The Four-Legged Chick

Polymelia occurs in numerous types of creatures but is particularly rare in birds.

The Four-Legged Chick

Reading Time: 4 minutes

By Rebecca Krebs 

It was Monday morning, hatching day here at North Star Poultry. Freshly hatched chicks of assorted breeds filled the incubator. Many of them would be on their way to new homes by that afternoon, but I planned to keep most of the Rhode Island Red chicks to raise as my future breeding stock. I couldn’t wait to see them. 

I got more than I bargained for. 

As I pulled the tray of chicks from the incubator, I noticed a pair of funny little legs sticking out of the mass of fuzzy bodies. I did a double take. A four-legged chick! I snatched up the chick and examined him more closely, unable to believe what I saw until I gently pulled on the extra legs attached to his backside — the legs didn’t come off! I ran into the other room to show my colleague. 

“You’ve never seen anything like this!” I said, shoving the chick rear-first toward her. She was shocked. The chick cheeped his indignation at such rude proceedings. 

I searched “four-legged chickens” online and discovered that the miniature limbs dangling from the chick’s posterior resulted from a rare congenital condition called polymelia. This peculiar chick was likely the first and last one I would ever see. 

The word polymelia comes from the Greek and means “many limbs.” Polymelia occurs in numerous kinds of creatures — including humans — but it is particularly rare in birds. The extra legs of polymelus creatures are often underdeveloped and malformed. My polymelus chick’s extra legs were nonfunctional but looked like perfect miniature versions of normal legs, thighs and all, except that only two toes grew on each foot. 

Several subcategories of polymelia exist, including pygomelia. Defined by the extra legs attaching to the pelvis, pygomelia was possibly the type my chick exhibited. His extra legs securely joined his body by shafts of bone positioned below his tail. X-rays would have been required to verify if it was a true case of pygomelia. 

Scientists are still working to understand what factors cause polymelia, especially in birds; possibilities include conjoined (Siamese) twins, genetic accidents, exposure to toxins or pathogens, and the environment during incubation. 

Freshly hatched chicks of assorted breeds filled the incubator. I couldn’t wait to see them. I got more than I bargained for.

My breeding flock of Rhode Island Reds — the polymelus chick’s parents — came to mind during my research. Could they carry genes that caused polymelia? Probably not. It’s hard to say for sure why my chick developed polymelia, but based on my research, I suspect that it was either a random genetic accident or a byproduct of artificial incubation (since humans can’t flawlessly imitate the incubation conditions under a mother hen, artificial incubation occasionally leads to defects). 

Ironically, the polymelus chick’s mother belonged to a new group of hens that I had introduced to my flock to maintain my Rhode Island Reds’ genetic diversity and prevent genetic problems caused by inbreeding. Apparently it was perfect timing for a polymelus chick to appear! The coincidence still makes me chuckle. 

Obviously this chick was staying on the farm with me. (I can just imagine someone’s reaction if they opened their shipment of fluffy, peeping chicks to discover…!) But I didn’t mind keeping him. Who gets the chance to personally observe a polymelus chicken? However, I worried that the chick wouldn’t survive his first meal. His extra legs seemed attached to his body where his vent should have been; if that was the case, he would be incapable of defecating and would die. I did eventually find his vent, but it was small and deformed. Sometimes he had difficulty passing droppings. 

The chick couldn’t live with the other chicks because they might have mistaken his extra feet for worms and unintentionally injured or stressed him by yanking his toes. At first he lived in the incubator and went on regular outings to eat and drink in front of the heater. After a few days, I moved him to a brooder where he had the companionship of one calm Black Star pullet chick. I hoped the Black Star chick would grow so accustomed to his anomaly that she could safely keep him company for his entire life. 

Despite the fuss made over him, the chick didn’t notice that he was a rather unusual specimen. He hatched healthy and feisty, and he behaved like a normal chick. I’ve always admired the tenacious and happy-go-lucky personalities of Rhode Island Reds. Nothing fazes their positive outlook on life. My polymelus chick was no different. When I took him on excursions away from the incubator, he flapped his tiny, downy wings in his excitement to be out in the big world — never mind the extra limbs swinging around behind him. 

Actually, if I didn’t look too closely, the chick was kind of cute. I’ve heard chickens like him labeled as “polymelus monsters,” but you’ve got to know a polymelus chick before you saddle it with that name.

Actually, if I didn’t look too closely, the chick was kind of cute. I’ve heard chickens like him labeled as “polymelus monsters,” but you’ve got to know a polymelus chick before you saddle it with that name. My chick wore an adorable expression and picked up his food with that pleased little flick of the beak which observers of chick behavior will recognize. Even his extra feet, complete with diminutive toenails, were cute in their own right. 

Many creatures with polymelia live normal, quality lives, and I looked forward to watching the chick grow into a rooster. But sadly, my little polymelus chick passed away at two weeks old as a result of his malformed vent. Though he lived only a short time, he gave me a unique hands-on opportunity to learn about polymelia. I’ll always be glad for that. 

Sources: 

Hassanzadeh, B. and Rahemi, A. 2017. Polymelia with unhealed navel in an Iranian indigenous young fowl. Veterinary Research Forum 8(1), 85-87. 

Ajayi, I. E. and Mailafia, S. 2011. Occurence of Polymelia in 9-Week-Old Male Broiler: Anatomical and Radiological Aspects. African AVA Journal of Veterinary Anatomy 4(1), 69-77. 

Rebecca Krebs is a freelance writer and genetics aficionado who lives in the Rocky Mountains of Montana. She owns North Star Poultry, a small hatchery that breeds Blue Laced Red Wyandottes, Rhode Island Reds, and five exclusive chicken varieties. Find her farm online at northstarpoultry.com.   

Originally published in the April/May 2020 issue of Backyard Poultry and regularly vetted for accuracy.

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