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Vultures

Susie Kasielke

Natural History

The Old World vultures are classified in the family Accipitridae, now in the order Accipitriformes,
while the New World vultures are classified in the family Cathartidae, now in the order
Cathartiformes (Table 19.1). Both families were formerly included in the order Falconiformes but
have recently been reclassified based on genetic and morphological characteristics (Gill and
Donsker 2019). Their natural history strategies are the result of convergent evolution as the fami-
lies are not closely related.
Both Cathartid and Accipitrid vultures are obligate scavengers, spending much of their time
soaring at great heights to watch for activity on the ground that might indicate a feeding opportu-
nity. They often feed together in large numbers in a guild of avian scavengers that may include
other vultures, eagles, storks, and/or corvids. They also compete with mammalian scavengers such
as coyote, jackal, fox, hyena, and bear. Their foraging strategy relies on a high degree of learned
behavior, with young birds remaining with their parents for a year or more as they absorb the for-
aging traditions of the population.
These large vultures are long-lived, with both species of condor as well as the King Vulture often
living more than 50 years in captivity. Andean Condors have been recorded to have lived as long as
70 years and males have produced offspring as late as 50 years. For both families, age-related dis-
ease and reproductive senescence have been documented infrequently and primarily in birds taken
from the wild at unknown ages.
In Cathartid vultures, males are slightly larger than females and all but the Andean Condor are
essentially monomorphic, although there are subtle differences in adult coloration between gen-
ders. All are primarily cliff nesting, utilizing sheltered ledges and caves, or occasionally open hol-
lows in large trees, with no added nest material.
The California Condor is critically endangered due largely to habitat loss and lead poisoning.
Thanks to captive propagation and other intensive management efforts, there are now over 500
birds, more than half living in the wild with many pairs breeding. The Andean Condor is listed as
near-threatened. Detailed census data are lacking, but the population continues to decline due to
multiple factors including human persecution. The remaining Cathartid species are currently
listed as least concern for conservation.
As with all Accipitriformes species, female Accipitrid vultures are somewhat larger than males.
All species are otherwise monomorphic and all build large stick nests, either on cliffs and ledges or

Hand-Rearing Birds, Second Edition. Edited by Rebecca S. Duerr and Laurie J. Gage.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.