They're So Bad The Ants Won't Even Eat Their Dead Bodies!
I used to shoot them. We all knew they were evil. My friend Chepo told me he would shoot them any time he found them on his farm. "They're so bad," he told me, "that nothing will eat them, not even the ants." We all knew it was illegal, but we did it anyway and felt entirely justified in doing so. I mean, how could anyone justify protecting something so evil that it will eat a live baby as it is being born, emerging from its mother's womb? Sometimes they get so excited in their feeding frenzy that they even eat the mother's vulva and teats when she is flat on her side and can't stand up because of the birth contractions. When they find any helpless creature down on the ground they pluck out its eyes, eat its tongue, nose, anus and udder, even before it's dead. Now, many years later, I realize that everything has its place in nature; everything plays its role in the ecological balance, regardless how hateful their natural habits may seem to us. I don't even hate them anymore.
It almost seems like a past life back in the 1970's and early 1980's when we raised cattle on Hacienda Barú. Large numbers of all three species of vulture were a common sight soaring on the thermals above the cow herds, especially at calving time when there was plenty to eat. We didn't mind them cleaning up the placentas left from the calving cows, but the scenario described above was all to frequent and most cattlemen killed vultures in one way or another. If you shoot them whenever they come around, the vultures become wary and tend to keep a little more distance from the livestock. They learn quickly.
Of the four species of vulture found in Costa Rica, two are a common sight in the skies over Dominical, the turkey vulture (Cathartes aura) and the black vulture (Coragyps atratus.) A third species, and the only one that could be called attractive or impressive, the king vulture (Sarcoramphus papa,) is also found in this area, but in much smaller numbers and less frequently. Additionally a very large, beautiful hawk, the crested caracara (Polyborus plancus,) is often seen feeding on carcasses side by side with the vultures. The caracara is a very adept raptor that hunts for food when no carrion is available. Locally it is called quebrantahuesos, meaning, "bone breaker," because of its habit of carrying the bones of dead animals high into the air and dropping them on a hard surface, then descending to eat the marrow from within the shattered pieces. Possibly because of the caracara's strong talons, the vultures often yield to it in disputes over morsels of dead flesh.
The turkey vulture is the smaller of the three species and is easily distinguished by its red head, similar to that of a turkey. The black vulture has some white visible on the tips of the underside of its wings, all the rest of its body being black. Although it is nearly 50% heavier than its redheaded cousin, it has a slightly shorter wingspan. You can easily distinguish between these two in flight by the large amount of gray on the underside of the turkey vulture's wings. The adult king vulture is mostly white with black trim and a multicolored head splotched with red, yellow, orange, blue and purple. In many ways it resembles a condor more than a vulture. At 3.5 kilograms the king vulture is twice the weight of the black vulture and 2.5 times the weight of the turkey vulture. The king vulture has a wing span of 2 meters. All three species have feather less heads.
The Ecotravellers' Wildlife Guide, Costa Rica, by Les Beletsky, quotes a Maya legend that tells of the vultures and how they came to be black and bald: In the old days, vultures were actually handsome, white birds with feathered heads, which ate only the finest fresh meat; they had an ideal life. One day, the vulture family, out soaring in the sun, spied a feast laid out on banquet tables in a forest clearing. They swooped down and ate the splendid food. Unfortunately for the vultures, the food had been set out by nobles as an offering to the gods. The nobles schemed to punish the unknown culprits. They set out another feast in the clearing and hid behind trees with their witch doctors. When the vultures returned for another meal, the nobles and witch doctors raced out from the trees and threw magic powder on the birds. The vultures, in their panic to escape the people, flew straight up and got too close to the sun, scorching their heads, causing their feathers to fall out. In the clouds, the magic powder turned their white plumage to black. When they returned to earth, the Great Spirit ruled that for their thievery, from that day forward, vultures would eat only carrion. (A.L. Bowes 1964)
In December of 2001 I flew over Corcovado National Park in a small plane with two wildlife photographers. During the hour and a half flight we saw at least a dozen king vultures and very few turkey and black vultures, the latter two mostly along the beach, and the former always over the forests. This is indicative of the difference in their modes of locating carrion. The king vulture relies primarily on smell whereas the black vulture counts entirely on sight. Apparently the turkey vulture uses a combination of both senses. The king vulture's splendid sense of smell allows it to locate carrion on the forest floor beneath the rainforest canopy. F. G. Stiles and D. H. Jansen in an article in Costa Rican Natural History, tell of a king vulture at Corcovado National Park that located a dead sloth wrapped in a plastic bag and buried 5 centimeters deep in the forest floor litter. The black vultures often follow the king and turkey vultures when they descend beneath the rainforest canopy.
As I came to understand the vultures and their importance as scavengers, I came to admire many of their attributes, communication being one of the most impressive. Although the black vulture may appear to be less adept at locating its food, it seems to have the best communication skills. According to Les Beletsky there is evidence indicating that communal roosting sites tend to serve as communication centers where birds exchange information about food supply. The black and turkey vultures often roost communally in groups of five or more. The king vulture is a very solitary bird that roosts alone. I have always been impressed at how fast the vultures can zero in an a dead or dying animal, but years ago I had an experience that makes me think that their communication skills may be even more impressive than researchers suspect.
In 1972 my work took me weekly to Guanacaste in northwestern Costa Rica. I used to say that there wasn't a place in the entire province where you couldn't see at least one vulture in the sky. In December of that year, there was a horrible earthquake in Managua, Nicaragua that left around 14,000 fatalities. The newspapers told of enormous flocks of vultures that descended on the city to consume the thousands of dead human bodies that the overburdened rescue workers had not yet buried. For the two weeks following the Managua earthquake I was unable to locate a single vulture anywhere in the skies of Guanacaste Province of Costa Rica. The first black silhouettes appeared in the blue skies far to the south near the outskirts of the city of Puntarenas, about 500 kilometers south of Managua. I can't prove that the Guanacaste vultures went to Managua, but the circumstantial evidence is very compelling. This brings up the question of how the vultures learned about the windfall of carrion over such a great distance. I don't know the answer and I've never read anything that might give a clue.
Vultures are a common site along roadways where they feed on the road kill, mostly small creatures like toads, crabs, opossums and iguanas hit by cars. They are also common around garbage dumps where they pick through the organic garbage in search of morsels of meat. They arrive soon after a dead fish or turtle washes up on the beach, or a nest of baby turtles hatch and the hatchlings go trudging across the sand to the sea. At Hacienda Barú, when we still had horse and cattle pasture they would come quickly to the area where the tractor and mower was chopping weeds. Cattle egrets and hawks were first to show up and kill any small animal that ran out of the brush fleeing the blades of the mower. Groups of turkey vultures and black vultures arrived a little later to scavenge through the residue in search of dead rats, lizards, crabs and snakes. The crested caracara both scavenged and hunted. King vultures are seldom seen at these sights. They tend to stay over the jungle.
I once observed a group of turkey vultures trying to retrieve an opossum from the high voltage electrical lines where it had been electrocuted the previous night. The large black birds' feet weren't designed for perching on electrical cables, and their awkward attempts to balance on the swaying lines, grab the opossum, whose tail was wrapped around and baked to the electrical cable, reached the point of hilarity. Finally one lucky bird managed to tear the dead body loose from the cable by the tail and fly away. The carcass turned out to be heavier than the tired vulture could carry in its beak. A few meters from the cables the dead opossum dropped to the ground and the entire group of about five turkey vultures rapidly descended to fight over the carcass. The one that had managed to get the opossum off the line had to wait on the sidelines and rest after his difficult struggle, while his buddies fought over the goodies.
We've all smelled the foul odor of a rotting carcass killed along the road. Here in the tropics, putrefaction is rapid and the amount of road kill is high. Can you imagine what the roadside would smell like if the vultures weren't around to play their role as clean up crew? What would the beach smell like if the dead fish just layed there and rotted? As disgusting as the vulture's habits may seem to us, they have a key role in nature's scheme of things, cleaning up the rotting flesh and recycling it back into the ecosystem. The acid in their digestive system is so powerful that no bacteria can survive the trip through the vulture's stomach and intestines. This allows them to eat things that would kill a human and make many carnivores sick. It has even been said that the acid in a vulture's stomach will dissolve a fish hook.
Is Chepo's statement that, "Nothing will eat them, not even the ants." true? I don't know, but I've never seen anything eat a vulture's carcass. Whenever I check on one a day after it dies I always find it to be partially dried out with a slight smell than isn't quite as bad as most of what the vulture eats. In a week there won't be anything left but feathers. I've never seen ants eating them, but something does. Maybe its only bacteria. If any of you readers know I'd like to hear from you.
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