Predator and prey5/26/2023 ![]() The moth can out-hear the sonar system ofthe bat in much the same way as a radar detector in your carwarns you of a police car in wait. North American moths can hearthe sonar calls of a big brown bat ( Eptesicus fuscus), oneof their most common predators, when it is almost 100 feet away.Even the most optimistic echolocation researcher will admit thisis much further than the distance at which the bat hears its ownechoes from the moth. This early-detection system works well for the mothbecause its ears are so sensitive. The moth actson this information by adjusting its wingbeat to fly away fromthe bat. This lets the moth know from whichside the bat is approaching and how far away it is. When a flying moth firsthears a bat’s echolocation calls, the sounds are faint and affectonly one of the moth’s ears. ![]() Since then, researchers around the world have continued tofill in the picture. It was the work of Kenneth Roeder and his students andcolleagues (notably Asher Treat) in the 1950s and 1960s thatprovided the initial insights into the hidden lives of moths andbats. Moths that can hear the approach of a bat and respondto its attack stand a 40% less chance of being consumed. ![]() Thenonsocial use for hearing has resulted in moth ears beingtone-deaf, though this limitation apparently has not hindered themoths much. Some moths do use sounds in theirmating behavior, but the relative rarity of this suggests thatbat-detection is the most common purpose for their ears. They usuallycommunicate to members of the opposite sex, or to others, usingchemicals called pheromones. When it comes to social communication, moths, for the mostpart, have little use for sophisticated ears. When we listen, our ears pickout thousands of subtle changes in the pitch of the voices we usefor communication. Our ears, by contrast, haveover 15,000 sound receptor cells each, but we use our sense ofhearing for more complicated tasks. The ears of moths were the firstto be discovered and still amaze us with their exquisite design.Depending upon what family they belong to, moths have ears ontheir waists, their abdomens, or their faces, and they equip themwith only one to four nerve cells. Today, ears that serve as bat detectorsare found in certain moths, lacewings, and preying mantises andare suspected in some beetles. Some insects moved back intothe day, and others remained nocturnal, but evolved a new sense:a way of hearing the echolocation calls of hunting bats. Becoming nocturnalinitially solved these problems, but once bats evolved theirsonar into the sophisticated tool it is, the night was no longersafe.ĭifferent insects adopted different strategies to cope withsuch efficient nocturnal predators. One ofthe best ways of remaining uneaten is simply to be very still.This tactic, however, presents problems when it comes to findingfood, mates, or places to rear young. Many use visual defenses, such as camouflagingthemselves or packing their bodies with noxious chemicals andthen advertising their distastefulness with bright colors. Staying alive during the day is a complicated affair forinsects. The eyes of mostnocturnal vertebrate predators were poorly designed for the dark,and as a result, many insects like moths, caddisflies, andbeetles evolved a nocturnal lifestyle. More people should watch it.While many insects are fair game for bats, not all of themare easy to catch some moths have evolved remarkable strategiesto evade bats.īefore the appearance of bats, more than sixty million yearsago, the night was a relatively safe time for insects to moveabout, free from most hungry birds and mammals. Prey does something similar, but Predators comes with a suite of its own ideas and expands the universe in interesting ways.
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