frog is itself threatened with extinction due to development and other threats. Restoring Sharp Park will help both imperiled species thrive. For more information on these two species and the park visit the Wild Equity web site.

Saturday, October 1, 2011

A Matter of Priorities

The Brown Treesnake, Boiga 
irregularis.US Fish & Wildlife

The word ecology is of uncertain origins, it may be derived from the Greek eco, meaning home, or the Latin oeconomia meaning household management.  In either case ecology refers to the economy of nature. Nature's economy is the flow of energy and matter through ecosystems and it is not unlike the flow of cash through society.

Given the current political climate, the country seems divided by those who want to make the wealthy, wealthier (by making the poor, poorer - although they don't admit to this) and those who want to maintain a strong middle class with a more even distribution of wealth.  Returning to the ecosystem analogy, imagine an ecosystem with an excessive number of carnivores (the wealthy - or brown treesnakes) who consume most of the omnivores and herbivores (middle class and poor - or the local bird and lizard fauna). In such an ecosystem the carnivores would soon run out of food and would then start to consume each other.

Those who are complaining about Washington spending too much money, the rhetoric is really code for - you are not spending enough money on my projects or my friends. They really don't want to stop government spending, just control who gets the money. I am all for my tax dollars going for projects that work to restore ecosystems, expand scientific research, and increase jobs for the middle class, but some folks don't agree. Hence, the following article.

HONOLULU (AP) — The Defense and Interior departments are chipping in $2.9 million to rescue a program preventing an invasive snake species from hitchhiking rides from Guam to Hawaii and other warm climates on cargo ships and planes.

Congressional earmarks for years paid to control brown tree snakes, a reptile native to Australia and the Solomon Islands that has eaten to extinction nine out of 11 forest birds on Guam since it was accidentally introduced there after World War II.

Scientists fear the snakes would wipe out Hawaii's many endangered birds if they became established in the 50th state.

Even so, the program was on course to be canceled on Friday — the last day of the current fiscal year — after Congress abandoned earmarks this year. The prospect had alarmed those in Hawaii who try to prevent invasive species from harming the state's fragile environment, and who are already having a harder time doing their jobs because of state budget cuts.

But The Associated Press learned the program got a last-minute reprieve when the Interior and Defense departments last week signed agreements to fund it for the next nine months. The Pentagon is contributing $2.4 million, and Interior is pitching in $500,000.

"We don't want a break in service, obviously, and so that's why there was very much concern over the budget situation," said Mike Pitzler, who oversees the program as the Hawaii, Guam and Pacific Island state director for the U.S. Department of Agriculture's wildlife services section.

The departments are only committing to nine months of funding because they are concerned by the cost at a time when all parts of federal government are grappling with budget cuts. They're expected to discuss in coming months how to continue the program for the last quarter of the fiscal year and beyond.

Pitzler said Thursday he would look for ways to restructure and cut costs, but he's not sure how he can do this without affecting the scope of the work.

"My job will be to make sure that our work isn't compromised, our ability to prevent snakes from leaving Guam is not compromised," he said.

Sen. John McCain, R-Arizona, and others have questioned over the years why the Pentagon should pay to control snakes on Guam.

The program has been the target of fierce critics of earmarks. In 2009, the Citizens Against Government Waste included brown tree snake control in its "Congressional Pig Book" highlighting alleged examples of government pork barrel spending.

Pitzler said the vast majority of cargo leaving Guam belongs to the Navy and the Air Force, so it's natural that the Pentagon pay to screen for the snakes. The program not only protects warm climates like Hawaii and Texas where the snakes would thrive, but also military bases in those states.

The funding pays for 58 workers who maintain 4,000 snake traps around Guam, look for snakes that climb fences at night, poison the reptiles, and search cargo leaving the island.

They use dogs while hunting for snakes hiding on ships and planes leaving Guam, placing a priority on cargo heading for warm locations.

The World’s Most Threatened Sea Turtle Populations


29 September 2011, IUCN Press Release

Top sea turtle experts from around the globe have discovered that almost half (45%) of the world’s threatened sea turtle populations are found in the northern Indian Ocean. The study also determined that the most significant threats across all of the threatened populations of sea turtles are fisheries bycatch, accidental catches of sea turtles by fishermen targeting other species, and the direct harvest of turtles or their eggs for food or turtle shell material for commercial use.

The recent report, produced by IUCN (International Union for Conservation of Nature) Marine Turtle Specialist Group (MTSG) and supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF), is the first comprehensive status assessment of all sea turtle populations globally. The study, designed to provide a blueprint for conservation and research, evaluated the state of individual populations of sea turtles and determined the 11 most threatened populations, as well as the 12 healthiest populations.

“This assessment system provides a baseline status for all sea turtles from which we can gauge our progress on recovering these threatened populations in the future,” explained Roderic Mast, Co-Chair of the MTSG, CI Vice President, and one of the paper’s authors. “Through this process, we have learned a lot about what is working and what isn’t in sea turtle conservation, so now we look forward to turning the lessons learned into sound conservation strategies for sea turtles and their habitats.”

Five of the world’s 11 most threatened species of sea turtles are found in the northern Indian Ocean, specifically threatened populations of both Loggerhead Turtles (Caretta caretta) and Olive Ridley Turtles (Lepidochelys olivacea) are found in the northern Indian Ocean in waters and on nesting beaches within Exclusive Economic Zones (EEZs) of countries such as India, Sri Lanka and Bangladesh.. Other areas that proved to be the most dangerous places for sea turtles were the East Pacific Ocean (from the USA to South America) and East Atlantic Ocean (off the coast of western Africa).

“The report confirms that India is a home to many of the most threatened sea turtles in the world,” said Dr. B. C. Choudhury, head of the Department of Endangered Species Management at the Wildlife Institute of India and a contributor to the study. “This paper is a wake-up call for the authorities to do more to protect India's sea turtles and their habitats to ensure that they survive."

The study also highlighted the 12 healthiest sea turtle populations in the world, which are large and currently populations facing relatively low threats. Five species, such as the Hawksbill Turtle (Eretmochelys imbricata) and the Green Turtle (Chelonia mydas) have populations among these dozen thriving habitats which include nesting sites and feeding areas in Australia, Mexico and Brazil. Other areas that harbor healthy turtle populations include the Southwest Indian Ocean, Micronesia and French Polynesia.

“Before we conducted this study, the best we could say about sea turtles was that six of the seven sea turtle species are threatened with extinction globally,” said Dr Bryan Wallace, Director of Science for the Marine Flagship Species Program at CI, and lead author for the paper. “But this wasn’t very helpful for conservation because it didn’t help us set priorities for different populations in different regions. Sea turtles everywhere are conservation-dependent, but this framework will help us effectively target our conservation efforts around the world.”

Now that you have the bad news here is the good news. Below is a map of the 12 healthiest sea turtle populations. Both of these graphics are available on-line