A hummingbird bobs up and down beside a tree in a simple SVG scene, with a light blue sky and green foliage providing the backdrop. The animation relies on D3 v7's `transition` method to move the bird’s `cy` attribute between two vertical positions in a looping sequence. The example uses basic SVG shapes—`rect` and `circle`—and demonstrates a minimal, self-contained D3 animation without external data sources or complex rendering.