Visual worlds chapter 7 animal seeing

This is an excerpt from the book Visual Worlds, co-authored by James Elkins and Erna Fioren>ni The book is available on Amazon Please send comments, ques>ons, and sugges>ons to jelkins@saic.edu Animal Seeing To understand human vision, it is helpful to contrast its apparent Leading Concepts naturalness against other kinds of seeing This contrast does not in- Umwelt trichromatism bees’ violet ommatidia pseudopupils mimesis countershadowing visual world volve any claims that we can see like eagles or snails, or experience the world in the ways they might By considering the vision of animals it is possible to de-naturalize our own, and return to our thinking on human visual perception with some assumptions removed There are several arguments against the idea that we can share sensory experiences with animals In Theoretische Biologie (1920) the Estonian biologist Jakob von Uexküll (1864–1944) argued that even simple organisms like amoebas have sensory worlds, Umwelten (Umwelt is German for environment, but in Uexküll’s conception it means the immediate embedding that the animals can perceive) We can study those sensory worlds, but we cannot experience them In looking at apparently simple organisms such as ticks, jellyfish, and marine worms, we are liable to radically Umwelt [Germ.] literally, “surroundings”; the immediate sensory world that an animal can perceive around itself, and by extension its experiential universe underestimate the sensory richness or nuance the animals experience The essay “What Is it Like to Be a Bat?” (1974) by the American philosopher Thomas Nagel (b 1937) makes a similar argument from a very different perspective Nagel proposes that a bat’s echolocation (using reflected sound waves to locate objects) is not “like” any of our senses, and so its sensorium cannot be compared to any of ours (This is a subsidiary point in his essay, which is often misinterpreted: his purpose was to define consciousness as a state in which “there is something that it is like to be that organism.” This has developed into a research topic called variously “embodiment studies” and neurophenomenology.) We open this chapter with some examples of different visual configurations, presented for comparison with human experience The chapter’s second topic is visual displays—colored patterns on animals’ bodies—and how | elk90915_ch07_087-102.indd 87 87 11/19/19 05:42 PM 88 | ANIMAL SEEING they may be perceived Visual displays such as “flash coloration” and camouflage can be theorized using existing models Some animals, however, possess or enact extremely complex )RUFDPRXȨDJH WKHRULHVVHH &KDSWHU‚ visual displays, and it is not known how they are perceived by the animals they target It is plausible that such animals have correspondingly complex visual Umwelten, analogous to the subtlety we attribute to human visual perception Animal vision is not necessarily only a matter of prey or mate detection; there are communities of animals with complex interrelated ways of seeing They can be thought of as nonhuman examples of visual worlds The chapter concludes with an example of such a system of visuality, in order to make the case that theorizing on social networks of vision should not be confined to the human 7.1 Examples of Animal Seeing trichromatism sensitivity to color based on three independent channels, each connected with a different type of light receptor (cone cell) in the retina Each type of cone cell has maximum sensitivity to light of a different color, or wavelength bees’ violet a combination of yellow and ultraviolet light frequencies that humans cannot detect but which is a primary color in the vision of bees elk90915_ch07_087-102.indd 88 We have three kinds of color receptor cells in our retinas; they are normally maximally sensitive to blue, green, and yellowish-green (see Chapter 3, section 3.2) Bees and some other insects have the same kind of cells sensitive to three colors (this is, they are also trichromats like humans), but the sensitivity of their cone cells peak in different parts of the spectrum Honeybees, for example, have maximum sensitivity to blue, yellow, and ultraviolet (UV) The third sensor is sometimes called bees’ violet, although ultraviolet wavelengths are not perceptible to humans as violet or any other color That means that the color world experienced by bees depends on mixtures of different wavelengths than we experience This suggests several possibilities: (a) (b) Bee colors are simply unimaginable to us; Bees see the same colors, but shifted to different parts of the spectrum It isn’t possible to answer psychological propositions like these, but it is possible to combine behavioral research with neurobiological data to find out more about the bees’ Umwelt, the world they are able to sense around them By studying bees’ neurons, the biologist Lars Chittka has mapped bees’ “color space,” showing how bees combine the different wavelengths they perceive In the graph at right in Figure 7.1, ultraviolet is represented as black From this kind of data it is possible to infer how bees mix colors In human subtractive color mixing (such as paints), for example, yellow + red = orange, as every child learns; but for bees orange + blue = bluegreen In human additive color mixing (using lights), bluegreen + red = white; but in bees, bluegreen + UV = white 11/19/19 05:42 PM 7.1 Examples of Animal Seeing LMC − + UG Green Blue UV U−B+G− Lobula Medulla Retina Lamina (B) Rel excitation of blue vs UV - green chromatic mechanism Protecereb rum (A) | 89 Blue 440nm 400nm 490nm White 350nm 550nm 590nm Green UV −1 −1 Rel excitation of UV vs green chromatic mechanism This doesn’t answer the psychological problem, but it shows how different the color spaces bees inhabit are from ours Of all animals, perhaps the one with the most elaborate visual system is the mantis shrimp (Figure 7.2) Compared to its sensing capabilities, we humans are nearly blind Mantis shrimps have two eyes on mobile stalks Each has at least 10 kinds of photoreceptors The eyes have a mid-band with six rows (see the inset picture at the top right of Figure 7.3) The top and bottom halves of the eye sense linearly polarized light, the kind that is typically made visible to us by polarizing filters, or controlled by sunglasses Four of the six rows of the eyes’ mid-bands sense UV, infrared, and color The other two sense circularly polarized light, a capacity that is very rare in the animal world The circularly polarized light detectors are apparently used in interactions with other mantis shrimps, whose shells are colored—invisibly to humans—in patterns that are visible only in circularly polarized light In addition, the ultraviolet receptors in the eyes’ mid-bands have four receptors within the UV, which the mantis shrimp may perceive the way we perceive colors thanks to our three kinds of cone cells They may, in other words, see more “colors” in the UV alone than we see in the entire visible spectrum If you look at a mantis shrimp’s eyes, you see three dark areas where the ommatidia (the many small “facets” of a compound eye) are pointing most directly at you These are called pseudopupils Humans see in 3-D thanks to our two pupils; the mantis shrimp can utilize 15 different combinations of stereoscopic information from its pseudopupils (Each eye can perceive 3-D information using its top pseudopupil in combination with its mid-band pseudopupil, and so forth.) It is possible the mantis shrimp sees the third dimension far more accurately than we (It’s interesting to consider that our vision might be deficient in 3-D information, because we normally elk90915_ch07_087-102.indd 89 Figure 7.1 Bee color processing (left) and color space (right) ommatidia the many small facets of a compound eye, common in insects, crustaceans, and other animals pseudopupil in a compound eye, a dark spot that shows where a group of ommatidia are directly facing you 11/19/19 05:42 PM 90 | ANIMAL SEEING Figure 7.2 Mantis shrimp (A) D (B) L M DH mid-band row row row row row row VH (C) Figure 7.3 Mantis shrimp, eye, and detail of the mid-band of one eye elk90915_ch07_087-102.indd 90 11/19/19 05:42 PM 7.2 How Complex are Animals’ Visual Worlds? | 91 consider that we see all the depth there is to see But the moon, for example, appears flat to us, simply because it is small in our visual field.) There is much more to the Umwelt of the mantis shrimp that we cannot mention here It also has the fastest strike of any animal, measured at 10,000 times the force of gravity: so fast and strong that it boils the sea water in advance of its striking appendages But its vision alone is measurably beyond ours: in a Venn diagram, illustrating the relationship between sets, groups of things sharing something in common, human vision would be a small subset of mantis vision 7.2 How Complex are Animals’ Visual Worlds? One of the relatively unknown aspects of animal visual perception is its complexity Some animals present intricate visual displays, but their complexity is largely unstudied both because some species are rare, and because scientific experimentation generally requires simplification An example is the pelagic (open ocean) comb jelly (Ctenphore) Lampocteis cruentiventer, filmed on the BBC documentary The  Blue Planet (2001) It signals in an outlandishly complex manner; the detail frames in Figure 7.4 only hint at the rapid motion of the colors The lights are as intricate as notes in a symphony Figure 7.4 The Ctenphore Lampocteis cruentiventer, details of display elk90915_ch07_087-102.indd 91 11/19/19 05:42 PM 92 | ANIMAL SEEING Figure 7.5 Maratus spiders, showing mating displays elk90915_ch07_087-102.indd 92 If this complexity is evolutionarily determined, then it must be perceived by other comb jellies—but how? Another recently documented example is tiny salticid (jumping) spiders of the genus Maratus As of 2014, 43 species had been described, with an astonishing variety and complexity of mating displays (see Figure 7.5) The Australian scientist Jürgen Otto— the leading specialist on Maratus—keeps an online gallery that shows the range of these displays) As in other small insects, the variability within each species can be great, with reproductive advantage going to spiders that can display slightly different chromas, hues, values, or motions Figure 7.6 samples the display of one species, Maratus linnaei; photos 3–8 show variations in the pattern in six individuals In addition, these spiders perform mating dances, so the iridescence and colors would be shown in particular sequences and from particular angles With this, Maratus salticid spiders are a good corrective to the common assumption that within a species, many animals look more or less the same An analogous variety of the patterns and shapes can be seen in the small leaf-hopper, Bocidium globulare, which attracted the attention of the French sociologist, anthropologist, and critic Roger Caillois (1913–1978) in the 1930s In such cases it is not known what the intended recipient of the displays sees, and just how complex an Umwelt is involved Uexküll’s famous opening example is a blind mite, which is sensitive to only one chemical, butyric acid, that is given off by mammals It waits at the top of a blade of grass or on a leaf, and when it senses that chemical, it jumps If it lands on something warm that has hair, it bites and drinks, regardless of what fluid it finds (experiments show it will drink poisons as well as blood) If it lands on something cold, it crawls until it finds another stalk to climb and wait Uexküll’s argument is that even with only four elements in its “biosemiotic” world—the odor butyric acid, the temperature of mammalian blood, the texture of hair, and gravity—the tick’s experience may well have infinite gradations The same applies to the other examples we are considering: a ctenophore watching a color 11/19/19 05:42 PM 7.2 How Complex are Animals’ Visual Worlds? display or a salticid spider watching a fan dance may be experiencing a visual world of an order of complexity we can hardly estimate It is especially difficult in these cases for us to see without applying our aesthetic and historical expectations to these patterns A recent debate about a fly that apparently has ant patterns on its wings shows the danger here: it turned out human researchers are probably the only animals that see the fly’s wing patterns as ants Biology is replete with examples of visual displays that are not understood Even in northern biomes, where brightly colored animals are less common, there are cases where coloration is enigmatic Geometrids, a common kind of moth, are an example A few geometrid caterpillars (including “inchworms”) are poisonous and have bright warning colors Most are thin and mimic twigs But in some cases it is difficult to determine what the caterpillar has evolved to mimic The Woolly Gray caterpillar (Figure 7.7) has a distinctive pattern, but as one scientist comments, “the adaptive significance of the Woolly Gray’s coloration, assuming it has been crafted by natural selection, escapes us.” | 93 Figure 7.6 Maratus linnaei displays Figure 7.7 Lycia ypsilon (Woolly Gray) caterpillar and imago (adult) elk90915_ch07_087-102.indd 93 11/19/19 05:42 PM 94 | ANIMAL SEEING Figure 7.8 Nematocampa resistaria (Filament Bearer) caterpillar mimesis mimicry, used in many different contexts, including art, literature, and evolutionary adaptations A narrow understanding of mimesis equates it with replication (a mimetic image in this sense resembles what it denotes); a broad understanding of mimesis understands it as comparison Aristotle used the term specifically for imitation of nature See imitation 6HH&KDSWHUIRU PLPHVLV “It is difficult for us to imagine what the larva is mimicking,” the entomologist David Wagner writes of the second caterpillar illustrated in Figure 7.8, although “the overall effect is not unlike a fallen, brown flower with exerted [visible] stamens”—an odd thing for a caterpillar in a tree to be mimicking Neither of these caterpillars seems to be camouflaged, like the pheasant shown in Figure 5.8 They seem to be examples of mimesis (mimicry), but it is not clear what they are mimicking Note in both these illustrations that entomologists call the adult imago: literally the “image” of the larval stage, as if the caterpillar were an incomplete representation, and the moth its image (Imago is Latin for “image”; see Chapter 1.) In all the examples in this chapter, there is a distinction between what is visible to us and what is visible to members of the animal’s own species (or to a bird that might be contemplating one of these caterpillars) Our sense of pattern, color, and visual detail in animals is as deeply anthropomorphic as our instinctive love of furry mammals, and it is more insidious because we may be entirely unaware of it For some writers, the complex visual displays of animals like comb jellies, Maratus spiders, and Australian bowerbirds (which collect blue and purple objects into sculpted “bowers”) suggest that some animals have aesthetic practices, and that beauty is a category that transcends the human That argument depends on the universalization of the concepts of beauty and aesthetics, both of which are products of just a few centuries of European theorization Our argument here is rather about complexity: potential mates for male Maratus spiders can presumably distinguish small variations in quite complex patterns, and in that respect their visual experience should not be construed as somehow simpler than ours 7.3 Deep-Sea Visuality Deep-sea fish and other animals often have photophores—lightemitting organs—and specially adapted eyes for sensing other animals in extremely low-light conditions Photophores have a large number of functions, and together with the variety of light-sensing capacities This bioluminescent community comprises a set of of seeing and being seen that may be considered as an example of the “regimes” or systems of visuality that are commonly studied in human social contexts elk90915_ch07_087-102.indd 94 11/19/19 05:42 PM 7.3 Deep-Sea Visuality | 95 There are at least a half-dozen proposed functions of for bioluminescent organs in deep-sea animals Five of them are presented in the following sections Attracting Mates Perhaps the most self-evident function is display intended to attract mates The comb jelly (as in Figure 7.4) is an extreme example of that Most displays are much simpler Prey Detection The Photostomias fish has photophores that act like flashlights to find prey One is visible in Figure 7.9, behind the fish’s eye When the fish senses that it might be seen by a larger fish, it can cover the photophore, effectively turning off its built-in flashlight Prey Luring Bioluminescence can also be used to attract potential prey Several species of deep-sea fish have bioluminescent lures, which are extensions of the fish’s body, usually near or in the fish’s mouth, with glowing bulbs at the end Some species have barbels (whisker-like organs, seen for example in catfish), and others have escas (special retractable lures) The anglerfish has both an elaborate bioluminescent esca and a chin barbel In the dark, only the esca and barbel would be visible (see Figure 7.10) Startling and Confusing Predators Some patterns of bioluminescence work by misdirecting potential predators, so they cannot see the outlines of the animal they intend to eat, or so that they bite just part of the animal and miss the rest A possible example is the hydromedusa Aequoria victoria, which luminesces a thin blue ring, leaving the bulk of its body invisible The medusa could presumably survive an attack on the area of the ring Other organisms possess the equivalent of flash or disruptive coloration, which is common for example in insects and birds The scyphomedusa Atolla flashes a light show of moving colors when it is threatened; presumably that display has the same effect as a startling insect or suddenly colorful bird elk90915_ch07_087-102.indd 95 Figure 7.9 Photostomas fish with photophore open (top) and closed (bottom) 11/19/19 05:42 PM 96 | ANIMAL SEEING Figure 7.10 Linophryne anglerfish Countershadowing Figure 7.11 The lanternfish Myctophid, view from below In low-light conditions predators look upward, searching for the silhouette of their prey against the dim light that filters down from the surface of the ocean If an animal has photophores on the lower half of its body, it might be able to erase its silhouette and blend with the weak ambient light Strangely, the ventral photophores using such countershadowing as a camouflage strategy are not always uniformly distributed as a human viewer might expect if the goal is to achieve invisibility (Figure  7.11) Many such examples remain unexplained Together these and other bioluminescent configurations comprise a complex visual world, in which creatures are seen in various ways: partly, inadequately, suddenly, or inaccurately Their identities are concealed, revealed, and dissimulated These acts of seeing and being seen suggest that even in the attenuated, nearly nonvisual world of the deep ocean, there are visual communities as complex as ours (Like our visual worlds, this deep-sea visual world is not limited to sight; sound and other senses are also involved The Belgian biologist Eric Parmentier, for example, has documented a number of sounds that fish make.) * elk90915_ch07_087-102.indd 96 11/19/19 05:42 PM 7.3 Deep-Sea Visuality | 97 TEXT BOX 7.1 Other Color Visions “Bees’ purple” is the tip of the iceberg in animal color vision Lower animals can sense ultraviolet light using their pineal glands, independently of their eyes; the chemical involved is one of five kinds of opsin, which is a photosensitive chemical found in photoreceptor cells in the retina The biotechnologist Mitsumasa Koyangi and others have made a phylogenetic tree of vertebrate opsin types, revealing an entire menagerie of nonhuman light sensitivities, including human green and blue, but also chemicals such as “lamprey red,” “goldfish red,” “goldfish green,” “chicken blue,” “clawed frog parapinopsin,” “rainbow trout parapinopsin,” and “catfish parapinopsin.” This shows that human color vision, which we necessarily experience as full—missing nothing, seeing the full range of colors—is demonstrably limited Ci-opsini1 lamprey parapinopsin (370) clawed frog parapinopsin rainbow trout parapinopsin 100 100 VA PP (UV) catfish parapinopsin toad pinopsin 97 100 chicken pinopsin (470) non-visual marine lamprey P-opsin zebrafish VAL (500) 100 P lamprey red chicken iodopsin (571) goldfish red (559) 100 mouse green (508) human green (530) human red (560) chicken violet (415) mouse UV (359) 100 human blue (424) goldfish blue (441) 94 100 96 chicken blue (455) goldfish green (506) chicken green (508) 100 UV/ Violet Visual goldfish UV (359 100 95 Red Blue Green lamprey rhodopsin (500) goldfish rhodopsin (492) chicken rhodopsin (503) 100 99 100 elk90915_ch07_087-102.indd 97 Rh mouse rhodopsin ( 498) human rhodopsin (497) 11/19/19 05:42 PM 98 | ANIMAL SEEING TEXT BOX 7.2 Double Foveas The fovea is the portion of the retina that has the highest density of receptors, and therefore the sharpest vision In human eyes the fovea gives us the sharpest part of our vision, so we feel that we are always looking in the direction of our sharpest vision (Chapter 3, section 3.3) Over half of all birds, including birds of prey and hummingbirds, have two foveae in each eye, called “shallow” and “deep.” These birds have high-resolution stereo vision when they use both eyes to look ahead, but at the same time Reference line they see in high resolution off to each side Raptors (birds of prey) may spiral in toward their prey to make use of their highest-resolution foveae, which look out to the side If we had two foveae in each eye, we would have our choice of directions in which to look to get the sharpest vision That might change the sense of phrases like “where I’m looking” (because it would be always three places at once), or “looking straight ahead” (because “straight ahead” is just a way of naming the area of sharpest vision) 1.0 Relative receptor density LOS of deep fovea Shallow fovea 0.5 Deep fovea Shallow fovea 0 Section through a falcon’s head at the foveal plane both foveae (shallow and deep) & the center of the pupils are onthe plane Los, line of sight 45 Angle of line of sight (degrees) 90 Relative receptor densities along the foveal plane of a falcon A relative density of represents 62,000 receptors/square mm [Both figures from Tucker (2000b)] The examples in this chapter are just indications of what a less human-centric sense of vision might be Each instance of animal seeing makes our own vision and visuality seem less natural and transparent, and enriches our sense of what a visual world might be Perhaps the end point of such inquiries will be a biovisuality or an ecovisuality, elk90915_ch07_087-102.indd 98 11/19/19 05:42 PM Further Reading which would entail a biosemiotics (a general study of signs by which animals communicate) At the least, future studies of visuality in the humanities could include the animal along with the human; in doing so they would only be following concerns that are already well-developed in biology and ecology Further Reading Uexküll, Jakob von: Theoretical Biology, 1926 Nagel, Thomas, “What Is It Like to Be a Bat?,” Philosophical Review 83, no (1974): 435–50, doi:10.2307/2183914 JSTOR 2183914 Nagel, Uexküll: see further Thinking with Animals: New Perspectives on Anthropomorphism, edited by Lorraine Daston and Gregg Mitman, 2005; Derrida, The Animal That Therefore I Am, 2008 neurophenomenology: David Wudrauf, Antoine Lutz, et al., “From Autopoiesis to Neurophenomenology: Francisco Varela’s Exploration of the Biophysics of Being,” 2003 visual worlds: see also Martin Jay’s “Scopic Regimes,” Vision and Visuality, 1983; Empires of Vision: A Reader, 2014 bees: Lars Chittka and Axel Brockmann, “Perception Space—The Final Frontier”; Karl von Frisch, An Account of the Life and Senses of the Honey Bee, translated by Dora Isle and Norman Walker, 1970; Tania Munz, “The Bee Battles: Karl von Frisch, Adrian Wenner, and the Honey Bee Dance Language Controversy,” Journal of the History of Biology 38 (2005): 535–70 mantis shrimp: Thomas Cronin and Justin Marshall, “A retina with at least ten spectral types of photoreceptors in a mantis shrimp.” Nature 339 (6220) (1989): 137–140, https://doi.org/10.1038/339137a0; Sonja Kleinlogel and Andrew G White AG (2008) “The Secret World of Shrimps: Polarisation Vision at Its Best.” PLoS ONE 3.5 (2008): e2190, doi:10.1371/journal.pone.0002190l; Justin Marshall and Johannes Oberwinkler, “Ultraviolet Vision,” Nature 401 (1999) salticid spiders: Jürgen Otto, “An Illustrated Review of the Known Peacock Spiders of the Genus Maratus from Australia,” Pekhamia 96 no (2011); for Jürgen Otto’s Maratus Online Gallery: https://www.flickr.com/photos/59431731@N05/; for the “fan dance”: “Spiders of the Mungaich Group from Western Australia,” Pekhamia 112, no (2014); also https://www.flickr.com/photos/59431731@N05/ sets/72157625910288895/ in Jürgen Otto’s Maratus Online Gallery fly with ant patterns on its wings: Morgan Jackson, on biodiversityinfocus.com, November 2013, regarding a fruit fly in the family Tephritidae caterpillars: David Wagner et al., Geometrid Caterpillars of Northeastern and Appalachian Forests, 2001 beauty as a category that includes animals: David Rothenberg, Why Birds Sing: A Journey Into the Mystery of Bird Song, 2005 and Thousand-Mile Song: Whale Music in a Sea of Sound, 2008 the hydromedusa Aequoria victoria: see the Bioluminescence webpage, biolum.eemb ucsb.edu sounds fish make: Parmentier, “Sound Production in the Clownfish Amphiprion clarkii,” Science, 2007; tinyurl.com/leyp9rp Text Box 7.1: Sandra Sinclair, How Animals See: Other Visions of Our World, 1985; P D Sturkie, Sturkie’s Avian Physiology, 1998 Text Box 7.2: Mitsumasa Koyangi et al., “Bistable UV Pigment in the Lamprey Pineal,” Proceedings of the National Academy of Sciences 101 no 17 (2004), doi: 10.1073/ pnas.0400819101 elk90915_ch07_087-102.indd 99 | 99 visual world the totality of ways of seeing and being seen particular to a given species, such as a wide range of color sensitivity or partial invisibility to others Informally, a reference to the various visual practices discussed in this book See Umwelt 11/19/19 05:42 PM elk90915_ch07_087-102.indd 100 11/19/19 05:42 PM Conclusion PART TWO To complement and counterbalance the theoretical orientation of Part One of the book, in Part Two we considered seeing practices that serve concrete purposes, calling them types of seeing Exploring the nature of those categories of seeing we noted that they often overlap, as the case of staring shows (Chapter 5, section 5.1): as protracted looking, it can consist in the accumulation of many gazes and glances Peering, on the other hand, can be split into very different varieties (section 5.2) We called static peering the act of looking in order to answer questions about the identification or meaning of an object Here it emerged that the detailed observation of particulars can distort our understanding of the functions and intentions originally invested into the objects we observe: looking at high-resolution details from pointillist paintings, for instance, alienates us from the effects the painters originally intended; endoscopic peering with robotic cameras inside pyramids conveys a visual experience of something intended never to be seen Peering also raises the question of the subjects of seeing, which can as well be its objects, as the case of camouflage shows: it is a curiously redundant form of gaze, consisting of a continuous looking and counterlooking that we called mutual peering Glimpsing and glancing (section 5.3) yield incomplete understandings, but are sometimes the best way to catch salient characteristics and trigger intuitive decision-making In sum, staring, peering, glimpsing, glancing, and other kinds of “minor” seeing might well be considered as types of seeing as important as the thoroughly theorized types like gazing (Chapter 4) In Chapter 6, we reviewed theories of the connection between sight and other senses The intermingling of senses in perception and cognition is one of the major constituents of all types of seeing and cannot be ignored, in spite of the general predominance of sight, which remains the preferred medium for representing the other senses Animal seeing, we argued in Chapter 7, is also an indispensable subject for a fuller understanding of human vision: animals have forms of vision conceptually incompatible with ours and knowing about them can illuminate our notions about the apparent naturalness of human seeing Categorizing practices of seeing in this part of the book and considering its relation to other senses and to animal vision discloses that the mixture of gazes implicit in different types of seeing varies depending on the purpose of seeing and on the motivation and expectation of those looking This multiplicity of types of seeing erodes the monolithic authority of the theory of the gaze considered in Chapter 4, and suggests that sometimes seeing is better imagined as a series of different kinds of encounters, each one of which may be given its own conceptualization | elk90915_ch07_087-102.indd 101 101 11/19/19 05:42 PM elk90915_ch07_087-102.indd 102 11/19/19 05:42 PM ... of mantis vision 7. 2 How Complex are Animals’ Visual Worlds? One of the relatively unknown aspects of animal visual perception is its complexity Some animals present intricate visual displays,... 93 Figure 7. 6 Maratus linnaei displays Figure 7. 7 Lycia ypsilon (Woolly Gray) caterpillar and imago (adult) elk90915_ch 07_ 0 87- 102.indd 93 11/19/19 05:42 PM 94 | ANIMAL SEEING Figure 7. 8 Nematocampa... elk90915_ch 07_ 0 87- 102.indd 96 11/19/19 05:42 PM 7. 3 Deep-Sea Visuality | 97 TEXT BOX 7. 1 Other Color Visions “Bees’ purple” is the tip of the iceberg in animal color vision Lower animals can