Birds and human figures feature throughout the abstract periods of this artist, and towards the end of his career he would start to merge them together into a fantastical, dream-like set of creatures which were fairly easy for him to produce, because they were just an extension of what had gone before. He was closely related to the Surrealists at times in his career, and this use of imagination was another example of that. They were most famous for re-arranging items from reality, rather than producing entirely fictional things such as this. Miro himself never desired to be a part of any specific art movement, officially, but he did respect other artists and clearly displayed strong influences from different movements at different times in his career, including impressionism, modernism, cubism and surrealism.
This massive piece took a long period to complete. The artist is known to have worked on it from 1972 to 1978 and the design is created from a complex glass mosaic. It was a highly ambitious project which he would not have taken on earlier in his career. Perhaps he felt that many avenues of his career had already been covered, time and time again, and so a new challenge was needed as his career was coming to a close. Health can also limit artists in their later years, where an adjustment will often need to be made in terms of the materials used and also the level of productivity. We all remember Matisse's cut-outs, some of which he completed whilst confined to a wheelchair. We must also remember the extraordinary Frida Kahlo's whose paintings were produced in spite of health issues which sadly lasted most of her lifetime.