EI 



E 



■"""II III! 



2C 



"5~~t= 



Opening - 10 cm 



2m 



2B 





I 



15cm 



H 



15 cm 

 old down fork 



Figure 2.— Restraint devices used to immobilize small to medium sized fur seals. A) A bar with 

 a deep yolk which restrains by preventing the animal from backing up. B) A bar with a shallow 

 yolk which restrains by pressing down on the seal's neck. C) A hold-down fork that pins the 

 animal's head to the ground using hand pressure only. D) A board with "V" notches which 

 wedge behind the skull and prevent the animal from backing up. 



This bar provides restraint by producing downward pressure on the 

 animal's neck. The sides of the inverted U and wooden yoke prevent 

 the animal from turning its head from side to side, so that the animal 

 can escape only by "backing out" of the bar Downward pressure on 

 the bar may restrict the animal's air passage, and inhibit breathing. 

 For this reason one person must always attend the seal, varying the 

 pressure on the bar to maintain a balance between restraint and 

 asphyxia. This person must be familiar with symptoms which seals 

 display under physical and physiological stress. This device is strong 

 and portable, but large, strong seals can stand up with the restraint 

 bar around their necks. 



Another version of the restraint bar (Fig. 2d) uses a plywood board 

 with two vertical plywood "blades" attached to one end. The upper 

 blade is hinged at one side and passes in front of the attached lower 

 blade when closed. Each blade has a 65° angle V notch, 20 cm (8 in) 

 deep, cut in its center so that the closed blades create a diamond 

 shaped opening. Restraint results from the opening being adjusted 

 around the neck so that the skull cannot be withdrawn backward 

 through the diamond. The upper blade can be tied in place, and straps 

 can be placed over the seal so that the animal need not be attended 

 continually. The seal's airway cannot be obstructed by downward 

 pressure because of the depth of the lower V notch. This board can be 



