. Brigham Young University science bulletin. Biology -- Periodicals. Biological Series, Vol. 10, No. 4. Ecology of Raptorial Birds 33 or summits of low hills. If constructed on the summit of a hill, it is usually situated atop a rock, and if on the side of a hill, a jutting ledge of rocks forming a natural shelf is selected to hold the bulky, loosely-constructed nest in place (Fig. 11). Behle, Woodbury, and Cottam (1943) describe ground nests located along the 1846 route of the Donner Party on the Great Salt Lake Desert north of Knolls, Utah. Tliese nests varied in size up to 6 feet in height
. Brigham Young University science bulletin. Biology -- Periodicals. Biological Series, Vol. 10, No. 4. Ecology of Raptorial Birds 33 or summits of low hills. If constructed on the summit of a hill, it is usually situated atop a rock, and if on the side of a hill, a jutting ledge of rocks forming a natural shelf is selected to hold the bulky, loosely-constructed nest in place (Fig. 11). Behle, Woodbury, and Cottam (1943) describe ground nests located along the 1846 route of the Donner Party on the Great Salt Lake Desert north of Knolls, Utah. Tliese nests varied in size up to 6 feet in height and 9 feet in diameter at the base and were composed of AUenroIfea roots and stems. The second most common type, the juniper nest, closely resem- bles the ground nest. It is usually constructed five to eight feet above the ground (Fig. 12). Nests similar to those found in the present study area are described by Cameron (1914) in Mon- tana and Bowles (1931) in Washington. Bent (1937) describes nests in North Dakota which were situated 40 feet above the ground in tall swamp oaks. Nests I observed were composed of heavy sticks, manure, and other rubbish, and lined with grass, strips of bark, and paper. Wil- liams and Matteson (1947b) recorded a nest lined with paper in Wyoming. They also re- ported that nests located by Wyoming biologists in the year 1S80 were composed almost entirely of dried buffalo bones. During the present study, 17 of 22 active nests were on southern or eastern exposures. These data suggest that nest site preference is influenced by the direction of the sun's rays. Exposure should be important during the earlv spring months. Even in the wanner months of June and July, nests facing south and east might be preferable. Those with easterly exposures would receive the warm morning sun and be shaded in the hot afternoons. McGahan (196S) found that most of the Golden Eagle nests in his study area faced either south or '^r â ^. Please note that these images a
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