The crow presented in a bad state. He was shaking incredibly hard, while his eyes rapidly flickered open and shut and his beak chattered uncontrollably. While I was holding the crow, he wrapped his toes around my fingers, and I could feel the heat his small body was putting off: he had a very high fever, to boot.
While the intense tremors could be a sign of spinal trauma, his high fever indicated the likelihood of toxins in the bird's system, which can cause both tremors and a high temperature. What the toxins were, we don't know. He could have feasted on a rotten bit of food, or ingested some kind of chemical or oil left out or dumped by a human.
Luckily, with a few doses of activated charcoal mixed with sterile water, the crow's body was able to rid itself of the toxins. His fever and tremors were completely gone less than 24 hours after being admitted into our care. The crow is recovering nicely and is a likely candidate for release back into the wild.