The range of frequencies at which birds call in an environment varies with the quality of habitat and the ambient sounds. The acoustic adaptation hypothesis predicts that narrow bandwidths, low frequencies, and long elements and inter-element intervals should be found in habitats with complex vegetation structures (which would absorb and muffle sounds), while high frequencies, broad bandwidth, high-frequency modulations (trills), and short elements and inter-elements may be expected in open habitats, without obstructive vegetation.    Low frequency songs are optimal for obstructed, densely vegetated habitats because low frequency, slowly modulated song elements are less susceptible to signal degradation by means of reverberations off of sound-reflecting vegetation. High frequency calls with rapid modulations are optimal for open habitats because they degrade less across open space.   The acoustic adaptation hypothesis also states that song characteristics may take advantage of beneficial acoustic properties of the environment. Narrow-frequency bandwidth notes are increased in volume and length by reverberations in densely vegetated habitats. 
When Team Israel at the 2017 World Baseball Classic 's outfielder Cody Decker brought the team's mascot, "Mensch on the Bench", a five-foot-tall stuffed toy that looks a bit like a rabbi or Hasidic Jew, with him to Asia from the United States for the WBC, Decker said, "He’s a mascot, he’s a friend, he’s a teammate, he’s a borderline deity to our team.... He brings a lot to the table.... Every team needs their Jobu . He was ours. He had his own locker, and we even gave him offerings: Manischewitz , gelt , and gefilte fish ... He is everywhere and nowhere all at once. His actual location is irrelevant because he exists in higher metaphysical planes. But he’s always near."    
As someone who deeply enjoys both dudes’ styles of play, it’s a cool drop of relief to see them shut up the skeptics and sustain good tennis for a whole week to make a final of this magnitude. But as someone who has watched both long enough to know, I would not go so far as to confidently project big things for either at the . Open, which begins next week. They’re just a little too volatile for any bold predictions. Just hold out modest hope and believe it when you see it. The unending Federer-Nadal show has been pleasant enough, but, c’mon—let them duel for year-end No. 1 and leave this dang thing for someone else. It’s bizarre to see it in writing, but in 2017 the most radical outcome might simply be someone in their 20s lifting a major trophy.