This couple of falcons, which have nested under the tiled roof of a block of flats, mate on the TV antenna on top of the roof, making a characteristic squeaking sound. In spring, this happens very often indeed (several times a day).
<a href="//commons.wikimedia.org/wiki/User:Annatsach" title="User:Annatsach">Annatsach</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>