Silver Vulture
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Silver
Vulture, Glabercephalus
argentus L 58-78 cm, WS 1.4-1.7 m (140-170 cm), Family: Cathartidae
IUCN Conservation
Status: Least concern (LC)
Description:
Large
raptor with long, broad wings and very short tail. Smaller of the two native vultures,
smaller than the Novasola Condor. Head, bill, and tail seem proportionally
small. Black overall with silver edging to back and shoulder feathers; head
bare of feathers with brownish leathery skin, yellowish eyes, pervious nostril,
and pale bill. Sometimes extends bare neck which appears quite long and
slender. Folded wings often extend past tail. In flight, appears mostly dark
with distinct tri-colored underwings with light coverts and dark trailing edges,
carries wings angled in a ‘V’ shape, and feet may extend past tail tip.
Voice:
Generally
silent. Primary vocalizations, when given, are guttural barks and hissing, most
often during feeding in groups. They may also click their beaks.
Habitat:
Extremely
common, their range covers the entirety of Novasola, including Kosatka and the
Francis Islands. While they tend to prefer open to semi-open areas like
prairie, chapparal, scrubland, savannah, and tundra, they are also found in
deciduous and evergreen woodland and forests as well as mountains, rocky cliffs
and canyons. They are frequently seen in developed areas including rangeland, farmland,
and rural and suburban areas, though they often compete with corvid scavengers
in more developed lands.
Discussion:
Notorious
and homely, the oft-unpopular Silver Vulture is regularly judged unfairly as ugly
or grotesque, though in reality they are fascinating birds and play a crucial
role in Novasola’s ecosystem. It is a prolific and consummate scavenger, easily
observed soaring and riding thermals in search of carcasses or feeding off
roadkill on highways. Alone in its genus Glabercephalus, which means “bald-headed”
in Latin, the Silver Vulture is the smaller and more common of two endemic
species of New World vulture, with the other being the giant Novasola Condor. These
vultures are members of clade which includes the Black Vulture and Turkey
Vulture of the mainland, and is considered a sister taxa to Cathartes, the Turkey Vultures.
Silver
Vultures are most common in open or semi-open spaces, especially range and
farmlands, prairie, chapparal, scrubland, and savannah, but they are still frequently
seen in a diverse array of other ecosystems like woodland and forests,
mountains, wetlands, and more developed urban and suburban areas. Though they are
common and can be found in most areas, they do seem to show a preference for
open areas in a mosaic or mixed landscape of open and forested patched which
provide optimal foraging and roosting habitat. At night, they roost in trees or
on cliff faces or occasionally atop tall buildings, though they try to avoid
less secluded spots. Outside the breeding season, vultures will form large
flocks and roost communally, with the largest roosts numbering over a hundred birds.
During the breeding season, however, vultures will form solitary pairs and nest
on cliffs, ledges, in crevices, caves, trees, and in old, unused nests of other
large birds, as well as old or abandoned human structures. Though they don’t
build a full nest, sometimes content to just scrape an indent into the substrate,
pairs may return and reuse nest sites every year. Both sexes take part in
incubating eggs and rearing chicks. Juveniles remain with the parents for
almost a full year, and then often remain close their entire lives.
Though
technically a bird of prey, and one of the most common, the Silver Vulture like
other vultures subsists almost entirely on carrion. They locate food through
both sight and smell. Their sense of smell is extremely refined, though not as
strong as a Turkey Vulture’s, so they rely more on their eyesight than do
Turkey Vultures. In cases where Turkey Vultures can be found on Novasola, which
is not too uncommon, it has been noted that Silver Vultures will follow Turkey
Vultures to carcasses. Without Turkey Vultures present, Silver Vultures are
usually the first to spot a carcass since their combined senses of smell and
sight are still stronger than most other scavengers. Most New World Vultures have weak or almost non-existent senses of smell and forage by sight, so the Silver Vulture's scent capabilities indicate a close relationship with the Cathartes vultures, including the Turkey Vulture. Vultures will soar and
ride thermal updrafts to keep them airborne while they search for food. When
they do spot a carcass, vultures descend upon it quickly, and soon more
vultures arrive, often leading to large numbers of vultures at a food source.
Because they often gather in numbers at feed sites, Silver Vultures can manage
to defend carcasses from other scavengers like ravens, condors, and eagles,
despite being smaller and weaker than those birds, which they would be unable
to do one-on-one, and it is thought their group feeding evolved expressly for
this. A flock of Silver Vultures can strip a carcass clean extremely quickly if
undisturbed by other scavengers. They prefer large to mid-sized carcasses,
often outcompeted by ravens and other corvids for small items and by condors
and eagles for the largest items. Silver Vultures will occasionally scavenge
fish or marine carcasses, though this is rare, likely to avoid competition with
condors. They are most often seen on the sides of roads at roadkill, but Silver
Vultures also utilize dumps, landfills, and bone pits.
Some
ranchers mistakenly believe vultures will attack and kill newborn or even adult
cattle, though this is completely unsupported by data. Nevertheless, they are
frequently considered pests and many landowners illegally put out poison to “manage”
vultures. Silver Vultures defecate on their feet to keep cool, and will
projectile vomit as a form of defense. Because of these behaviors and
associations with death and pestilence, Silver Vultures were persecuted
vigorously. Across the globe, vultures have faced extreme prejudice and steep
population declines and crashes, resulting in severe ecosystem breakdowns
because vultures provide such an important role in decomposition, nutrient
cycling, and disease suppression. Thankfully, Silver Vultures saw special
protections and have rebounded well, now considered one of the most numerous
endemic birds of prey on Novasola.
Though
common now and most often seen along roadsides while driving, the Silver
Vulture was not so easily observed by Richard Reichwald at the turn of the 20th
century. Most farmers or ranchers shot or poisoned vultures on sight in those
days, and roadkill hadn’t yet become a reliable food source considering there
were no automobiles in the territory until at least 1918. Nevertheless,
Reichwald did manage to see plenty of vultures prior to the publishing of Native
Birds, and he even went so far as to camp by a cattle carcass just to more
closely observe them.
“Messrs.
Peterson and Farr alerted me to a Mr. James Widman, a local rancher who has solicited
their services to exterminate a wolf which has already familiarized itself with
two of Mr. Widman’s cows. Knowing my interest in studying the habits of Novasolan
scavengers, they suggested I approach Mr. Widman and inquire as to the location
of the most recent kill. Soon enough, another of Mr. Widman’s cattle lay dead
and he took me to the grizzly site within half a day. Immediately obvious to me
was that this cow, fully grown and hardly touched, was no wolf kill. None the
less, Mr. Widman allowed me to pitch my tent on his property near to the
carcass so that I may observe the buzzards as they come in.
…
Though
my many mistakes included setting up camp downwind of the putrid animal, whose fetid
stench seemed to overwhelm the very atmosphere of the pasture and permeate
every fabric I so desperately used to cover my nose and mouth, I was glad to
have persevered them, as not long after Mr. Widman departed did a Vulture
descend upon the corpse, and soon after many more. I had a clear and unobstructed
vantage point from my camp from which I could observe the buzzards, in a
feeding frenzy, do unspeakable acts of violation to the carrion. I have noted
already I do not believe the Vulture’s beak to be strong enough to rip apart
the hide of a fully grown cow, and I sit here affirmed. Instead, the Vultures
focused their feeding only to softer exposed flesh and openings, namely the
eyes, tongue, utters, and orifices unsuitable for publication.
…
This
morning was no less foul, aided not by the unseasonable heat, but also not
without interest. I awoke to witness a solitary buzzard perched atop the
carcass, feeding lethargically on whatever remained of the cow’s lips. It
seems in the night other creatures had their chance at the cow, for it now had
many lacerations across its bulk, with much of its abdomen gone entirely, most
certainly the act of a large predator like a lion or bear. A chill crept down
my spine when I thought of the closeness of such a predator to my
sleeping head.
A
pair of ravens, who yesterday had been waiting impatiently nearby for their
chance at scraps, now outnumbered the Vulture and chased him off his perch. Not
long after, a dark shadow engulfed the carcass until a Condor, like a chief of
rot, flew into view and scared off all other scavengers, including the fox
which had been snooping on the horizon. It no doubt noticed the ravens and
their loud morning calls, and soon quickly spotted the corpse. I had the
pleasure to view such a dominant and macabre creature for at least an hour
until, satisfied with its gorging, it flew off to the north, only then allowing
the buzzards to return. Now that the cow had been fully opened and much of the
skin torn away, the Vultures had easier access to the flesh and now an immense kettle
of buzzards feasted on the carrion.
Either
content with my viewing, or too upset by the malodor, I resigned to dismantle
my camp and return to town. As I arose to do so, the Vultures quickly began to
vomit their meals in a horrid display of post-glutton panic and flew off.” –
Richard Reichwald, personal log, May 30, 1906. Later abridged and published in Native
Birds of Novasola, 1912