Birds prepare their eggs for the worst, whether the risk comes from predators or just the location of their nests. Here are 13 birds with the MOST AMAZING EGGS:
(1) AFRICAN JACANA : These long-legged shorebirds build a flimsy nest that floats on water. When the bird steps o to the nest to incubate the eggs, the whole thing sinks. Fortunately the eggs are “water-proof”.
(2) FORK–TAILEDSTORM—PETREL : This Alaskan bird’s eggs ‘must survive on their own for long stretches in cold weather’, while the parents fly long distances scouting for food. Impressively, most of the eggs survive. They have a “high tolerance for cold” and can also “delay their hatching” if the parents are away for a long time.
(3) COMMONMURRE : Despite breeding high up on cliffs, these black-and-white seabirds lay their eggs directly o to the rocks, without building a nest to hold them in place. It sounds reckless, but the eggs are a “long, pointed shape that stops them from rolling off the cliff”. What’s more, the egg-shells have “cone-like structures that make the eggs SELF-CLEAN “. This is useful, because MURRE colonies are tightly packed, so the eggs get showered with ‘guano’ , as well as salty water from the neighbouring sea. When water lands on the eggs, its “water-repelling” shell causes the water to gather into “spherical drops”. As the “drops” roll off the eggs, they clean them.
(4) MALLEEFOWL : They bury their eggs in a mound of compost layered with sand. This keeps the developing chick warm, but it also needs to breathe. So, the eggshells have “large pores and are extremely thin”. The eggs are also large, relative to the size of the bird, which allows the chick to become quite fully developed. That way it can move on its own after hatching, when its parents will not be around. In addition, the eggs have a high “yolk content”. This lasts through their long incubation period, and helps the chicks grow strong so they can make their own way out of the mound.
(5) HOOPOE : (In Arabic the name is “HUDHUD” ) —— After building its nest in a tree cavity, the Hoopoe produces a “stinky brown secretion” and coats its eggs with it. Bacteria, in the secretion, make anti-microbial proteins, which guard the eggs against infection. The eggshell has “specialized tiny craters to hold the secretion in place”.
(6) AMERICANROBIN : The blue-green colour of a robin’s egg may signal to the male that the female, and therefore, the offspring, is healthy. Chicks emerging from eggs with “vivid hues” are more likely to be fed, by males, than those chicks from “pale eggs”.
(7) BLACKTERN : This bird builds “floating nests” out of damp vegetation. As a result, eggs are exposed to more humidity than those of ground-nesting terns, whose nests are dry. This ought to mean that the eggs should lose less water, because the difference between the water vapour levels of the egg and its surrounding is small. That is a problem, as for the chick to develop normally, the eggs must lose about 15% of its mass in water. So, the eggshell has lots of holes : it has 30 more pores per square centimetre than a similar-sized egg of a ground-nesting tern.
(8) JAPANESE QUAIL : A female Japanese Quail is selective about where she lays her eggs. She chooses a background that “matches either the colour of her eggs or their pattern”, whichever is “more striking”. If her eggs have only a “faint pattern”, the female chooses a site that matches their colour. But if they have a “strong pattern”, she goes for a site that blends with it, which hides the “contour” of the egg. This means that the female must know the “pattern” of her own eggs.
(9) GREAT TINAMOU : While the Great Tinamou is a drab brown, its eggs are glossy and coloured. That is odd : it is a ground-nesting bird, and they normally camouflage their eggs. But the Tinamou’s eggs serve a purpose. They draw the attention of other females and “signal them to use the sme nesting site”. The more eggs are piled up all together, the better the odds that any given egg will survive, as a predator “cannot eat them all”.
(10) RED–WINGED BLACKBIRD : If a Red-Winged Blackbird breeds at high altitudes, its eggs have a “smaller pore area ” than if it was breeding “near sea level”. This ensures that the eggs don’t get dehydrated, which is a risk high up where the atmospheric pressure is low.
(11) COMMON OSTRICH : Ostriches lay the largest eggs of any living bird. However, compared to the bird’s size, they are quite small. The eggs are “round with thick shells” giving them enough strength to bear the weight of the incubating bird “without being crushed”. Even though they are laid on the ground, the eggs are white. This makes them more conspicuous to predators, but, crucially it also “helps them keep cool in the heat of the day”.
(12) SNOWY OWL : They nest during the Arctic summer. It’s nest is a “scrape” dug out of the earth, where it incubates its eggs for about a month. The 24-hour daylight contains harmful ultra violet radiation, but, fortunately, the thick eggshell “acts like a filter” controlling which kind of light gets into the egg. Much of the ultra violet radiation is “blocked”, while the beneficial visible light is allowed in.
(13) COMMON CUCKOO : It famously lays its eggs in other birds” nests. Their eggs “mimic those of their hosts in colour and pattern, tricking the hosts into accepting them as their own. Cuckoo eggs also have unusually strong eggshells, so that even if the host bird figures out what has happened, it will find it difficult to “puncture” their egg. They start pecking at the shell sooner, and are “heavier than the host chicks when they hatch”.
—————- STRANGE & BEAUTIFUL EGGS.