Echolocation

When people think of echolocation they rightly think of bats but there are several different types of animals that use echolocation.

Bats are split into 2 orders: microchiroptera and megachiroptera.

Microchiroptera which are smaller of the 2 orders. These bats use their echolocation while hunting and for navigating this has allowed bats to inhabit a variety of different habitats and to eat different food sources This ability has allowed bats to make up 25% of all mammal species that is the same % of all other non-rodent mammal species combined.

25% Bats 25% non rodent species and 50% of all mammal species are rodents this shows how successful bats as a species are.

Echolocation works by the bat makes clicks from their mouths bounce off an object and goes back to the bat which allows the bat to know how far away the object is. you may have seen the noses of bats look weird and this just allows the bat to better read the echolocation.

The majority of microchiroptera use their echolocation to hunt insects such as the Common Pipistrelle, insects can detect echolocation even before the bat can detect them so they will know if a bat is hunting them and will try different methods. There is now an arms race between insects and bats some moths such as tiger moths us clicks to either warn the bat it is poisonous or the clicks are used to jam the bats echolocation either way tiger moths are 5 times less likely to be caught than non clicking moths. The first strategy is to fly away but if the bat is catching up it will make sharp turns to try and flank the bat and get to a safe zone. If this fails the insect will do a last ditch attempt to escape and drop to the ground and stop moving hoping the bat can't find them.

Insects seem to be winning the arms race but some bats are fighting back such as the whispering bat who's echolocation is quieter than most other bats up to 40 times quieter and most insects can't detect this frequency until the bat is 3.5 meters away compare to 30 meters away for most other bat species.

Other bats use their echolocation to hunt other food sources, the greater bulldog bat in South America that hunts fish using echolocation looking for ripples in the water and using their large tail membrane as a net to catch the fish.

Bats use echolocation at different frequencies so using a bat detector you can tell which bat is flying above your head.

Megachiropter which are the large fruit eating bats and for along time it was believed for a long time that megachiroptera did not use echolocation but has been discovered that they do, these bats make noise from there arms which then bounce of an object and back to the bat similar to microchiroptera. The echolocation used by megachiroptera is a far more basic form of echolocation and is mainly used to help in navigation. Fruit bats are important pollinators and pollinate over 300 different species of fruit. When you see bats hanging upside down this is them in a relaxed straight unlike humans when we relax our hands it opens with bats when they relax their feet and arms it closes.

Some facts you may not know about bats is that bats evolved from an animal related to flying lemurs which are the closest non primate relative to humans so bats are closer related to humans than to insectivores such as shrews. Bats also have fairly good eye sight which is similar to humans.

Terrestrial mammals have also evolved to use echolocation; one of these mammals is the shrew; some of the shrew species that use it are the common european shrew and northern short-tailed shrew.

The other mammal is the tenrec which inhabits madagascar, these animals have evolved to resemble hedgehogs, mice, shrewa and opossums. Some species such as the shrew like tenrec have evolved to us echolocation.

It's believed shrews and tenrecs use echolocation to help navigate rather than to help find food.

Some birds also use echolocation such as the Mexican oilbird and the cave swiftlet found in countries such as Java and Bali. These birds use their echolocation to help navigate as they are both found in caves. The echolocation used by birds and terrestrial mammals is far more basic than the echolocation used by bats in the microchiroptera order.

Thanks for reading

Dane Stewart


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