30 January 2006

Threatened land snails of Istanbul

One of the land snail surveys we did during our 2004 summer expedition in Turkey was at a location west of Istanbul and consisting of limestone meadows north of a brackish water lake known as Küçükçekmece. The results of our survey just got published1.


Tim (left) and Francisco at one of our stations (C3) during the land snail survey of the Sazlı Dere (Reedy Creek) area in June 2004. (To properly view the Turkish characters set the encoding of your browser to Unicode, UTF-8.)

We found 24 species of land snails, 21 of which were native to our survey area. One unexpected find was Albinaria caerulea, a species that previously had been assumed to have been introduced to the Istanbul area. But based on its abundance and distribution pattern, we decided that it was actually native to our survey area. The list of all the species we found is in our paper.


Xerolenta obvia, a native of the istanbul area, aestivating on a lichen covered limestone rock.

In a 2003 book2 published by the Turkish branch of the World Wildlife Fund, this area was designated as an Important Plant Area under serious threat from development. Our observations and the photographs we took during our survey further support the imminent threat this unique area is facing. The creek had recently been dammed to provide water for the ever growing population of Istanbul. This, of course, flooded some of the valley, but there were still enough hills and rocks left for snails and other wildlife. The water basin surrounding the dam is protected, at least on paper, but the areas further away from the dam are rapidly disappearing under concrete and asphalt.


This low hill with limestone rocks was our last station (C12) during the survey. The lake in the background towards the south is Küçükçekmece. All around this hill there were residential buildings. We were probably the first and the last ones to collect snails there.



1. Örstan, A., Pearce, T.A. & Welter–Schultes, F. 2005. Land snail diversity in a threatened limestone district near Istanbul, Turkey. Animal Biodiversity and Conservation 28: 181-188. Download pdf copies from here or here.
2. Özhatay, N., Byfield, A. & Atay, S., 2003. Türkiye’nin Önemli Bitki Alanlari [Important Plant Areas in Turkey]. WWF Türkiye, Istanbul.

29 January 2006

Istanbul: then and now


Map of Constantinople, Stambool, 1844. From Maps of the Society for the Diffusion of Useful Knowledge, vol. 1. Downloaded from http://www.davidrumsey.com.

Until about the late 19th century, Istanbul proper was the walled city occupying the peninsula in the 1844 map above. To the north, across the Golden Horn (Haliç), was Galata, once a Genoese colony. Surrounding the city were numerous köys (villages). For example, Karaköy (Black Village) across the Golden Horn and Arnavutköy (Albanian Village) along the Bosphorus. The villages were separated from each other by more or less degraded, but nevertheless uninhabited and undeveloped land that included agricultural fields, orchards and cemeteries.

Since then Istanbul has absorbed all of the former villages and turned into one megacity. Its population in 1927 was about 800,000; by 2000 it had grown to 10 million. Istanbul is an overgrown, overpopulated city. That basically sums it up.

Contrast the 1844 map above with the satellite picture from 2000.


ASTER image of Istanbul taken on 16 June 2000. Vegetation appears red, urban areas blue-green. Picture is from NASA.

Surprisingly, there are still some wildlife refuges left, at least for land snails, in and around Istanbul. But they are disappearing fast. Every time I visit Istanbul since 2000 I try to collect snails in every suitable location that I come across in the city and in its neighborhoods. Such places have included ruins of ancient buildings, steep wooded slopes on either side of the Bosphorus and old cemeteries.

In the summer of 2004 we carried out a snail survey at a highly threatened unique limestone district just outside the city. That will be the topic of tomorrow’s post.

27 January 2006

Stuck between a rock and a wet place

For many animals that live at the edge of the water, the rigid designations "terrestrial" and "aquatic" are meaningless. There are many animals that are equally comfortable both on land and in water and others that obligatorily spend their juvenile stages in water and adult lives on land. Take, dragonflies, for example, whose larvae grow in freshwater. Are they terrestrial or aquatic insects?


I have written about another such animal, Littoraria angulifera, the snails in the picture above. The first time I saw these snails in a mangrove forest in Florida, I didn’t know what species they were and assumed they were some terrestrial tree snails, for which Florida is famous. About a year later I returned to the same location with a more knowledgeable friend who correctly identified them. However, one cannot find L. angulifera in standard references for land snails like Pilsbry's Land Mollusca of North America, because they are considered to be "marine" snails. Imagine a marine snail that doesn’t like to get wet!

"Adult L. angulifera were never found submerged but always occurred above the water line. During low tide periods, snails might migrate down [a concrete seawall] into the encrusted zone to feed, but as they became wet with the rising tide, they moved up and remained out of the water.1"

To become completely liberated from the sea, an animal must fulfill three requirements. First, it must be able to obtain oxygen from the air. Second, it must be able to prevent excessive water loss from its body. Third, it must be able to reproduce on land. Successful reproduction on land, in turn, requires that 3 conditions be satisfied: 1. unless the animals are parthenogenetic or can reproduce asexually, either a mechanism must evolve to safely transfer sperm from a male to a female or the animals must become selfing hermaphrodites (hermaphrodites that fertilize their eggs with their own sperm); 2. the free-swimming veliger stage of the mollusk embryo must be suppressed; 3. the embryo must be protected from drying either inside a hard-shelled egg or by being deposited in a damp location or by remaining inside the mother’s body until fully developed.

Note that sperm transfer doesn’t necessarily involve mating. For example, in some species of pseudoscorpions, which are terrestrial animals, sperm is transferred from a male to a female in a little packet, a spermatophore, without the 2 sexes ever coming together. A male leaves its spermatophore in a suitable location and a female, if she happens to chance upon one, takes up the sperm directly from the spermatophore2.

Littoraria angulifera and its relatives (family Littorinidae) satisfy the first 2 requirements: they can breathe air and their shells, which evolved in the oceans and were definitely a preadaptation for terrestrial life, protect them from drying when they are out of the water. However, they remain marine snails, at least in biologists' eyes, because when the time comes, the adults must return to the sea to spawn. In Florida this takes place during warmer months of the year (May to October) when the adults mate and the females release their larvae into the sea. The planktonic larvae first develop in the sea and then settle at the shore. As the snails get older, they move away from the edge of the sea as if they are repelled by their ancestral home.


Development of zonation in Littoraria angulifera. As the snails get older from November to May, they move away from the edge of the sea. Compiled from Gallagher & Reid, 1979.

Had the littorinids' ancestors evolved a way to modify the veliger larva and at the same time evolved some sort of protective egg, they would have paved the way towards full terrestriality.

Nevertheless, the littorinids' life style is just another way to exploit what the environment offers and is as good as any other way of surviving. They live on land and use the opportunities provided by the sea to propagate. And when the conditions are right, they can reach enormous numbers as I wrote about in this post.


1. Gallagher, S.B. & Reid, G.K. 1979. Population dynamics and zonation in the periwinkle snail, Littorina angulifera, of the Tampa Bay, Florida, region. Nautilus 94:162-178.
2. Peter Weygoldt. 1969. The Biology of Pseudoscorpions. Harvard University Press.

26 January 2006

Deer and snails revisited

In early December of last year I had a post discussing whether overabundant deer could impact forest snails and slugs negatively. I had written that post as a critique of the conclusions of 2 published papers. Subsequently, I revised what I had posted here and sent it to Tentacle, the newsletter of the IUCN/Species Survival Commission Mollusc Specialist Group. After he received my submission, the editor, Robert Cowie, contacted the authors of the papers that were the subjects of my manuscript and asked for their responses. My piece and the responses of the other authors (Jean-Louis Martin and Otso Suominen) just got published in No. 14 of Tentacle.

Jean-Louis Martin and Otso Suominen responded to some but not all of the issues I raised. I am not, however, going to repeat here everything that is already in Tentacle and I am certainly not going to beat this topic to death. If you want to read my criticism and the responses to it, you may download a copy of Tentacle 14 from here.

There are several other interesting notes in Tentacle 14 that I may review here this weekend.

25 January 2006

Flying clausiliids

In a previous post, I discussed the possibility of the transfer of land (and aquatic) snails by birds and listed some literature providing records of snails found on birds. The presence of snails on remote volcanic islands can only be due to transport by humans, birds (and perhaps other animals), floating debris and the wind (also discussed briefly in this post). One such group of islands is the Tristan da Cunha archipelago midway between South Africa and South America. Since these islands were never connected to a continent, all species endemic to them must have evolved from ancestors that arrived after the islands formed volcanically. Therefore, one puzzle in a case like this is to determine who those ancestors were and where they came from.

A group of land snails endemic to the Tristan da Cunha islands were until recently placed in a genus of their own, Tristania (family Clausiliidae). However, anatomical studies suggested that Tristania belonged to the genus Balea, which is represented in Europe and in the Azores by several species of land snails.


Balea perversa. Shells of adults are 8-10 mm long. (Picture from Kerney & Cameron, 1979. A Field Guide to the Land Snails of Britain and North-west Europe.

In a paper published in this week's Nature, Gittenberger et al.1 demonstrate, using mitochondrial DNA sequence comparisons, that the Balea species in Tristan da Cunha (and also those in the Azores) evolved from a single ancestral species that was probably transported from Europe over the ocean first to the Azores and then to the Tristan da Cunha islands.

However, the possible culprits that may have been responsible for the dispersal of these snails are yet to be identified. In the supplementary information to their paper, the authors discount 2 species of migratory birds, the greater shearwater (Puffinus gravis) and the Arctic tern (Sterna paradisaea), because these birds apparently do not come ashore in Europe. They suggest that nonspecific wading birds are more likely to have been responsible for the transport.

To clinch the case, all we need now is a bird caught with live Balea on its body.


1. Gittenberger E., Groenenberg D. S. J., Kokshoorn B.& Preece R. C. 2006. Nature, 439:409.

Dr. Crick regrets he is unable to cure your disease

I have been going thru the Francis Crick Papers at the U.S. National Library of Medicine website. There are a lot of interesting documents, correspondence, photographs, etc.

I thought Crick's reply card to refuse invitations was not only amusing but also indicative of what sorts of requests he was receiving. This was about the time he had received the Nobel Prize.

24 January 2006

George Gaylord Simpson (1902-1984)

"…I was born with or somehow very early acquired an uncontrollable drive to know and to understand the world in which I live."
G. G. Simpson, Concession to the Improbable


George G. Simpson was a vertebrate paleontologist and one of the architects of the so-called synthetic theory of evolution developed during the mid-20th century. I recently read his 1978 autobiography, Concession to the Improbable. It took me, with many interruptions, about 2 months to finish it, mainly because, the book, initially interesting, got duller and duller as Simpson got older and older, so to speak.

The most exciting period in Simpson's life appears to have been during the early 1930s when he made several trips to Patagonia and other parts of South America to collect fossils. The chapters dealing with that period are also the most interesting parts of this book. Simpson volunteered to serve during World War II and spent 2 years as an intelligence officer in North Africa. His refusal to obey General Patton’s order that he shave his beard was witnessed by a reporter and subsequently publicized in the U.S. media. (Simpson was under General Eisenhower's command and had his permission to wear a beard.)

Simpson returned to South America in later years. During a 1956 expedition along some tributaries of the Amazon at a remote corner of Brazil, a tree fell on Simpson seriously injuring him. It took his companions 8 days to transport him to a hospital in New York. It was 2 years before Simpson could start to walk again with the help of a cane.

Early in the 1960s, presumably because of his declining health, Simpson seems to have stopped going on fossil collecting trips. Nevertheless, he continued to travel widely, but mainly either to attend scientific meetings or to study museum collections or to convalesce. I thought the chapters about those trips were mostly uninteresting. Simpson gives endless details, apparently copied from his diaries, about every city he and his wife visited, the people they met, the hotels they stayed in and even the meals they had. I skipped many of those pages.

During his latter years, Simpson studied fossil penguins, but it seems that all of his "field trips" during those years were to museum collections and his trips to Antarctica to observe live penguins were all on commercial cruises. Doing serious research while vacationing is not a bad idea, though, and I too try to incorporate a research project into all of my vacation plans.

Simpson was a prolific writer. In addition to many scientific papers, he wrote books on as diverse subjects as evolution, statistics, horses, penguins and the Kamarakotos Indians of Venezuela. He even wrote a posthumously published science fiction novella, The Dechronization of Sam Magruder, which I reviewed here. Simpson, who described himself as an etymophile, coined the term paleospheniscologist, a person who studies fossil penguins. During a time when he was the only such person he declared himself to be the world's greatest (and worst, according to one of his daughters) paleospheniscologist.

Considering Simpson's contributions to the field, the book offers disappointingly little on evolutionary theory. The most interesting part along these lines was the very brief account of the discussion Simpson and his friend Theodosius Dobzhansky had on speciation after having witnessed the biodiversity of the Great Barrier Reef in Australia:

"It is a matter of common observation in communities more fully studied that similar species live together if, and usually only if, each has a way of life sufficiently distinct so that they do not compete in at least one, even trivial, aspect of it…The trouble was that we could not see this differentiation for many species in the reef. Some of the different species of corals, for example, seemed to be coexisting in the same niche. We could only conclude that we did not know enough about them or that there was some hitch in the theory…"

Additional biographies of G. G. Simpson are available here and here.

23 January 2006

A ruthless predator


This is a juvenile eastern red-backed salamander (Plethodon cinereus). There are 2 color morphs (phases) of this species: red-backed and lead-backed. The pictured specimen was obviously the latter morph.

Unlike many other salamander species that have aquatic larvae, the eastern red-backed salamander spends all of its life cycle on land even though it does not have lungs and obtains its oxygen thru its skin. Because they need to keep their skins wet at all times, these salamanders live in damp places in forests, for example under logs, rocks and in wet leaf litter. I found this individual under a small log on top of rotting leaves. Such places are also the preferred habitats of most land snail species of eastern forests. Not surprisingly, salamanders and land snails are usually found together and snails are among the favorite preys of salamanders1, 2.

In one laboratory study2, adult P. cinereus were kept for 3 months in containers (microcosms) with leaf litter containing various macroinvertebrates, including snails and slugs. At the end of the study, salamanders significantly reduced the density of macroinvertebrates in their containers (see figure below from the cited paper). The authors2 noted that "The six taxa absent from litter bags in salamander microcosms, but present in controls, were all macroinvertebrates: slugs, snails, centipedes, ants, adult beetles, and zoraptera." Salamanders may be small and cute, but they are also very efficient predators.



1. Craig A. Harper & David C. Guynn Jr. 1999. Factors affecting salamander density and distribution within four forest types in the Southern Appalachian Mountains. Forest Ecology and Management 114:245-252.
2. B. Michael Walton & Sonya Steckler. 2005. Contrasting effects of salamanders on forest-floor macro- and mesofauna in laboratory microcosms. Pedobiologia 49:51-60.

22 January 2006

How to view this blog properly

A friend just warned me in an e-mail that some characters on my posts, the quotes, the apostrophe and the Turkish characters, will not display properly unless the encoding is set to Unicode (UTF-8). If you are using Internet Explorer, you may change the encoding under View. If you are using some other browser, I am sorry but I don't know how to help you. I wasn't aware of this problem before, because everything looks fine on all the computers I use. We apologize for any inconvenience this may have caused you.

In the meantime, I will try to fix the characters.

An update on a previous post on butterflies

Last Tuesday I reviewed Hazards of Butterfly Collecting by Torben Larsen. Yesterday, I received an e-mail from Larsen who had read my post. With his permission, I have posted the e-mail in the comments of my review.

21 January 2006

Saturday nite's beer review: Bomonti Ale from a century ago

Tonite I present the review of a beer I've never drunk and will never drink: a beer that was brewed in Istanbul early in the 20th century.

The first commercial breweries on the lands of the Ottoman Empire appeared towards the end of the 19th century1. Although strict adherence to Islam forbids the drinking of alcohol, because of its relatively low alcohol content, beer was apparently not considered an alcoholic beverage at that time and the establishment of breweries was sanctioned by the Ottoman administration. Another factor that may have made it easier for the breweries to obtain permits was that they were all owned by non-Moslems.


An undated advertisement for the Bomonti brewery in Istanbul from Toplumsal Tarih. "Beer guaranteed of pure malt and hops without salicylic acid."

The first large scale brewery in Istanbul was that of the Swiss Bomonti Brothers that started production in 1890. During the early years, beer was brewed using top fermentation. Therefore, their beer was probably an ale. It was sold at popular "beer gardens".


Ladies enjoying beer at Bomonti's Beer Garden in Istanbul in an undated photo from Toplumsal Tarih. From their attires and the fact that they were drinking beer in public, I am assuming they were not Moslem, but were either Armenian, Jewish or Greek.

How can I review a beer that I have never tasted? Well, it turns out that someone who tried Bomonti's beer a long time ago wrote about it. That person was Hagop Mıntzuri2 (1886-1978), a long-lived Armenian citizen of, first, the Ottoman Empire, and then, the Turkish Republic. In his memoirs3, Mıntzuri tells the story of his first visit to the Bomonti Beer Garden with his more experienced friends sometime between 1898-19004 (my translation):

"The glasses with beer on the tables were gleaming light orange in the sun. I thought they were honey sherbet5. Filtered pure honey is that color. They put full glasses in front of us at the table. Thinking that I was drinking sherbet, I lifted the glass with a great appetite. But no sooner did I take a sip than I got shaken and put it back down. It felt so bitter that I couldn't keep the beer in my mouth and spitted it out. They insisted that I drink it. 'No, I won't drink it!' I said…Those at the next table were also Armenians. They looked at me. Let them look. Even though the glasses on the tables were very pretty, glittering like gold, it wasn't anything that could be drunk, it was bitter."

From Mıntzuri's story we learn that Bomonti's beer had a golden color and was bitter. However, Mıntzuri's impression of the bitterness of the beer may have been strengthened by the fact that he had never had beer before and was, therefore, unfamiliar with the flavor of ordinary beer.

I don't quite care for bitter beers either, but I would love to jump on a time machine, if I could, and travel back to 1900 just to relax at Bomonti's Beer Garden for an hour drinking their beer.

Cheers!

Note added 20 July 2010: I did have a Bomonti beer in Istanbul in June 2010! The review of it is here.


1. The source of my information on the breweries of the Ottoman Empire is the article by Ercan Eren titled "Bomonti ve Olimpos" in the December 2005 issue of Toplumsal Tarih, the monthly Turkish history magazine of Tarih Vakfı.
2. I am using the Turkish spelling of Mıntzuri's name with an "undotted i" between the M and the n.
3. Hagop Mıntzuri. 1993. İstanbul Anıları (1897-1940) (Istanbul Memoirs). Tarih Vakfı Yurt Yayınları.
4. If the dates are correct, he would have been not older than 14.
5. A sherbet would have been a very sweet drink made from fruit juice and sugar and/or honey.


Index to the Snail's Tales' Beer Reviews

19 January 2006

Bird on Bird

I and the Bird #15

The brown creeper feels no pain.
I want to send him a horned owl, but the post office is stolen.
As the hooded merganser stands inside the rain.
The spoon-billed sandpiper don't like no stollen.

I am sitting here teaching a snowy owl chess.
The 4 woodpeckers could help me at the least.
Someone hit a deer making a bloody mess.
A hungry hawk shows up for the feast.

I saw you in the garage with a flock of wild turkeys.
Sooner or later the birds in California must know.
The classic prize in Texas would be slurpies,
If I knew how many buntings there were in the snow.

Down at the Mall there was one American coot.
The birds at the feeder better not go near the beast.
That guy in the white house is quite moot.
But whose eggs are those in the east?

I hear the house finch is yellow.
Rainbow bee-eater he is in the valley.
That'll make the goose and the turtles quite mellow.
The caged bird is stuck with the Memphis blues in the alley.

If you want to catch a dipper, don't use a trident
When a bird gets into the house to eat your shoes.
Jean-Paul Sartre got lucky, but it was an accident.
Guillemot must have had the highway blues.


Well, this is as bad as (or rather as good as) I can write a poem. Yes, I was listening to Bob Dylan's Blonde on Blonde while I put this together. That explains it all, doesn't it? My apologies to Mr. Dylan.

Thanks to everyone who contributed a post. The next I & the Bird will be at Dharma Bums on 2 February.

18 January 2006

Reptile clan gets together


Birds are feathered reptiles. Recent discoveries of feathered dinosaurs in China strongly support the theory that birds evolved from dinosaurs. Turtles are, of course, reptiles first appearing in the fossil record about 200 million years ago.

When I first saw this Canada Goose (Branta canadensis) and a group of turtles (they appear to be Northern Red-bellied Cooters, Pseudemys rubriventris) together at a local lake last weekend, my immediate reaction was to grab the camera, hide behind a tree and take some shots. Then, it gradually dawned on me that I was witnessing a reunion of distant relatives even though the participants seemed to be ignoring each other. But, hey, how friendly would you be if some of your 200-million year old relatives showed up for a visit?


Read more about the evolution of birds and reptiles at the following sites:

Feathered dinosaurs

Did Birds Evolve from the Dinosaurs?

Reptiles

17 January 2006

A dangerous activity: chasing butterflies

larsen

What is better to read in the dead of winter than a book on butterfly collecting? The author of the book Hazards of butterfly collecting is Torben B. Larsen, a well-known lepidopterist who has visited, lived and worked in dozens of countries in Europe, Africa, the Middle East, southern Asia and southern America. And wherever he went he collected butterflies.

Hazards of Butterfly Collecting
is a delightful 250-page book of short accounts, rarely more than 3 pages long, of Larsen's butterflying adventures illustrated with many black and white photographs of people, places and, of course, butterflies. Larsen has had his share of hazards, including car accidents, guerillas with machine guns, an arsenic bottle that broke and cut his wife's hand (when they were more than 2 hours away from the nearest doctor), a case of snow-blindness (from counting butterflies for 12 h in the bright sun), a jump out of a helicopter that had just taken off (to catch a butterfly, of course), an almost fatal malaria attack (luckily he was in England at the time), drunk soldiers (with machine guns) who were convinced that Larsen was a murderous spy and a smelly tribesman who sneaked into Larsen's car and ate his sandwiches. As the authors also admits, however, the book's title is somewhat misleading since many stories are about collecting butterflies in reasonable safety, most have more or less happy endings and all leave you smiling. And the book is not only about field trips; there are many fascinating tidbits of butterfly natural history, ecology, evolution and biogeography with citations to the scientific literature.

My only criticism of the book is that it has many typos, usually in the form of missing or wrong words. Perhaps, the corrections were kept to a minimum to keep the cost down. Economics may also explain why the pictures are not in color, even though the captions sometimes refer to the butterflies' colors. Nevertheless, if you like butterflies, insects or otherwise doing field work in any branch of natural history, you are likely to enjoy reading this book. I hope Larsen will write at least another one.

The book was published in the United Kingdom in 2003. I don't know if it is available in the U.S. I got my copy last October from the Pemberley Books in the UK via their website.

16 January 2006

Lunch hour animal tracking

A noon walk one day last week along Paint Branch, a creek in College Park, Maryland, produced a set of very fine racoon (Procyon lotor) prints in the damp sand; the finest I've seen.



There were also a bunch of white-tailed deer (Odocoileus virginianus) tracks also in the sand on the flood plain of the creek. They were quite distinct, indicating that they had been made recently, probably the nite before.



Finally, in the small and much degraded wooded lot along the creek I chanced upon the leftovers from someone who had apparently dined on a little bird. A knowledgeable friend identified the feathers as those of a downy woodpecker (Picoides pubescens).



Previous posts featured tracks of raccoons in mud and of deer in snow.

13 January 2006

Snails, knights and a king who married his sister


In the antiquity, southwestern portion of the present day Turkey was known as Caria. One of the better known Carians was their king Mausolus (Maussollos)1 who ruled between 377-353 B.C.E. A major accomplishment of Mausolus, besides winning his sister Artemisia’s hand in marriage, was to move his capital from the inland Mylasa (present day Milas) to the coastal Halicarnassus (present day Bodrum). Upon Mausolus’s death, Artemisia succeeded him and built for her brother-husband a magnificent tomb in Halicarnassus, the Mausoleum, which became one of the 7 Wonders of the ancient world. The Mausoleum, built of marble and other rock types and about 50 m high, was decorated with sculptures on all sides, some fragments of which are now in the British Museum. The picture above shows what the original building may have looked like2.

We now fast forward to 1402 when the Knights Hospitallers, coming from Rhodes, arrived at Halicarnassus to build a castle as a stronghold against the Ottomans advancing on the Anatolian mainland2. Looking for building material, the knights ran into the Mausoleum. Exactly what state the monument was in at that time is not known, but Jeppesen2 thinks it may have been in "a deplorable state of preservation". Regardless of its condition, this huge pile of rock was just what the knights needed. They transported almost all of the rock to a narrow peninsula stretching into the Aegean and built a huge castle that still stands and is now an underwater archaeology museum.

I enter the story in August 2000 when I visited Bodrum for a few days. I visited the Castle of the Knights and with the help of the underwater archaeologist Cemal Pulak, who spends his summers at the museum, collected snails, especially large numbers of the clausiliid Albinaria brevicollis, which was quite abundant on the marble walls of the castle.


Albinaria brevicollis on a wall of the Castle of the Knights in Bodrum.

Cemal also directed me to the limestone outcrops on the hills behind the city. There, I found another clausiliid, Albinaria lerosiensis, but no A. brevicollis. On our drive back up north, we stopped at the ruins of Iasos, north of Bodrum, where I found, once again, A. brevicollis.

The presence of A. brevicollis in the castle, but not on the hills behind Bodrum struck me as odd. During the dry Mediterranean summers most Albinaria species aestivate attached to rocks and their unintentional human-assisted transport on building materials have been documented. Could the snails have been introduced to the castle? But without knowing whether or not A. brevicollis lived elsewhere on the Bodrum Peninsula, I could not come up with a good answer.

I returned in August 2002 to conduct a survey of the land snails of the Bodrum Peninsula, something that hadn’t been done before. Our survey results, recently published, established that there were 3 species of Albinaria on the peninsula (map below): A. lerosiensis, A. munda and A. brevicollis. And we found the latter only in the castle. It was definitely introduced there, but from where?


Subsequent detective work offered a reasonable answer. Our archaeologist friends directed us to a publication on the marbles of the Mausoleum3, where it was indicated that one source for the marbles may have been the quarries at Iasos. And that’s where I had collected A. brevicollis, not just at the ruins, but also in the countryside away from Iasos, indicating that the species was native to that area (see map above). Francisco Welter-Schultes and I eventually came up with this scenario that we included in our paper: A. brevicollis was originally introduced to the Mausoleum on marbles from Iasos. The snails survived on the monument for more than 1700 years and from there they were brought to the Castle of the Knights, where they still live.

Do you think Artemisia ever noticed the snails crawling on her husband’s tomb?


A wonder of the world in August 2002. This is where the Mausoleum once stood.


1. All information on the history of Halicarnassus is from Bean, G. 1971. Turkey Beyond the Maeander. According to Bean, Mausolus was actually never a “king”, but “virtually an independent ruler” of Caria, which was nominally ruled by the Persian Empire. Bean also mentions that Mausolus and Artemisia had no children, which was probably a good thing in their case. Marriage between siblings seems to have been a Carian custom, for Bean mentions that Mausolus’s brother Idrieus, who succeeded Artemisia, married their younger sister Ada. She eventually became the ruler of Caria.
2. Picture of what the Mausoleum might have looked like is from Jeppesen, K. undated. The Maussolleion at Ancient Halicarnassus. [Booklet purchased at the Mausoleum in Bodrum, August 2002.] Jeppesen gives the date of the building of the castle as about 1495.
3. Walker, S. & Matthew, K.J. 1997. The marbles of the Mausoleum. In Jenkins, I. & Waywell, G.B. (eds.). Sculptors and Sculpture of Caria and the Dodecanese. British Museum Press.

12 January 2006

One hell of a big worm


How is this for backyard composting? Photo from Age.

A month-old news item from the Australian newspaper Age (via Worms of Endearment) is about the relocation of a colony of the Giant Gippsland Earthworm (Megascolides australis), living in the path of a planned road. These evolutionary marvels, endemic to Australia, are unfortunately threatened because of degradation and loss of their habitats.

Megascolides australis (phylum Annelida) is truly a giant among terrestrial invertebrates; according to this document lengths of adults average under 1 m. Reading about this earthworm reminded me of another month-old item, the 330 million-year old fossil trackway of a huge water scorpion that had been discovered in Scotland1. The author estimated that the water scorpion that had laid the tracks was about 1.6 m long and 1 m wide. What is more interesting is that the animal was apparently walking on land. Assuming that the identification of the animal and the estimate of its size are correct, this finding implies that arthropods much larger than the extant terrestrial species can survive on land at least temporarily. But as opposed to giant annelids, giant permanently terrestrial arthropods never seem to have evolved.

This may be because of difficulties associated with water conservation. The body shapes worms, giant or not, allow them to easily burrow into damp soil where they are protected from desiccation. Large arthropods, on the other hand, would have difficulty burrowing deep unless they evolved more worm-like bodies.


1. Whyte, M.A. 2005. A gigantic fossil arthropod trackway. Nature 438:576.

10 January 2006

Prospecting for snails on a cold afternoon


While taking a walk on a cold and windy afternoon last weekend, I spotted a couple of things―I believe they are called pallets―discarded on a wooded slope. Pallets are wooden frames about 1 m x 1 m that are used as shipping crates. From the condition they were in it looked like they had been there for several years. Whenever I come upon something wide and flat in the woods (and anywhere else) I can’t resist the urge to lift it up and look under it. The picture on the left shows one of the raised pallets supported by my tripod.

The first thing I noticed under the pallet was a large snail shell that I could identify right away as Mesodon thyroidus, a common denizen of the forests around here. Then, I found another one and another one and another one...At the end I had 9 empty adult M. thyroidus shells.


There was also a small juvenile of the same species dormant in its shell. I took the empty shells, but put the juvenile back under the pallet. I also noticed 2 clusters of slug eggs, probably those of an Arion introduced from Europe. The tulip poplar (Liriodendron tulipifera) seed at the lower left corner provides a scale.


Next I looked under the other pallet, which was about 10 m away. There I found 2 more empty M. thyroidus and 2 empty shells of the larger Neohelix albolabris.


These snails seem to like to take refuge under these pallets. The moral of today’s tale is that trash left where it shouldn’t have been left isn’t always bad.

09 January 2006

Unexpected discoveries on a cold afternoon

What started out as a routine daily walk one afternoon over the weekend turned into one with several finds in a span of less than 2 hours: 14 snail shells, the ruins of an old farm, a deer carcass and a turtle shell.

All of these were in a small wooded area not too far from my house. I am afraid the area, just outside a park, has been set aside for development. Besides other animals, there are some deer living there. Once they develop the area, the deer will become a nuisance and then people will start complaining that there are too many deer and that something should be done about it. It never dawns on the complainers that maybe the real problem is that there are too many people and that too much of the land is being taken away from the deer and the other animals.


I find deer bones quite frequently in the woods; I even found a skull with huge antlers once. But entire carcasses of recently died deer are rare in the wild (but not along the roads), perhaps because they get eaten quickly. So this find was unusual in that respect. It was not a pleasant sight, although it didn't smell too bad, probably because it was cold. I will return early in the spring and try to recover the skull. Hopefully by then the bones will have been picked clean.

The carcass was under a fallen tree, one side of which was blocked by the branches and undergrowth. I wonder if the deer took refuge there instinctively during its final moments to partially protect itself from potential predators (although there aren't any around here). Are deer known to do die in secluded spots?

On my way back, I found a turtle shell on the ground. It looked like some animal had chomped off the front end of it. From the patterns on the remaining scutes (the large scales covering a turtle's carapace), I have identified the turtle as the Eastern Box Turtle, Terrapene carolina carolina. Occasionally, I come across live box turtles in the woods around here.


I will write about the snail shells I found and the old farm I photographed in separate posts.

07 January 2006

Papers read this week: Basteria vol. 69

Musical accompaniment: Terry Riley: In C, played by Bang On a Can.

Basteria is the scientific journal of the Dutch Malacological Society. Usually one or two issues, comprising one volume, are published each year. Most papers are in English, some that are specifically about the malacofauna of the Netherlands tend to be in Dutch.

Both issues of the latest volume of Basteria, 69, were published at the end of November, 2005. My copies arrived near the end of December. I have found a couple of the papers especially interesting.

Heij, A. De & R.P. Baayen. Seasonal distribution of cephalopod species living in the central and southern North Sea. Basteria, 69:91-119.
Ten species of cephalopods were collected in the central and southern North Sea during 1996-2003. The seasonal distributions of individual species depend on temperature and salinity.


Two of the North Sea cephalopods: Rossia macrosoma (top) and Eledone cirrhosa.


Verdcourt, B. A new species of Vitrina (Gastropoda, Pulmonata, Vitrinidae) from Kenya, with a discussion of the genus in East Africa. Basteria, 69:147-156.
The land snail family Vitrinidae contains many species of snails that have shells that are much smaller than their bodies. Such species, known as semislugs, provide important clues for the evolutionary stages that led from fully-shelled snails to full slugs, which may or may not have vestigial shells inside their bodies.

In this paper, the author describes a new vitrinid snail, Vitrina chyuluensis from an altitude of 1960 m in Kenya. All vitrinids appear to live at high altitude mountains. In a previous post, I briefly mentioned a possible evolutionary reason for the displacement of semislugs to high altitudes.


The shell of the holotype of Vitrina chyuluensis.



Photos are from the cited papers.

06 January 2006

Friday nite's beer review: Yuengling Porter

yueng

Now don't get the idea that I've spent my Friday afternoon drinking beer. I had this last nite. I don't review here the beers I don't like. Recently, I tried some India pale ales, but disliked their odd aromas. Yuengling's Porter, on the other hand, has a rich yet smooth flavor with no bitterness or peculiar aroma. It is also very dark. I think it is going to be one of my favorites.

The Yuengling Brewery at Pottsville, Pennsylvania, claims to be the oldest one in the U.S. It was founded in 1829 by David G. Yuengling, a German immigrant. The original spelling of his last name must have been Jüngling, meaning "young man". In fact, the English word youngling comes from jüngling. But, despite what they say at their web site, jüngling is not pronounced "ying-ling". That certainly makes it sound oritental, doesn't it?


Index to the Snail's Tales' Beer Reviews

05 January 2006

Me and Bill down by the schoolyard

Congratulations, Aydin!
Your IQ score is 138


This number is based on a scientific formula that compares how many questions you answered correctly on the Classic IQ Test relative to others.

Your Intellectual Type is Facts Curator. This means you are highly intelligent and have picked up an impressive and unique collection of facts and figures over the years. You've got a remarkable vocabulary and exceptional math skills — which puts you in the same class as brainiacs like Bill Gates. And that's just some of what we know about you from your test results.

This is the result I got from the "Classic IQ Test" I took at Tickle. What they think they know about me is probably wrong. I don’t have "exceptional" math skills, I am not good at math. I barely passed the mandatory math classes I had to take back in college. Actually, I consider myself a slow learner. But, hey, if they think I am smart, why argue with them, right?

Tickle wouldn't tell me which questions I answered wrong without a payment. You want money? Go ask Bill.

Anyway, it was a fun test. I am curious to know what they tell a person who does really bad on one of these tests. You are a moron in the same class with Zippy the Pinhead. To find out, I may go back and take the test again and this time pick what I think are the wrong answers to most questions.

04 January 2006

Same old, same old yellow snow

I am jealous of Nuthatch at bootstrap analysis who posted about blue snow and of Pamela at Thomasburg Walks who posted about red snow. All I have for show and tell today is boring yellow snow.

yelosno

The perpetrator, identified by its characteristic 2-toed tracks in the snow, was a white-tailed deer, Odocoileus virginianus.

02 January 2006

Sleeping the winter away

In areas where the climate is the Mediterranean type, land snails aestivate during the dry and hot summers and are active during the fall, the mild winters and the spring. In contrast, in the eastern U.S., where there is no dry season, land snails are active throughout the summer and spend the cold winters inside their shells in a dormant state. For the past 4 years or so, I have been studying the colonies of Oxyloma retusa (family Succineidae) at a small local lake. Although O. retusa is a land snail, it always lives near the water, usually within a few centimeters of it. In the spring and summer I find them abundantly crawling on the mud or on cattails growing out of the water. However, in the winter the snails are very difficult to locate. The snails just disappear, somehow survive the winter and reappear late in March in the same spots.

I have followed their generation cycle for several seasons. In early April of every year I find only juveniles, which suggests that only the juveniles survive the winter. All the adults die early in the fall. There is a slight possibility that all the snails die during the winter and juveniles are brought every spring by the water birds from the south. However, one piece of evidence eliminates this mechanism as a major contributor to the snail population. Early in the spring most snails' shells have a "winter stop"—a line across their shells showing where the edge of the shell was the previous fall before they stopped growing. In other words, the snails with a winter stop are most likely to have wintered at the spot.

That is, however, circumstantial evidence. I wanted to prove directly that the snails spend the winter at the same location where they spend their springs and summers. The only way to do that was to find live snails there in the winter. So about a week ago on a cold day, took my camera and went out to my usual study site, a long (about 6 meters) and narrow (only a meter or so wide) piece of muddy land extending into the lake. I spent about a half an hour in the cold wind searching thru the piles of rotting leaves and cattail stalks. People were probably watching me from their warm homes across the lake and wondering what on earth I was doing.

I succeeded. I found one snail, only one, but that was enough. As I had suspected that the snails in the winter would be juveniles, this one was tiny, just 4 mm long (adults grow to be more than 10 mm long). Stuck to a piece of rotting leaf and completely oblivious to its surroundings, it was waiting for the warm weather. I positioned it in the sun and quickly took several pictures of it. The arrow in the left-hand picture below points at the edge of the snail's body within its shell. Unlike most other pulmonate land snails, succineids cannot withdraw too far into their shells. (See my previous posts here, here and here for examples of how far into their shells other pulmonate snails can withdraw.)

oxylomdcmbr

I still needed to prove that the snail was alive and that it wasn't just a dead, frozen snail. So I brought the snail home. Once it warmed up it came out of its shell and started exploring its new surroundings.

oxylomdcmbr3

There must be more snails out there, but they are hard to find. Perhaps I am not looking at the right places. Their habitat is frequently covered with ice during the winter. It is possible that to avoid freezing the snails migrate away from the water towards higher ground, although the one I found was not far from the water. I don't think they can bury into the soil, because their shells are very fragile. In any case, now I have enough evidence to confidently conclude that the juvenile Oxyloma retusa survive the winter at their summer habitat. The snails that were there early in the fall will be the ones that will start growing in late March of this year. I will probably go back there early in March and do another search.