Roadkill refers specifically to animals, not humans or objects, that have died due to traffic. The vultures were feeding on the roadkill.
Pro Tip 2/3
Caution Indicator
Mentioning roadkill can warn drivers to be more attentive to their surroundings. Driving through wooded areas at night increases your chance of encountering roadkill.
Pro Tip 3/3
Sensitive Subject
Some people might find the topic of roadkill upsetting or uncomfortable. She changed the subject quickly when her brother started talking about the roadkill they saw.