The eye of a passeriform bird, the European starling (Sturnus vulgaris): eye movement amplitude, visual fields and schematic optics

1986 ◽  
Vol 159 (4) ◽  
pp. 545-557 ◽  
Author(s):  
Graham R. Martin
Keyword(s):  
Eye Movement ◽  
Visual Fields ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Movement Amplitude

Visual Field Accuracy and Eye Movement Direction: A Child's Eye View

1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Eye Movement ◽  
Visual Fields ◽  
Movement Direction

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.

Effects of an introduced, novel prey on diet and reproduction in the diet-specialist European Starling (Sturnus vulgaris)

2019 ◽  
Vol 97 (3) ◽  
pp. 225-231
Author(s):  
T.D. Williams ◽  
A. Cornell ◽  
C. Gillespie ◽  
A. Hura ◽  
M. Serota
Keyword(s):  
Prey Item ◽  
Brood Size ◽  
Natural Experiment ◽  
Prey Species ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Tarsus Length ◽  
Negative Effects ◽  
Diet Specialization ◽  
Specialized Diet

Diet specialization has important consequences for how individuals or species deal with environmental change that causes changes in availability of prey species. We took advantage of a “natural experiment” — establishment of a commercial insect farm — that introduced a novel prey item, black soldier flies (Hermetia illucens (Linnaeus, 1758)), to the diet-specialist European Starling (Sturnus vulgaris Linnaeus, 1758). We investigated evidence for individual diet specialization (IDS) and the consequences of diet specialization and exploitation of novel prey on breeding productivity. In all 4 years of our study, tipulid larvae were the most common prey item. Soldier flies were not recorded in diets in 2013–2014; however, coincident with the establishment of the commercial insect farming operation, they comprised 22% and 30% of all prey items in the diets of European Starling females and males, respectively, in 2015. There was marked individual variation in use of soldier flies (4%–48% and 2%–70% in females and males, respectively), but we found little evidence of dichotomous IDS, i.e., where only some individuals have a specialized diet. We found no evidence for negative effects of use of soldier flies on breeding productivity: brood size at fledging and chick quality (mass, tarsus length) were independent of the number and proportion (%) of soldier flies returned to the nest.

scholarly journals Global change affects differently at local scales animal populations: why Starlings still expands to the south while other temperate species go to the north?

2021 ◽  
Author(s):  
Alexandra Rodriguez ◽  
Giuseppe La Gioia ◽  
Patricia Le Quilliec ◽  
Damien Fourcy ◽  
Philippe Clergeau
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Distribution Area ◽  
The South ◽  
The North ◽  
Animal Populations ◽  
The World ◽  
Landscape Transformations

Global change, which regroups global warming, landscape transformations and other anthropic modifications of ecosystems, has effects on populations and communities and produces modifications in the expansion area of species. While some species disappear, other ones are beneficiated by the new conditions and some of them evolve in new adapted forms or leave their ancient distribution area. As climate change tends to increase the temperature in several regions of the world, some species have been seen to leave areas in equatorial regions in order to join colder areas either towards the north of the northern hemisphere or towards the south of the southern one. Many birds as have moved geographically in direction to the poles and in many cases they have anticipated their laying dates. Actually, two tit species that use to lay their eggs in a period that their fledging dates synchronize with the emerging dates of caterpillars are now evolving to reproductive in periods earlier than before the climate change. Several species are reacting like that and other ones are moving to the north in Europe for example. Nevertheless, and very curiously, European starling, Sturnus vulgaris, populations are behaving on the contrary: their laying dates are moving towards later spring and their distribution area is moving towards the south. In this study we explore and discuss about different factors that may explain this difference from other birds.

Visual pigments, oil droplets and cone photoreceptor distribution in the european starling (Sturnus vulgaris)

1998 ◽  
Vol 201 (9) ◽  
pp. 1433-1446 ◽  
Author(s):  
N S Hart ◽  
J C Partridge ◽  
I C Cuthill
Keyword(s):  
Visual Pigment ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Visual Pigments ◽  
Double Cone ◽  
Temporal Region ◽  
Oil Droplets ◽  
Tetrazolium Chloride ◽  
Oil Droplet ◽  
Single Cone

Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance (<IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG= "3">max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured oil droplets which cut off light below 572 and 514 nm, respectively. The 449 nm <IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max pigment was associated with a 'colourless' oil droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent oil droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive (<IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT= "12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max 563 nm) visual pigment. The principal member of the double cone contained an oil droplet with a topographically variable cut-off wavelength below 471 nm; the oil droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a <IMG src="/images/symbols/lambda.gif" WIDTH="8" HEIGHT="12" ALIGN="BOTTOM" NATURALSIZEFLAG="3">max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.

Discrimination Between Movements of Eye and Object by Visual Interneurones of Crickets

1969 ◽  
Vol 50 (3) ◽  
pp. 723-732
Author(s):  
JOHN PALKA
Keyword(s):  
Eye Movement ◽  
Voluntary Movement ◽  
Compound Eye ◽  
Visual Fields ◽  
Object Motion ◽  
Visual Environment ◽  
Inhibitory Mechanism ◽  
Object Movement ◽  
Moving Stimulus ◽  
Homogeneous Environment

1. One large neurone on each side of the cervical and thoracic ventral nerve cord of crickets responds to object motion anywhere in the visual field of the ipsilateral compound eye, but not to the forced or voluntary movement of the eye itself. 2. This discrimination between self-movement and object-movement is accomplished by an inhibitory mechanism mediated by the same eye. 3. Inhibition must be present because a potent moving stimulus becomes ineffective if presented during a forced eye movement. 4. Its visual origin is demonstrated in two ways: (a) abolishing all known mechanosensory feedback does not disrupt the mechanism, but (b) alteration of visual conditions does so in a predictable way. Sweeping the eye past a complex visual environment suppresses the neurone's response to a concurrently or subsequently presented moving target, whereas the same movement past a simplified or homogeneous environment produces little or no inhibition. 5. Responses to eye movement itself are greatly enhanced in appropriately simplified visual fields, reinforcing the conclusion that the inhibition preventing response in complex fields is of visual origin. 6. Suggestive evidence for an additional inhibitory mechanism associated with voluntary movement is presented.

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