Category Archives: Charismatic fauna

Male fireflies — vigor of youth an aphrodisiac

Flickr user James Jordan used a flash and a slow shutter speed to capture a firefly’s glow

By John Upton

Evenings are sparkling across great stretches of the northern hemisphere, where pulses of nitric oxide are being produced in fireflies’ abdominal cells to trigger harmonies of alluring green-yellow flashes. The nitric oxide briefly prevents parts of the cell that turn sugar into useful energy from consuming oxygen, allowing that oxygen to penetrate deeper into the cell, where it fuels a light-producing reaction involving a compound devilishly dubbed luciferin.

The constellations are cacophonies of courtships – the beetles have emerged from years of larval life spent underground, where they munched on worms and similar prey – and now they have mere weeks to procreate. Every night of their short adult lives is dedicated to procreation: Males fly and flash their wares, while females prop themselves on grass blades and invisibly judge their suitors. When a female likes what she sees, she flashes a response that draws him near.

While these unheard mating calls bring males and females together, new research published in Proceedings of the Royal Society – Biological Sciences reveals that something far more substantive determines the male’s success as a breeder.

The male wraps his sperm in a sustenance-rich package called a spermatophore, which is offered to the female. Adult fireflies do not eat, and spermatophores help provide females with energy needed to produce, bury and lay their eggs.

Fireflies emerge in warm months to breed / Flickr: davedehetre

Tuft University researchers Sara Lewis and Adam South discovered that the size of the spermatophore offered by a common North American firefly is more influential than the flashiness of his bioluminescence in determining whether he will sire young. The larger a firefly’s spermatophore, the more likely it is that a female will invite him to mount her — and, once they have copulated, the more likely it is that she will lay eggs bearing his young.

That means the virility of youth is crucial in helping a male firefly pass on his genes to the next generation.

“Our previous work has shown that making those spermatophore gifts is costly to males,” Lewis told me. “The gifts get smaller across sequential matings, and males’ mating rates slow down.”

The researchers also discovered hitherto unknown steps in the hours-long copulation of Photinus greeni, the species of firefly studied, which they explain in this video:

Our ape brethren — some kill, some love

By John Upton

Five to seven million years ago, as the climate cooled around them, our ancestors began to shy away from some of their hitherto ilk. The forefathers of ourselves and of the neanderthals stopped sleeping with the foremothers of the bonobos and the chimpanzees, and vice versa. We went our separate evolutionary ways.

A female bonobo. All she needs is love. / Flickr: Princess Stand in the Rain

While wanderlust scattered our predecessors around the world, the other apes remained exclusively in Africa. Some 2 million years ago, the African landscape was cleaved by a new cascade — the Congo River. Unable to cross this vast waterway, the other apes split into two species. The bonobos lived on the river’s south; the chimpanzees to its north.

With the extinction of the neanderthals 30,000 years ago, these two species of apes became our closest relatives. We share 98.7 percent of our genes with each of these species. Bonobos and chimps, meanwhile, share 99.6 percent of their genome with each other.

But those tiny genetic divergences belie dramatic differences in behavior that developed as the bonobos and chimps evolved into independent species.

A male chimpanzee. Natural born killer. / Flickr: Rickydavid

The chimpanzees developed and refined the darkest sides of the human character. They rape, they murder, they form gangs and posses that fight deadly battles.

The bonobos, meanwhile, came to adopt our make-love-not-war traits. They frolic and revel in merrymaking from the time they are babies until they die. They live in peaceful matriarchal societies. And they freely sleep with multiple partners to bond and have fun — including with same-sex partners.

The genetic differences and similarities between the three ape species were announced this week in the journal Nature by an international team of scientists after they sequenced a bonobo’s genome for the first time. Human and chimpanzee genomes were sequenced previously.

But the new genetic data doesn’t reveal why the two sides of the human character are divided so dramatically between our two closest relatives. The researchers speculate that our shared ancestor may have exhibited the entire spectrum of behaviors, just like us.

“Chimpanzees and bonobos each possess certain characteristics that are more similar to human traits than they are to one another’s,” the researchers wrote in the paper. “No parsimonious reconstruction of the social structure and behavioural patterns of the common ancestor of humans, chimpanzees and bonobos is therefore possible. That ancestor may in fact have possessed a mosaic of features, including those now seen in bonobo, chimpanzee and human.”

The Congo River is the world’s deepest river. Flickr / United Nations Photo

Cross River gorillas caught on video

By John Upton

There are two species of gorillas — Eastern and Western, both of which live exclusively in Africa. Cross River gorillas are an extremely rare subspecies of the Western gorilla. Just 250 of the great apes are believed to live today.

In a world first, using a camera hidden in a tree, conservationists working in Cameroon’s Kagwene Gorilla Sanctuary shot video of eight of them traipsing down a jungle trail.

Wait or scroll through to the 38-second mark to watch one beat his chest and charge past the hidden camera in an apparent show of aggression and domination.