Qs people asked me on science and my replies to them - part 247

There is currently no consensus regarding the definition of life. One popular definition is that organisms are open systems that maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment, respond to stimuli, reproduce and evolve.

Even if we take all these parameters into account, the universe as a whole cannot be considered as living because the inanimate part of it is more than the living part. The universe doesn’t do all these things mentioned above.

Then how can you consider it as living?

However, some people come up with strange ideas and explanations. Like this one:

The universe: inanimate space or a living organism?

Q: What is the scientific explanation behind flamingos changing their colour from white to pink as they age?

Krishna: The name flamingo means in Portuguese/Spanish - actual word ‘flamengo’ -  ‘flame-coloured’ which has a  relation to their vibrant feathers, however, they aren’t actually born pink. Instead, when flamingo chicks hatch they have a dull grey or dirty white colouration to their feathers. Young flamingos flaunt grey/white colour feathers and only develop their pinkish hue after delving into a diet of brine shrimp, crustaceans and blue-green algae – food that would likely kill other animals.

Pink and orange flamingos Image source: google images

Flamingos tend to live in inhospitable, relatively remote wetlands – lakes so alkaline in pH it could burn human flesh off the bones. Within this water, however, is an untapped resource of food like crustaceans, cyanobacteria and diatom algae which are actually re-orange in colour due to a chemical known as beta carotene. All of these foods can be dangerous to many other animals as they contain toxic chemicals called carotenoids which are also found in carrots, sweet potatoes and spinach.

So, how are flamingos able to eat these foods without falling seriously ill? Thanks to their specialised metabolism, the birds are able to process these harmful chemicals in the liver, breaking them down into functional components and pigments. It’s these pigments that eventually stain a flamingo’s feathers.

Once eaten, enzymes in the flamingo’s digestive system break down the beta carotene and the red-orange pigments are absorbed by the fat in its liver. These fats are then deposited in the flamingo’s feathers and skin as it grows. As their diet is almost exclusively from sources rich in beta carotene, flamingos gradually become pink. 

The colouration of flamingos can vary because carotenoid levels in algae and crustaceans also vary across the world. Flamingo species found in the Caribbean are often bright red or orange, while those in drier areas tend to be paler pink in colour. Without a high enough concentration of beta carotene-rich food, the pink feathers would moult away and new paler feathers would start to grow. Their skin, mucous membranes, egg yolks and even fat are stained pink and similar colours like orange.

Although the sight of a colourful flamingo is a familiar one, there are a number of ways they can lose their distinctive hue. Carotenoids themselves can bleach in the sun, something the flamingo species Phoenicopterus roseus combats by preening themselves directly with pigments secreted from their glands, giving their feathers a lustrous pink shine.

 It’s also worth noting this only works with pink pigments – you can’t feed a flamingo blue food dye and hope it turns sapphire.

Interestingly, while flamingos are pink primarily as a by-product of their diet, their colour takes on a special significance during mating season. As a flamingo, the pinkier you are, the healthier and better quality you are – it’s a direct reflection of how good you are at foraging. And you can use that to attract a mate in a courtship ritual.

Watch this beautiful court ship dance of flamingos

The flamingos will pair off within their group based on who’s the best dancer and who has the greatest colour.

Flamingos are also one of few birds that feed their young with crop milk. This is different from the milk produced by the mammalian species, the crop milk produced by flamingos is a highly nutritious bright pink secretion made in an adult’s throat, and is so densely packed with carotenoids that when breeding season is over both male and female parents often appear white, losing the pink colouration from their feathers.

Despite numerous reports of blue flamingos appearing online, there is no evidence to suggest these are anything more than internet hoaxes. However, there have been a number of sightings of a rare black flamingo in Cyprus. It is thought that it suffers from a pigment condition called “melanism”, causing an overproduction of melanin making it black.

Watch this rare black flamingo ....

However, not all flamingos will be involved in the dancing ritual – and many of these birds won’t be pink at all. Flamingos – both male and female – can lose their pink pigments outside of breeding season. That’s because the breeding is so intensive and so much of their food is used for their chicks.

The collective noun for flamingos going about their everyday activities such as feeding, is a ‘stand’. However, when in the midst of their courtship dance, a group of flamingos are known, amazingly, as a flamboyance.