BirdWalk Newsletter 4.2 - Magnolia Plantation and … Newsletter 4.2.2017 ... vulture’s stomach...
Transcript of BirdWalk Newsletter 4.2 - Magnolia Plantation and … Newsletter 4.2.2017 ... vulture’s stomach...
BirdWalk Newsletter 4.2.2017
Walk conducted by Perry Nugent Newsletter written by Jayne J Matney
Magnolia Plantation and Gardens
Vultures! On a global scale,
vultures are divided into
two groups-Old World and
New World species. The
traditional Old World
species are separated into
their own taxa because they
are not associated with the
others. Old World vultures
are found in Europe, Africa,
and Asia, while the New
World vultures are located
in North and South
America. Therefore,
vultures are on all
continents except for
Photo by Paula Collins Antarctica and Australia.
In this area, the Black
Vulture (Coragyps atratus) and the Turkey Vulture (Cathartes aura) are present in
our skies. Until very recently, New World vultures were thought to be related to
the stork, but new DNA evidence indicates they are more closely related to our
birds of prey. There are actually seven different species of New World vultures. In
general, they have bald heads to prevent dirty feathers on the head when eating
dead carcasses, but also for thermoregulation. Most people would not, at first
exposure to them, think of them as endearing. But once you get to know them,
vultures can be considered endearing because of their tight social structure and
behaviors as well as what they provide for us environmentally.
Photo by Richard Hernandez
Basically, vultures congregate in groups, and depending upon what they are doing
will determine what the group is called. “Kettle” is a reference to these birds in
flight while a “committee” rests or roost in trees, and a “wake” is distinguished by
a group that is feeding. Vultures rarely attack animals except if they are sickly or
wounded. They are gluttons when food is available, and then sleep off the day’s
feast- much like some people at Thanksgiving. Even though vultures prefer areas
of forests next to open space, or farmland ranges, they are well known for being
adaptive to human existence. They are quite often spied along roads, dumpsters,
landfills, and garbage dumps, and can often be seen roosting on electrical pylons.
Vultures are monogamous, feed their young by regurgitation for as long as eight
months after fledging, and roost in communities so that they can reunite with
others. The Cornell Lab of Ornithology describes the vulture to have a very “fierce
family loyalty” and
social bonding unlike
most other birds. Black
vultures actually hunt
for food with the turkey
vultures because the
turkey vultures have a
much better sense of
smell. Once the carcass
is found, the black
Photo by Jo Frkovich vultures will begin
forming their wake and
share the winnings, which scares the turkey vultures away because they prefer to
feed individually by taking turns. Being solitary feeders, the wake will be too
intimidating to the turkey vulture and will eventually vacate the carcass leaving
the black vulture scavengers with the “pickings”. Sometimes black vultures have
been seen wading after floating carcasses. A well evolved stomach of steel, the
vulture’s stomach acidity is so high that they can digest what other animals
cannot- even rotten and infected carrion that other scavengers cannot. They will
evade predators by regurgitating at them and lightening their own load to get
away.
In courtship, the vultures, like
most raptors, will have special
dances in flight which resemble a
“follow the leader” behavior. They
don’t put much effort into nest
building in caves, crevices, ledges,
and thickets – all on the ground.
The 2 eggs (this number is almost
always the case) are pale gray-
green with brown blotches. Both
vultures in the pair will take turns
incubating as well as feeding the Photo by Jo Frkovich
hatchlings. They do this by regurgitating
food out of their crops to the young.
Both types of vultures soar high in the air using warm thermals to carry them with
less use of their own energy. It is interesting to note that the Black vulture has
short, quick wing beats and soars very proficiently, but the turkey vulture has
more of a strong, deep wingbeat and is a bit wobbly in their soaring skills.
Photo by Jo Frkovich
Appearances are different with these two types of vultures as well. To contrast for
identification purposes, the black vulture is glossy black with white inner primary
feathers and white-shaped stars on the underwing, has a dark bill at the base with
ivory to yellow tip which is narrow with a hook at the end, and has a bare, small,
black head. Its wings are broad and rounded and the tail is short and rounded.
The black vulture holds its wings differently from the turkey vulture while soaring.
The turkey vulture’s wings are also broad, but are two toned underneath which is
very noticeable when soaring. The head of the turkey vulture is primarily red
although young ones do have black heads. The tail is longer than the black
vulture’s tail and the broad wings have noticeable wing tips like fingers.
Fun Facts:
Vultures hiss instead of talk
New World vultures urinate down their legs for protection against, and
reflection of the sunlight. In addition, this acid kills bacteria that could
otherwise be found there after eating on putrid carcasses and can also be a
coolant during evaporation.
Even though Turkey Vultures outnumber the Black Vultures, the Black
Vulture is the most numerous vulture in the Western Hemisphere.
The oldest fossil of vulture was found in Europe dating back at least 34
million years.
The oldest Black Vulture was at least 25 years and 6 months while the
oldest Turkey Vulture on record was at least 16 years and 10 months.
Black Vultures are known to prevent nonrelative vultures to come into their
roosting community.
As vulgar as the dead carcasses are, vultures are selective enough to leave
behind the scent glands of skunks!
Vultures have excellent immunities. Outrageous diseases such as anthrax,
botulism and cholera can be killed by the stomach acids and immune
systems of this bird’s body.
Photo by Paula Collins
Photo by Jo Frkovich
Natalie Hendrickson, of the Center for Birds of Prey in Awendaw, S.C., is quick to
point out that the vultures here in this country are primarily killed by automobiles
(because of their tendency to eat road kill), and lead poisoning from gunshot
pellets they may eat while feeding. Pesticides were a distinct problem in the past
which is not as problematic as before but can also be a factor. The vulture’s
inaccurate stereotype of being nasty, disease causing animals to have around has
caused major declines in some areas. But now scientist are discovering that
vultures actually prevent disease by cleaning up and preventing other scavengers
(mammal scavengers such as coyote, dogs, and wild cats) that are more
undesirable from coming in and overpopulating and carrying disease that can be
passed on to humans.
A case which is used as a study on this phenomenon was in India and Nepal. A
veterinary drug, used on animals and found in animal carcasses of which vultures
consumed, built up within the vulture tissues which caused death and a decline in
their population. Because of the lack of concern over this misunderstood group of
birds, India was very late in responding to this decline. Now they are suffering
from infectious diseases in their country and will not recover the vulture
populations for many decades to come. From a conservational standpoint here in
North America, the Black Vulture populations have increased during the 1966 to
2014 census. Prior to this, the vultures were being hunted and killed because of
misunderstandings until the 1970’s when attitudes changed. DDT pesticides were
also a key factor for their demise, but this was remedied soon enough for a
comeback for many types of birds impacted. Now, they are numerous and are not
on the watch list. They get a “least concern” status by the IUCN. The moral of the
story? Vultures are our friends. We need to protect them.
This past Sunday, 4.2.2017, fifty-seven species were spotted with six participants
involved in the investigation. The nesting of birds is in full swing and babies of
early nesters are being seen! Wood Duck with their ducklings appeared for the
seekers giving a total of 22. A pair of Canadian Geese, 75 Blue-winged Teal, 7
pied-billed Grebe, 2 Double Crested Cormorant, 60 Moorhen, and 60 American
Coot were in attendance as well. The Anhinga are dominating the trees with many
nests. The Great Blue Heron, are starting to tend to their babies, while the Great
Egret, Snowy Egret, and White Ibis are following suit by settling on nests. The
Audubon Swamp is also housing these birds in addition to Little Blue Heron,
Green Heron, Black-crowned Night Heron, and Wood Stork. A Wilson’s Snipe at
the cross dike and over one hundred Laughing Gulls flying over added more to the
list.
A highlight of the walk was seeing the Swallow-tailed Kite near Ravenswood.
Some other highlights for the group were the nest building antics of the White-
eyed Vireo and the Blue-gray Gnatcatcher this week! Not only did they see the
usual Carolina Wren scattered all over the property, but the birdwatchers also
located a House Wren near the cabin area. The Savannah Sparrow and the Swamp
Sparrow made the list as well. Always an added “must see” were the Bald Eagles.
This week the bird watchers were able to see 1 adult and 2 juveniles (one of
which was a “this year’s” baby)!
3 Red-shouldered Hawk showed
their majestic attitudes. 2 Osprey
showed off their skills.
Red-bellied, Downy, and Pileated
Woodpecker were all accounted
for this week. Eastern Phoebe,
Blue-headed Vireo, Red-eyed
Vireo, Tree Swallow, Ruby-
crowned Kinglet, Hermit Thrush,
Gray Catbird, Cedar Waxwing,
Northern Parula, Yellow-rumped
Warbler, Yellow-throated Warbler,
and Pine Warbler made this list as
well. To round out the crew of
birds located on the property on
this day included: Mourning Dove,
Common Yellowthroat, Tree Swallow, “Osprey” Photo by Chuck Fuhrman
American and Fish Hawk, Carolina
Chickadee, Tufted Titmouse, Northern Mockingbird, Prothonotary Warbler,
Northern Cardinal, Red-winged Blackbird, Common Grackle, and Boat-tailed
Grackle.