Monday, January 28, 2013

Costa Rica's Vultures.... so prevalent they could be the National Bird!

Travel anywhere in Costa Rica and you're bound to see several species of Vultures soaring high overhead. Known in Spanish as "Zopilotes", whether it is the Black Vulture (Coragyps atratus), the Turkey Vulture (Carthartes aura), or the surprisingly majestic King Vulture (Sarcoramphus papa), there is no way you can spend a day in Costa Rica without spotting large flocks of these ghastly yet at times elegant birds.

Black Vulture
Field marks: Large, heavy-bodied, carrion-eating, black bird, with short tail and broad plank-like wings tipped with white. Wingspan: 5' Length: 2'-2'4" W-L ratio: 2.3:1 Weight: 4.5-6 lbs

Turkey Vulture
Field marks: Large, dark brown, heavy-bodied and small-headed, carrion-eating bird, with a longish tail and two-toned underwings. Wings held above the horizontal in a strong “V.” Wingspan: 5'6" Length: 2'2"-2'8" W-L ratio: 2.4:1 Weight: 3.5-5 lbs


Black and Turkey Vulture Factoids:
• Black & Turkey Vultures belong to the family Cathartidae, a group of 7 species of New World Vultures.
• Black Vultures, rarely flap in flight using broad plank-like wings that allow them to soar in small wind thermals.
• Black Vultures search for carrion exclusively by sight, often following Turkey Vulture’s to take advantage of these bird's acute sense of smell to find food.
• Black & Turkey Vultures sometimes take live prey.
• Black & Turkey Vultures usually roost together in family units.
• Black Vultures nest on the ground and on the floors of abandoned buildings.
• The range of Black Vultures has been expanding northwards since the 1950s.
• Most scientists now believe Turkey vultures and Black vultures are more closely related to storks than to other raptors.
• Turkey Vultures get their name from their red, featherless heads resembling Wild Turkeys (Meleagris gallopavo).
• Turkey Vultures may be more closely related to storks than other raptors.
• Turkey Vultures are the most migratory of all of the New World Vultures.
• The Turkey Vulture’s plumage is dark brown, not black.
• When flying, Turkey Vultures, hold their wings in a “V” above their backs, creating a slight dihedral that stabilizes their flight.
• Turkey Vultures often roost in groups of several hundred birds.
• Turkey Vultures communicate vocally in hisses and grunts.
• Nestling Turkey Vultures projectile vomit to defend themselves.
• Turkey Vultures have weak feet, and are unable to carry off their carrion.

This is so exciting, please tell me more Vulture Facts!
Along with the Turkey Vulture, the Black Vulture is one of the most abundant New World vultures. Prevalent in North America, vultures also breed throughout Central
America and much of South America. Black Vultures are typically found in open or partly forested habitats, often in close proximity to human activity. Traditional communal roost sites can consist of 100's of birds, some of these sites are used for decades at a time, often occupied year-round, especially in areas of temperate climates such as Costa Rica. Roosts are thought to play an important role in the social lives of vultures as a place for juveniles and adults to interact and as a staging area for foraging groups to assemble. Turkey Vultures and Crested Caracaras often roost together with Black Vultures.

Identification
Black Vultures have featherless dark gray to black heads and necks and are ugly as hell. They appear completely black when perched, however obvious white patches near
the wingtips are clearly visible when in flight and you will see these hideous birds everywhere. The gray legs and toes often are stained whitish with excrement, oh my.....isn't that nice. Adult Black Vultures have dark bills with bone-colored tips and their heads and the upper half of their necks are dark gray and covered with wrinkles (hey, wait! I think I'm starting to look like a vulture myself!). Unlike Turkey Vultures, an easy distinction between the two species is Black Vultures hold their wings flat when soaring, rock less, and flap more frequently. The Turkey Vulture are masters at soaring above the canopy, rarely flapping their wings and holding them in a “V” shape, while rocking side-to-side, skillfully using the shifting wind thermals to do the work for them.

Breeding Habits
Unlike the Black Vultures, Turkey Vultures prefer open and forested habitats, typically avoiding urban and suburban areas. In the Americas, both species breed in farmlands, rangelands, forests, and low-elevation mountains. Generally, it only eats the skin and harder parts of the tissue of its meal. Vultures are monogamous and pairs
are believed to mate for life, now isn't that romantic? In fact, family members associate more closely with each other than with other individuals over their lifetime. I guess carrion is like comfort food and brings families together! Vultures do not build a nest, instead laying their eggs in rocky crevices, caves, tree cavities, hollow logs, and such. Vultures though gawky on the ground, perform
incredible aerial displays during courtship, with males circling the females with their necks extended, exhaling loudly and making chasing and diving maneuvers. A successful courtship eventually results in two eggs, which are then incubated for 32-45 days. This romantic couple works together incubating the young, with both parents also sharing the feeding of regurgitated food to their young as often as 20 times a day. Gosh, this romance just keeps getting better! The happy little family generally remains in close contact until the next breeding season, at which time the parents chase their offspring away from the nest site.....their done, time to move on. After leaving their parents, juveniles enter a wandering stage while learning how to search for carcasses on their own. I wonder what the learning curve on that one is?

Feeding Habits
Black Vultures are dirty little opportunistic aerial scavengers. Feeding on carrion of all types and sizes, unlike the Turkey Vultures, this species does not have a keen sense of smell and relies entirely on visuals to locate food. Black Vultures
typically fly at higher altitudes than Turkey Vultures and monitor the behavior of predators and other scavengers in order to find their food. They frequently follow successful Turkey Vultures to carcasses, then aggressively chase them away and taking it as their own. Large numbers of Black Vultures quickly
gather at food sources preferring fresh carcasses, but consuming decaying meat as well. Occasionally Black Vultures capture live prey, most of which are young, weak, or small sickly mammals or birds. Black Vultures also scavenge through trash, feed on vegetable matter including sweet potatoes, pumpkins, coconuts, and in Costa Rica, the fruit of oil palms. Because Turkey Vultures find food using their sense of smell as well as by sight, they are able to locate carcasses on the forest floor beneath dense forest canopies and are better able to rely on fresh food, but will resort to decaying meat when necessary. Generally, the King Vulture actually prefers to eat the skin and harder parts of the tissue for its meal.

Less Common Vultures of Costa Rica
The King Vulture (Sarcoramphus papa) is a colorful large bird found in Central and South America. This vulture lives predominantly in tropical lowland forests stretching
from southern Mexico to northern Argentina, and does not frequent the coastal zones as much as the other vulture species. Large with a predominantly white body, the King Vulture has gray to black ruff, flight, and tail feathers. The head and neck are bald, with the skin color varying, including vivid colors of yellow, orange, blue, purple and red. The King Vulture has a very noticeable yellow fleshy caruncle on its beak. This vulture is a hearty scavenger with an exceptionally strong beak and it often is the one to make the initial cut into a fresh carcass. King Vultures have been known to live for up to 30 years in captivity, I'm hoping at a zoo and not as someone's ghastly avian pet!

Ecology and behavior
The King Vulture can soar effortlessly for hours, only flapping its wings on occasion. While in flight, they hold their wings flat only slightly raising the tips, holding their small heads low, they often appear headless while in flight. These vultures have also been observed engaging in tandem flight which is thought to be a
part of their courtship behavior. Only one or two birds generally descend to feed at a carcass, although up to ten or so may gather if there is a significant amount of food. One of the truly most disgusting features of this species of vulture, is it's said to use urohidrosis, (defecating on its legs) to lower its body temperature. How pleasant, glad to know that. The King Vulture actually lacks a voice box, (wish my husband did sometimes), although it can make low croaking noises and wheezing sounds while in courtship and bill-snapping noises when threatened. The only natural predators for the King Vulture are snakes, which will prey upon the vulture's eggs and young or large cats such as jaguars, which may surprise and kill an adult vulture while feeding at a carcass. Predators? Defecating on the legs? Gross, I'm not hanging out with these guys!

Breeding
The reproductive behavior of the King Vulture in the wild is poorly known. From
mostly captivity they have learned that King Vultures mate for life and generally lay a single unmarked white egg in a nest in the hollow of a tree. To ward against potential predators, the vultures keep their nests foul-smelling. The parents share incubating and brooding duties until the chick is about a week old, with the chicks later taking their first flights at about three months of age.
Because of its large size and beauty, the King Vulture is an attraction at zoos around the world and is a popular photo opportunity when spotted around Costa Rica.

So there you have it! Most everything you ever wanted or didn't want to know about Vultures! Those majestic birds you've been watching fly around your Costa Rica Hotel or Costa Rica Vacation Rental Home each day, may actually have been disgusting flesh eating Vultures! Ew, that's gross! If truth be told though, these birds can actually be quite friendly and comical acting. Some have no fear to waddle right up to your feet if you leave them some fresh food. Besides, there is no arguing that these beasts serve their purpose in the food chain and natural ecology by providing a natural cleaning up of disgusting road kill. So people!! Let's embrace this important species and thank Mother Nature for the vultures!
Okay, so maybe we aren't quite ready to make them the National Bird yet, but have you ever seen Costa Rica's National Bird? Beyond it's beautiful song, it's not particularly impressive! Pura vida!!

Author:
Kimberly Barron, originally from Malibu, California has lived in Parismina and Manuel Antonio, Costa Rica for 20 years. Starting as a certified tour guide, she spent 15 years managing fishing lodges on the Caribbean Coast and later 4* & 5* Hotels on the Pacific Coast of Costa Rica. Currently semi-retired, Kimberly still works as the Marketing Director for Byblos Resort & Casino and Hotel Makanda by the Sea.

Sources:
www.hawkmountain.org/
www.en.wikipedia.org/wiki/Black_Vulture
www.en.wikipedia.org/wiki/King_Vulture

2 comments:

  1. Esto es muy bonito website.it es útil para people.Make asegúrese de informar a su médico acerca de cualquier medicamento a base de hierbas que está tomando.
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  2. Interesting stuff, there's an episode of the X files (Season 2 Episode 22) where I believe that there are turkey vultures. Could you confirm this?

    Thanks.

    ReplyDelete