VIGORS' S WREN 195 



mens of the California races of Bewick's wrens, taken in every month 

 of the year. A little more than 97 percent of the food consisted of 

 insects and less than 3 percent of vegetable matter. Six stomachs 

 contained seeds, and one held what was supposed to be fruit pulp. Of 

 the animal food, various bugs (Hemiptera) were the largest item, 31 

 percent; these included the black olive scale, a very injurious species, 

 leaf bugs, stink bugs, shield bugs, leaf hoppers, treehoppers, and jump- 

 ing plant lice. Beetles (Coleoptera) amounted to over 21 percent of 

 the food; ladybirds were the only useful beetles eaten, but they 

 amounted to only 3 percent, against 10 percent of harmful weevils ; the 

 stomachs of two wrens contained 85 and 80 percent of engraver beetles, 

 which live under the bark of trees and do much damage to the timber ; 

 other beetles, mostly leaf beetles, were eaten to the extent of 8 percent. 

 Ants formed about 7 percent and wasps 10 percent of the food. Cater- 

 pillars and a few moths and some cocoons constituted a little less than 

 12 percent and grasshoppers 4 percent of the wren's diet. Very few 

 flies were eaten, and spiders made up more than 5 percent of the 

 total food. 



Eegarding the feeding habits of Vigors's wrens, Mr. Miller (1941) 

 writes: "Foraging takes place on the ground and on the limbs and 

 foliage of bushes and trees. In foraging, the birds use their bill for 

 picking insects off leaves and branches, for flicking over leaves on 

 the ground and, less commonly, for digging insects from cracks in 

 bark. They do not scratch for food. They forage rapidly, and this 

 activity takes up the larger part of their time. The method of forag- 

 ing varies in accordance with the size and distribution of the plants 

 in their habitat. In early spring the male of a mated pair forages 

 high up in brush and trees, and his mate forages low down in brush 

 and weeds." 



Behavior. — ^Mr. Miller says: "The relations of Bewick Wrens to 

 other vertebrate animals of their habitat are mostly neutral. They 

 probably are preyed upon to a slight extent by bird-hawks and owls. 

 Where the wrens nest about buildings in suburban areas, they some- 

 times have conflicts over nesting sites with House Wrens, titmice, and 

 other small birds. Under these circumstances the Bewick Wrens 

 usually retreat. Some individuals have been found roosting in cav- 

 ities. Bathing in both dust and water occurs." 



Laidlaw Williams (1941) has published an interesting paper on the 

 roosting habits of chestnut-backed chickadees and Bewick's wrens. The 

 wrens used two types of roosts, on the sides of buildings and beneath 

 a canopy of fallen dead needles on a Monterey pine bough. On the 

 side of one building the wren roosted in a vertical crack between two 

 rustic slabs of bark, resting on a horizontal slab over a window ; on four 

 rainy nights a wren roosted on a wire under the eaves of a house and 



