The phrase “born of desperation” impacts the tone of the passage by conveying a sense of sorrow and urgency surrounding Federigo's actions. It suggests that his decision to sacrifice the falcon was not a frivolous one, but rather a profound act driven by a deep and somewhat hopeless yearning for Monna Giovanna’s affection. This reflects both the nobility and the tragic nature of his love, emphasizing that his extreme act was not simply about impressing her but stemmed from a place of emotional distress and longing. Therefore, the most fitting interpretation is:
The phrase conveys a sense of hopelessness and selflessness in Federigo’s actions, indicating that his love for Monna Giovanna led him to make a sacrifice out of a sense of urgency or need.