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Current position
Fellow, Visual Sciences, RSBS
Research interests
The overarching framework which binds the different facets of my work lies in the desire to understand the mechanisms of decision making that are evident in the behaviour and strategies exhibited in the daily life of animals. I am particularly interested in the way in which sensory systems and sensory processing influence and shape animal behaviour. Several projects in which I am involved are briefly described below.
- Colour vision in marsupials: In this project we are describing marsupial colour vision. Using behavioural, physiological and anatomical methods, we are currently exploring the perception of colour in the tammar wallaby. Unlike most mammals some marsupials appear to have trichromatic colour vision (that means they have three different spectral channels similar to some primates). However, it is yet unclear where the third spectral sensitivity comes from.Project collaborators: Wiebke Ebeling, Jan Provis, Riccardo Natoli.
- visual ecology of fiddler crabs: This is a large, collaborative project that aims to define the visual processing requirements the crabs face in their daily struggle for life. We address a variety of questions that include, intra-specific signaling (colour and motion), burrow defence and predator avoidance. One of the main questions we are currently working on is how the crabs need to organize their anti-predator responses given that they have only incomplete sensory information about the location and direction of movement of predatory birds. In the effort to answer this question, we simultaneously measure, in the crabs' natural habitat, their behavioural response together with the detailed sensory information they have available during predation events. Project collaborators: Andreas Pfeil, Ali Alkaladi, Martin How, Jochen Smolka, Jochen Zeil, Tanya Detto.
- Motion signals: Motion signals are poorly understood because they are both difficult to describe and difficult to manipulate in animals. In this area of research I collaborate with others in two projects. Martin How is currently endeavoring to determine the structure of fiddler crab waving. Richard Peters is working on the selective pressures that have shaped the structure of an antagonistic motion display in the jacky lizard.
- Flight stabilization and optic flow in insects: In this collaborative project Norbert Boedekker is using high speed video recordings of free flying insects to determine how these insects measure and use optic flow information during flight.
- Plumage colouration in fairy wrens: Male fairy wrens show off their beautiful blue head and cheek patches during their courtship display. By carefully measuring the reflectance of this structural colour under different viewing geometries, we are endeavoring to determine what the actual visual signal is that they present to the females. Project collaborators: Andrew Cockburn, Paul Cooper, Teresa Ward.
Selected Publication
Hemmi JM & Zeil J (2007). The Ecology of Information Processing. In Marine Ecology, ed. Connell SD & Gillanders BM, Oxford University Press, Oxford. pp441-442 (in press) (accepted: 22.1.2007)
Zeil J, Boeddeker N, Hemmi JM & Stürzl W (2007). Going Wild: Toward an Ecology of Visual Information Processing. In Invertebrate Neurobiology, ed. North G & Greenspan R, Cold Spring Harbor Press. (in press)
Zeil J, Boeddeker N and Hemmi JM (2007). From Visually Guided Behaviour to Behaviourally Guided Vision. In New Ecyclopedia of Neuroscience, ed. Squire LR. Elsevier (in press)
Detto T, Backwell PRY, Hemmi JM & Zeil J (2006) Visually mediated species and neighbour recognition in fiddler crabs (Uca mjoebergi and Uca capricornis). Proceedings of the Royal Society of London B, 273, 1661-1666
Hemmi JM, Marshall J, Pix W, Vorobyev M and Zeil J (2006) The variable colours of the fiddler crab Uca vomeris and their relation to background and predation. Journal of Experimental Biology 209, 4140-4153
Zeil J, Hemmi JM & Backwell PRY. (2006) Quick Guide: Fiddler Crabs. Current Biology 16, R40-R41
Zeil J & Hemmi JM (2006) The visual ecology of fiddler crabs. Journal of Comparative Physiology A, 192, 1-25
Vladusich T, Hemmi JM & Zeil J (2006) Honeybee odometry and scent guidance. Journal of Experimental Biology, 209, 1367-1375
Hemmi JM (2005) Predator avoidance in fiddler crabs. 1: Description of behaviour. Animal Behaviour 69 603-614
Hemmi JM (2005) Predator avoidance in fiddler crabs. 2: The visual cues involved. Animal Behaviour 69 615-625
Hemmi JM & Zeil J (2005) Fiddler crabs as prey: Sensory-motor abilities and flexibility of behaviour in an arthropod. Marine Ecology Progress Series, 287, 274-278
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
Hemmi, J. M. & Zeil, J. 2003. Robust judgement of inter-object distance by an arthropod. Nature, 421, 160-163.
Hemmi, J. M. & Zeil, J. 2003. Burrow surveillance in fiddler crabs. 1: Description of behaviour. Journal of Experimental Biology, 206, 3935-3950.
Hemmi, J. M. & Zeil, J. 2003. Burrow surveillance in fiddler crabs. 2: The sensory cues. Journal of Experimental Biology, 206, 3951-3961.
Hemmi, J. M., James, A. & Taylor, W. R. W. 2002. Colour opponent retinal ganglion cells in the tammar wallaby retina. Journal of Vision, 2, 608-617
Hemmi JM, Maddess T, Mark RF (2000) Spectral sensitivity of photoreceptors in an Australian marsupial, the tammar wallaby (Macropus eugenii). Vision Research 40: 591-599
Hemmi JM 1999. Dichromatic colour vision in an Australian Marsupial, the tammar wallaby. Journal of Comparative Physiology A, 185, 509-515
Hemmi JM & Grünert U 1999. Distribution of photoreceptor types in the retina of a marsupial, the tammar wallaby (Macropus eugenii). Visual Neurosciences, 16, 291-302.
Hemmi JM & Mark RF 1998. Visual acuity, contrast sensitivity and retinal magnification in a marsupial, the tammar wallaby (Macropus eugenii). Journal of Comparative Physiology A, 183, 379-387.
Maddess T, Hemmi JM, James AC (1998) Evidence for spatial aliasing effects in the Y-like cells of the magnocellular visual pathway. Vision Research 38: 1843-1859
Hemmi, J. M. & Menzel, C. R. 1995. Foraging strategies of long-tailed macaques, Macaca fascicularis: directional extrapolation. Animal Behaviour, 49, 457-464.
Ward PI, Hemmi JM, Röösli T (1992) Sexual conflict in the dung fly Sepsis cynipsea. Functional Ecology 6: 649-653
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