Pheasants' heads cool rapidly as they prepare to fight then heat up
afterwards (Credit: Martin Clay)

Pheasants' heads cool rapidly as they prepare to fight then heat up afterwards (Credit: Martin Clay)

Pheasants' heads cool rapidly as they prepare to fight – then heat up afterwards, new research shows.

Scientists from the University of Plymouth and Exeter used thermal cameras to watch juvenile pheasants, and see how their temperature changed during aggressive interactions that establish the pecking order.

They found that pheasants – both the instigator and the recipient of the aggression – grew more cool-headed before a fight, due to a stress response in which blood rushes to the body's core. Their heads became hotter again after the confrontation, as normal blood flow was restored.

Published in the journal Philosophical Transactions of the Royal Society B, the new study was funded by the European Research Council and the Association for the Study of Animal Behaviour.

While male and female pheasants followed a similar pattern of cooling and heating before and after a fight, females were cooler on average. Changes in blood flow are an important part of the stress response in multiple animal species, in a variety of different situations.

The pheasants in the study were six or seven weeks old. They were captive at the time, but were later released into the wild.

Study shows pheasants lose their cool after fighting (Credit: Martin Clay)
Study shows pheasants lose their cool after fighting (Credit: Martin Clay)
Study shows pheasants lose their cool after fighting (Credit: Martin Clay)

Dr Mark Whiteside, Lecturer in Animal Welfare at the University of Plymouth, said:

"Thermal cameras provides a unique opportunity to non-invasively measure dynamic changes in physiological state over a short period of time. Using this technique we were able to measure responses to aggressive interactions, in semi-natural environments, in real time."

Dr Tim Fawcett, of the University of Exeter, added:

"We were surprised that both individuals in these aggressive encounters followed a similar pattern of cooling and heating. We expected that a fight would be more stressful for the pheasant on the receiving end of the aggression, and therefore that we'd see a stronger response in them. We can't say for certain what causes this pattern, but it could be that maintaining a place at the top of the pecking order is just as stressful as being at the bottom."

The paper comes 100 years after Norwegian zoologist Thorleif Schjelderup-Ebbe coined the term "pecking order" in his PhD thesis about chickens.

  • The full study – Knoch et al: Hot-headed peckers: thermographic changes during aggression among juvenile pheasants (Phasianus colchicus) – is published in Philosophical Transactions of the Royal Society B.

Studying the welfare of pheasants

Dr Mark Whiteside is both a behavioural ecologist and applied ethologist who has spent several years studying the behaviour and welfare of pheasants in both captivity and in the wild.

He has previously used pheasants as a model to understand more about the evolutionary consequences of cognitive, physiological and behavioural traits, i.e. their impact on individual movement patterns, survival and reproductive success, and in turn heritability of those traits.

However, his current research focuses on the pheasants themselves, to improve their welfare.

Dr Mark Whiteside
Dr Mark Whiteside

“Pheasants are ornate, complex and evocative and up to 34 million are reared in the UK each year. These numbers are similar to that of chickens produced for egg production. However, unlike chickens, we know little about pheasant welfare. Perhaps, this is because pheasants differ in that after a period when they are reared in captivity, they are released into the wild where they are subject to natural pressures and, typically, high mortality rates.
“Such differences between the lives of pheasants and other production animals makes studying them both crucial and complicated. We may not be able to assume the same welfare indicators and rearing environments that have been used in other production systems are appropriate for pheasants. For instance, chickens have been selected through the process of domestication to invest energy in growth or egg production. For captive reared pheasants, on the other hand, we may need to invest time and energy into developing skills that will help them move, eat and reproduce in a complex, natural environment, filled with predators, disease and competition.
“We need to develop species-specific indicators of welfare and use these to inform management practice. This is why studies that investigate novel and non-invasive ways of measuring welfare, like the use of thermography or acoustics, are essential in understanding pheasant welfare.“

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