Why Vultures are the only full time Scavengers?
While most carnivores scavenge on occasion, few species can make a living of it. Infact, among all known vertebrates, only vultures are the obligate scavengers. How did vulture manage to thrive on a lifestyle that no other vertebrate has figured out ?
Large Soaring fliers: Aerial scavengers outcompete land based ones mainly because their height and vision allows them to scan much more rapidly for a carcass. Soaring is hugely beneficial over flapping flight even after accounting for reduced speed as soaring allows vultures to cover vast distances with minimal energy.
Social Network: Vultures are plugged into their scavenger social network and look to other vultures to spot aerial thermals. These thermals can be often fickle and inconsistent but with right thermal they can just spread their wings and soar. Social networks also provide information on carcasses as they look for other vultures returning from a meal or descending onto a carcass from a great distance.
Corrosive Acids: Vultures stomach acid is more acidic than car battery acid and about 100 times more acidic than human gastric juice. This allows them to safely digest rotting carcasses that contain toxins and bacteria like cholera/anthrax that could be lethal even to other scavengers
This high ratio of information gain to energy spent and powerful gastric juices along with other adaptations have allowed vultures to live as full-time scavengers, while other species can only manage it part time.