Scotopic and photopic vision in the california ground squirrel: Physiological and anatomical evidence

1976 ◽  
Vol 165 (2) ◽  
pp. 209-227 ◽  
Author(s):  
Gerald H. Jacobs ◽  
Steven K. Fisher ◽  
Don H. Anderson ◽  
Martin S. Silverman
Keyword(s):  
Ground Squirrel ◽  
California Ground Squirrel ◽  
Photopic Vision ◽  
Anatomical Evidence

Directional filter characteristics of optic nerve fibers in California ground squirrel (Spermophilus beecheyi)

1984 ◽  
Vol 52 (6) ◽  
pp. 1200-1212 ◽  
Author(s):  
M. E. McCourt ◽  
G. H. Jacobs
Keyword(s):  
Optic Nerve ◽  
Ground Squirrel ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Nerve Fibers ◽  
Field Size ◽  
Image Motion ◽  
Spermophilus Beecheyi ◽  
California Ground Squirrel ◽  
Preferred Direction

Directional units in the optic nerve of the California ground squirrel (Spermophilus beecheyi) were studied with respect to their response to diffuse light, preferred directions of motion, tuning for preferred direction, the relationship between spatial and directional tuning characteristics, and receptive-field size and areal summating properties. Directional units in the ground squirrel optic nerve are of the “on-off” type. No purely on or off units were encountered in a sample of 356 directionally selective fibers. The distribution of preferred directions of image motion for 356 units was significantly anisotropic; greater than 50% of the directional units prefer motion in the direction of the superior-nasal visual quadrant. Mean directional bandwidth, measured at half-amplitude response, for 39 units was 88.5 degrees. The distribution of directional bandwidths suggests that two subpopulations of directional units may exist a broadly tuned (106.4 degrees bandwidth) group preferring image motion in the superior-nasal direction, and a narrowly tuned group (59.9 degrees bandwidth) with a uniform distribution of preferred direction. Tuning for direction of motion and for spatial frequency were significantly positively correlated in a sample of 35 directional units. Area-vs.-response measures for directional units show that they possess excitatory discharge centers with a concentric antagonistic surround, plus a larger suppressive surround activated specifically by moving luminance contours, which may be asymmetric. Critical activation areas for directional units, as measured along orthogonal orientations, were highly positively correlated. This suggests that these receptive fields possess the property of linear spatial summation, not of luminance flux, but of areas of moving luminance contours.

California Ground-Squirrel Trapping Influenced by Anal-Gland Odors

1989 ◽  
Vol 70 (2) ◽  
pp. 428-431 ◽  
Author(s):  
T. P. Salmon ◽  
R. E. Marsh
Keyword(s):  
Ground Squirrel ◽  
Anal Gland ◽  
California Ground Squirrel

The California Ground Squirrel

Nature ◽  
1946 ◽  
Vol 158 (4022) ◽  
pp. 771-772
Author(s):  
E. HINDLE
Keyword(s):  
Ground Squirrel ◽  
California Ground Squirrel

Ecology of the California Ground Squirrel on Grazing Lands

Ecology ◽  
1949 ◽  
Vol 30 (1) ◽  
pp. 112
Author(s):  
E. Raymond Hall ◽  
Henry S. Fitch
Keyword(s):  
Ground Squirrel ◽  
California Ground Squirrel ◽  
Grazing Lands

scholarly journals Use of zinc phosphide for California ground squirrel control

2000 ◽  
Vol 19 ◽  
Author(s):  
Terrell, P. Salmon ◽  
Desley, A. Whisson ◽  
W., Paul Gorenzel
Keyword(s):  
Ground Squirrel ◽  
Zinc Phosphide ◽  
California Ground Squirrel
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