The Gruesome Side of Gift-Giving; The Nursery Web Spiders Story
Giving gifts to the hosts when attending an event is a sign of respect and gratitude for humans, but for some spiders gift-giving is a struggle between life and death.
A new study published in the journal Biology Letters revealed that male nursery web spiders tends to bring gift to female when mating to avoid being eaten alive.
According to the report from Los Angeles Times, researchers analyzed a series of more than 280 spider couplings in a lab. They discovered that male spiders that brought no gift for their partners were 15 percent most likely to cannibalized, while males with gift have only 3.6 percent chance of being eaten alive.
Science Magazine reported that 15 male nursery web so spiders that showed without gift were eaten alive before by the female before copulation, while one males spider that brought a gift were still eaten but after copulating.
Researchers also noted that the size of the gift may affect the duration of copulation. Bigger gifts tend to be rewarded with longer sex, increasing the amount of sperm to be transferred. On the other hand, male spiders with much smaller gift were cut-off during copulation.
Male nursery web spiders, just like male humans, are very clever. There are times that these spiders wrap inedible plant seeds and their leftover meals in their silk and present to female spiders. However, female spiders, just like female humans, can determine fake gifts.
When the female spider found out that she received a fake gift, she terminates their copulation with the male spider. In order not to anger the female spider and ensure their safety, male spiders tends to play dead. But oftentimes, these playing dead spiders were also eaten by the females.
The researchers then propose that the gift-giving behavior of male nursery web spiders has evolved partly as a counter-adaptation to female aggression.