Songbirds can control their metabolic rate so well they will NEVER become overweight, new research shows
- Scientist believes he has discovered why there are no overweight songbirds
- Birds control their weight by altering singing patterns to use more or less energy
- These species can also physiologically control their weight by unconsciously tweaking their digestive or cellular metabolic activity
View
comments
A curious scientist has discovered why songbirds never get fat, despite gorging themselves on garden seed feeders.
The chirping birds have the ability to change their metabolism or digestive process in order to alter how much nutritional value they absorb from their food.
As a result, the animals always obtain the perfect amount of nutrients – never getting too fat or too thin.
Scroll down for video
Songbirds have an inherent ability to change their metabolism or digestive process in order to alter how much nutritional value they absorb from their food (stock)
Dr Lewis Halsey from the University of Roehampton was watching a small gathering of finches in his London garden when he decided to investigate why he has never seen an overweight songbird.
‘The passerine birds at the bird feeders near my home never seem to get fat despite having this buffet constantly available to them, but there are people who get heavy when exposed to that kind of all-you-can-eat environment,’ explained Dr Halsey.
The biologist from the University of Roehampton wondered whether the amount of energy birds put into singing, fidgeting, or exercising is behind the efficient weight management.
-
Mystery of the extinct elephant bird SOLVED: Slash marks on… Burlier birds get the worm! Avian pecking order is… Eight species of bird – including the much-love bright blue… Wildfires driven by climate change are ‘reshaping the US…
Share this article
He conducted an extensive literature review, published today in the journal Trends in Ecology & Evolution, to see what allowed these birds to monitor their weight so well.
‘I wanted to investigate possible behavioural and physiological mechanisms, aside from just food consumed and exercise completed, that help animals control their energy budgets and body weights; there’s more going on than just how many calories you’ve put into your face,’ Dr Halsey explained.
An alternative explanation is that any birds that do gain weight become easy targets for predators and are quickly picked off, however, Dr Halsey believes this is unlikely.
Dr Halsey says this predation pressure would eventually cause evolution to remove that tendency from the population.
The latest study reveals birds are able to control their weight subconsciously.
WHY DO BIRDS SING?
Birds use their voices to communicate with other birds.
Sharp tunes are an efficient way to communicate over long distance, especially when you are small and live in dense habitats like rain forests.
Most bird species use specific calls to identify themselves and to communicate a nearby threat.
Birdsong is a specialised type of call used by many species to help them mate.
Almost exclusively a male activity, birdsong helps the singer to indicate he is fit, healthy and ready to breed.
The researchers say it could be that any fat birds become easy targets for predators and would be picked off, but Dr Halsey believes this is unlikely. That predation pressure would eventually cause evolution to remove that tendency from the population (stock)
‘Birds are capable of balancing energy intake by increasing their daily metabolic rate or decreasing the efficiency with which they are able to extract energy from ingested food,’ Dr Halsey said.
‘For a given amount of food, an animal can unconsciously adjust how efficiently it uses the energy from it either behaviourally, for example by changing wingbeat frequency or singing patterns to use more or less energy, or physiologically, in terms of digestive or cellular metabolic efficiency.’
Based on his findings, Dr Halsey believes the simplistic notion of how the body absorbs nutrients needs redefining to account for these subtle changes.
‘We need to remember that ‘energy in’ isn’t what’s shoved down the beak but what’s taken up through the gut and then what’s extracted by the cells; looking at it as just the amount of food consumed is too simplistic,’ he says.
‘And this goes for humans and other animals, not just songbirds.’
Source: Read Full Article