Written by Staff Writer at CNN
A unique form of vulture is now observed in a range of native African bees in which males are among the most carnivorous of animals, and females among the least so.
Bees found in the African savannah are associated with the insect-rich Lolla Valley — but researchers identified a single carnivorous vulture that exists nowhere else in the world, including in that region.
‘I am a bee’
Males were found to be the predators in the swarm. Researchers studying vulture bees during the 2014-2017 round of the Malawian survey for the Senegalese and the Ivory Coast project called “The Changing Role of Honey Bees in the National and Ecological Economy” noticed that the birds were located at the most larvae-based sites.
These insects are classified as “pygmy” among their relatives that eat insects in an advanced manner, as scientists haven’t described a feathered insectivore.
The research was conducted in 2013 by Edward Kolape, now a postdoctoral fellow at Cardiff University, while he was working on what is now the second edition of the Malawian survey, published last week in the international journal PLOS One.
“I noted that the vulture was the only bird in the swarm and didn’t move and was covered in specialised digestive bacteria known as tracheae,” Kolape explained in an email.
Scientists are calling these insects “pygmy” vultures, which eat insects (file image) Credit: Alice R.Y. Chen/Alamy
“I approached the population management manager who was a vulture specialist and I asked if I could collect some specimens to experiment with.”
In his follow-up study in 2014, Kolape analyzed specimens of bees used for the Malawian survey to determine whether they may be predating upon mollusks that allow the bees to find larvae.
He said he found “nothing to suggest I had been wrong” to think that vultures were ripping through larvae on a “comparable basis” to insects.
“It has been theorized that vultures might use special stomach organ structures similar to parasites,” he said. “In order to obtain these I asked my colleagues to look at how some entomological organisms also collect nectar from insects and by extension, larvae, which then help it to cultivate colonies and to build up and spread its natural microbiota.”
This enabled him to establish how different bacteria are associated with the eating habits of different species.
Factbox: Insect-eating birds
“What I found was that males eat primarily any larvae and females feed mainly on eggs, which include larvae,” he said.
“The male (male vulture) would have, if I understand it correctly, absorbed the larvae from the ‘pretty boy’ bees” he said, referring to vultures that feed on beneficial insects.
In the male vulture, the bacteria prevents any residue from the diet, and perhaps even deprives it of a nutritional richness in the meat.
In females, the mitochondria — the energy-producing part of the cells — are stimulated by bacteria, which means that the mollusks do not get a nutritional boost either.
Kolape said he plans to continue the work, to determine why bees with the specific bacteria are abundant and spreading.
“(Vultures) are very important because they eat carcasses and clean their territory,” he said. “It is a `smoke and fire’ system that conserves resources that are poor in certain areas like Lolla Valley.”