NATURAL HISTORY OF THE SWAINSON'S WARBLER 59 



more closely took parts of 3 days, mostly between 7 and 11 a.m. 

 Building was resumed in the late afternoon of each day between 

 4 and 5 p.m. However, during the late afternoon building period 

 no more than half a dozen trips were made to the nest each day. 

 The female made between 100 and 125 trips each morning. From 

 9:25 to 10 a.m. one morning, she made 34 trips, an average of 

 about one trip a minute. During any sustained period she spent an 

 average of 24 seconds at the nest, with a range of 9 to 70 seconds. 

 The female sometimes chipped a few times while working on the 

 nest. During the nest-building period, her mate rarely sang after 

 8 a.m. 



All nest materials were gathered from the ground vnthin 30 

 feet of the nest. Dry leaves, used in the bulky part of the nest 

 and the outer layer, were obtained from the drier part of the 

 woods ; the cypress needles and red maple flower pedicels used in 

 the lining came from a wet spot near the nest site. 



Nests are constructed of a rather wide assortment of materials, 

 but there is a selection of certain plant parts. The number of 

 species of plants represented in a nest depends somewhat on the 

 composition of the forest in which the nest is located. There sel- 

 dom were more than a dozen species of plants in the nests I ex- 

 amined. The number of plant pieces in a Pendleton Ferry, Ark., 

 nest totaled 418; there were 323 in a Dismal Swamp nest. The 

 most pieces were in the lining of the cup. Sticks are seldom used 

 in nests, and the few that occur seem almost incidental. But the 

 first of three nests built by a female in a single season in the 

 Dismal Swamp contained a great many sticks, which is the reason 

 why it weighed more than the second and third nests. 



In canebrakes the foundation of a nest is often a bunch of dead 

 leaves that have lodged in the axils of a cane stalk. The Dismal 

 Swamp female that built three nests used the relatively large 

 leaves of the swamp magnolia as a platform for each of them. 

 Each was at a site where several greenbrier vines crossed a hori- 

 zontal limb of a shrub, so that the half dozen magnolia leaves 

 formed a rather level base. Deposited upon these magnolia leaves 

 were dried leaves, sticks, vines, and tendrils that formed the 

 rather loose outer layer of the nest. Most of the leaves were 

 swamp magnolia, red maple, red bay, and greenbrier. Most of the 

 sticks were greenbrier. 



The next layer was more compact, consisting almost entirely 

 of decomposed or skeletonized leaves of the swamp magnolia. 

 This layer formed the outer shell of a cup composed of finer 

 materials in which the eggs were deposited. In positioning the 



