Researchers at the Natural History Museum in London have unveiled a method to infer what extinct vultures and other birds of prey typically ate. The findings were published in the Journal of Zoology (JOZ).
By comparing the skulls of 22 living vulture species, the study showed that bone morphology is a reliable predictor of each species’ preferred feeding approach.
Today, the vulture lineage comprises 23 recognized species, split into two distinct families. Afro-Eurasian vultures belong to the Accipitridae family, which also includes golden eagles and hawks. The North American vultures form the Cathartidae family, among which the California condor is a notable member.
Despite evolving separately, members of these two groups often specialize in different parts of a carcass. Researchers categorize their feeding strategies into three roles: rippers, swallowers, and scrapers.
Rippers consistently tackle tough materials such as leather and sinew. Swallowers focus on softer innards like intestines and other internal organs, while scrapers target inedible portions of the remains.
Such specialization in carcass-part preferences enabled various vulture species to coexist and evolve without direct competition for the exact same food source. In turn, skull and beak morphology adapted to support these divergent diets.
The study found that the skull shapes of vultures fall into three groups that align with distinct feeding habits. Predators develop broader skulls and stronger beaks suited for tearing through hard tissues, scrapers possess the thinnest beaks designed to collect small debris, and gobblers feature a relatively narrow skull with a longer beak, optimized for accessing soft interiors.
When the researchers examined eight non-vulture birds of prey that inhabit similar ranges and environments, their skulls appeared markedly more uniform in shape and less diverse than those of scavengers.
In a final note, the researchers discuss how skull variation among scavenger birds reflects ecological adaptations that reduce direct competition and support a range of feeding strategies within shared habitats.