Do chickens smell?
The answer is no, and you probably won’t even know it’s there.
A study published in Nature this week finds that chickens smell a lot more than they do in humans, with the results revealing an evolutionary past of about 60 million years that’s shaped the smell of many breeds of birds.
The research team used the smell system of the domestic chicken, the domestic dog, and a different species of bird, the cockatiel.
“We found that the smell was not always present,” said study lead author Michael J. Leeson, a research associate at the University of Wisconsin, Madison.
“So the fact that chickens actually have a really strong sense of smell is really surprising.”
It wasn’t clear how this evolved, but researchers believe the scent of the chickens may be a way of keeping track of the number of other males and females in a flock.
“It’s a form of paternity and so when a male is coming up, he wants to make sure that his other females are nearby,” Leeson said.
“It’s the way that we’re able to determine when there are females nearby that’s really important.”
“It seems like chickens have been around for a long time and this is the first time that we have a very, very strong and robust scent system,” Leison said.
The study, conducted by the University and University of Minnesota, focused on domestic chickens, with dogs, cats, goats, sheep, and mice included.
It was based on the research of researchers from the U.S. and Canada, as well as from other institutions, including Cornell University, the University at Buffalo, and the University in Berlin.
In the study, the researchers compared a variety of breeds of domestic chickens with other breeds and found that domestic chickens are able to detect chemicals emitted from the surrounding environment, as if they were in the vicinity of a chemical detector.
For the first part of the study the researchers used a range of different methods, including measuring levels of ammonia in a chicken’s urine, looking at a chicken with a collar, and examining the smell emitted from chickens.
They also measured the chemical composition of the environment, looking for the presence of chemicals with similar molecular structures.
They also examined the scent emitted by the domestic cat and found it to be more complex than that of other breeds of chickens.
“They have a strong sense, and it’s just a combination of smell and other kinds of information,” Leesons said.
In all, the team examined about 5,000 domestic chickens.
In addition to looking for chemicals that could be linked to the presence or absence of smell, the study also looked at the chemical profiles of the birds that lived in their cages and found the birds with the strongest scent emitted more chemicals.
“This suggests that they’re using this as a signal of paternity, to ensure that their chicks are around other males,” Leoneson said.
When the scent was blocked by the presence and absence of other male, the animals with the most powerful scent emitted the least chemicals.
However, the most interesting result was the finding that domestic cats with the greatest sense of scent also emitted the most chemicals, suggesting that their sense of smelling can be enhanced through the presence, or absence, of other cats.
Leesons hopes that this study will help shed more light on the evolution of scent.
“When we’re looking at things like smell, smell is not something that is easily understood by humans,” he said.
“But this study shows that a sense of odor is a very important form of signalling for the survival of an individual, and that this is something that animals use to decide when they’re ready to breed.”
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