World No. 1 Serena Williams acknowledges the crowd after winning her match against Monica Niculescu of Romania during the BNP Paribas Open at Indian Wells Tennis Garden in Indian Wells, Calif. Charls Baus/CSM /LANDOV hide caption

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Rafael Nadal (right) shakes hands with Tim Smyczek after winning a match at the Australian Open on Jan. 21. Rob Griffith/AP hide caption

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Imogen Davis catches Rufus, a Harris hawk, in the stands above Centre Court at Wimbledon. Rufus scares off pigeons who try to eat the ryegrass on the tennis courts. Peter Macdiarmid/Getty Images hide caption

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Stanislas Wawrinka of Switzerland kisses the Australian Open trophy during the awarding ceremony after winning the men's singles final against Spain's Rafael Nadal on Sunday in Melbourne, Australia. Xu Yanyan/Xinhua/Landov hide caption

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Li Na of China celebrates after defeating Dominika Cibulkova of Slovakia during their women's singles final at the Australian Open tennis championship in Melbourne, Australia, on Saturday. Rick Rycroft/AP hide caption

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Rafael Nadal of Spain celebrates after defeating Roger Federer of Switzerland during their semifinal Friday at the Australian Open tennis championship in Melbourne. Aaron Favila/AP hide caption

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Novak Djokovic of Serbia wipes the sweat from his face during his quarterfinal loss to Stanislas Wawrinka of Switzerland at the Australian Open tennis championship in Melbourne. Aaron Favila/AP hide caption

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