Why Bird Eggs Come in Different Shapes
The shape of the bird’s eggs varies considerably. Brown hawk owls pose round eggs melon. Maleo Indonesia have the shape of watermelon. The last sandstones of errors fall as a lawyer. What is this diversity of forms?
In 1966, Neal Smith, a specialist staff at the Smithsonian Tropical Research Center in Panama, explained the way eggs gulls teardrops. These birds nest on the oceanic rocky cliffs, where the danger of round things rolling over the edge is high.
Thus eggs, weighted at one end, roll in a closed circle if they are affected. Another theory suggests that the pointy ends of the eggs fit better under the heel, an unleaded area in the abdomen, incubating adults.
This raises the question: if conical eggs can not roll over the cliff, why are seabird eggs weighed less at one end? Why jeopardize the survival of your eggs? Another said that the number of eggs put so much changes form. But no theory has so far provided a broad interpretation.
Six researchers from four countries and many disciplines – evolutionary, computer, mathematical and physical biologists – have carried out the first comprehensive study to explain the wide variety of forms.
“I think combining different views on the shape of eggs, training function has allowed us to explore the evolution of bird eggs in a new and synthetically,” Mary Caswell Stoddard, Assistant Professor at Princeton University and author Principal of the study, says the cable.
The Stoddard team analyzed an enormous amount of data from 50,000 eggs of 1 400 species of birds, both living and extinct.
When evaluating egg shapes according to asymmetry and length, the researchers found that they occupied an oval continuous tower bezel.
This contradicts previous studies that have classified eggs into separate classes based on limited samples.
Right in the middle of the broad spectrum is the graceful Prinia a sizeable flamboyant grasshopper found in some parts of northern India. Their eggs are neither too round, also conical or too long. Most eggs are consistent with this egg shape rather than the familiar one.
What holds the egg together and gives it shape? One might think that this is the shell, but even after removing the egg it still maintains its shape.
The authors propose that the bilayer of the soft membrane of it together. Thus, acting on the pressure membrane probably affects the final shape in which the egg. The egg absorbs the water in the development of the housing shell, creating an internal pressure. External constraints are also pressed against the membrane.
What could these pressures? The researchers developed a hand index to evaluate the effectiveness of the flight and have correlated with the shape of the eggs.
The narrow birds pointed to wings, like swifts and sablonneurs, of high rank in the index, like owls, with short wings and rounded tips. Strong drivers, those with a high index index, tend to have oval or conical eggs.
“We have found that a large-scale, egg shape is related to the ability to fly in birds,” Stoddard said.
“We believe that birds, to keep the body smooth for flight, developed and asymmetrical elliptical eggs to increase the volume of eggs without increasing the width of eggs – is advantageous for narrow and refined body.”
As and how the birds evolved from small terrestrial bipedal dinosaurs and went to heaven, their bodies lose weight and become more refined. It also limits the width of the oviduct. But birds can not reduce the size of their eggs to match the width of the reproductive tract.