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Current Research Projects

Visual Ecology of Fiddler Crabs

The eyes of most arthropods show variations of resolving power, absolute light sensitivity, spectral and polarization sensitivity throughout the visual field. These eyes thus do not sample the world in a uniform fashion like a video camera. Their properties are matched to specific visual habitats, which are characterised not only by the distribution of light in the natural environment, but also – because vision operates in a closed-feedback loop - by the specific behaviour of animals.

We presently attempt to reconstruct the visual world of fiddler crabs. We do this firstly by analysing the distribution of light, including its spectral and polarization composition from the viewpoint of crabs with the help of video cameras, UV-cameras and a spectrographic imager (casi, Itres, Canada). Secondly, we study the mechanisms of behaviour in fiddler crabs, by filming their reactions when they are confronted with crab and bird dummies (e.g. Hemmi&Zeil (2003) Nature 421: 160-163), or when their homing abilities are tested (e.g. Zeil (1998) J Comp Physiol A183: 367-377).

Our aim is to establish a complete inventory of visual tasks in fiddler crabs and to describe these tasks in terms of the underlying image and information processing requirements (see Zeil&Hemmi (2006) J Comp Physiol A192: 1-25).

We hope that this ethological and ecological approach will enable us to quantify the subtle selective pressures that have driven the evolution of visual systems (well, at least of this particularly weird one). The results will help us to formulate hypotheses that can be tested in behavioural and neurophysiological experiments.

Why Fiddler Crabs?

Fiddler crabs live in a visually structured, simple and predictable world. They inhabit intertidal mudflats, are active on the surface during low tide and indulge in a rich social life. They carry their eyes on long vertical eyestalks and the eyes are kept in a constant orientation relative to the local visual horizon by a visually driven control system. The projection of the visual environment onto the retina is thus practically invariant and well defined. The distribution of resolving power in the crabs' eyes is well known (cf. Zeil&Al-Mutairi (1996) J Exp Biol 199: 1569-1577).

The crabs are central place foragers, operating from a home burrow, and have an activity range of about 1 square metre. This means that their complete behavioural repertoire can be described in great spatial and temporal detail, that the visual tasks the crabs are confronted with can be identified and that the information processing involved can be characterized reasonably well (e.g. Land&Layne (1995) J Comp Physiol A 177: 81-103; Zeil&Zanker (1997) Vision Res 37: 3417-3426); Hemmi&Zeil (2003) Nature 421: 160-163).

In addition, the social context in which the crabs navigate and make decisions is of great interest to behavioural ecologists (e.g. Christy, Backwell&Schober (2003) Behav Ecol Sociobiol 53: 84-91), so that the well-defined ethological context allows us to measure the relevant “information content” of vision in these animals. For instance, Tanya Detto, in collaboration with Pat Backwell has recently shown that Australian fiddler crabs recognize species and neighbours by their distinct colour patterns (Detto, Backwell, Hemmi, Zeil (2006) Proc Roy Soc Lond B (online)).

Mobile robotic gantry (left) and Panoramic imaging device (right) (© Jochen Zeil)

View-based Homing & Flight Control in Insects

The second major research area, which we are interested in concerns the problem of landmark guidance in homing insects. Javaan Chahl and Martin Hofmann from the Biorobotics Group [http://cvs.anu.edu.au/bioroboticvision/brv.html] have built a mobile platform carrying a robotic gantry that can be used to move a panoramic imaging device (Chahl&Srinivasan (1997) Applied Optics 36: 8275-8285) along defined paths outdoors.

The gantry is now being used to record natural scenes from the viewpoint of homing insects with the aim of understanding the principal constraints of view-based homing under natural conditions (Zeil, Hofmann&Chahl (2003)) and to investigate the natural image motion signals available for flight control (Zanker&Zeil (2005) Network: Computation in Neural Systems 16: 357-376).

Because it can be taken for a walk, the gantry is unique in the world and is currently being used in collaboration with Johannes Zanker (Royal Holloway, England) and Martin Egelhaaf (University of Bielefeld, Germany) as a research tool to reconstruct natural optic flow and to replay it to fly visual interneurons, using a flight simulator in Bielefeld (see Boeddeker, Lindemann, Egelhaaf, Zeil (2005) J Comp Physiol A 191: 1143-1155).

Completed Honours Projects.
(co-supervised with Paul Cooper & Rob Magrath, Division of Botany and Zoology, ANU).

Tim Jensma: Visual cues and response to predators by the semi-terrestrial crab Heloecius cordiformis.
Tanya Detto: Signalling and the Role of Colour in the semaphore crab Heloecius cordiformis.
Alex Hodgson: Foraging activity and tandem recruitment in the Australian Sugar Ant Camponotus consobrinus.

Sam Reid: Foraging behaviour of saw flies: How do they know the way home?

Research Collaborations

Stephen Achal, Itres, Canada: Hyperspectral Imaging (CASI)

Pat Backwell, Division of Botany and Zoology, ANU: Fiddler crab behaviour
Marilyn Ball, Ecosystem Dynamics, RSBS: Ecophysiological Imaging

Samir Deeb, University of Washington, Seattle: Colour vision in fiddler crabs
Martin Egelhaaf, University of Bielefeld, Germany: Reconstruction of natural optic flow
Cole Gilbert, Cornell, USA: The Satellite Fly tracking system
Justin Marshall & Misha Vorobyev, University of Queensland: The variable body colours of fiddler crabs
Doekele Stavenga, University of Groningen, The Netherlands: Optics of fiddler crab eyes
Johannes Zanker, Royal Holloway, England: Motion vision ecology

Publications (May 2006)

Journal articles:

Zeil J, Hemmi JM (2006) The visual ecology of fiddler crabs. Journal of Comparative Physiology A 192: 1–25 [pdf 1623kb– Copyright Springer Verlag]

Zeil J, Hemmi JM, Backwell PRY (2006) Quick Guide: Fiddler Crabs. Current Biology 16: R40-R41

Detto T, Backwell PRY, Hemmi JM, Zeil J (2006) Visually mediated species and neighbour recognition in fiddler crabs. Proceedings of the Royal Society of London B (in press)

Vladusich T, Hemmi J M, Zeil J (2006) Honeybee odometry and scent guidance. Journal of Experimental Biology 209: 1367-1375

Zanker JM, Zeil J (2005) Movement-induced motion signal distributions in outdoor scenes. Network: Computation in Neural Systems 16: 357-376

Vladusich T, Hemmi JM, Srinivasan MV, Zeil J (2005) Interactions of visual odometry and landmark guidance during food search in honeybees. Journal of Experimental Biology 208: 4123-4135

Boeddeker N, Lindemann JP, Egelhaaf M, Zeil J (2005) Responses of blowfly motion-sensitive neurons to reconstructed optic flow along outdoor flight paths. Journal of Comparative Physiology A 191: 1143-1155

Zeil J (2005) Don’t underestimate the little ones! Book Review of Prete FR (ed) Complex worlds from simpler nervous systems. Journal of Experimental Biology 208:1771-1772.

Hemmi JM, Zeil J (2005) Animals as prey: Sensory-motor abilities and flexibility of behaviour in an arthropod. Marine Ecology Progress Series 287: 274-278.

Stavenga DG, Stowe S, Siebke K, Zeil J, Arikawa K (2004) Butterfly wing colours: scale beads make white pierid wings brighter. Proceedings of the Royal Society of London B271: 1577-1584.

Detto T, Zeil J, Magrath R, Hunt S (2004) Sex, size and colour in the semaphore crab Heloecius cordiformis. Journal of Experimental Marine Biology and Ecology 302: 1-15

Hemmi JM, Zeil J (2003) Robust judgement of inter-object distance by an arthropod. Nature 421: 160-163.
Download PDF [Hemmi&Zeil_Nature2003.pdf] [pdf 312kb]

Zeil J, Hofmann MI, Chahl J (2003) The catchment areas of panoramic snapshots in outdoor scenes. Journal of the Optical Society of America A 20: 450 – 469.
Download PDF [Zeil-Hofmann-Chahl_JOSA2003.pdf] [pdf 3055kb – Copyright OSA]

Zeil J, Hofmann M (2001) Signals from ‘crabworld’: Cuticular reflections in a fiddler crab colony. J Exp Biol 204: 2561-2569.
Download PDF [Zeil&Hofmann_JEB2001.pdf] [pdf 356kb]

Zeil J (2000) Depth, behavioural context, and natural illumination: Some potential limitations of video-replay techniques. Acta Ethologica 3: 39-48.

Pix W, Zanker JM, Zeil J (2000) The optomotor response and spatial resolution in the visual system of male Xenos vesparum (Strepsiptera). J Exp Biol 203: 3397-3409.
Download PDF [Pix et al_Strepsiptera_JEB2000.pdf] [pdf 497kb]

Oliveira RF, Rosenthal GG, Schlupp I, McGregor PK, Cuthill I, Endler JA, Fleishman LJ, Zeil J, Barata E, Burford F, GonÁalves D, Haley M, Jakobsson S, Jennions MD, Körner KE, Lindström L, Peake T, Pilastro A, Pope DS, Roberts S, Rowe C, Smith J, Waas JR (2000) Considerations on the use of video playbacks as visual stimuli: The Lisbon workshop consensus. Acta Ethologica 3: 61-65

Land MF, Gibson G, Horwood J, Zeil J (1999) Fundamental differences in the optical structure of the eyes of nocturnal and diurnal mosquitoes. J Comp Physiol A 185: 91-103

Voss R, Zeil J (1998) Active vision in insects: An analysis of object-directed zig-zag flights in a ground-nesting wasp (Odynerus spinipes, Eumenidae). J Comp Physiol A 182: 377-387.
Download PDF [Voss&Zeil_JCP1998.pdf] [pdf 1434kb– Copyright Springer Verlag]
[The original publication is available at http://link.springer.de or at http://link.springer-ny.com]

Zeil J (1998) Homing in fiddler crabs (Uca lactea annulipes and Uca vomeris: Ocypodidae). J Comp Physiol A 183: 367-377.
Download PDF [Zeil_JCP1998.pdf] [pdf 256kb – Copyright Springer Verlag]
[The original publication is available at http://link.springer.de or at http://link.springer-ny.com]

Zeil J (1997) The control of optic flow during learning flights. J Comp Physiol A180: 25-37.
[pdf 1592kb – Copyright Springer Verlag] [Zeil_OpticFlow_JCP_1997.pdf]
[The original publication is available at http://link.springer.de or at http://link.springer-ny.com]

Layne J, Land MF, Zeil J (1997) Fiddler crabs use the visual horizon to distinguish predators from conspecifics: A review of the evidence. J Mar Biol 77: 43-54

Kelber A, Zeil J (1997) Tetragonisca guard bees take expanding and contracting patterns as indicating unintended displacement in space. J Comp Physiol A 181: 257-265

Zeil J, Zanker JM (1997) A glimpse into crabworld. Vision Res 37: 3417-3426.
Download PDF [Zeil&Zanker_Vision Res1997.pdf] [pdf 1109kb – Copyright Elsevier]

Horváth G, Zeil J (1996) Kuwait oil lakes as insect traps. Nature 379: 303-304

Zeil J, Al-Mutairi M (1996) The variation of resolution and of ommatidial dimensions in the compound eyes of the fiddler crab Uca lactea annulipes (Ocypodidae, Brachyura, Decapoda). J Exp Biol 199: 1569-1577.
Download PDF [Zeil&AlMutairi_JEB1996.pdf] [pdf 217kb – Copyright The Company of Biologists])

Zeil J, Kelber A, Voss R (1996) Structure and function of learning flights in bees and wasps. J Exp Biol 199: 245-252.
Download PDF [Zeil-Kelber-Voss_JEB1996.pdf][pdf 259kb]

Collett TS, Zeil J (1996) Flights of learning. Current Directions in Psychol Sci 5: 149-155

Voss R, Zeil J (1995) Automatic tracking of complex objects under natural conditions. Biol Cybern 73: 415-423

Brünnert U, Kelber A, Zeil J (1994) Ground-nesting bees determine the distance of their nest from a landmark by other than angular size cues. J Comp Physiol A 175: 363-369

Zeil J, Wittmann D (1993) Landmark orientation during the approach to the nest in the stingless bee Trigona (Tetragonisca) angustula (Apidae, Meliponinae). Insectes Sociaux 40: 381-389

Zeil J (1993a) Orientation flights of solitary wasps (Cerceris; Sphecidae; Hymenoptera): I. Description of flight. J Comp Physiol A 172: 189-205

Zeil J (1993b) Orientation flights of solitary wasps (Cerceris; Sphecidae; Hymenoptera): II. Similarities between orientation and return flights and the use of motion parallax. J Comp Physiol A 172: 207-222

Pix W, Nalbach G, Zeil J (1993) Strepsipteran forewings are haltere-like organs of equilibrium. Naturwissenschaften 80: 371-374

Wittmann D, Radtke R, Zeil J, Lübke G, Franke W (1990) Robber bees (Lestrimelitta limao) and their host: chemical and visual cues in nest defense by Trigona (Tetragonisca) angustula (Apidae: Meliponini). J Chem Ecol 16(2):631-641

Zeil J (1990) Substratum slope and the alignment of acute zones in semi-terrestrial crabs (Ocypode ceratophthalmus). J Exp Biol 152:573-576

Kelber A, Zeil J (1990) A robust procedure for visual stabilisation of hovering flight position in guard bees (Trigona (Tetragonisca) angustula, Meliponinae). J Comp Physiol A 167: 569-577

Zeil J, Wittmann D (1989) Visually controlled station-keeping by hovering guard bees of Trigona (Tetragonisca) angustula (Apidae, Meliponinae). J Comp Physiol A 165:711-718

Nalbach H-O, Zeil J, Forzin L (1989) Multisensory control of eye-stalk orientation in space: Crabs from different habitats rely on different senses. J Comp Physiol A 165 :643-649

Zeil J, Nalbach G, Nalbach H-O (1986) Eyes, eye stalks and the visual world of semi-terrestrial crabs. J Comp Physiol A 159:801-811

Zeil J (1986) The territorial flight of male houseflies (Fannia canicularis). Behav Ecol Sociobiol 19 :213-219

Zeil J, Sandeman R, Sandeman D (1985) Tactile localisation: the function of antennal movements in the crayfish Cherax destructor. J Comp Physiol A 157:607-617

Dahmen H-J, Zeil J (1984) Recording and reconstructing three-dimensional trajectories: a versatile method for the field biologist. Proc R Soc Lond B222:107-113

Zeil J (1983a) Sexual dimorphism in the visual system of flies: The compound eyes and neural superposition in Bibionidae (Diptera). J Comp Physiol A 150: 379-393

Zeil J (1983b) Sexual dimorphism in the visual system of flies: The free flight behaviour of male Bibionidae (Diptera). J Comp Physiol A 150: 395-412

Zeil J (1983c) Sexual dimorphism in the visual system of flies: The divided brain of male Bibionidae (Diptera). Cell Tissue Res 229: 591-410

Zeil J (1979) A new kind of neural superposition eye: the compound eye of male Bibionidae. Nature 278: 249-250.

Invited Reviews, Book Chapters, and Edited Books:

Zanker JM, Zeil J (2002) An analysis of the motion signal distributions generated by locomotion in a natural environment. In Würtz RP, Lappe M (eds) Dynamic Perception. Workshop of GI section 1.0.4 “Image Understanding” and the European Networks MUHCI and ECOVISION. Akademische Verlagsgesellschaft, Berlin, pp 203-208.

Zanker JM, Zeil J (2002) An analysis of the motion signal distributions emerging from locomotion through a natural environment. In Bülthoff HH et al (eds) Biologically Motivated Computer Vision. Lecture Notes in Computer Science 2525: 146-156.
Download PDF [Zanker&Zeil_Lecture Notes_BMCV_2002.pdf] [pdf 553kb – Copyright Springer Verlag]
[The original publication is available at http://link.springer.de or at http://link.springer-ny.com]

Zeil J, Layne J (2002) Path integration in fiddler crabs and its relation to habitat and social life. In: Wiese K (ed) Crustacean Experimental Systems in Neurobiology. Springer Verlag, Heidelberg, Berlin New York, pp227-247.

Zanker JM, Zeil J (eds) (2001) Motion Vision: Computational, neural and ecological constraints. Springer Verlag, Berlin

Zanker JM, Zeil J (2001) Processing motion in the real world. In Zanker JM, Zeil J (eds) Motion vision: Computational, neural and ecological constraints. Springer Verlag, Berlin Heidelberg New York. pp1-9

Eckert MP, Zeil J (2001) Towards an ecology of motion vision. In Zanker JM, Zeil J (eds) Motion Vision: Computational, neural and ecological constraints. Springer Verlag, Berlin Heidelberg New York. pp333-369

Zeil J, Egelhaaf M (1998) Visual ecology and neural coding. In Elsner N, Wehner R (eds) New neuroethology on the move. Proc 26th Goettingen Neurobiol Conf Vol 1, Thieme Verlag, Stuttgart, pp 347-351

Collett TS, Zeil J (1998) Places and landmarks: an Arthropod perspective. In Healy S (ed) Spatial representation in animals. Oxford University Press, pp18-53

Dahmen HJ, Wüst RM, Zeil J (1997) Extracting egomotion parameters from optic flow: Principal limits for animals and machines. In Venkatesh S, Srinivasan MV (eds) From living eyes to seeing machines. Oxford Univesity Press, Oxford, p174-198

Collett TS, Zeil J (1997) Selection and use of landmarks by insects. In Lehrer M (ed) Orientation and Communication in Arthropods. Birkhäuser Verlag, Basel, pp. 41-65

Bottjer S, Braun K, Cline H, Dudai Y, Fernald RD, Hammer M, Kelly D, Mello C, Reymann K, Scheich H, Vincent J-D, Zeil J (1994) To what extent does experience reorganize the brain and behavior? In: Greenspan R, Kyriacou B (eds) Flexibility and constraint in behavioral systems. John Wiley, Chichester New York, pp 133-145

Zeil J, Nalbach G, Nalbach H-O (1989) Spatial vision in a flat world: Optical and neural adaptations in arthropods. In: Singh RN, Strausfeld NJ (eds) Neurobiology of sensory systems. Plenum Press, New York, pp 123-137.