the modest birder (12) Jac. P. Thijsse

December and January were colder than usual and bird life around the feeders, in spite of some interesting moments (e.g. what looked like 2 immat. White Throated Sparrows with a black spot on the chest that turned out to be Tree Sparrows when I decided to pay attention with my binoculars: an interesting example of being too lazy and assuming that all were the usual White-throats while Tree Sparrows are rare visitors) were not different enough from previous winters to merit a long entry. On the other hand I spent a good deal of time in my armchair reading. One of the books, a collection of Jac. P. Thijsse's essays from the periodical De Levende Natuur (DLN), took me back to my youth, especially to my grade school years. These essays were collected by Th. just before his death in 1945, but edited for publication after Word War II in 1946, by Luke Tinbergen.

I have mentioned both Tinbergens in other entries ("On reading a National Geographic" and "On a biography of Niko Tinbergen" - Luke's older brother). Thijsse (1865-1945), in addition to his duties as a teacher, was a long time editor of the DLN, and a founder of the Association for the Preservation of Nature Monuments (Natuurmonumenten) of which he was the Secretary. He was, together with Eli Heimans, a fellow teacher, a prolific writer and popularizer and their enthusiasm was infectious. They also inspired the students that formed the Netherlands Youth Organization for Nature Study (NJN) in 1920 of which the Tinbergens as well as I (20+ years later) were members. My mother, who said she had gone to a school where Heimans had been headmaster, took me one day, I was 9 I think,, on a trip to a ruined medieval castle that was within walking distance of Thijsse's Hof, a five acre landscape garden that held all the plants growing wild in the Dutch dunes. So we stopped there also. He happened to be there on his daily walk and she nudged me to ask him the name of several plants that I saw there for the first time. He was then about 78, but still a statuesque gentleman, standing straight in his three-piece suit and bow tie. Not someone I then thought you could walk up to and ask for the name of plants. But I did and he was without pretensions even taking the trouble asking how I came to be interested in plants and pleased when I told him my mother had given me one of the books he and Heimans had written (see below). The he asked where I lived and encouraged me to take the little book along on the family's Sunday walks. I have been reminded several times of his appearance by an illustration in books about him where he stands amidst people on an excursion that he still led occasionally in those years.

As in the case of Niko T. there are some parallels between the activities of the young Thijsse and my own; they are the more remarkable as Thijsse was already 65 years old when I was born. It shows how little family life had changed in spite of the economic and social developments in the intervening years. During our grade school years both Thijsse and I were surrounded by the habitats (he much to the South of Amsterdam and I to the immediate North), that he and Heimans were to describe in In sloot en plas [In Ditches and Ponds] that my mother gave me when I got my first aquarium at the age of 8 or 9. That little book was part of a series introduced by Van vlinders, vogels en bloemen [Of Butterflies, Birds and Flowers]; each described the different Dutch levensgemeenschappen [lit: communities of life] or habitats announced in the title of the series. In the first book this then fairly new concept was slipped in by way of Greek mythology to introduce the Atalanta butterfly (Vanessa atalanta; Red Amiral in the US), a beautiful as well as common butterfly. Its eggs are laid on the stinging nettle and the writers "guided me" from a neglected dirty corner of a nearby house where nettles were abundant, to a rural road, armed with a piece of paper and a pencil to write down the "signalement" (of which they gave several samples) where the Atalanta and its relatives might be sunning themselves. Another unattractive habitat was the home of thistles; these were introduced by an anecdote explaining why the thistle was Scotland's national symbol. They are the host plant of the Painted Lady and the flowers attract not only butterflies but birds too, among which the Thistle Finch (Carduelis carduelis) is the most colorful. Thus I learned that much beauty can be found amidst the "ugly" plants we warned away from. One of my teachers was fond of encouraging us by citing the motto of Prince Federick Henry, the Queen-consort, Per aspera ad adstra [through the rough to the stars] which admirably fits the approach of that introductory little book.

There was, of course, a very practical reason for treating each habitat separately, namely the distances between them. In the 1890s only the upper and well to do middle classes had the time and money to travel and even in as small a country as ours, getting from the wet meadows environments to the dunes or the beach, only between 25 to 35 kilometers from my home took 2 hours in 1938 and a walk there would thus involve an entire day. The heath and forests were still father away and even in the 1950s you might have to walk an hour from the nearest  railroad station  and thus the focus on each habitat per book was convenient as well as affordable. Het Wandelboekje(1900) [The Walker's Booklet] was more general with suggestions of what to look for during short strolls not far from home. It also focuses on plants and insects so that one did not need costly equipment. After all, both authors were then working as teachers in the poorer sections of Amsterdam and were themselves not all that well paid. That little book incidentally also tells us that most people didn't think of taking walks during the inclement weather months when most people already had to walk several kilometers from and to their work: the excursions are arranged in a "yearly" cycle that only covers the months of March through September. It was not until 1944 that Thijsse prepared a new edition that was to include every month, because by then NJNers and others were in the field at any time even if, during WWII and the late 1940s, it meant surviving the cold by means of layering old newspapers next to our underwear.

A much larger "coffee table" book was Het Vogeljaar [the bird year], first published in l904, of which I got the 1946 reprint, beautifully illustrated with (black and white) photographs, as a birthday present. I have it still and read it when nostalgia for the landscapes of my youth needs remedy. When I first read it I came to admire the Starling for which Thijsse had a soft spot (which was shared by Rachel Carson who, in 1939, published an article called "How About Citizen Papers for the Starling?" [which was imported from Europe]. It was one bird that was always with us, in the city as well as on the meadows where it rambled in the grass between the legs of the cows. But I have since developed a great dislike for that a greedy and aggressive dominator at my feeders where they are even avoided by the  larger Blue Jay; only once or twice did I see a Redbellied Woodpecker succeed in forcing a Starling off the suet. But its rambunctious behavior and softly murmured song with its humorous variations that caused Thijsse to select the Starling for his bookplate which showed a drawing of several Starlings clinging to some phragmitis stems that were bent by a typical Dutch wind above the motto Onbekommerd  [without worry]. Starlings now put me on alert to prevent it from nesting in my covered rain gutters and clogging up the works.

Thijsse's motto may be a reflection of his religious childhood and inspired by the gospel of Matthew when Christ consoles his disciples to consider the lilies and birds that are alive and beautiful without worrying and admonishes them not to worry about the day of tomorrow because each day had enough of its own cares. Recently a selection of his letters has been published in the Netherlands with the title "Wanhoop nooit aan de vooruitgang" [Never Despair of Progress]. It's more specific than his motto and occurs in a letter of encouragement towards the end of his life (de died in 1945, during the German occupation of WW II and after the years of the Great Depression). But both his motto and that encouragement typify his personality. It is a sentiment that comes out very strongly in his letters to teenagers whose interest in nature caused them to write the Great Man. These letters reminded me of my brief encounter with him in "Thijsse's Hof."

Like Thijsse I often played hooky to watch the bees and the birds or rather the salamanders and fishes. It seems however that I got punished less than Thijsse, probably because my father came home after my wet clothes had been changed and also because my mother was the contact with my teachers so that my father may not have known about my truancy (I have a vague memory of my teachers thinking that I was sickly). Yet I was disciplined from time to time for a variety of reasons and once in while I was set to write 50x or 100x the same line as Th.: "Lord, set a watch before my mouth" (which after the exercise was no longer a prayer and thus not heeded). Having realized that Thijsse, Niko T. and I all played hooky as part of developing our knowledge of nature, I wonder whether such truancy was a precondition for greatness; in that respect I missed the boat.

As a teenager I too spent the summer vacations roaming around in reed fields, though mostly I paddled through our watery environment in a kayak I had found in the attic of the local yacht harbor and that my eldest brother had fixed up. As I talked about my adventures with some of my teachers I was asked to give talks in the (Headmaster's) biology class, for example on the courtship flights of Common Terns and Snipes or the floating nests of Grebes and Black Terns. Thus I was doing the same, at about the same age as Thijsse when he was a an apprentice teacher. In my final year I contracted a serious pleurisy and could not go to school for six months. Again like Th., who suffered from the same illness (but in his early 30s) I sought the allegedly healing effect of fresh and clean air and I could be found on every nice day (there were enough rainy days to study for my final comprehensives) somewhere in the fields.

During one of those vacations I took the same long walk Th. described in 1896 in the first of his collected essays (but mine was on a sunny day). The landscapes had not yet changed much and I remember most of the flowers, probably because they were new to me. Even 6 years ago, when I was last there, whole stretches looked the same and several of the regions we traversed some 50 years apart, are now declared cultural heritage sites and managed in a traditional, pre-WW II manner. When I took that walk, I had not read any issue of the DLN; it must have been an instance of what one of Th.'s close collaborators called the "Thijsse effect" (thijsseficatie). As a recent member of the NJN, I then was eager to learn about where "specialists" went and that walk had become an excursion tradition.

As I am reading these DLN essays I become aware how much I was influenced by Thijsse. My connection to him is a good example of the idea in Six Degrees of Separation, though in my case it was only two or three degrees, for example by way of the Tinbergen brothers and other NJNers. Niko's work, culminating in his Ph.D thesis on digger wasps etc. as well as in the essays in Curious Naturalists (1958, 1974) are extensions of observations Thijsse described in his DLN articles and the title of NT's autobiographical essay "Watching and Wondering" (which I already mentioned in Lazy Ch. B. #10) is a precise summing up of the "Thijsse method," namely the observing of what happens and asking questions about the how and why. It is the sort of thing I did as a young naturalist and what I now do again in my retirement. The observations and speculations I have recorded in previous LChB. entries, Th. would spin out in his friendly conversational style; often they would include remarks like "our younger [nature students] will find here much of interest that will enlarge our knowledge." These younger people were NJNers and occasionally he praises their journal, Amoeba, for serving well in spreading the gospel of nature's beauty. This beauty was both visual and intellectual.

There is an odd difference between the young Tinbergen as well as myself and Thijsse who was the most influential advocate for the Dutch conservation movement. As I recall the Holland of my childhood with all its open spaces, Thijsse appears to have been farsighted, for after WW II the country underwent a rapid expansion of even small towns and Amsterdam swallowed up entire villages. The meadows and bogs where I roamed have been reduced to 1/3 of their size. Yet, already in 1901 Thijsse warned of the loss of bird species as a result of new agrarian methods, the disturbing of nests, the destruction of habitats to create more agrarian land, the lowering of water tables and scientific forestry (i.e. the introduction of monoculture): "Birds are fellow creatures whose [evolutionary] development must fill us with amazement." NJNers were of course aware of the need for conservation and once in a while a NJN President (elected for one year) would make conservation the center of his program. But, as I remember the 1940s, most were rather willing to leave the actual work to our elders. There was a notable exception in the late Forties when unheard of protest by a NJN faction interrupted the annual meeting of Natuurmonumenten which in the end made even Thijsse despair of reconciling the then president with his friend and long term collaborator in Natuurmonumenten. Yet, those of us, whose parents were not members of Natuurmonumenten had no access to the important preserves and resented their closure to such serious nature students as we thought ourselves to be. Not that it kept some of us out and I too received my citations from the local constabulary. In an essay from 1938 (the pre-agro-chemical era), Thijsse pleads for the preservation of wilderness areas because agriculture, forestry, etc. have a continuous need of scientist trained in the study of the different phenomena of nature and he points specifically to scientists who as NJNers received their first scientific training in field studies. The "Letters" show that Thijsse actually agreed with most of the suggestions of the "rebel" NJNers.

There was one notable exception to the general acquiescence in the work of our elders and that actually involved a large slice of "my" bogs known as Twiske after the slow moving river that began at the locks near our house and flowed along our garden where I had my kayak. The region was to be made into a typical Dutch polder as part of the government's (much needed) policy of providing jobs. There was a widespread movement against this project and the NJN sprung into action. But it was all discouragingly in vain; dikes were thrown up, canals were dug and then, after WW II when there was work aplenty, the project was abandoned after all and now large areas are kept wild and lakes were created for water sport. But we learned that preserves of Natuurmonumenten were not save after all as the project gobbled up the few parcels it owned.

NJNers were divided on how preserves should be managed. Most favored leaving them alone so that, as Thijsse repeatedly argued, the environment of the pre-historic Netherlands might be restored in them, a process that would offer study opportunities to the younger nature students for generations. These NJNers were thus critical of the practice of exploiting preserves in the traditional manner by farmers in exchange for income with which to buy other preserves. Thijsse himself was more flexible and once he reluctantly favored the creation of a habitat in the oldest preserve for the introduction of an extremely rare West European butterfly that occurred in only one place elsewhere in the Netherlands. Other NJNers, no less critical, were in favor of the changes that now, after a generation, have been adopted with a vengeance by Natuurmonumenten, as a result of so many former NJNers having assumed leadership roles in the organization, for example it now has volunteers that interfere in its preserves to remove invasive species and to keep the preserve as much as possible in the state for which it was acquired. Today the primary objective is to maintain bio-diversity and to protect threatened species.

One of the results of experiences like Twiske, was that many of us became active in making inventories of an area that was threatened in order to have scientific evidence of its natural wealth. Luke Tinbergen's 1942 Birds In Their Domain, which I later received a a birthday present, described types of habitats and how certain birds preferred one over the other as well as how many birds a habitat could support. It became a sort of handbook for those of us who wanted to inventory an area, for example the fairly wild mixed woods near my high school that was created as a park (and where in its beginning my mother had pushed me in a perambulator). Because there was a German camp in part of it, it had not been cut down for fuel by the local people. In April and May I went there way before school, to map the singing perches of the different species. Luke's book is an example of Niko's major interest, i.e. "ethology" or the study of animal behavior in their natural setting. Luke concentrated most on what today is generally referred to as the carrying capacity of a habitat for a specific species, the type of study that became known as eco-ethology. I have always been more interested in a species breeding' territory that can be mapped by means of the male's singing perches for I have observed that such territories can be used for foraging by other species that may hunt for the same food, for example caterpillars. But my observations are only occasional and thus anecdotal.

Among the collection of Thijsse's essays there are several on the morphology of flowers and how bumblebees find the plants and the honey. Here also there is a link with Tinbergen who set a member of his workgroup in Oxford, Aubrey Manning, to pursue that subject as his doctoral work. Ethology ultimately sought to find out how an animal's behavior affected the survival of the species and was thus of a Darwinian inspiration. Thijsse, who was well read in English, German and French (he lent foreign language books to friends) may well have read Darwin's The Form of Flowers,, for in one of his essays he relates how he specifically went to observe bumblebees to show that a Belgian scientist was mistaken in his conclusions about what helps a bee find his flowers. Thus we can speak of a genealogy of biologists whose observations led them to ask questions and seek answers.

Many NJNers were botanists, Thijsse's first love. With Heimans he had authored a fat Flora, arranged on the Linnaean system. It was rather unwieldy even though I had learned the system in biology class. They had illustrated it with their own drawings, often in great detail. I was reminded of them as Tijsse's DLN essays are similarly illustrated. It's all rather amazing that they could do it, after all they were only trained as grade school teachers and while that training included drawing, they clearly had talent. The edition I got as another birthday present had become still fatter and very scholarly as professional botanists, complete with Ph.D.s were engaged for the many revisions. I soon gave up dragging it along in favor of an old gas mask container in which I collected the day's unknown plants. Botany had the advantage of being a cheap past time, for apart from the Flora, the container, notebook and pencil, no other equipment was required. An NJNer of Luke Tinbergen's generation, Victor Westhoff, wrote a the NJN manual on plant sociology for those who inventoried specific plots. They generally belonged to the Sjokgroup [sjokken=to trudge] and had their own (stencilled) journal called Kruipnieuws [Crawlnews] as much of their work was done on one's knees. Much fun was made of them and Victor, who wrote serious poetry, wrote a self mocking verse that's not easily translated:"Sjokking is a strange activity,/you mostly lie on your lazy bod;/you taste a bit of grass and chew some moss while phantasizing wildly. Rain splashes on your notebook, but never mind, you must write; mud penetrates your pants, but you keep going/ and will never forget that time full sjok and dampness." I did some inventories of sphagnum bogs near Twiske as one of the volunteers gathering material for an old NJNers doctoral research. Rather than counting the same plots for several years, we tried to find several plots in various stages of development. It was painstaking work to write down every plant, their number, their manner of growth in the community. Then you had to measure the thickness of the peat layer and its Ph as well as the depth of the groundwater (which by that time had seeped into your pants). My area was thought important as it was slowly recovering from the injection of salt during the Great Flood of 1916 (when the sea water covered the area to a height of 6 feet).

I was never a very participating NJNer, primarily because since the beginning, when Saturday was still a workday, the excursions were on Sunday and only after I had finished High School did I have the liberty of skipping Sunday duties, i.e. attending church. Most of the other activities of the Amsterdam district were held in the southern part of the city which was a bit of time consuming travel, but I did attend lectures by former NJNers who had become professional biologists, later I gave some informal talks myself, for example the one on the courtship flights of the Common Tern that I also wrote up for the Inktzwam [Inkcap], the organ of the Amsterdam district. Later I went to some of their weekend camps but by that time I had become a merchant mariner and was away most of the year.

One, to me, amusing aspect of the collected essays are the referenes to Th.'s walks, his sitting or even lying down in the dune grasses or on a pile of dried seaweed to watch whatever natural event had caught his attention. Thus he wrote: "What could give greater pleasure than lying in the dunes and observe all that goes on?" In another piece, already sixty, he addressed his readers: "You may think 'what does this man, lying in the dunes all day long?' But I intend to go on doing this and even more after I retire; I advice you to follow my example." And in Vogeljaar, observing some Wheatears on a barbed wire fence he remarks that the fence was one "he still had to get over" and that in a book for the then well-to-do burghers for whom climbing over barbed wire was a "Not-Done." His walks with his students, a practice he helped establish in the school program, became legendary. There are old photographs of him wearing a well made and not old three-piece suit that behoved a teacher, including his hall mark bow tie (that he apparently never took off in public). In one picture he walks up a dune followed by a line of students, the young ladies in dresses wearing summer hats. It's a sign of his times when there was not yet something like an L.L.Bean Outdoors catalogue. In his late seventies, alone and under the difficult circumstances of the War years, he was less well groomed. Two NJNers who came to report to him on the birds of his favorite preserve, found him, as they recorded, delightfully dressed in a rumpled shirt and his bow tie had slipped down a little, "just how you imagine an old nature lover." Other times, other mores, but I truly enjoyed reading these essays. They introduced my childhood hero in his own words and in the process I got to recall much of my own adventures, both aspects being almost equally enjoyable.