The Pocket Gopher. 143 



any such special trap should be about three inches beyond the 

 choker, so that when the former is tripped by pressure of the 

 earth the animal will have his neck well in the noose. 



The "California" gopher trap and the "0. K." gopher trap 

 are almost identical in appearance and design. Both are easily 

 and quickly set, and good results are obtainable by the use of 

 either one. Each consists of a small box with one end open 

 for the entrance of the gopher's head. At the opposite end of 

 the box a small hole is bored to admit a ray of light. The box, 

 when the trap is set, practically forms a continuation of the 

 burrow. It should be placed with the open end close up to the 

 opening into the lateral and the line of contact between trap 

 and lateral sealed with a few handf uls of earth so that no light 

 may reach the burrow except through the small hole in the end 

 of the box. The trigger is skeleton in form so as not to ob- 

 struct this light, and depends vertically from the center of the 

 box. 



The "Out 0' Sight" gopher trap is built like the "California," 

 except that the sides and end of the box have been omitted 

 simply the roof is left for the attachment of the working parts. 

 This trap is to be set in the same manner as the two just de- 

 scribed, but one end has to be supported by means of a small 

 stick laid across the opening into the burrow and sods must be 

 used to exclude all light, except the ray which is to attract the 

 attention of the gopher. Plainly the disadvantage in the use 

 of this trap is in the greater length of time required to set it, 



The "Newhouse" gopher trap is entirely of steel. It is ar- 

 ranged to trip in the same way as the other, but instead of a 

 choker it has three sharp prongs which strike down into the 

 neck of the animal. It is the least efficient of all of the makes 

 of special gopher traps we have tried. If properly set it must 

 be supported by a stick at one end, and so covered by sods as to 

 leave only a small chink open. It is so light that a gopher 

 coming with his load will upset it oftener than spring it. The 

 small size of the trap also permits it t to be drawn back into the 

 burrow if the animal is caught. In this way we lost half of our 

 traps the first week of our experiments. If used at all they 

 should be secured with chain and stake. A few experiments 

 seem to indicate that this trap gives much better results when 

 used in the smaller burrows of the plains pocket gopher. 



The best time to trap is in the spring and fall, particularly 



