1. Curiosity: The blackbird might simply be curious about the car and its occupants. Birds are known for their curiosity and may approach objects or people to investigate them.
2. Familiarity: If the car is parked in an area where blackbirds are common, the bird may be familiar with the surroundings and not perceive the owner, girlfriend, or the car as a threat.
3. Comfort: The blackbird might find the car to be a comfortable spot to perch. The car's surface may provide warmth or a good vantage point for the bird to observe its surroundings.
4. Territorial Behavior: If the blackbird considers the area around the car as its territory, it might be asserting its dominance by staying put even when approached by the owner or girlfriend.
5. Imprinting: It's possible that the blackbird may have imprinted on the adult, seeing them as a parental figure. This can happen if the adult has been consistently providing food or other resources for the bird.
6. Misidentification: The blackbird might mistake the owner or girlfriend for a potential source of food or shelter, especially if they are holding or wearing something that resembles food or nesting materials.
7. Stress or Injury: If the blackbird is stressed or injured, it might exhibit unusual behavior, such as not being scared off by humans.
8. Cultural Significance: In some cultures, blackbirds are considered symbolic or spiritual creatures, and their presence may be interpreted as a sign or message.
It's important to note that bird behavior can be influenced by various factors such as their species, personality, past experiences, and the specific context of the situation. Without further observations or information, it's difficult to determine the exact reason for the blackbird's behavior in this particular case.