Bird populations declining due to drought and heatwaves

Hi everyone, I’ve noticed in the last few weeks the number and variety of birds seem significantly down. In my garden I’ve only seen wood pigeons and the odd magpie (I leave out water and change it daily and have a small wildlife pond). Literally not seen a song bird anywhere for weeks and it seems significantly quieter and (no bird song). Has anyone else noticed this? And is it due to the weather and drought. Many thanks