Story from the EarthTeller, March 2004

Fran's column first appeared in The Environmentor, Volume 8, Issue 3, March 2004, Page 6.

TURKEY VULTURE AND CHICKEN HAWK

 

Turkey Vulture was looking bad.

 

Chicken Hawk flew down and landed next to him on the fence rail. "What's the matter with you, cousin? You look terrible."

 

"Oh," said Turkey Vulture, "I'm about to starve. I haven't had a thing to eat in days."

 

"Why not?" asked Chicken Hawk. "Look at all the tasty game around here: birds, mice, rabbits."

 

"Yes, but they're alive. You know I only eat dead stuff. That's my job. I'm supposed to wait for things to die."

 

Chicken Hawk shook his head in disgust. "It's not your job to starve. Why wait, when hunting live game is easy! See that rabbit in the grass? Watch me!" and he launched himself into the air. He flew high overhead and then dived for that rabbit, showing off.

 

The rabbit saw her enemy approaching and ran for cover in the taller grass by the fence post. Chicken Hawk changed course in mid-dive, following her. Turkey Vulture watched as Chicken Hawk hurtled down out of the sky -- a flew SPLAT into the fence post.

 

Turkey Vulture nodded. "Thanks. I knew something would die if I waited long enough."

 

##  -- adapted from a Cajun folktale. 

There are many other folktales about the origin of Vulture, why its head is bald, why it eats dead animals.

 

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VET MEDICINE KILLS VULTURES

 

Vultures eat dead stuff.

 

The farmers of India, Nepal, and Pakistan depend on vultures to clean up dead cattle before diseases such as hoof-and-mouth or anthrax can spread. The Parsi sect (Zoroastrian religion) depends on vultures for the "sky burial" of their dead. But the vultures were vanishing...

 

Since the late 1990's, South Asian vulture populations have crashed up to 95%. Foxes multiplied and spread rabies, further complicating the problems of farmers and Parsis, but there was all this dead stuff to eat...

 

In 2000 the Peregrine Fund (based in Boise, Idaho) began an investigation with the Ornithological Society of Pakistan. They suspected a disease, like bird flu, but found none. Instead, 85% of the dead vultures showed signs of acute kidney failure -- but the researchers couldn't find the usual causes: pesticides, heavy metals, other chemicals.

 

South Asian vets commonly prescribe diclofenac, a cheap drug similar to ibuprofen, for animals suffering from fever or injury. Sometimes those animals die anyway. Vultures eat dead stuff. 

 

Since an overdose of diclofenac can damage kidneys in humans (who use it for arthritis), researchers tested the dead vultures -- and found diclofenac residues. In experiments, captive vultures were fed diclofenac-treated carcasses. Within days, they died of kidney failure. It seems that vultures are VERY sensitive to diclofenac.

 

We knew that pesticides and other environmental toxins threaten bird populations. We knew that when prescription drugs get into the water supply, acquatic organisms sometimes develop abnormally. But this is the first time that a prescription drug has been caught poisoning birds.

 

The Peregrine Fund and other organizations hope to ban veterinary use of diclofenac in India, Nepal, and Pakistan. Fortunately it does not accumulate in the food chain like D.D.T. But for the vultures of South Asia, it is lethal even when used properly as veterinary medicine -- if the animal patient dies. 

 

Because vultures eat dead stuff.

 

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Sources:

Science News Jan 31, 2004 (vol 165 pp 69-70)

 

http://www.nwhc.usgs.gov/disease_information/other_diseases/diclofenac.j... has links to several reports.

 

Follow-up activities: What are some ways that prescription drugs (antibiotics, anti-depressants, hormones, beta-blockers) etc can get into the soil water or air? What are some other consequences?