DIRECT SEEDING. 37 



palatable than grain. In many cases it is their natural food, and they 

 are wonderfully diligent and expert in searching it out. Many ex- 

 periments in the direct seeding of hardwoods and conifers have failed 

 because nearly all of the seed was eaten by mice, chipmunks, and other 

 animals. Where tree seed attractive to rodents is to be sown it is neces- 

 sary, therefore, to consider the systematic poisoning of the area as an 

 essential operation. In the experiment conducted at the Coconino 

 Experiment Station seed spots were sown to yellow pine and then 

 covered with small portable screens which effectively protected them 

 from rodents and birds. The successful germination in these spots 

 and the absolute failure in similar unprotected spots adjacent showed 

 how important an adverse factor animals are in reforestation. 



In the spring of 1910, in cooperation with the Biological Survey, 

 intensive studies of the damage from rodents were conducted at a 

 number of places where direct seeding was in progress, while on 

 many other sowing areas observations were made by Forest officers. 

 In nearly every case a different species of animal was found to be the 

 chief cause of damage. There are, of course, a great many species 

 of mice, chipmunks, and ground squirrels, and a number of different 

 kinds of tree squirrels. Each species appears to have distinctive 

 habits, while the food and activities of the same species differ greatly 

 with the time of year. The kind of poison bait and the manner of 

 applying it must, therefore, be adapted not only to the species of 

 animal to be destroyed, but to the taste and activities at the time the 

 poisoning is done. 



In a certain locality on the Black Hills Forest, in the spring of 

 1910, where 600 acres were to be sown to Austrian pine, yellow pine, 

 and Scotch pine, it was found that white-footed mice of the genus 

 Peromyscus were gathering and eating from 20 to 25 per cent of the 

 seed, while in another locality on the same Forest chipmunks (Euta- 

 mais quadrivittatus} proved to be the important factor in the seed- 

 ing operations. With the assistance of experts from the Biological 

 Survey these pests were greatly reduced in numbers and their depre- 

 dations practically stopped by means of poisoning. Chipmunks of 

 one species or another are abundant in most of the National Forests, 

 ground squirrels are common arid troublesome, and mice, especially, 

 of the genus Peromyscus, constitute a widespread pest. With the 

 systematic use of poison, however, these pests can be so reduced as to 

 be practically harmless. A good formula for poisoning chipmunks 

 and ground squirrels is the following, which was recommended by 

 the Biological Survey and has been used with good results : 



Strychnia sulphate 1 ounce. 



Saccharin 1 teaspoonful. 



Gloss, or laundry starch I cupful. 



Water 1 quart. 



Barley " 20 pounds. 



