Humans aren’t the only animals who give gifts

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While you are thinking about the perfect gifts for loved ones this holiday season, male scorpions make the perfect spit balls for theirs. Although spit balls seem unattractive to us, the female Scorpio – a tanned, slender, winged-bodied insect less than an inch long – finds the nutrient-packed saliva ball a tasty treat. In fact, while she eats the gooey goodness, she rewards the male with an opportunity to mate with her.

And scorpions aren’t the only animals to offer besides humans; spiders, squids, snails, birds and many more strive to impress with gifts. Most of the gifts exchanged between these species are wedding gifts – that is, everything (beyond sperm and ovum) that is exchanged during mating or courtship to increase the donor’s chances of reproduction.

Bridal gifts range from prey wrapped in fine silk to proteins and hormones that increase the chances of mating and offspring survival. “The variety of things you find in wedding gifts is simply fascinating,” says Adam South, assistant professor at the Cummings School for Veterinary Medicine at Tufts University, who has studied sexual selection in arthropods for 15 years. .

Benevolent insects

One of South’s favorite bridal gifts is the one from the firefly. During sex, male fireflies provide their partners with gift packages of semen and nutrients called spermatophores. When transferred to the female, the spermatophore fertilizes her eggs and provides her with protein and nutrition. Fireflies do not eat in adulthood, so the extra food extends its lifespan.

Mating fireflies. (Credit: Andreas Kay / CC BY-NC-SA 2.0 / Flickr)

The spermatophore also contains chemicals that increase the number of eggs it produces. And, as if that weren’t enough, the male packs the spermatophore with a defensive substance called lucibufagin which protects the female and her offspring from being eaten. “The firefly system is very honest and cooperative,” South says, reflecting on the many gifts male fireflies bestow on their partner and offspring. “Maybe I’m just a hopeless romantic at heart, but I just think it’s a great story.”

Man mugwort cricketsor mugwort grigs, on the other hand, offer self-sacrificing bridal gifts to women. While they mate, he lets her chew on her fleshy hind wings – sucking up hemolymph (an insect equivalent to blood) for food. “If the male has these nice, big, cool wings, then she’ll nibble on them and they’ll mate for longer,” South says. Females can be demanding, however. If the male’s wings are already shredded, she will refuse. So, it is generally “one and done”For male cricket.

Mating mugwort crickets. (Credit: Kevinjuge / CC-BY-SA-4.0 / Wikimedia Commons)

Nursery spiders also present a meal to their potential partners, but it is not found on their body; the males wrap a freshly caught insect in silk and offer it to the females who catch their eye. Like the sagebrush cricket, she may refuse if that sounds unattractive. When it does, male nursery spiders become shameless new gifts – they simply add more wrapping to the gift and present it again to the same female.

Instead of pushing it away, the female usually accepts this second offer and mating ensues. Scientists attribute this change of mind to chemicals that the male adds to his silk to increase the attractiveness of the gift to the female. (Or maybe she’s just a cinch.)

Big-hearted birds

Perhaps the most horrible gifts are those given by large gray shrikes. The men put on macabre exhibitions of their hunting skills in impale a prey on thorns and twigs where females are likely to see them. A female shrike selects a mate based on her macabre collection, and during courtship, the male may offer kills directly to his potential lifelong mate. Bigger items like snakes and lizards, of course, get him more points than smaller ones like bees and grasshoppers.

Large gray shrike. (Credit: Marek Szczepanek / CC BY-SA 3.0 / Wikimedia Commons)

In a rare, cross-species exchange, crows are known to give gifts to humans. “We recorded it, and many people witnessed it,” says John Marzluff, professor of wildlife science at the University of Washington and author of Raven Gifts: How Perception, Emotion, and Thinking Make Clever Birds Behave Like Humans.

Marzluff has heard several stories of raven gifts: A crow gave away a woman’s false teeth. Another, after being freed from a fence, brought prey to his human rescuer. Through the Internetpeople tell stories of crows leaving them little treasures in exchange for food. “They are very social animals,” says Marzluff, “and there is no reason to think that they would not bond or preferably associate with other species that are important to them. “

Whether out of friendship or love, gifts between animals are more common than you might think. “You can see the basis for this behavior in many different taxa,” South says, “so it’s probably something that has evolved a number of times because it’s critical to the reproductive capacity of both males and females. “

The fundamental motivation behind giving gifts – to find a mate or to form a bond – is a good reminder to us humans of the real purpose of holiday gifts: to create and strengthen social relationships so that our loved ones continue to enjoy. blossom. Don’t take a page out of the nursery spider book and disguise an unappreciated gift with more wrapping paper, as it is less likely to work in the human realm.


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