#mating

Male Milkweed Butterflies Feed On Live Caterpillars To Steal Chemicals Which Function As “Wedding Gifts” To Their MatesButterflies are generally peaceful creatures. But not all of them. There are butterflies who are brutal, specifically male milkweed butterflies. These butterflies will do anything to please their mates, including feeding on young caterpillars — their family’s young. Yup. That’s how brutal some butterflies can be. But what reason would they have to target young caterpillars? The answer is, these caterpillars are a great source of chemicals, which the adult males use to produce mating pheromones. These pheromones serve as gifts to the females during courtship.Milkweed butterflies have been previously reported to feed on dead chemical-containing insects, but these butterflies doing the same thing on living insects is a first. PhD candidate Yi-Kai Tea, the lead author of the study, says that this is the first time such behavior was documented.“The behaviour does not fit neatly in the traditional modes of predation, parasitism, or mutualism, and so presents a new challenge to evolutionary theory. We have coined it ‘kleptopharmacophagy’ – chemical theft for consumption.”To supplement the chemical supplies they obtain as caterpillar juveniles, the butterflies engage in a behaviour known as “leaf-scratching”. “They damage [chemical containing] plants with their sharp tarsal claws, liberate plant juices and imbibe them using their long, curly tongues,” said Mr Tea.Scratching at live caterpillars, however, had never previously been reported. “Caterpillars are essentially bags of macerated leaves; the same leaves that contain these potent chemicals the milkweed butterflies seek out. To adult butterflies, they may simply be an alternative source of chemicals on which to feed,” said Mr Tea.The study has been published over at Ecology’s The Scientific Naturalist.Nature sure is weird, and could sometimes be horrible.(Image Credit: Yannkemper/ Wikimedia Commons)#Butterflies #MilkweedButterflies #Kleptopharmacophagy #Mating #Ecology #Entomology #Pheromones #Caterpillars

Why Do Gorillas Beat Their Chest?There are many sounds one might hear in the wild. The sound of a gorilla chest beating, however, is clearly in category all its own. For one thing, chest beating is a non-vocal act that can both seen and heard.Why does a gorilla chest beat? The initial assumption was that chest beats were used to scare off rival mates and attract females. Scientists curious about these non-vocal signals have begun to dig deeper. They wanted to know exactly how a chest beat was able to scare other males.  New research has uncovered that chest beat sounds revealed the body size of the chest beater. The larger the body size, the lower the peak frequency of the chest beat.Gorillas appear to be able to differentiate this difference in peak frequencies. A rival male, hearing the sound of another's chest beat, would be able to assess their opponent. The sound would help them determine if they should fight or flee the chest beater.Image: Dian Fossey Gorilla Fund#Gorilla #ChestBeating #PeakFrequency #Mating #animalbehavior

Fin-to-Fin Synchronized Swimming: Courtship In Basking SharksDespite their frightening appearance and gigantic size, basking sharks actually pose no danger to us humans, as they only feed on zooplankton. In fact, they might even have something in common with us.Just as a human being holds hands with his significant other while they have a romantic walk in the park, basking sharks also have their own: fin-to-fin contact while doing synchronized swimming. Scientists have caught a glimpse of the romantic world of basking sharks when they studied six of these aquatic giants for 123 hours.Matthew Witt, one of the people in the fieldwork, described the moments as “utterly phenomenal.” Jessica Rudd, who led the fieldwork, described it as “really fascinating.”Copulation may not have been recorded on camera, but Will is confident that that is what may have happened next, as these types of behaviors are often what happens before mating, as they have observed from other sharks.The research was recently published in the journal PLOS One.(Image Credit: University of Exeter and NatureScot)#BaskingSharks #MarineScience #MarineBiology #Courtship #Mating