PRUESER] THE MOURNING DOVES 263 



the waste fields and meadows furnish seeds for them. Wood 

 sorrel, bam grass and prairie grass seeds are eaten in large quanti- 

 ties. In the stomach of one dove, more than 7,000 seeds of wood 

 sorrel (oxalis strict a) have been found. I do not know of any bird 

 that is a better exterminator of that prolific weed than the mourn- 

 ing dove. 



So often mourning doves are mistaken for passenger pigeons 

 which are now rarely seen at all in this country, but at one time 

 were very numerous. Their nesting colonies in the northern 

 woods, numbered into the thousands. It is possible that there are 

 a few isolated pairs of pigeons in northern Michigan and Wisconsin. 

 Mourning doves can readily be distinguished from the passenger 

 pigeons by their size. They are about a foot long whereas the 

 pigeon measures nearly seventeen inches. Another marked differ- 

 ence is that the pigeon's back is a grayish blue, the dove's grayish 

 brown. The males of both doves and pigeons have the irridescence 

 on the sides of the neck. The nests are much alike, a mere plat- 

 form of rough sticks. The pigeon arranges her twigs in a tree, 

 preferably near streams and lakes, while the dove is more likely to 

 lay her irregular wreath of sticks on the ground. 



The Los Angeles Nature-Study Exhibition 



Charles Lincoln Edwards 



The second annual nature-study exhibition of the Los Angeles 

 City Schools was held June 6th. Throughout the day a constant 

 stream of school children and their parents attested the interest 

 aroused by this subject in the 75,000 pupils of the grammar schools. 



In order to emphasize certain lines of the work, ten prize awards 

 were made. During the year a nature club had been organized in 

 each of the 127 grammar schools, with the purpose of going on field 

 excursions, collecting animals and plants and building up school 

 museums. In order that the collecting instinct might be properly 

 guided, the friends of man — like toads, horned lizards, snakes and 

 birds — ^were protected, and if taken from the field, were kept in 

 live-boxes for observation. On the other hand harmful animals — 

 like many of the insects — were preserved and their life-histories 

 and economic relations demonstrated. 



