Drifting with the GPS drift

When preparing the previous post on GPS drift I wondered what would happen if you would drift along with the drift. Yesterday I had 30 minutes to spare and I gave it a try. I went to the park, switched on the GPS in the middle of the field, stood still and waited for the device to 'move' and then I followed its direction. This caused the direction to change and I proceeded to follow the new direction, etc. etc. In effect GPS drift only provided a first random direction before I created a feedback loop where I was following myself with a delay. Often the direction switched between opposite cardinal directions with great speed and several times I got dizzy by trying keeping up, sometimes I just had to let the thing come to rest before resuming the chase. Disorienting! 

A GPS night drift

After my complaint in a previous post about my GPS's failure to capture my postal rounds with the accuracy I was hoping for, three readers came up with possible explanations. I still think it has to do with recording rates (there is more time between 'clicks' than it takes me to walk in and out of a front garden) rather than any technical or strategical reason. But I was intrigued by the suggestion of GPS drift, the phenomenon of a GPS device recording movement while it is just laying motionless on a table somewhere. So overnight I left my device next to the window recording while I was sleeping and the above shows its paths, a random walk with one outlier travelling 588 meters. The squares blame technical inaccuracies, but I prefer another explanation: the earth is playing while the satellites are obeying the routines of the military-industrial complex.

Postman Pat Psychogeographix first Carto-Chaotic results

Overlay of four GPS traces of one of my three postal rounds, click to enlarge. The overlay was made manually by stacking the individual tracings for *artistic* effect. This round consists of two distinct parts. One part is a collection of five streets in the top left corner, the second part is at the right. You can clearly discern the difference between me biking back and forth and me delivering on foot. 

Even though I am recording points at maximum rate the device fails to keep up with my meandering through broad streets and garden paths.The trace below, from my round in Garden Village shows what I mean. Here the streets are all completely straight and nearly every house has a front garden and from the trace you would expect to see this, but instead the lines haphazardly average out as lines on a polygraph. Maybe I should slow down. Now You understand why things could have been worse.

'Molongo' is the new buzz word

In a paper called "Long-Term Foraging Expeditions (Molongo) among the Baka Hunter-Gatherers in the Northwestern Congo Basin, with Special Reference to the 'Wild Yam Question'" Hirokazu Yasuoka "describe[s] and analyze[s] a long-term foraging expedition (molongo) among the Baka of the northwestern Congo Basin as an example Long-Term Foraging Expeditions of foraging life in tropical rainforests. On the basis of these data, I then discuss the potential of tropical rainforests as a human habitat." 

There is lot of energy intake calculating going on in this paper but for our purpose it is enough to give you a few of the images and that part of the text that explain the daily proceedings of the Baka life during the vacations expedition. What amazes me is how slow the trek proceeds. The final camp is roughly 50 kilometres away but it takes 16 days to get there while it only takes 6 days to get back. On the molongo people take it slow. 

An important sociocultural aspect of molongo is the value placed on a nomadic life in the forest. When on the move, the group would usually decamp at about eight o’clock in the morning, often breaking into several sections to variously hunt such animals as they encountered or gather plants and honey. In the early afternoon when they decided on the location of the new camp, the women began to build huts of saplings and large Marantaceae leaves, while the men again went hunting with spears or to look for honey. When fresh tracks of a large animal were found, the hunter and his assistants perused it with the gun. The Baka moved the campsite every few days before arriving at the final camp of Mongungu, where they continued to use the forest intensively for their 43 night stay. 

Once at the Mongungu camp the men set cable snares along seven routes of 2–4 km stretching in a radial pattern from the camp. Hunters visited their snares every three days, because trapped animals spoiled within two days of dying. Men searched for honey or hunted with spears on the other days. The women went out digging for wild yams every two or three days, sometimes accompanied by their husbands. The wild yam species harvested most frequently was Dioscorea praehensilis, which can be found in large quantities in one place. Almost all of the cable snares and the major gathering sites for wild yams were within 3 km of the camp, so the most intensively used area was approximately ∼30km2.

The article is behind the academic firewall, with many tanks to a reader for the PDF.

The great albatros wanders

From google scholar one can lean a lot about the wander-pattern of the great albatross. No wonder shooting them is such a bad idea.

Fungi Forage trail in Mexican highlands

 

"A new method for tracking pathways of humans searching for wild, edible fungi" discusses the best way to use GPS to track mushroom foraging behaviour of the Nahua in Mexico. The paper contains a trail of one forager, notice the change in altitude in a 5-hour trek.  

Searching behavior is a fundamental activity performed by organisms in order to increase their probability to survive, grow and reproduce by finding food, refuges or mates. Humans are no exception. Every day we can readily observe how we, consciously or unconsciously, search for and find a great variety of items, an ability that surely has its origins in our evolutionary past, including as hunter-gatherers.

Eskimo songlines / Eskimo highways

"The Trail as Home: Inuit and Their Pan-Arctic Network of Routes" by Claudio Aporta is a dense article connecting Canadian Inuit land use and oral knowledge in recent and historic times with personal observation that give some stunning insights into the Eskimo way of life and the human talent for humanizing a harsh terrain. A related article by the same author is here and here.

We were traveling the route that days before Abraham Tagunak had mapped for us. Tagunak, a well-known elder and traveler from Naujaat, had followed that same route for the first time when he was a little boy several decades ago. It was the same trail that members of the Fifth Thule expedition used in the 1920s. It had also been used by Captain Hall’s Inuit guides in the 1860s. In fact, it seems certain that this trail and the place names around it were known to Iligliuk, the Inuit woman who acted as a guide for Captains Parry and Lyon in the 1820s. What is remarkable about this is that trails in the Arctic are not permanent features of the landscape. On the contrary, they disappear when the sled tracks get covered after a blizzard, and as the snow and ice melt at the end of each spring. The spatial itinerary, however, remains in people’s memory and materializes again when the next trailbreaker makes the trip.

to Inuit, the Arctic was in fact a network of trails, connecting communities to their distant neighbours, and to fishing lakes and hunting grounds in between. Based on the data collected during that trip and after mapping over sixty trails in several communities of the territory of Nunavut, I argue here that this network extends across most of the Canadian Arctic, most likely including areas that were not the focus of this research. Since Inuit did not use maps to travel or to represent geographic information, this enormous corpus of data has been shared and transmitted orally and through the experience of travel since time immemorial. Although new trails or new segments of trails are sometimes created to accommodate new travel needs and transportation technologies, while a few others are abandoned, most of these trails are so old that they are part of Inuit’s distant history, perhaps beyond oral memory and certainly beyond the limits of written documentation.

The implications of this premise are several: (1) it rejects the idea of the Arctic as a barren place, or an empty land inhabited by geographically remote and isolated communities (still present in the popular imagination); (2) it implies that Inuit have made systematic use of the Arctic environment as a whole; (3) it suggests that trails are, and have been, significant channels of communication and exchange across the Arctic; (4) it presumes that some  types of oral history and knowledge can be accurately transmitted through generations, and (5) it proposes that an important part of Inuit cultural identities is better understood in terms of moving as a way of living.

On place names:

The importance of place names in Inuit culture has been pointed out by several authors. I have elsewhere shown the connection between trails and place names. The mapping of place names makes this connection evident to the point that often the existence of trails can be guessed just by knowing where the named places are. In other words, the spatial layout of the names suggests the existence of a particular itinerary. Figure (above) indicates the presence of a trail across the northern tip of Baffin Island. Through the use of these names, a narrator can describe a trail, identifying creeks, lakes, hills, portages, stone cairns, and landing spots. The oral description of the trail (or the narrative of the journey) will help a listener picture how the horizon will look from the trail, and what kind of features a traveler should expect.

The trail as home:

During his travels in the Eastern Canadian Arctic, Knud Rasmussen documented a ritual just before a newborn child undertook her first journey. After describing the ritual and the prayer, Rasmussen noted that “this was the child’s first journey, and the little girl ... had to be introduced to life by means of [a] magic formula”. Being introduced to the first journey was, in a way, being introduced to life, as if both living and moving were part of the same journey. The trail was a place where life unfolded. Life on the trail involved the learning from an early age of an immense amount of geographic and environmental information, as the individuals experienced the land through actual or figurative travel. Through that process, a sense of community was also developed. The oral and experiential knowledge learned on the trails is, in fact, intertwined with information on and understanding of topographic features, environmental dynamics, and ecology of the familiar region. As Inuit travel to less familiar or more distant regions, this knowledge needs to be acquired from neighboring communities, which suggests a system of tenure in which knowledge equals survival (social and physical). It is through accessing this corpus of knowledge that Inuit travelers from distant communities would be able to find the good trails and the resources necessary to live in other regions.

Yanomami forage trails / ethnocartography of reticular space

"Ethnogeography and Resource use among the Yanomami" looks at the hunting and forage trails used by a Brazilian Yanomami village. It argues that space to the Yanomami is organized reticular and not concentric and zonal. Reticular? I've looked it up for you, it means: "1) Resembling a net in form; netlike. 2) Marked by complexity; intricate." I'm not entirely sure what the observations that the Yanomami use different systems of pathways adds to the table of forage psychogeography. Maybe it is a way of showing that paths connects places without laying claim to the space it traverses?

The spatial patterns of the Yanomami’s use of forest natural resources have traditionally been described or represented by anthropologists as concentric zones of exploitation (gardening, hunting, and gathering) outlined by approximate contours. Three types of concentric zones are usually distinguished: one close to the collective house, which includes the gardens, one for daily hunting, gathering, and harvesting, and, finally, one for long-distance collective hunting expeditions (hwenimu) and wild fruit gathering (waimi huu, yanomoa˜i-). This anthropological “zonal model,” which lacks any indigenous cultural recognition, projects onto Yanomami productive activities an ethnocentric conception of successive “rings” of decreasing degrees of resource exploitation similar to the classic agricultural model proposed
by J. H. von Thunen.

The methodology we adopted, allowing a fine-grained record of the Yanomami’s exploitation of natural resources, enabled us to produce a very different spatial model, this time structured by the collective knowledge and use of a web of identified forest paths (principal and secondary) tying together notable sites labeled by toponyms (hunting and gathering camps, former habitation and garden sites, groves of fruit trees, geographic features, and so on). In Yanomami cultural cartography, this complex network of paths and places is, moreover, closely interwoven with the intricate branching of the hydrographic network (made up of named rivers and streams), which constitutes another primary spatial reference.

From this new perspective, the Yanomami ethnogeographic organization of space appears to be reticular—structured by a crisscrossing network of sites (points) and routes (lines)—rather than zonal. By taking into account this emic structuring of space based on networks, as opposed to the conventional etic perspective in anthropology and geography, we aim to contribute toward a spatial model of tropical-forest resource use through data that are both quantitatively more precise and qualitatively more compatible with Yanomami social practices and cultural concepts.

Forage Psychogeography

The above image is a classic piece of situationist every-day-life self-cartography. It is a schematic map of Paris with lines drawn between the point of origin (home) and the destination of travels made in a year. I was first published as an illustration to Guy Debord's  'Theory of the Derive' and it means to show how limited our ordinary use of the city is and how little we therefore know of our immediate surroundings; the function of the derive is to break this territorial straight-jacket. Notice that it assumes that the territory is Paris whole, the city and not the countryside, while you could argue that your territory is not a given but the space you need for your everyday needs.   

Below is GPS drawing made by Jeremy Wood of a generative psychogeographical walk in London. The idea being that the algorithm (for example: second left, first right, third left, repeat) will generate a coiling movements from somewhere to neverwhere reaching all points in between.

The current interest in the 'edible city' I find interesting for several reasons but most of all because it is a reinvention or an accidental return/rediscovery of foraging. Our fascination with roads and trails (and desire paths), and with centralized power and accumulation of wealth is a dual neolithic invention: the forager needs to travel the roads less travelled and leave the trail to survey the entire territory with intense awareness; survival depends on it. Foraging, the lifestyle of the forager, demands/creates another way to relate to your environment and your fellow people.     


Listen to Richard B. Lee and Richard Daly (The foreword to the The Cambridge encyclopedia of hunters and gatherers):  

Found among many but not all hunter-gatherers is the notion of the giving: environment, the idea that the land around them is their spiritual home and the source of all good things. This view is the direct antithesis of the Western Judeo-Christian perspective on the natural environment as a "wilderness". 

The foraging lifestyle guarantees a level of freedom and leisure that has been forever lost to those people who succumbed to the caloric revolution of agriculture 10-12.000 year ago. At the heart of the re-evaluation of the hunter and gatherer stands Marshall Sahlin's classic essay 'The original affluent society', surely the only anthropological classic to be regurlaly reprinted as a punk zine. Sahlin makes an interesting case for nomadism itself as a technique for freedom and a mindset for being out there.


Listen to Marshall Sahlin:

The manufacture of tools, clothing, utensils, or ornaments, how- ever easily done, becomes senseless when these begin to be more of a burden than a comfort. Utility falls quickly at the margin of portability. The construction of substantial houses likewise becomes absurd if they must soon be abandoned. Hence the hunter's very ascetic conceptions of material welfare: an interest only in minimal equipment, "if that; a valuation of smaller things over bigger; a disinterest in acquiring two or more of most goods; and the like. Ecological pressure assumes a rare form of concreteness when it has to be shouldered. If the gross product is trimmed down in comparison with other economies, it is not the hunter's productivity that is at fault, but his mobility. 

I would love to see a year's worth of GPS of traces of a GPS-collared nomadic Amazon Indian, but lacking these the following traces of animals make the point clear enough. The first image of the Situationist-map clearly shows a centre, a number of locations in the periphery. The various animal GPS-traces below show a full use of the territory, with the open spaces in the imaginary boundaries of its home range always ignored for a good (geographical) reason. GPS-collars generally aren't recording continuously, but make lan/lon snapshots perhaps every 12 hours, the straight lines therefore should be replaced, in one's mind, with a meandering line, suggesting an ever deeper coverage, use and knowledge of the land.

Location points (blue dots) of Alaska wolf NW025 (April 3 - June 4, 2002) connected in chronological order (red line), and the minimum convex polygon (blue line) of its home range. The cluster of locations at the top center of the home range indicates a den site.

Arctic wolf Brutus’ locations (small circles) since capture on 08 July 2009 to 30 November 2009. Each location is joined to the next consecutive location 12 hours apart with a line, resulting in what we call a “spaghetti” map.

Finland wolves Irina (n=576) and Retu (n=513) locations connected in chronological order,

April - August, 2004.

The movement patterns of collared zebra 6865 during the month of April. Zebra 6865 was collared on the 1st April and for the month of April exhibited a central place foraging strategy, returning regularly to the waterholes near to where she was collared. 

The complete movement patterns for collared zebra 6872 from 3rd April until 27th May within the Makgadikgadi Pans National Park. The movement patterns of zebra 6872 show the response to the rainfall of the 2nd and 3rd May followed by its eventual migration west to the Boteti region arriving on the 22nd May.

The collared hyena went on two excursions to the Bakers Bay seal colony, which is more than 60 km away from his western territory boundary. His home range estimate was 1400 km.

The red lines show the movements of nine caribou with GPS satellite locator collars during 2006-2007. These caribou belong to the Kenai Lowland Herd. The summer range is shown by the dense red color on the west side covering the Kenai gas fields, and the Kenai River flats to north of the Kenai airport. The winter range lies generally east of Sterling. The route lines clearly indicate that the caribou avoid roadways and developed areas. 

These are Swedish bear tracks in Sweden the underlying maps is missing to prevent poachers from utilizing the data.

Sea-routes for whales, seals and whatever, but beautiful!

Something completely different, the Apollo 11 traverse map.