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- Golden eagles usually mate for life. A breeding pair is formed in a courtship display. This courtship includes undulating displays by both in the pair, with the male bird picking up a piece of rock and dropping it only to enter into a steep dive and catch it in mid-air, repeating the maneuver 3 or more times. The female takes a clump of earth and drops and catches it in the same fashion. Small sticks may also be used in this display. Compared to the bald eagle, golden eagles do not repeat courtship displays annually (which is believed to strengthen pair bonds) and rarely engage in talon-locking downward spirals. Golden eagles typically build several eyries within their territory and use them alternately for several years. Their nesting areas are characterized by the extreme regularity of the nest spacing. In 9 studies of annual nest spacing, the average minimum distance between nests range from 16 km (9.9 mi) apart in Norway to 8 km (5.0 mi) apart in Switzerland. Nests in Scotland may found at anywhere from 10 to 65 pairs per 1,000 km2 (390 sq mi), with an average of over 20 pairs found per area. In much of continental Europe, densities of less than 10 pairs per 1,000 km2 (390 sq mi) are typical. In the United States different areas had from 10 to more than 20 pairs on average per 1,000 km2 (390 sq mi). Wyoming had the greatest densities of breeding golden eagles of any complied study, though numbers were comparable to western Scotland as there were an average of just over 20 pairs per 1,000 km2 (390 sq mi), with greatest estimated densities of possibly 125 per area. In Wyoming, the distance between nests ranged from 3.1 to 8.2 km (1.9 to 5.1 mi), averaging 5.3 km (3.3 mi). In the wooded peatlands of Sweden and Belarus, a maximum of 5 pairs appear to occur per 1,000 km2 (390 sq mi). In Quebec, the distance between nests ranged from 8 to 44.7 km (5.0 to 27.8 mi). In the Snake River canyon in Idaho, nests are 5 to 8 km (3.1 to 5.0 mi) apart, while two other nearby studies in Idaho found the average distance were 4.3 km (2.7 mi) and 4.39 km (2.73 mi), respectively. The nesting density for a breeding population near Livermore, California, and the Altamont Pass Wind Farm is among the highest in the world for golden eagles, with at least 44 pairs in 1997, a density of one pair per 19 km (12 mi). Due to the consistency of use by golden eagle pairs, population densities change generally happens only quite gradually. (en)
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