While working at World
Bird Sanctuary’s Stone Zoo bird show in Boston,
I have learned to make three major distinctions indicative of raptors:
excellent eyesight, strong grasping feet and a sharp, curved beak.
Steven Spielberg’s
Jurassic Park has made Velociraptors famous, but what do these prehistoric
“raptors” have in common with modern raptors? They certainly don’t have a
curved sharp beak or grasping feet.
It turns out Velociraptors
and other theropod dinosaurs with raptor in their name such as Oviraptor or Eoraptor aren’t even closely
related. However they are united under
the Maniraptoran clade, which means “seizing hands,” a nice parallel to extant (meaning
living today) raptors’ seizing feet. They are
defined as being more closely related to birds than other dinosaurs.
Dromaeosaurid (photo: wikipedia by Tom Parker)
Dromaeosaurs, or “running lizards,” are a group of Maniraptors containing Velociraptors and
other “true” prehistoric raptors defined by their large grasping hands, a
stiffened tail and one large, slashing claw on each foot. Modern birds of the
Aves class are the sister group to Dromaeosaurs. You can compare an artists’
rendition of an extinct raptor
to our extant raptor, Diablo
the Tawny eagle below.
Today we have many
different raptors within Aves, which
belong to different groups as well. The orders Accipitriformes, Strigiformes
and Falconiformes are an example of convergent evolution and each produced
unique raptor species.
Accipitriformes is the
most diverse raptor order consisting of many different families of eagles,
hawks, harriers, kites, osprey, the secretary bird and Old World vultures. New
World vultures of the Americas are not related to Old World vultures of Africa,
Europe and Asia. They have merely
evolved to fulfill similar ecological niches.
Baton Rouge, a King Vulture, is a New World Vulture (photo: Gay Schroer)
New World vulture
phylogenic placement has proven to be difficult with DNA evidence supporting
their inclusion in both the bird orders of Accipitriformes
and Ciconiiformes or storks. Old World vultures are true raptors, while New
World vultures lack the strong grasping feet of raptors. You can make this
comparison between Osiris the Egyptian vulture (Old World) and Baton Rouge the
King vulture (New World) at our Stone Zoo bird show.
Riley, a Barn Owl (photo: Aurora Potts)
Strigiformes consist of
two main families of owls; barn owls and typical owls. Owls are mostly
nocturnal and are therefore more sound sensitive than other raptors. Barn owls
belong to the family Tytonidae. Their
face is heart-shaped and their legs are longer than that of Strigidae owls.
Typical owls belong to the more varied family, Strigidae. You can see these
distinctions on Riley the American Barn owl and Reese the Great Horned owl at our
Stone Zoo bird show.
Reese, a Great Horned Owl (photo: Aurora Potts)
Naturally, Falconiformes
are falcons, which are more closely related to songbirds and parrots than they
are to any other raptor (believe it or not). Falcons are the speedy and agile
birds of prey that use their tomial tooth at the end of their beak to break
their prey’s spine. You can see the notch that is the tomial tooth on this
Peregrine falcon on exhibit at Stone Zoo.
A Peregrine Falcon on exhibit at Stone Zoo
Even though extinct and
extant raptors are hardly related, you can see all these fascinating predators
possess many adaptations. Their unique
characteristics allow for a wide variety of species to share the generally
speedy seizing and grasping raptorial name in prehistoric times and up to
modern day.
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