Jochen Zeil

Australian National University | ANU · Research School of Biology (RSB)

Solitary foraging insects, such as ants, maintain an estimate of the direction and distance to their starting location as they move away from it, in a process known as path integration. This estimate, commonly known as the “home vector,” is updated continuously as the ant moves1, 2, 3, 4 and is reset as soon as it enters its nest,⁵ yet ants prevent...

We constructed a large projection device (the Antarium) with 20,000 UV-Blue-Green LEDs that allows us to present tethered ants with views of their natural foraging environment. The ants walk on an air-cushioned trackball, their movements are registered and can be fed back to the visual panorama. Views are generated in a 3D model of the ants' enviro...

Solitary foraging ants rely on vision when travelling along routes and when pinpointing their nest. We tethered foragers of Myrmecia croslandi on a trackball and recorded their intended movements when the trackball was located on their normal foraging corridor (on-route), above their nest and at a location several meters away where they have never...

Wasps and bees perform learning flights when leaving their nest or food locations for the first time during which they acquire visual information that enables them to return successfully. Here we present and test a set of simple control rules underlying the execution of learning flights that closely mimic those performed by ground-nesting wasps. In...

We provide a detailed analysis of the learning walks performed by Myrmecia croslandi ants at the nest during which they acquire visual information on its location. Most learning walks of 12 individually marked naïve ants took place in the morning with a narrow time window separating the first two learning walks, which most often occurred on the sam...

Recent work on virtual reality navigation in humans has suggested that navigational success is inversely correlated with the fractal dimension (FD) of artificial scenes. Here we investigate the generality of this claim by analysing the relationship between the fractal dimension of natural insect navigation environments and a quantitative measure of...

We show in a comparative analysis that distinct retinal specializations in insect ocelli are much more common than previously realized and that the rhabdom organization of ocellar photoreceptors is extremely diverse. Hymenoptera, Odonata and Diptera show prominent equatorial fovea-like indentations of the ocellar retinae, where distal receptor endi...

We used contrast-optimized micro X-ray computed tomography (mCT) to trace the profiles of the full complement of large ocellar L-neurons in the male orchid bee Euglossa imperialis. We find that most L-neurons collect information from either the dorsal or the ventral retinae in both median and lateral ocelli, with only three neurons associated with...

In his book on sexual selection, Darwin [1] devoted equal space to non-vocal and vocal communication in birds. Since then, vocal communication has become a model for studies of neurobiology, learning, communication, evolution, and conservation [2, 3]. In contrast, non-vocal "instrumental music," as Darwin called it, has only recently become subject...

Panoramic views of natural environments provide visually navigating animals with two kinds of information: they define locations because image differences increase smoothly with distance from a reference location and they provide compass information, because image differences increase smoothly with rotation away from a reference orientation. The ra...

Supporting methods for gradient descent and ground plane removal. (DOCX)

A comparison between hill climbing and gradient descent algorithms. Shown are the catchment volumes (top rows) and example paths (bottom rows) for three reference image heights at Site 2 (columns) as determined by hill climbing (HC, top) and gradient descent algorithm (GD, bottom). Paths start at 30 randomly chosen grid-points within the panoramic...

The effect of removing the ground plane on the slope along the path of hill climbs. Panels show the paths of failed hill climbs up to the point at which they became sub-threshold. The left panes show failures at Site 3 with the full panorama, and the right panes show the failures for the same site when we removed the pixels below the panorama’s hor...

We used contrast-optimized micro X-ray Computed Tomography (mCT) to trace the profiles of the full complement of large ocellar L-neurons in the male orchid bee Euglossa imperialis. We find that most L-neurons collect information from either the dorsal or the ventral retinae in both median and lateral ocelli, with only three neurons associated with...

Individual differences in response thresholds to task-related stimuli may be one mechanism driving task allocation among social insect workers. These differences may arise at various stages in the nervous system. We investigate variability in the peripheral nervous system as a simple mechanism that can introduce inter-individual differences in sens...

In addition to compound eyes, honeybees (Apis mellifera) possess three single lens eyes called ocelli located on the top of the head. Ocelli are involved in head-attitude control and in some insects have been shown to provide celestial compass information. Anatomical and early electrophysiological studies have suggested that UV and blue-green photo...

Ants can navigate over long distances between their nest and food sites using visual cues [1, 2]. Recent studies show that this capacity is undiminished when walking backward while dragging a heavy food item [3–5]. This challenges the idea that ants use egocentric visual memories of the scene for guidance [1, 2, 6]. Can ants use their visual memori...

Ants of the Australian genus Myrmecia partition their foraging niche temporally, allowing them to be sympatric with overlapping foraging requirements. We used histological techniques to study the light and dark adaptation mechanisms in the compound eyes of diurnal (Myrmecia croslandi), crepuscular (M. tarsata, M. nigriceps) and nocturnal ants (M. p...

Ant foragers are known to memorise visual scenes that allow them to repeatedly travel along idiosyncratic routes and to return to specific places. Guidance is provided by a comparison between visual memories and current views, which critically depends on how well the attitude of the visual system is controlled. Here we show that nocturnal bull ants...

Nesting insects perform learning flights to establish a visual representation of the nest environment that allows them to subsequently return to the nest. It has remained unclear when insects learn what during these flights, what determines their overall structure, and, in particular, how what is learned is used to guide an insect's return. We anal...

We investigated the functional anatomy of the visual system in the Australian 'Redeye' cicada Psaltoda moerens, including compound eyes and ocelli. The compound eyes have large visual fields, about 7500 ommatidia per eye and binocular overlaps of 10-15(o) in the frontal and of 50-60(o) in the dorsal visual field. The diameters of corneal facet lens...

Ants occupy a range of ecological niches and as a result come in a stunning variety of shapes and sizes. Despite this variation, sympatric species face similar challenges in having to perform a range of tasks such as communicating with nest-mates, foraging for food and navigating through the environment. It has been shown that smaller animals must...

Ants are thought to be special among Hymenopterans in having only dichromatic colour vision based on two spectrally distinct photoreceptors. Many ants are highly visual animals, however, and use vision extensively for navigation. We show here that two congeneric day- and night-active Australian ants have three spectrally distinct photoreceptor type...

Much evidence has accumulated in recent years, demonstrating that the degree to which navigating insects rely on path integration or landmark guidance when displaced depends on the navigational information content of their specific habitat. There is thus a need to quantify this information content. Here we present one way of achieving this by const...

Insects use antennal sensilla to not only detect chemical and mechanical cues but also to sense changes in temperature, humidity and CO2 levels. But very little is known about the variation in numbers, size and structure of sensilla in ants. Here we describe in detail the array of sensilla on the apical segment of the antennae of the nocturnal Aust...

Sensory drive theory contends that signalling systems should evolve to optimize transmission between senders and intended receivers, while minimising visibility to eavesdroppers where possible. In visual communication systems, the high directionality afforded by iridescent colouration presents underappreciated avenues for mediating this trade-off....

Cheeseman et al. (1) claim that an ability of honey bees to travel home through a landscape with conflicting information from a celestial compass proves the bees' use of a cognitive map. Their claim involves a curious assumption about the visual information that can be extracted from the terrain: that there is sufficient information for a bee to id...

We review here what is known from behavioural, anatomical and physiological studies about polarisation sensitivity in the hymenopteran insect groups of ants, wasps and bees. We briefly summarise the behavioural evidence for the use of polarised skylight in orientation and navigation, including some lesser known or less accessible older work, and th...

Ants, bees and wasps are central place foragers. They leave their nests to forage and routinely return to their home-base. Most are guided by memories of the visual panorama and the visual appearance of the local nest environment when pinpointing their nest. These memories are acquired during highly structured learning walks or flights that are per...

We describe the structural organization of the ommatidium in the compound eye of the fiddler crab, Uca vomeris, at both the light- and the electronmicroscopical levels. We pay particular attention to the organization of the optical system, the retinular cells, the rhabdom and of pigment cells. Although the fiddler crab compound eye is of the apposi...

We caught solitary foragers of the Australian Jack Jumper ant, Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked th...

In ants, we know most about the foraging patterns at the colony level. We know surprisingly little about the foraging behaviour of individual foragers and how they shape the behaviour of the colony. To identify spatial and temporal variation in foraging behaviour at the individual level, we studied at two nests the solitary foragers of the Australi...

Ants, bees and wasps are central place foragers. They leave their nests to forage and routinely return to their home-base. Most are guided by memories of the visual panorama and the visual appearance of the local nest environment when pinpointing their nest. These memories are acquired during highly structured learning walks or flights that are per...

A number of models for insect navigation have been developed to explain the results of behavioural experiments and to be tested in simulations or on robotic platforms. However, it remains difficult to evaluate these models in a generic and objective way, beyond the specific results they have been developed to explain and beyond the specific environ...

Miniaturisation is the reduction of adult body size in a given lineage over an evolutionary timescale, where further reduction in size is not possible due to physical limits on the function of biological systems. Studying miniaturisation allows a better understanding of the design constraints operating on a given system and an opportunity to observ...

A number of models for insect navigation have been developed to explain the results of behavioural experiments and to be tested in simulations or on robotic platforms. However, it remains difficult to evaluate these models in a generic and objective way, beyond the specific results they have been developed to explain and beyond the specific environ...

Ants are efficient navigators, guided by path integration and visual landmarks. Path integration is the primary strategy in landmark-poor habitats, but landmarks are readily used when available. The landmark panorama provides reliable information about heading direction, routes and specific location. Visual memories for guidance are often acquired...

For developing and validating models of insect navigation it is essential to identify the visual input insects experience in their natural habitats. Here we report on the development of methods to reconstruct what insects see when making navigational decisions and critically assess the current limitations of such methods. We used a laser-range find...

The ‘jack jumper’ ants, Myrmecia croslandi travel as far as 15m from the nest to find food. Being solitary and highly visual foragers, these ants navigate remarkably well without the help of recruitment and pheromone trails, relying solely on their individual navigational abilities. However, any inexperienced, solitary forager leaving the nest for...

Ants are efficient navigators, guided by path integration and visual landmarks. Path integration is the primary strategy in landmark-poor habitats, but landmarks are readily used when available. The landmark panorama provides reliable information about heading direction, routes and specific location. Visual memories for guidance are often acquired...

Here we report on the nocturnal bull ant Myrmecia pyriformis, a species whose activity to and from the nest is mainly restricted to the dawn and dusk twilight respectively. Recent research on M. pyriformis has focussed on its visual system, the timing of activity patterns, and the navigational strategies employed by individuals while foraging. Ther...

For developing and validating models of insect navigation it is essential to identify the visual input insects experience in their natural habitats. Here we report on the development of methods to reconstruct what insects see when making navigational decisions and critically assess the current limitations of such methods. We used a laser-range find...

Flying insects keep their visual system horizontally aligned suggesting that gaze stabilization is a crucial first step in flight control. Unlike flies, hymenopteran insects, such as bees and wasps do not have halteres that provide fast, feed-forward angular rate information to stabilize head orientation in the presence of body rotations. We tested...

Polarisation sensitivity is based on the regular alignment of dichroic photopigment molecules within photoreceptor cells. In crustaceans, this is achieved by regularly stacking photopigment-rich microvilli in alternating orthogonal bands within fused rhabdoms. Despite being critical for the efficient detection of polarised light, very little resear...

The ability to learn the location of places in the world and to revisit them repeatedly is crucial for all aspects of animal life on earth. It underpins animal foraging, predator avoidance, territoriality, mating, nest construction and parental care. Much theoretical and experimental progress has recently been made in identifying the sensory cues a...

We have re-investigated the organization of ocelli in honeybee workers and drones. Ocellar lenses are divided into a dorsal and a ventral part by a cusp-shaped indentation. The retina is also divided, with a ventral retina looking skywards and a dorsal retina looking at the horizon. The focal plane of lenses lies behind the retina in lateral ocelli...

Animals avoid temperatures that constrain foraging by restricting activity to specific times of the day or year. However, because temperature alters the availability of food resources, it is difficult to separate temperature-dependent effects on foraging and the occupation of temporal niches. By studying two congeneric, sympatric Myrmecia ants we i...

To efficiently provide an animal with relevant information, the design of its visual system should reflect the distribution of natural signals and the animal's tasks. In many behavioural contexts, however, we know comparatively little about the moment-to-moment information-processing challenges animals face in their daily lives. In predator avoidan...

Navigating animals are known to use a number of celestial and terrestrial compass cues that allow them to determine and control their direction of travel. Which of the cues dominate appears to depend on their salience. Here we show that night-active bull ants attend to both the pattern of polarised skylight and the landmark panorama in their famili...

Purpose. When an observer moves through the three-dimensional world, a characteristic field of velocity vectors is generated on the retina. Although many theoretical, psychophysical, and physiological studies have demonstrated the use of such optic flowfields for a number of navigational tasks under laboratory conditions, surprising little is known...

Animals are active at different times of the day and their activity schedules are shaped by competition, time-limited food resources and predators. Different temporal niches provide different light conditions, which affect the quality of visual information available to animals, in particular for navigation. We analysed caste-specific differences in...

The Australian desert ant Melophorus bagoti shows remarkable visual navigational skills relying on visual rather than on chemical cues during their foraging trips. M. bagoti ants travel individually through a visually cluttered environment guided by landmarks as well as by path integration. An examination of their visual system is hence of special...

Because vision operates in closed loop, the organization of behavior plays an important role in visual information processing by facilitating image processing through the separation of rotational and translational optic flow (the pattern of image motion on the retina of a moving observer) and by actively generating visual information through specia...

Insects use memorised visual representations to find their way back to places of interest, like food sources and nests. They acquire these visual memories during systematic learning flights or walks on their first departure and update them whenever approaches to the goal have been difficult. The fact that small insects are so good at localisation t...

We present a new combination of lenses and reflective surfaces for obstruction-free wide-angle imaging. The panoramic imaging system consists of a reflective surface machined into solid Perspex, which together with an embedded lens, can be attached to a video camera lens. Unlike vision sensors with a single mirror mounted in front of a camera, the...

Fiddler crabs use elaborate, species-specific claw-waving displays to communicate with rivals and mates. However, detailed comparative studies of fiddler crab signal structure and structural variations are lacking. This paper provides an analysis of the claw-waving displays of seven Australian species of fiddler crab, Uca mjoebergi, U. perplexa, U....

Understanding the evolution of animal signals has to include consideration of the structure of signal and noise, and the sensory mechanisms that detect the signals. Considerable progress has been made in understanding sounds and colour signals, however, the degree to which movement-based signals are constrained by the particular patterns of environ...

What do visual neurons compute? A recent review [1 • Carandini M. • Demb J.B. • Mante V. • Tolhurst D.J. • Dan Y. • Olshausen B.A. • Gallant J.L. • Rust N.C. Do we know what the early visual system does?.J. Neurosci. 2005; 16: 10577-10597 • Crossref • Scopus (322) • Google Scholar ] states that current models of the primary visual cortex (V1) of...

Effective communication is critically dependent on the successful transfer of information and, because environmental and social conditions can affect signal transmission, animals should be able to adjust their signals to optimize reliability. We show, apparently for the first time in a movement-based signal, that visual displays are adjusted with r...

Animals relocating a target corner in a rectangular space often make rotational errors searching not only at the target corner but also at the diagonally opposite corner. The authors tested whether view-based navigation can explain rotational errors by recording panoramic snapshots at regularly spaced locations in a rectangular box. The authors cal...

Two recent studies testing navigation of rats in swimming pools have posed problems for any account of the use of purely geometric properties of space in navigation (M. Graham, M. A. Good, A. McGregor, & J. M. Pearce, 2006; J. M. Pearce, M. A. Good, P. M. Jones, & A. McGregor, 2004). The authors simulated 1 experiment from each study in a virtual r...

Social insects have evolved remarkable physiological adaptations and behavioural strategies that enable them to access new temporal foraging niches (for example [1 • Gehring W.J. • Wehner R. Heat shock protein synthesis and thermotolerance in Cataglyphis, an ant from the Sahara desert.Proc. Natl. Acad. Sci. USA. 1995; 92: 2994-2998 • Crossref • P...

Animal signals are optimized for particular signaling environments [1-3]. While signaling, senders often choose favorable conditions that ensure reliable detection and transmission [4-8], suggesting that they are sensitive to changes in signal efficacy. Recent evidence has also shown that animals will increase the amplitude or intensity of their ac...

To respond appropriately to communication signals, animals must have the ability to decipher signal meaning. At a basic level, interpreting the difference between territorial and courtship signals can be vital for the survival and reproduction of social animals. Male and female fiddler crabs communicate with claw-waving dis-plays, but the function...

Panoramic image differences can be used for view-based homing under natural outdoor conditions, because they increase smoothly with distance from a reference location (Zeil et al., J Opt Soc Am A 20(3):450-469, 2003). The particular shape, slope and depth of such image difference functions (IDFs) recorded at any one place, however, depend on a numb...