- continued, part 2 -

NEST–BUILDING OF THE HIGHER APES


Nests as a subhuman handicraft

Bernstein (1969) describes the basic elements of nest–building as relatively stereotypical, even under differing circumstances. The animal either crouches or stands upright on both legs. On trees, it usually stands or sits on branches which grow horizontally from the main stem. With its arms, it pulls a few strong branches toward itself and holds them down with one of its feet (Fig. 3). Whether broken, cracked, or simply bent, the branches are then interwoven. By turning its body several times and repeating the same procedure, an elastic platform is gradually made, a tiny horizontal surface in the precipitous surroundings. Then - generally in a crouching position - the animal pulls in thinner branches. They are braided to a ring or wreath of about 60-80 cm in diameter. Finally, the nest is cushioned, partly with thin twigs torn from the branches, partly with materials transported from elsewhere. Twigs sticking out are knocked into the surface by using the back of the hand. The whole procedure takes about one to five minutes. Goodall (1962) speaks of structural elements (foundation' and 'crosspieces', see Fig. 4). Crosspieces are joined in a rough kind of basketry. She describes the manufacture as "quite complicated" (:460) and says: "Some chimpanzees work methodically, turning in a complete circle during the making of a nest." (:460) Later the same author (Van Lawick-Goodall 1971) writes: "Those nests which I could study from close distance were put together and braided with twigs, often in a quite complicated manner". In Uganda and in Eastern Belgian Congo, Bolwig (1959) studied about 50 nests of mountain gorillas and about 30 nests of chimpanzees with regard to the materials used, their construction, location, and use. He was mainly interested in the question of right- and left–handedness. Among gorillas, he distinguished different types of ground nests, among the chimpanzees tree and ground nests. He further differentiated the tree nests into crown and fork nests. His remarkable report not only provides detailed descriptions but also valuable drawings (Fig. 5). Further descriptions of constructional details are given by Mackinnon (1971, 1974), Albrecht/ Dunnet (1971), Harrisson (1969), Goodall (1962), Izawa/ Itani (1966, s. Fig. 6), Nissen (1931), etc. (see Fig. 7-13). Mackinnon distinguished four technical aspects and also mentioned how animals transported nesting materials with their mouths or feet, pressed them under their arms or used the so-called 'shoulder-chin pinch'. Nissen (1931) mentions "daybeds" with "roofs" or "umbrellas" among chimpanzees.

An essential aspect of nest–building is its daily routine. Nest–building is most intimately related to daily activities. All authors are in accord regarding the following: from a certain age on, every individual builds itself a new nest at least once a day throughout its lifetime of 30 to 40 years. Goodall (1962) says: "Nest-building is a daily routine in [the life of] chimpanzee today." (:460)

Building materials vary

Bernstein (1962) made a comparative study of chimpanzees born in captivity and in the wild and showed that the kind of material used is not of great importance. In captivity, woollen blankets, plastic hoses, and the like were used much the same as branches, twigs, leaves, and grasses were in the wild. But, of course, when they use homogeneous artificial materials the animals never attain the same complexity of construction as they do with the various materials available in the wild. But what is important is this basic openness to various materials. In the wild it implies that constructive behaviour can basically relate to a wide spectrum of materials provided by a particular environment. Harrisson (1969) surveyed nest–building using statistical methods. Over a relatively long period, she studied a few animals constantly. For the first time in a wild habitat, she discovered that the materials used can vary considerably. She reported that stones were used to build nests . Also remarkable is an observation by Galdikas-Brindamour/ Brindamour (1975). In connection with ground nests of the orang–utang in Indonesia, she observed animals piling up pieces of wood in a manner which reminded her of human constructions of wood.

Tree and ground nests and their location in the environment

The consideration of the position of nests in their environment began with measuring the height of their locations. Oertzen (acc. to Reichenow 1921:74) gave a first rough typology with regard to height. Of 16 gorilla sleeping nests, which he found clustered in a place in Southern Cameroon, he distinguished nine nests on the ground, and seven at a height of 3-5 metres in the branches of trees. Nissen (1931) measured about 100 chimpanzee nests with regard to their distance from the ground. "The figures vary from 13 to 105 feet, [~4-32m] the average being 38.4 feet [~12m]." (:41) Goodall (1962:457) also gave similar statistics with regard to height. Nowadays, the main distinction is drawn between tree and ground nests. This distinction is extremely important because these two types correspond to two completely different spheres of movement: the former to the arboreal and the latter to the terrestrial. All three species of pongids move within these two spheres in quite different ways and are physically adapted accordingly. In the arboreal space, the animals moves in a more apelike manner. An upright hanging and swinging position of the body is essential. The prehensile hand and stereoscopic vision (the eyes facing forward for exact estimation of distance are characteristic for subhuman primates) are further important characteristics. On the other hand, terrestrial movements are closer to the human way of locomotion. At the human level, the terrestrial way of life with bipedal locomotion (which freed the hands from the function of transporting the body), precision grip of the hands, focused spatial sight and a highly developed brain are extremely evolved determinants.

Consequently, the change from the arboreal to the terrestrial environment - as seen clearly among the pongidae - is taken as the basis of evolutionary explanations in anthropology. By the formation of large savannas, climatic changes are said to have changed the arboreal conditions of the pongids in such a way as to increasingly favour terrestrial life. Under these circumstances, the distinction of tree and ground nests becomes extremely important. The function of pongid nests changed and, in the transition from tree to ground, its form also changed in relation to the different structure and nature of the materials available on the ground. In the treetops the nest is a secure platform which protects the animal from falling down when its visual communication with the environment is blocked by darkness. It also allows the animal's large body to lie horizontally during periods of sleep and rest.

Regarded as an artefact, the tree nest is only part of a large and naturally standing unit, the tree. In the terrestrial environment the ground nest becomes an individually constructed tectonic unit erected by the animal. Functionally, it no longer serves to protect the animal from the high risk of falling. It may merely be a kind of cushion, if grasses are heaped on the ground. But if it is made with rooted bushes or in a bamboo grove, it can be considered as a standing construction which gains stability from 'artificially' combined elements. With regard to the expected variety of materials available on the ground, the ground nest also becomes a tectonic object with a great potential for the development of its constructed form. If we think more in terms of the interaction between the animal and this type of nest, it shows characteristics which can be seen in close connection with essential aspects of physical evolution: the erect body posture, bipedal locomotion and the freeing of the hands with the development of the precision grip, focused stereoscopic view and - with more and more 'learnt' processes of construction - a development of the brain.

With regard to these criteria, it must be of interest to recapitulate briefly what observations in the wild have revealed about the location of nests. Chimpanzees are both arboreal and terrestrial, and this also applies to their nest–building . Chimpanzees build tree nests for the night, while, during the day, they usually build their siesta or resting nests on the ground. Nissen (1931) found a relationship of 50 to 50% for chimpanzees. On the other hand, gorillas live more terrestrially. According to several authors, this is due to their body weight. Male chimpanzees weigh about 70 to 75 kg. The mountain gorilla weighs about 300 kg, the coastal gorilla about 250 kg. Male mountain gorillas always sleep in ground nests, while the females and infants sleep in nests among the branches of trees. Thus, on the basis of such surveys, we can account for a constant number of routinely fabricated ground nests.

Typology of form

In regard to form too, the distinction of tree and ground nest is elementary and essential for a typology.

Tree nests are about 60-80 cm in diameter. Nissen (1931) reports that they are built in those parts of trees where branches are sufficiently strong to support the animal's weight but not so thick as to be no longer manipulable. A choice, a judgment is involved! The form of the nests is characterized by an outer circular wreath of twigs. In the centre, the nest shows a cavity in which the animal can sleep or rest securely on its side or back. Infants pass the night in their mother's nest. These combined mother-child nests are slightly bigger than usual and often have a bulge (Fig. 14).

Ground nests vary from simple grass, leaf, or twig nests close to the ground to 2-4 m high constructions produced in the undergrowth or in bamboo grooves. Grass nests generally are a simple circular accumulation of materials heaped on the ground, whereas the latter are definite tectonic structures, stable, handcrafted structures with some resemblance to human huts. To build such tower-like structures in a bamboo grove, the animal raises its long arms, hangs onto the stems, bends them down by the weight of his body, and then intertwines, or knots them together. Obviously, the object must possess considerable static resistance when, on completion of its building task, the heavy animal climbs up and - like a king on his throne - sits or rests and eventually lies down to sleep in this undoubtedly safe place.

Use of the nest

Depending on the time of day when the nests are built, they are called 'day' or 'night nests' or, in terms of their function, 'rest' or 'sleeping nests'. The former are usually built more or less carefully on the ground after the feeding period in the morning. Then the animals lie down to doze in the sun and digest their food. These nests are often also called 'siesta nests'.

Sleeping nests are built at nightfall. Observation is very difficult in this case. Authors report that these nightly nest-building activities were often more heard than seen: sounds of cracking branches and twigs, followed by silence. Albrecht/Dunnet (1971) report that chimpanzees prefer to build their sleeping nests close to their last feeding tree. Goodall (1962) reports the same for chimpanzees. Several authors, e.g. Goodall/Van Lawick (1963), have developed a sensitivity for the poetic atmosphere surrounding this nightly 'going to bed' among the heights of the treetops and for the first sounds of yawning in the early morning twilight, followed by the first toilet activities in the first rays of sunlight (Fig. 15-19).

But the use of nests is not restricted to sleep and siesta alone. We have already mentioned the mother-child nest. Van Lawick-Goodall (1971) mentions the chimpanzee nest as a sickbed. A lame chimpanzee affected by polio forces himself back and forth between the same three nests. In earlier literature, tree nests are mentioned as deathbeds. With all remaining strength, animals hurt by hunters provided themselves with a nest which prevented them from falling. They then bled to death, and their dead bodies remained 'buried' in the lofty nest. According to Lawick-Goodall it is uncertain, whether coupling occurs in nests, but loving couples build their nests close to each other. Furthermore, nest robbery was observed by Van Lawick-Goodall (1971). She describes how the male whom she named 'Goliath', pushed his female partner out of the nest she had just completed and settled into it. Obviously very angry, she nonetheless had to build herself a new one. The nest has another important function: that of a toy. Nissen (1931) mentions infants playing with something that looked like a small basket, obviously a tiny nest used as a toy. Goodall (1962) says that nest–building is learnt by playing with nests made on bushes or trees. Such descriptions of infants playing are indeed appealing. To the astonishment of the baby ape, such awkwardly fabricated nests always bounce up again and again.

The nest’s function as a shelter from rain or sun is often discussed, in particular, if rooflike accessories are observed. Van Lawick-Goodall (1971) is opposed to the idea of leaves and other devices having such a function. But Nissen (1931) mentioned day nests with an umbrella-like constructions among chimpanzees. Probably the discussion is prejudiced because it implicitly relates to naive ideas of apes building primitive huts. Maybe the differences in climatic adaptation between observer and observed are not taken into account. Several reports explicitly give the impression that rain in tropical rain forests - probably of the same temperature as the body temperature of the animals - does not bother them at all (Fig. 20, 21).

Nests as signs

Since nests generally last for several months (Harrison 1969), they become a kind of sign in the landscape - similar to the traces left by man with his building behaviour in his habitat. Nissen (1931) remarks the following: "The chimpanzee nest is a distinct and unique feature of the French Guinea bush. It is so different from all other objects encountered there, that it is almost impossible not to recognize such a nest, when seen, for what it is." (:40). Most nest are found in groups of trees. One to 13 nests are found in a tree. Nissen (1931) describes a case where, in four trees, he found 12 apparently very new nests. Three of the trees were closely adjacent, housing one, four, and five nests. One tree was 175 feet [~53m] apart and housed three nests (:40). "Although all members of a group did not usually sleep in one tree, their nests were rarely scattered over an area more than 200 feet [61m] in diameter." In the average, a surface of about 20km [12.4 miles] would house about 25 animals and about 1500 nests (Nissen 1931:41). Preference for certain locations within the home range of a group are clearly observable. Such clusters of nests on "habitual nest sites" (Harrisson 1969) become particularly interesting with regard to semantic questions. Durability is about two months in the average. Many authors take the nests not only as signs for human observers indicating the presence of pongids (whereby older nests are easily distinguished from newer ones!), but they take these "artificial" markers in a natural environment as signs for the pongids themselves as Mackinnon (1971, 1974) for example does in the case of orang–utans. Unfortunately, not many studies focusing on this aspect, have been undertaken. It would be of great importance to clarify the semantic significance of the nest because nests might prove to be part of a semantic system (own/other group's nests, old/new nests) allowing pongids to orientate in a social (intra-/intergroup) and spatiotemporal sense: "the leaves are completely dry; we must have been here a long time." Other questions may arise from such insights. E.g., if the nests form a semantic system which includes criteria of location and time, how do pongids distinguish their own nests from those of other groups? Are they provided with the ability to remember patterns related to qualities, form, situation in the landscape or spatial relations of nests in the trees or on the ground? Unfortunately, there is not yet sufficient data available to answer such questions.

Temporary camps

Due its interest in so called "spacing patterns", primate sociology has provided interesting material on the spatial distribution of pongid nest camps. With the exception of some initial studies, this very valuable line of research has not been continued. Kawai/Mizuhara (1959) drew up dwelling plans of the nest clusters made by mountain gorillas, giving the distances between the nests and their heights, the types of nests and their cleanliness (s. Fig. 22a). <2> Mackinnon (1974) mapped out the home range of orang–utan groups and marked the places where nests were found (Fig. 23). Nesting places with older and newer nests look like schematic aerial views of human villages. Nishida (1968) and Izawa/Itani (1966) also made maps of the landscape, which are reminiscent of human settlements (Fig. 1, 2, 24). Pongids are obviously social by nature and - like human nomads - move from temporary settlement to temporary settlement and, to some extent, between habitual nesting sites. These sites are located within a flexible home range, which is not clearly defined. Temporary campsites, when used, create a territorial area which seems to be respected by other groups.

Ecology and habitat in a wider sense

Emlen/Schaller (1960) surveyed an area in Central Africa - nearly as large as Switzerland - in which mountain gorillas live in many populations (Fig. 25).The landscape is described as ecologically very differentiated. A typology of vegetation showing foliage cover, undergrowth etc., is given, showing a lively habitat characterized by varying environments (Fig. 26). Different groups live in these environments, which also vary in terms of landscape and climate. The study offers a theory of settlement which sounds very human. According to this, clans expanded from the centre of the region towards its natural limits. Furthermore, Emlen/Schaller found differences in body and behaviour among various populations of mountain gorilla. This necessarily implies that pongid populations already show the effects of ecological conditions on their physical and behavioural evolutions. As regards to the latter, this means they develop customs or traditions which are locally specific. Emlen/Schaller could clearly distinguish mountain settlers from those living in the valleys.


SUMMARY AND CONCLUSIONS


Within the framework of the recent discussion on the "primordial hut" initiated by Rykwert (1972), we have tried to draw relevant materials into the sphere of cultural anthropology and architectural theory. The fact that it is still unusual for cultural anthropologists to discuss the 'constructivity' of pongid nest behaviour is due to the zoologists' focus on the instinctive aspect, which is dominant in the building of the vertebrate nest, but only partly accords for the pongid nest. The other element is acquired behaviour, a subhuman tradition. Technologically, and functionally too, the pongid nest has common characteristics with a human construction. It is an object which the animals use to provide for an essential need in their lives: the horizontal position while sleeping and nocturnal security in an arboreal environment blocking locomotion (stereoscopic vision). And it is an artefact made by a hand which closely resembles the human hand. It implies a direct hand-handicraft relation, which unfortunately is not taken into consideration for the simple reason that archaeology is fixed on the hand-tool-handicraft relation. In the nest–building behaviour of the pongids the hand is the tool! This direct hand-handicraft relation appears in a wide range of traditional human products, such as basketry, etc. But since it deals with flexible, nondurable plant materials, it could not be preserved in prehistory. Its history must be reconstructed systematically or ethno-archaeologically.

In the case of ground nests another aspect is important. The objects are not only handmade, they are subhuman artefacts which, standing upright and fixed in a particular place, are tectonic objects in a terrestrial environment. They can thus be interpreted as prototypes of the built form, of architecture. The individual who builds such objects becomes the 'archi-tekton' in the original Greek sense, the "first builder", in fact a first builder responsible for the site and quality of his daily-nightly resting place: his own nest.

Finally: at first sight, the pongid nest cannot be directly related to this or that cultural phenomenon, e.g., huts, cradles, or beds. This again would have to be considered as mere speculation. It is rather that the value of the pongid nest consists in providing us with a factually supported hypothesis which may help us to reconstruct a scientifically founded theory of architecture in the frame of a systematically surveyed field of human work behaviour (general ergology). The first aims of such an approach would have to be:

We have dealt with the nest–building behaviour of the higher apes. We stuck close to the observed facts and limited ourselves to an architectural point of view. This revealed that the nest is deeply interwoven with the higher apes' daily existence, it is integrated in the structures of day and night, outside and inside, movement and rest, exposedness and shelter. In architectural terms, it is an existential totality related to extremely primordial technological means.

There is, however, yet another aspect if we compare this existential totality of the nest with what is considered important to the early human past – the 'tool' of the so–called 'toolmaker'. From this perspective too, the chapter is not yet closed. Physical anthropology today searches for the origins of man in those East African regions where important climatic changes transformed tropical forests into open savannas (Oludvai gorge). With regard to our important typology of tree and ground nests, it is highly probable that the 'constructiveness’ shown served to bridge these environmental changes. The ground nest might have become the prototype of building par excellence. Horizontal accessibility increased enormously with this move from arboreal to terrestrial environment, both with regard to materials and to potential sites. It is highly probable that constructiveness evolved considerably, producing a notable diversity of materials, techniques, and forms. The objects are lost, obviously. But maybe the 'bones' registered in a lasting form those changes in body movement connected with the growth of constructional capacities: erect position of the body, increasing rotary motion of the wrist, perfection of the precision grip, increase of the brain, etc. Should new research and new discoveries prove this plausible in the near future, we shall be able to claim that architecture played a significant part in the 'creation' of man (Fig. 27).


Figures and figure captions
Notes
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