# City songbirds sing in higher pitch?

In this What I've Learnt Youtube video How Did Language Begin starting at the marked point, the author claims that the songbird in the city uses higher pitch to reduce echo bouncing. He later also claims that the indigenous people in the mountainous regions use whistle language to communicate to increase sound propagation distance. That runs counter to the fact that longer wavelength wave scatters less by obstacles of the same size. How does one reconcile the apparent contradiction?

that means the wavelength is $$\frac{343 m/s}{85 hz}=4,035 m$$ which is less than the size of a mountain or a building so by the effect and the situation you mentioned there wouldn't be a difference in the echo whether the wavelength is high or low