Romantic gifts in the animal kingdom
On Valentine’s Day, many of us try to woo our loved ones with small presents. But did you know that gift-giving to impress a potential mate is not unique to humans? Many other animals, specifically insects, spiders and birds, routinely employ this strategy. Perhaps the below examples will inspire you to forgo the cliché flowers and chocolates this year and to opt for a more original gift.*
1) Mouse kebabs
The Great Grey Shrike (Lanius excubitor) is the largest of the European shrikes, a group of attractive raptor-like songbirds. Great Grey Shrikes cache prey – mostly small mammals and large insects – by impaling it on thorns and sharp sprigs. During courtship, males present their prey kebabs to females, which choose their mates according to the size of the impaled prey. Males with the most impressive “larders” tend to have the greatest reproductive success.
2) Silk-wrapped treats
Paratrechalea ornata is a spider found along rivers and streams in large parts of South America. Male P. ornata present their females with prey items which they often wrap in silk. If the female accepts the gift, the male mates with her. However, some males trick females by offering them worthless silk-wrapped gifts – pieces of vegetation or even pre-consumed prey items. As the gift wrapping hides the content, females cannot tell the difference between a genuine and a false gift so tricksters abound!
The Common Scorpionfly (Panorpa communis) is found throughout Europe. Scorpionflies (Mecoptera) are ancient, carnivorous insects with an abdomen that resembles a scorpion’s. During a lengthy courtship ritual, males secrete a nutritious salivary mass which the females feed on during copulation. The larger the secretion, the longer the mating duration and the higher the chance of securing paternity. As the quantity of saliva a male can produce depends on his condition, males in poor condition are picky about which females they court to avoid wasting their precious secretions.
4) Ornamented love dens
Bowerbirds are a fascinating group native to New Guinea and Australia. To attract females, males build elaborately decorated structures or “bowers”. The Satin Bowerbird (Ptilonorhynchus violaceus) male constructs his bower out of carefully arranged sticks and decorates it with blue, yellow, and shiny ornaments, including berries, stones, flowers and pieces of plastic. As the male gets older, he develops a preference for blue objects. Females visit the bowers of their suitors and choose their mate based on how impressed they are with his decorating skills and dancing abilities.
5) Fitness-boosting sperm packets
The Ornate Moth (Utetheisa ornatrix) is found throughout Latin America and the southern United States. During mating, the male Ornate Moth gives the female a spermatophore, a secretion containing sperm, nutrients, and pyrrolizidine alkaloids. The female then partly transfers this gift to her eggs. The alkaloids confer resistance to her offspring because they are toxic to potential predators. Females select large males with the highest alkaloid content which can be distinguished by a specific pheromonal scent. Nutritious spermatophores are popular “nuptial gifts” in the insect world. In Decorated Crickets (Gryllodes sigillatus), for example, the female ingests the spermatophylax, the protein-rich, gelatinous mass surrounding the sperm.
6) Soggy weeds
Great Crested Grebes (Podiceps cristatus) are large, aquatic birds native to Europe and parts of Africa and Asia. In spring, pairs perform spectacular courtship dances on the water. During the display, mates conduct a “weed-ceremony” in which they swim away from each other and dive. After a few seconds, they reappear with a bill full of aquatic vegetation which they then present to each other while moving their heads from side to side. Both parents actively take part in nest building, egg incubation and rearing of chicks.
Perhaps the most extreme example of male devotion is that of the Redback Spider (Latrodectus hasseltii), a member of the “widow spiders” native to Australia. During the process of mating, the much smaller Redback Spider male somersaults to place his abdomen into the female's mouthparts. The female then happily feasts on her lover while mating continues. Males which are not fully consumed by the female die of their injuries soon after mating. While this seems like an entirely selfless act by the male, offering up his body as a meal for the female actually allows him to improve his reproductive success by increasing the duration of copulation and thus the number of eggs fertilised. Additionally, females which have already eaten a male are more likely to reject subsequent males.
*The IUCN Red List team assumes no responsibility for a potential adverse reaction to the presentation of such an original gift.