Many white bird species, such as gulls and geese, have black wing feathers. This is because black colour is the result of melanins that are incorporated into the feather while it is growing. Melanins make feathers stronger, especially in birds that fly long distances.
But among birds, parrots are unique: they sinthesize their bright reds, oranges and yellows, with pigments that are not found anywhere else. Unlike other birds, their colours are not derived from their diet.
These unique feather pigments may serve more functions than just visual communication in parrots, according to Edward Burtt, a professor at an American university. He noticed that some microbes, -Bacillus licheniformis, Bacillus pumilus and other Bacillus species- were eating feathers, and he also found that green feathers were resistant to bacterial degradation.
Dr Burtt's team first classified colourful feathers from thirteen parrot species into six general colour categories: blue, green, red, yellow, black and white. The team placed differently-coloured feathers into a bacterial medium containing Bacillus licheniformis, a bacteria that degrades feathers. They measured how much the bacteria broke down the feathers and compared this between feathers of different colours. The investigation resulted in clear conclusions: feather colour affected the bacterial degradation: white feathers degraded more rapidly than black, blue, green and red feathers.
Biochemical analysis of yellow molecules found that they are formed by small carbon chains with few double-bonds, while red ones have longer carbon chains with more double-bonds. In short, red molecules are bigger than yellow ones and have stronger bonds, so they should be more difficult for bacteria to break down.
Adapted from an article in guardian.co.uk, based on Burtt, E., Schroeder, M., Smith, L., Sroka, L. and McGraw, K. (2010) Colourful parrot feathers resist bacterial degradation. Biology Letters DOI 10.1098/rsbl.2010.0716
But among birds, parrots are unique: they sinthesize their bright reds, oranges and yellows, with pigments that are not found anywhere else. Unlike other birds, their colours are not derived from their diet.
These unique feather pigments may serve more functions than just visual communication in parrots, according to Edward Burtt, a professor at an American university. He noticed that some microbes, -Bacillus licheniformis, Bacillus pumilus and other Bacillus species- were eating feathers, and he also found that green feathers were resistant to bacterial degradation.
Dr Burtt's team first classified colourful feathers from thirteen parrot species into six general colour categories: blue, green, red, yellow, black and white. The team placed differently-coloured feathers into a bacterial medium containing Bacillus licheniformis, a bacteria that degrades feathers. They measured how much the bacteria broke down the feathers and compared this between feathers of different colours. The investigation resulted in clear conclusions: feather colour affected the bacterial degradation: white feathers degraded more rapidly than black, blue, green and red feathers.
Biochemical analysis of yellow molecules found that they are formed by small carbon chains with few double-bonds, while red ones have longer carbon chains with more double-bonds. In short, red molecules are bigger than yellow ones and have stronger bonds, so they should be more difficult for bacteria to break down.
Adapted from an article in guardian.co.uk, based on Burtt, E., Schroeder, M., Smith, L., Sroka, L. and McGraw, K. (2010) Colourful parrot feathers resist bacterial degradation. Biology Letters DOI 10.1098/rsbl.2010.0716
Red parrot feathers resist bacterial degradation
ResponderEliminarThis article talks about the behaviour of bacteria in parrot feathers depending on different colours.
The main idea is that bacteria broke down white feathers more rapidly than black (or another colour) ones.
It explains that parrots synthesize their feather colours with pigments that are not found anywhere else.
According to Edward Burtt these colours have a lot of functions.
Dr Burtt’s team first of all classified colourful feather into six colour categories. Secondly they placed the different feathers into a bacterial medium containing Bacillus licheniformis, finally they measured the feathers that were broke down by the bacteria and compared the results between the different colours. In conclusion white feathers get degraded more rapidly than other colours.
The most interesting idea about the article is that yellow molecules are formed by small carbon chains with few double-bonds and red ones have longer carbon chains with more double-bonds. This means that red molecules are bigger and stronger than yellow ones.
We think that these types of experiments are not very relevant to the advance of science, but it's very interesting to know this information.
Carla López Moreno
Gemma Nogués Camps
B1A
Muchas especies de aves blancas tienen plumas negras, que esto es el resultado de las melaninas que se incorporan a la pluma. Las melaninas hacen las plumas más fuertes, especialmente en las aves que vuelan largas distancias.
ResponderEliminarEntre las aves, los loros son únicos, porque tienen pigmentos que no se encuentran en ningún otro lugar. A diferencia de otras aves, sus colores no son derivados de su dieta.
Edward Burtt se dio cuenta de que las plumas verdes eran resistentes a la degradación bacteriana.
El equipo del Dr. Burtt clasificó las plumas de colores en seis categorías generales de color. El equipo colocó plumas de diferentes colores en un medio con bacterias que degradan las plumas.Después del experimento llegaron a unas conclusiones: las plumas blancas degradan más rápidamente que las plumas negras, azules, verdes y rojas.
Opinión:
Es un tema que no nos puede aportar mucho en nuestra vida pero es interesante.
Estela Granados
Noemi Castro
Moltes aus blanques tenen algunes plomes negres, gràcies a la melanina, aquestes plomes són més fortes, especialment per a les aus que migren i recorren llargues distàncies.
ResponderEliminarPodríem dir que els lloros son les aus amb pigment únic, ja que no es pot trobar a cap altre lloc aquest pigment. A les altres aus, a diferència dels lloros, els seus colors procedeixen del seu menjar.
Un estudi que va fer Edward Burtt es va adonar que les plomes de color verd eren més fortes (resistents) a la degradació bacteriana.
Van classificar els diferents colors en sis categories generals, això ho va fer el equip del Dr.Burtt, aquest mateix equip va col·locar els diferents colors de les plomes en un medi amb bacteries que degraden les plomes. Va arribar a una conclusió: les plomes blanques es degraden més ràpidament que les plomes negres, blaves, verds i vermelles.
Opinió:
Nosaltres no sabíem això i ho trobem com una curiositat interessant.
Macarena Lopez
Samara Masero
Meritxell Puchol
Red parrot feathers resist bacterial degradation:
ResponderEliminarThe article talks about the pigments of the feathers from the parrots.
Some scientifics discovered that feather colour affected the bacterial degradation, being white feather degraded more rapidly than black, blues, green and red feathers.
In our opinion it’s not useful that scientifics spend their time researching about parrots instead of investigating about lots of diseases that there are in the world.
Sandra Cuesta
Paola Vella
Noemí García