Search for dissertations about: "Insect vision"

Showing result 1 - 5 of 15 swedish dissertations containing the words Insect vision.

  2. 1. Neurons against Noise : Neural adaptations for dim light vision in hawkmoths

    Author : Anna Stöckl; Funktionell zoologi; []
    Keywords : vision; insect; hawkmoth; motion vision; spatial and temporal summation; dim light; neural processing;

    Abstract : All animals perceive the world through their senses, which form the basis for their decisions and motor actions. However, when these all-important senses reach their limit and cease to provide reliable information, the animal’s survival is threatened. READ MORE

  4. 2. Visual ecology of insect superposition eyes

    Author : Pär A Brännström; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; tiger beetle; hawkmoth; mayfly; insect; visual ecology; eye design; vision; compound eye; Djurfysiologi;

    Abstract : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. READ MORE

  5. 3. Adaptations for nocturnal vision in insect apposition eyes

    Author : Birgit Greiner; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; temporal and spatial summation; optical and neural adaptations; theoretical modelling.; Djurs anatomi och morfologi; Zoologi; dim light; vision; landmark navigation; nocturnal bees and wasps; Zoology; Animal anatomy; animal morphology;

    Abstract : Due to our own preference for bright light, we tend to forget that many insects are active in very dim light. The reasons for nocturnal activity are most easily seen in tropical areas of the world, where animals face severe competition for food and nocturnal insects are able to forage in a climate of reduced competition and predation. READ MORE

  6. 4. Go with the flow : visually mediated flight control in bumblebees

    Author : Nellie Linander; Funktionell zoologi; []
    Keywords : insect; vision; Bombus terrestris; flight control; optic flow; centring; flight speed; height; viewing angle; learning flight; Insect; vision; Bombus terrestris; flight control; optic flow; centring; flight speed; height; viewing angle; learning flight;

    Abstract : Despite their small brains and tiny eyes, flying insects are capable of detecting and avoiding collisions with moving obstacles, and with remarkable precision they navigate through environments of different complexity. For this thesis, I have investigated how bumblebees use the pattern of apparent image motion that is generated in their eyes as they move through the world (known as optic flow), in order to control flight. READ MORE

  7. 5. Movements in the dark : flying, landing and walking in insects

    Author : THERESE REBER; Funktionell zoologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; insect; vision; light intensity; bumblebee; retina; behavioural adaptation; flight; landing; dung beetle; nocturnal adaptation; sky compass; straight-line orientation;

    Abstract : Flying, as well as walking insects rely on vision to regulate locomotion, even in the dark when the visual system is much less reliable. To manage visual control of these behaviours at low light intensities, many insects have evolved optical adaptations, such as larger facet lenses and wider rhabdoms, and neural adaptations, such as spatial and temporal summation, to increase their visual sensitivity. READ MORE