Birds spread insect populations by flying their eggs to new locations

By Pol Allingham via SWNS

Birds spread insect populations after eating them by flying their eggs to new locations, reveals new research.

Flightless pregnant stick insects are being eaten and their eggs are transported hundreds of miles across landscapes that would usually be insurmountable for a walking bug, say scientists.

The eggs survive the journey in the avian intestinal tract, the experts believe.

They already suspected birds spread the insects, but have struggled actually watch a bird eating a pregnant bug and releasing its eggs elsewhere.

Taking a different approach, researchers at Kobe University, Japan, analyzed relationship patterns of Ramulus Mikado, a common Japanese stick insect.

Dr. Suetsugu Kenji said: “We made use of the idea of ‘genetic isolation by geographic distance’.

“According to this idea, when individual dispersal distances are smaller, such as in flightless insects, the accumulation of genetic mutations eventually leads to a positive correlation between genetic differentiation among locations and the geographic distance that separates them.

“Astonishingly, amidst a sea of limited active dispersal, we discovered identical genotypes jumping across vast distances, strongly indicating the past occurrence of passive long-distance genetic dispersal.

“The eggs of most insect species are typically fertilized just before being laid, relying on sperm stored within the female insects after copulation.

“However, in some stick insect species, females are parthenogenic, that is, they can produce viable eggs without fertilization.

“This finding invites researchers to delve deeper into the mechanisms of dispersal in various species and challenge long-held assumptions about the fate of organisms devoured by predators.”

The team discovered closely related genes separated by hundreds of kilometers.

Stick insects earned their name because their main strategy for survival is avoiding being eaten by predators, while many plants rely on something ingesting their fruit and dispersing their seed.

In light of the research, experts writing in Proceedings of the Royal Society B Biological Sciences said: “Death is not the end.”