31 May 2007

One hell of a big ring

bigring

Yes, it was on sale by one of the street vendors in Ortaköy, Istanbul. No, I didn't buy it. It was too big for any practical purpose. Got a photo op out of it, though, thanks to Simla.

Stop for the cat

stop4cat

This cat graffiti and the 2 similar ones in the previously posted photo were adorning a railroad overpass in College Park last week. They will be there until a maintenance crew comes along and paints over them. The people in charge of such affairs always seem to be determined to remove graffiti from everywhere and apparently believe that it is justifiable to spend their resources on such trivial matters. You can see some of the now painted-over former graffiti in the picture. I think a wall with patches of gray paint is infinitely uglier than one with colorful graffiti. Anyway.

A reader commenting on the previous photo wrote that this particular design was based on the work of the cat artist Louis Wain. I am not familiar with Wain's work, so I'll leave the judgment to others. There are some examples of Wain's cat paintings here.

30 May 2007

End of a shrew

shrew

This luckless little creature, a former resident of our backyard, met its end at the jaws of one of our cats last weekend. The last time she caught one of these I was able to interfere in time. But this time when I got to the scene of the incident, it was too late and the lifeless victim was already deposited on the rug inside the house. Luckily, there were no blood stains to clean.

It appears to be a northern short-tailed shrew (Blarina brevicauda). It is now out of the evolutionary game (hopefully, it had already reproduced), but not completely finished with its service to Snail's Tales. It is now being devoured by maggots in the backyard and that story, in all its glory and stink, will be posted here soon.

29 May 2007

A place to die for

yayla

The view of the mountain tops with patches of snow and the 2 green plateaus below were breathtaking. I was standing on a steep slope at an altitude of about 2400 m when I took this picture. The strenuous walk up there from way below where we had parked our car had also taken my breath away; I was starting to suffer from the diminishing oxygen levels in the air. The car was now just a white speck, barely discernible.

This took place earlier this month on the mountains towering above the small town of Gömbe in southwestern Turkey. And as you may have guessed, we were looking for snails on the limestone slopes, snails that are better adapted than us to living at such places. While my eyes were on the ground most of the time, I also couldn't help myself from stopping frequently, both to catch my breath and to observe and photograph the scenery.

Later, as I was descending, the details on the plateau started to come back into view. At about 2200 m, I could clearly make out the car and the roughly rectangular field of stones next to which it was parked. That was a cemetery.

cemetery1

What was a cemetery doing there, literally in the middle of nowhere and a long distance away from the closest village? Could this have been the resting place of the less fortunate snail collectors who had perished on the mountains? Unlikely.

The pastures of the plateau, watered by an enduring stream of melting snow, had probably been used for centuries by shepherds and the villagers seeking relief from the summer heat that sizzles the plains below the mountains. The cemetery, surrounded by a flimsy fence, was undoubtedly for those local folk who had died there.

cemetery3

Most of the graves were nothing more than elongated plots surrounded by field stones. If they once had headstones, those were gone now.

cemetery2

Only 2 of the graves had tombstones and only one of those still had legible inscriptions on it. It belonged to a woman named Hasibe Arıkan who had been born in 1940 and died in 1970. She was the daughter of a man named Abdurrahman. The line below her name reads "R. FATİHA" short for ruhuna fatiha, meaning "a fatiha (a prayer from the Koran) for her soul".

cemetery4

It looked like the burials stopped after 1970. My companions offered a possible explanation: the mountain roads and transportation over them had started to improve probably around that time and it had consequently become more feasible to bring down the dead or the sick people to hospitals.

I suspect during the period when this cemetery was used the bodies were placed without coffins directly into shallow pits. Why would anyone want to be in a coffin anyway, when one is lying on a green pasture surrounded by snow-covered mighty peaks?

27 May 2007

A young Helix aspersa

youngHaspersa1

The edible snail Helix aspersa, also known as Cantareus aspersus or as Cryptomphalus aspersus, has been spread all over the world by humans. Their land of origin may have been southern Europe. They have also been introduced to Turkey, perhaps by the Romans who liked to eat them, and are quite common in western Turkey in gardens, fields and ruins. Thanks to the unique patterns on their shells, they are among the easiest land snails to identify.

I found this young individual in Istanbul. I could tell that it hadn't completed its growth yet, because the edge of the aperture was quite soft. This soft area was marked off as a band ~3 mm wide (arrow in the photo). The veins covering the wall of the snail's lung were not visible thru this band, indicating that it was less translucent than the older portions of the shell. Either that or the lung didn't extend under the part of the shell that was still being built.

youngHaspersa2


The last picture shows the snail's pneumostome, the breathing hole, thru which the lung opens to the outside.

youngHaspersa3

25 May 2007

2 cats

2cats

24 May 2007

S.E. = S.D./√N

An article by Howard Wainer1 in the May-June issue of the American Scientist is about the equation that is the title of this post, where the ratio of a sample standard deviation (S.D.) to the square root of the sample size (N) gives the standard error of the mean of the sample (S.E.).

If you collect many samples from a population and calculate the mean of a certain variable for each sample, you will probably get as many different sample means as there are samples. The sample means will have a normal distribution and the standard deviation of that distribution will be the standard error, calculated as above.

The standard deviation of a sample is an estimate of the variability of the population from which the sample came, whereas the standard error is not a direct measure of the variability of the population. This is because the standard error depends on sample size. The larger the sample size, N, the smaller will be the standard error. To demonstrate this, I have carried out a simulation. From a "population" of 500 normally distributed numbers, I randomly picked 10 samples each of 10, 20, 30, 50 numbers, 5 samples each of 100 numbers and 4 samples each of 150 numbers. The plot below shows the distribution of the sample means as a function of sample sizes. You can see how the scatter of the sample means around the population mean (9.97, indicated by the red horizontal line; S.D. was 1.015) decreases as the sample size increases.

sim1r

The take-home lesson from Wainer's article is that the mean values of small samples are likely to have greater variation than those of larger samples and that any conclusions, not just purely scientific but also those with political and social implications, based solely on small samples must keep this in mind.

One example Wainer discusses in detail involves the claims put forward in the 1990s that smaller schools are better than larger schools. In reality, data seem to show that not just the schools with the highest performances, but also those with the lowest performances are more likely to be small, because of increased variation at small sample sizes. Another example is about an insurance company's ranking of the safest and least-safe cities in the U.S. that did not include any of the largest U.S. cities. The reason is that the safety ratings of the largest cities are closer to the national average, while smaller cities, perhaps mostly by chance, are more likely to be much better or much worse than the average.


1Howard Wainer. The most dangerous equation. American Scientist, May-June 2007, pp. 249-256.

23 May 2007

Naughty cats

naughtycats

Yes, they were mating.

According to Desmond Morris (Catwatching, 1986) the male cat bites the back of the female's neck during mating (see above) to immobilize her and to protect himself from a likely attack from his mate. Apparently, a cat's becoming limp in response to being held by the scruff of its neck is an evolved reaction that helps mother cats transport their kittens. Obviously, it also helps them propagate themselves.

Once I tried the neck-hold on one of my cats when I wanted to bring her in from the outside; for several weeks afterwards, I had deep gashes on my arms inflicted by her claws. I should have tried biting her neck instead.

21 May 2007

Old house and its knockers

Büyükada, the largest island off Istanbul in the Sea of Marmara, has been inhabited by humans for, I suspect, at least a couple of thousand years. So it is inevitable that there will be some really old houses on the island, although none is that old. We passed by this one on our way to the more remote corners of the island and the Monastery of Aya Yorgi. We couldn't quite tell if the house was still occupied (now as I examine the picture, I see what may be curtains in the upper windows).

oldhouse

The surviving old houses of Istanbul, usually from the early 20th century, sometimes have elaborately shaped large knockers on their doors. This one was no exception.

knockers

We have to remember that these houses were built long before there were such things as electrical door bells. One had to knock hard on the door if one wanted to be heard. Hence, a large knocker lessened wear and tear on one's knuckles. They may also have been status symbols.

We didn't think of testing the effectiveness of these knockers.

Ümit and his scorpion - 2nd episode

Our friend Ümit Kebapçı is supposed to be a malacologist, but whenever we are in the field he seems to spend more time collecting spiders, centipedes, scorpions and the like. A post from last summer featured him and a scorpion he had found.

During our last collecting trip together in Turkey a few weeks ago he found this large scorpion under a rock. He said it was an Iurus asiaticus.

Ümit&scorpion

It is amazing how much biodiversity was hidden under the rocks both in forests as well as exposed fields we visited in Turkey. We saw all sorts of arthropods, worms, snails, of course, and even a large frog. The latter will be the subject of a future post.

20 May 2007

A pilgrim at the Wall of Sugar Cubes

sugarcubes1

A place that I often visit whenever I am in Istanbul is Büyükada (Prinkipo), the largest of the so-called Prince (or Prince's, or Princes') islands off Istanbul in the Sea of Marmara. During my recent trip to Istanbul I spent a day on Büyükada with my friend Teri. We explored the southern end of the island, including, of all the places, the vicinity of the garbage dump, where we actually found quite a number of snails.

On our way back, we were on a dirt path heading towards the Monastery of Aya Yorgi (Ayios Yeoryios or Saint George) at the peak of the highest hill on the island. When it turned out that the trail wasn't going all the way up to the monastery but continuing along the western slopes of the hill, Teri decided that if we wanted to catch the next ferry boat back to Istanbul, we needed to leave the trail, climb up the hill and take a shortcut down from there. So we pushed our way thru the bushes and over and around the rocks.

When we reached the top, we found ourselves in front of a vertical cliff, blackened with soot and covered with little white objects. On close inspection, they turned out to be sugar cubes stuck to the rock with what appeared to be candle wax. Obviously, this was a rock frequented by the visitors to the monastery. Each cube was a votive offering, representing an expectation of a sweet miracle.

sugarcubes2

Going around the cliff we reached the front of the Monastery.

AyaYorgi

The place is a favorite destination on the island, despite the fact that it is at the end of a long steep climb. Infidel snail hunters visit the area looking for clues to the mysteries of evolution. Pious Greeks, and even devout Moslems, on the other hand, seek what they think is a deeper meaning.

Their yearnings remain behind in the form of sugar cubes. Until the next rain storm.

18 May 2007

It's official: I look like a scientist

Last Monday I arrived at the airport in Istanbul wearing my Tin Cloth Packer Hat by Filson. Not that I was expecting rough weather inside the building, but I had no better place to put it than the top of my head. Later, a security officer asked me to remove the hat so that he could compare me with my likeness in my passport. Hours later, at the JFK Airport in New York, I took the hat off preemptively before I got to passport control. As the passport officer was handing back my passport, I put the hat back on. The officer took a look at me and asked me where I worked. I told him. Then he asked me if I was a scientist. I said "Yes". He shook his head knowingly and said "You look like a scientist."

It must have been the hat.

scientist
The scientist and his hat in the field (photo by Ümit Kebapçi).

17 May 2007

Malacologist's sink

Helixinsink1

We collected these large Helixes at an apple orchard in southwestern Turkey a couple of weeks ago. They were very abundant. They must like the apples, although the ones I tried-the apples, not the snails-were not that tasty for my human taste buds. Later in my hotel room, the sink was a perfect temporary holding pen for them.

While the snails explored their new environment, leaving behind thick globs of slime, I was able to get close-up shots of them. Luckily, the hotel owner wasn't around at that time (this was a small mom and pop business, literally owned and operated by a nice elderly couple).

Helixinsink2

The species will be determined in the future.

15 May 2007

Archaeo+Malacology Group Newsletter No. 11

The AMG Newsletter No. 11 (and the previous 6 issues) is available here. This issue contains articles on the mollusks from Pompeii in Italy and from prehistoric wells and ditches in Cyprus, the clausiliid snails Papillifera papillaris and Elia moesta, abstracts of relevant papers and announcements of upcoming conferences of interest.

Explorer risks death, returns home safely

ölüm tehlikesi

Here I am about 10 days ago in southwestern Turkey carelessly leaning on some sort of electrical box that warns passersby of an increased risk of death that may arise from fooling around with it. I was only trying to get some good shots of swallows at their nests for the readers of Snail's Tales. I survived with only slight tingling sensations between my legs. Disappointingly, the experience didn't even come close to spending a few seconds in Woody Allen's orgasmatron.

Risk of electrocution from that box was probably quite negligible compared to my now increased risk of getting cancer or some other nasty disease from the amount of 2nd hand smoke I was exposed to while in Turkey. Alas, the Turks still haven't learned that smoking is not a good thing.

I will post the swallows' pictures some other time after I recover from my mild case of jet lag (that's why I am writing this at 5:45 in the morning).

(Thanks to Ümit Kebapçi for the picture.)

01 May 2007

Off to Dersaadet

Is there another major city that has had as many historical names as Istanbul has? And yes, Dersaadet was one of the names of Istanbul that was used primarily by the Ottomans prior to the 20th Century.

I am leaving this afternoon for that city of many names, the city that has become obscenely crowded since its quaint days more than a century ago (its population topped 10 million in 2000).

seraglio point
Saray Burnu (Seraglio Point), the promontory in the background, where the Ottoman sultans resided in the Topkapi Palace, until the mid-19th Century. Drawing from The Beauties of the Bosphorus by Julia Pardoe, 1839.

This trip wasn't actually on my schedule until the middle of March when an e-mail came from my friend Zeki Yildirim. It concerned some snail specimens we had collected in July 2006 in southwestern Turkey. We had been suspecting that we had an undescribed species, but Zeki concluded that for a definite diagnosis live specimens were needed for dissection. He told me that his group was planning to return in May to the same location. That's when I instantly developed an unstoppable urge to join them. Our field trips are so much fun that I couldn't have passed this opportunity.

Happy Malacologists
Happy malacologists in the back of a tractor in Turkey in July 2006. From left: Salih, Aydin, Hatice, Tim, Zeki.

I will be gone until 14 May. The field trip itself will take only 3 days; the rest of the time I will be in Istanbul. While I am in Turkey I will have intermittent Internet access and won't be able to post on the blog. Regular postings will resume on the 15th. I will return with good stories and lots of pictures.

So long.