Now that books purporting to show that man is just an ape at heart, and in other ways, are making the best seller lists, a handbook of the tribe itself should command more than ordinary interest. The idea of this book seems an excellent one: it indeed appears to meet its objective as a useful, working volume (a little bit on the bulky side) of the living primates. Falling between Osman Hill's multivolume, The Primates and something like Ivan Sanderson's, The Monkey Kingdom, it can be stated that the illustrations are good to excellent and the information conveyed to the reader (in telegrafese) is quite abundant. Obviously specialists in one or a few primate forms may be unhappy with the coverage. However, the reviewer, as an old (lapsed) Tarsiologist was glad to catch up with recent literature on this wonderful little beast. Only a very few primate forms are at all well studied in any systematic way and it is a measure of our relative neglect of our non-kissing cousins that of the 56 listed genera even the gestation periods are unknown in 26 and only approximately known in another 13. This makes for a large body of ignorance of the endocrinology of the primates, to mention but one area, and generalizations about their sexual behavior tenuous indeed. Identification of species is greatly enhanced by the compendious list of common, generic and specific names, and the volume would be a useful accompaniment on a visit to the monkey house of a good zoo were it not for the deplorable job of binding delivered by the Academic Press. A word about the reference list and index. Considerable reliance on secondary sources means that the reader must fight his way to the originals by a devious route. Figure 3 on p. 41 is a strictly personal example. It is astonishing that Ruch's Bibliographia Primatologica could escape documentation except on grounds of over-familiarity. On the other hand, Goodman's excellent papers on primate immunochemistry (and taxonomy) are all listed but tracing them into the text is a major task and the index is no help. I suspect that other such nuggets are lurking in the references, but not in the index. This reviewer is constantly surprised by the sheer energy expended in compiling longevity records of animals in captivity-and by their almost total meaninglessness. A more useful addition to Part III, the Appendix, would have been the emergence of the dentitions in the one form in which it has been definitively studied, M. mulatta (Hurme and van Wagenen). This Handbook is warmly recommended to students and workers in primate biology and to interested bystanders generally of \"This Simian World.\" H. R. CATCHPOLE Department of Pathology University of Illinois Chicago, Illinois

The Spread of Cancer.

A central theme in the study of animal navigation has been the extent to which such navigation requires the formation of an internal representation of space, the so-called " cognitive map." Although its properties remain disputed, it is now generally accepted that a map-like representation exists in the brain, and neurobiological studies, conducted in tandem with behavioral investigations, have done much to elucidate the neural substrate of the map as it operates in two dimensions. However, to date little is known about how the map encodes real-world, three-dimensional space. Using recent neurobiological and behavioral fi ndings, this issue is explored here. It is argued that the navigational problems in three dimensions are qualitatively as well as quantitatively different from those in two dimensions, and evidence suggests that, perhaps for this reason, horizontal and vertical space are processed separately in the vertebrate brain. The possible adaptive consequences of such an anisotropic. © 2011 Massachusetts Institute of Technology and the Frankfurt Institute for Advanced Studies. All rights reserved.

Navigating in a three-dimensional world

The study of spatial cognition has provided considerable insight into how animals (including humans) navigate on the horizontal plane. However, the real world is three-dimensional, having a complex topography including both horizontal and vertical features, which presents additional challenges for representation and navigation. The present article reviews the emerging behavioral and neurobiological literature on spatial cognition in non-horizontal environments. We suggest that three-dimensional spaces are represented in a quasi-planar fashion, with space in the plane of locomotion being computed separately and represented differently from space in the orthogonal axis – a representational structure we have termed “bicoded.” We argue that the mammalian spatial representation in surface-travelling animals comprises a mosaic of these locally planar fragments, rather than a fully integrated volumetric map. More generally, this may be true even for species that can move freely in all three dimensions, such as birds and fish. We outline the evidence supporting this view, together with the adaptive advantages of such a scheme.

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A basic set of navigation strategies supports navigational tasks ranging from homing to novel detours and shortcuts. To perform these last two tasks, it is generally thought that humans, mammals and perhaps some insects possess Euclidean cognitive maps, constructed on the basis of input from the path integration system. In this article, I review the rationale and behavioral evidence for this metric cognitive map hypothesis, and find it unpersuasive: in practice, there is little evidence for truly novel shortcuts in animals, and human performance is highly unreliable and biased by environmental features. I develop the alternative hypothesis that spatial knowledge is better characterized as a labeled graph: a network of paths between places augmented with local metric information. What distinguishes such a cognitive graph from a metric cognitive map is that this local information is not embedded in a global coordinate system, so spatial knowledge is often geometrically inconsistent. Human path integration appears to be better suited to piecewise measurements of path lengths and turn angles than to building a consistent map. In a series of experiments in immersive virtual reality, we tested human navigation in non-Euclidean environments and found that shortcuts manifest large violations of the metric postulates. The results are contrary to the Euclidean map hypothesis and support the cognitive graph hypothesis. Apparently Euclidean behavior, such as taking novel detours and approximate shortcuts, can be explained by the adaptive use of non-Euclidean strategies.

Non-Euclidean navigation

Insect navigation is strikingly geometric. Many species use path integration to maintain an accurate estimate of their distance and direction (a vector) to their nest and can store the vector information for multiple salient locations in the world, such as food sources, in a common coordinate system. Insects can also use remembered views of the terrain around salient locations or along travelled routes to guide return, which is a fundamentally geometric process. Recent modelling of these abilities shows convergence on a small set of algorithms and assumptions that appear sufficient to account for a wide range of behavioural data. Notably, this 'base model' does not include any significant topological knowledge: the insect does not need to recover the information (implicit in their vector memory) about the relationships between salient places; nor to maintain any connectedness or ordering information between view memories; nor to form any associations between views and vectors. However, there remains some experimental evidence not fully explained by this base model that may point towards the existence of a more complex or integrated mental map in insects.

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The internal maps of insects

There is evidence that wild animals are able to recall key locations and associate them with navigational routes. Studies in primate navigation suggest most species navigate through the route network system, using intersections among routes as locations of decision-making. Recent approaches presume that points of directional change may be key locations where animals decide where to go next. Over four consecutive years, we observed how a wild group of bearded capuchin monkeys used a route network system and Change Point locations (CPs) in the Brazilian ecotone of Cerrado-Caatinga. We built 200 daily routes of one wild bearded capuchin group. We used ArcGIS, the Change Point Test, Spatial Analysis in Macroecology (SAM), and statistical models to test the hypothesis that wild bearded capuchins use CPs located along routes in a different fashion than they use the CPs located at intersections of routes. A logistic regression model was used to determine the landscape variables affecting capuchins' directional changes at intersections or along routes. CPs at intersections were important points of travel path changes, whereas CPs along routes represented a zig-zag movement along the routes following the landscape features. CPs at intersections were associated with steeper terrains and shorter distances from important resources, along with better visibility of the home range. Our results support the hypothesis that intersections among routes in the route network system are located at points where monkeys have the best visibility available to make decisions on where to visit next.

Intersection as key locations for bearded capuchin monkeys (Sapajus libidinosus) traveling within a route network

. Movement patterns of bearded capuchin monkeys (Cebus (Sapajus) libidinosus) in northeastern Brazil are likely impacted by environmental features such as elevation, vegetation density, or vegetation type. Habitat preferences of these monkeys provide insights regarding the impact of environmental features on species ecology and the degree to which they incorporate these features in movement decisions. In order to evaluate environmental features influencing movement patterns and predict areas suitable for movement, we employed a maximum entropy modelling approach, using observation points along capuchin monkey daily routes as species presence points. We combined these presence points with spatial data on important environmental features from remotely sensed data on land cover and topography. A spectral mixing analysis procedure was used to generate fraction images that represent green vegetation, shade and soil of the study area. A Landsat Thematic Mapper scene of the area of study was geometrically and atmospherically corrected and used as input in a Minimum Noise Fraction (MNF) procedure and a linear spectral unmixing approach was used to generate the fraction images. These fraction images and elevation were the environmental layer inputs for our logistic MaxEnt model of capuchin movement. Our models' predictive power (test AUC) was 0.775. Areas of high elevation (>450 m) showed low probabilities of presence, and percent green vegetation was the greatest overall contributor to model AUC. This work has implications for predicting daily movement patterns of capuchins in our field site, as suitability values from our model may relate to habitat preference and facility of movement.

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A maximum entropy model of the bearded capuchin monkey habitat incorporating topography and spectral unmixing analysis

Natural selection for positional behavior (posture and locomotion) has at least partially driven the evolution of anatomical form and function in the order Primates. Examination of bipedal behaviors associated with daily activity patterns, foraging, and terrestrial habitat use in nonhuman primates, particularly those that adopt bipedal postures and use bipedal locomotion, allows us to refine hypotheses concerning the evolution of bipedalism in humans. This study describes the positional behavior of wild bearded capuchins (Sapajus libidinosus), a species that is known for its use of terrestrial substrates and its habitual use of stones as tools. Here, we test the association of terrestrial substrate use with bipedal posture and locomotion, and the influence of sex (which co-varies with body mass in adults of this species) on positional behavior and substrate use. Behavior and location of 16 wild adult bearded capuchins from two groups were sampled systematically at 15 s intervals for 2 min periods for 1 year (10,244 samples). Despite their different body masses, adult males (average 3.5 kg) and females (average 2.1 kg) in this study did not differ substantially in their positional behaviors, postures, or use of substrates for particular activities. The monkeys used terrestrial substrates in 27% of samples. Bipedal postures and behaviors, while not a prominent feature of their behavior, occurred in different forms on the two substrates. The monkeys crouched bipedally in trees, but did not use other bipedal postures in trees. While on terrestrial substrates, they also crouched bipedally but occasionally stood upright and moved bipedally with orthograde posture. Bearded capuchin monkeys' behavior supports the suggestion from anatomical analysis that S. libidinosus is morphologically better adapted than its congeners to adopt orthograde postures.

Positional behavior and substrate use in wild adult bearded capuchin monkeys (Sapajus libidinosus).

The exploratory behaviour and the ability of capuchin monkeys to use tools allows them to thrive at times and places of limited food and water abundance, such as in semi-arid environments. Here, we report the behaviours employed by individuals belonging to a wild group of bearded capuchin monkeys (Sapajus libidinosus) to access natural water sources in a dry forest of north-eastern Brazil. An adult female employed a twig as a tool and her tail to gain access to accumulated rainwater in a tree hole, and other individuals used their hands and mouth to manipulate orchids' pseudobulbs and the liquid endosperm of palm nuts. The behaviour of wild Sapajus to access water from non-food sources may enable them to circumvent the risk of dehydration in environments with reduced availability of fleshy fruits and with ephemeral and rare water sources. Our findings contribute to the still scarce but accumulating reports on primate drinking behaviour and to the knowledge of tool use in wild populations of capuchin monkeys, enriching our understanding of primate strategies to gain access to a vital resource under challenging conditions.

Luiz Carlos Matos Biondi

Papers

Intersection as key locations for bearded capuchin monkeys (Sapajus libidinosus) traveling within a route network

A maximum entropy model of the bearded capuchin monkey habitat incorporating topography and spectral unmixing analysis

Positional behavior and substrate use in wild adult bearded capuchin monkeys (Sapajus libidinosus).

Techniques Used by Bearded Capuchin Monkeys (Sapajus libidinosus) to Access Water in a Semi-Arid Environment of North-Eastern Brazil.