ArticleJournal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology2014
Retinal ganglion cell topography and spatial resolution of two parrot species: budgerigar (Melopsittacus undulatus) and Bourke's parrot (Neopsephotus bourkii).
Article in Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.
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8 citing papers in PubMed.
- Eye Morphology, Foveal Structure and Photoreceptor Composition in Both Foveae of Common Kestrel (Biology · 2026Article
- Humpback whale (Proceedings. Biological sciences · 2025Article
- Ecological and morphological correlates of visual acuity in birds.The Journal of experimental biology · 2024Review
- Close to Optimal Cell Sensing Ensures the Robustness of Tissue Differentiation Process: The Avian Photoreceptor Mosaic Case.Entropy (Basel, Switzerland) · 2021Article
- What Drives Bird Vision? Bill Control and Predator Detection Overshadow Flight.Frontiers in neuroscience · 2017Review
- Change of ultraviolet light transmittance in growing chicken and quail eyes.Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology · 2016Article
- How Lovebirds Maneuver Rapidly Using Super-Fast Head Saccades and Image Feature Stabilization.PloS one · 2015Article
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Abstract
Retinal ganglion cell (RGC) isodensity maps indicate important regions in an animal's visual field. These maps can also be combined with measures of focal length to estimate the theoretical visual acuity. Here we present the RGC isodensity maps and anatomical spatial resolving power in three budgerigars (Melopsittacus undulatus) and two Bourke's parrots (Neopsephotus bourkii). Because RGCs were stacked in several layers, we modified the Nissl staining procedure to assess the cell number in the whole-mounted and cross-sectioned tissue of the same retinal specimen. The retinal topography showed surprising variation; however, both parrot species had an area centralis without discernable fovea. Budgerigars also had a putative area nasalis never reported in birds before. The peak RGC density was 22,300-34,200 cells/mm(2) in budgerigars and 18,100-38,000 cells/mm(2) in Bourke's parrots. The maximum visual acuity based on RGCs and focal length was 6.9 cyc/deg in budgerigars and 9.2 cyc/deg in Bourke's parrots. These results are lower than earlier behavioural estimates. Our findings illustrate that retinal topography is not a very fixed trait and that theoretical visual acuity estimations based on RGC density can be lower than the behavioural performance of the bird.
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