Found in temporary desert pools and mangrove swamps, some species of killifish can go without water for weeks at a time. And their eggs are no different: no water, no problem! Now, scientists have found that the eggs of two killifish species are so hardy, they can withstand being digested by birds, too. The finding may be the first firm evidence supporting an idea that has long held sway in scientific circles—that birds disperse fish.
Among the 36 Lakshadweep islands dotting the Indian Ocean, one is particularly famous for its bird life. Pakshi Pitti is a flat sandbar that several species of seabirds come to for breeding. Devoid of predators such as rats and cats, and even humans, it is the perfect place for these birds to nest in.
Except, year after year fisherfolk from the nearby populated island of Kavaratti come to Pitti and plunder its wealth of seabird eggs. On every visit they make, they collect 14%–45% of the eggs. About 72% of the islanders of Kavaratti are involved in poaching and trading eggs from Pitti, showing that the network is quite vast.
The eggs are sought for their supposed medicinal properties, and their trade, scientists fret, could have a huge impact on the island’s seabirds, especially terns, whose numbers have plummeted from 20,000 in the mid-1900s to 970 in 2014.
Pitti was declared a bird sanctuary and afforded legal protection to stop this age-old practice of egg consumption. But a lack of regulation is defeating that purpose.
To know more, read my report published today in The Wire.
Photo credit: Ravichandra Mondreti
Greater Ani is not your regular cuckoo. Rather than dump its eggs in the nests of other species it builds its own and raises its young alongside other breeding Anis. The eggs bump into each other with quite some force as parent birds turn them during incubation. Now, researchers have shown that Anis have evolved eggs with the added protection of an uncommon mineral that keeps the eggs from cracking under pressure.
Vaterite, a form of calcium carbonate, sits on the eggshell of some birds in tiny spheres of varying size. It is less stable and abundant than calcite – another form of calcium carbonate that primarily constitutes the shell. Vaterite gives freshly laid Ani eggs their white chalky appearance. As incubation progresses, it gets scratched, exposing patches of the pigmented calcite underneath. When scientists studying nesting Greater Anis (Crotophaga major) in the Panama Canal noticed this change in the egg surface they decided to look deep into it.
Read the rest of the story here at Chemistry World.
Photo credit: Christina Riehl
Birds prepare their eggs for the worst, whether the risk comes from predators or just the location of their nests. This Easter I wrote about some of these amazing eggs for BBC Earth. Here’s one of the birds eggs I highlighted in my piece for their sheer camouflage (besides their beauty):
Japanese Quail (Coturnix japonica)
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, and which hides the contour of the egg. This means the female must know the pattern of her own eggs.
To read about other wonderful bird eggs, click here!