Those small birdhouses are often made from wood or  plastic . They are often made by local school or kindergarten students . I don’t think that there are birds that still live there
<a href="//commons.wikimedia.org/w/index.php?title=User:Nevermind_08&amp;action=edit&amp;redlink=1" class="new" title="User:Nevermind 08 (page does not exist)">Nevermind 08</a>
<span class="int-own-work" lang="en">Own work</span>