Scientists: Flies and penguins are no less romantic than people

Across the animal kingdom, lovers exchange gifts with the objects of their passion

Every year, Americans spend about $25 billion on Valentine's Day gifts. When it comes time to propose, a lover spends on average about $6,000 on an engagement ring, etc. But such large gifts are not just for people. Research across many species has found that romantic relationships often work better when they are accompanied by gifts.

Photo: Global Look Press

Scientists have proven that even some of the creepiest and creepiest creatures on the planet take part in the distribution of love gifts. Male flies, grasshoppers and some spiders offer free food to the objects of their affection.

“It’s like giving her a box of chocolates,” — explains ecologist Joris Cohen. He added that nuptial gifts in the wild usually apply to species that have separate male and female sexes and in which males give energy or special substances to females for laying eggs.

Dancer flies, which live on northeastern United States and Canada, differ from other animal species in that their females are more beautiful than their males. At dawn and dusk, females raise their wings, sucking in huge amounts of air to inflate their bright orange abdomens, which turn into disks about a third the size of a dime, allowing mosquito-sized males to see them silhouetted against the horizon.

“They look like little insect peacock tails,— describes biologist Darryl Gwynne. — When they really start breeding, there will be thousands of them.

And, like male peacocks, these insects sacrifice physical fitness for sex appeal: their scaled legs and plump bodies make them clumsy, so they are more likely to get caught in a web than males of this species.

Having a big belly, according to selection and evolution researcher Luc Bussiere, can indicate to a male that the female is in peak mating form.

«You can understand why males would want to mate with really fat females, — he explains. — First of all, she probably still has balls. And, more importantly, these eggs are probably almost ready to be laid.» But females who seem large and fertile can deceive males with their pumped up shiny bodies.

Male pisaurid spiders may also be liars, catching insects and wrapping them in webs to attract the attention of females and avoid being eaten. But males, who are not so good at hunting insects, often give the female fake food instead.

«In some cases, males actually cheat by passing on something unattractive, — notes Bussiere. — The fact that they gift wrap it allows them to hide inedible items inside.»

Sometimes gift-giving males can be quite bloodthirsty. The male great gray shrike, native to Europe, North Africa and Asia, attracts females by offering them food. But males don’t just carefully place the gift on the ground — they impale their prey on thorns and sharp twigs in places where females often pass. Edible gifts include rodents, lizards, large insects and even other birds. For the female, the larger the gift, the better.

Great gray shrikes — socially monogamous birds. The study found that when they cheat, they often do more work for their other lover. Observations of 22 males who successfully gave gifts to both their mate and another female showed that the male required on average four times more energy. More often, gifts not for the mate were rodents or other birds that were difficult to hunt, while the female usually received only insects, and sometimes no gifts at all.

Not all birds resort to violence as one of their romantic gifts. Some penguin species give stones to their mates during mating season. Subantarctic penguins are known to carefully select the smoothest pebbles they can find, while Adélie penguins sometimes sneak pebbles from their neighbors' nests to speed up the process. A gift in the form of pebbles is as practical as it is attractive — Birds use stones to build their nests. In the harsh Antarctic climate, where there are no trees or other plant materials, pebble nests elevate eggs and chicks above the cold ground.

«The male reproductive strategy of giving wedding gifts may not be common not a single animal that reproduces sexually, — concluded ecologist Monica Lodi. — If we do not go beyond this general habit, we will draw incorrect conclusions about the prevalence of this behavior or this way of life.