Very thought-provoking and beautifully written. Likely will need at least one full reread to get the most out of it due to the complex format.
In half of the text, Cisco reimagines Spinoza's Ethics from a bird's-eye view (har). Rather than thinking about god and inner life, birds would focus on the areas most important to them (finding a mate with a song, hatching, brooding, etc.). It's a cool idea. This Spinoza approach necessarily entails a lengthy, dry series of definitions, axioms, etc. I loved the idea, but it is dense and challenging. I can imagine it was a fun exercise to create it, but it was not as fun to read through the final result.
In the other half of the text, Cisco writes a beautiful series of scenes narrating the inner lives of a few individual birds (most importantly a songbird and a cuckoo). The drama that plays out between the birds spans the full range of what we typically think of as human emotions (love, longing, loss, greed, anger, obliviousness, suffering, rebirth). It's very interesting to imagine these birds living lives as full as ours, with unique personalities and experiences. Some may even invent whole philosophies of life, though without the ability to write anything down to share with each other.
Well worth checking out and taking slowly so you can soak it all in!