One life: Bats
29 October 2020
There are more than 1300 species of bats in the world, and they live in every continent apart from Antarctica. They vary greatly in size, some have a wingspan of 6-feet, whereas others are the size of a bee.
They are among the most misunderstood of animals – routinely feared and loathed as sinister denizens of the night. Except in China, where bats have long been celebrated as symbols of good luck and happiness. Their images embellished the palaces, thrones and robes of emperors.
Megabats and microbats
There are two main groups of bats; megabats and microbats. Most of the bat species are megabats. Megabats are not always bigger than microbats, but they are different in other ways. Many species are in fact bigger, and they all have bigger eyes as they do not have echolocation like microbats do. They also have a stronger sense of smell than microbats, which also helps them to find food.
Megabats drink nectar, eat fruit and pollen, and live in tropical areas. Whereas microbats feed on insects. The vampire bat is a microbat that is an exception to the rule, as they feed on blood from other mammals; mainly livestock and wild animals.
Nature’s conservationists
All of these species of bats play a vital role in the ecosystem, and bats are nature’s natural conservationists.
Microbats consume millions of insects each night. This means that they serve as a natural pest control for farmers, requiring the use of fewer chemical pesticides. This also saves farmers millions in costs!
Fruit-eating bats help to pollinate rainforests and other tropical areas, as they disperse the fruit seeds as they eat them. This helps against some of the damaging effects of deforestation for logging and agriculture.
Other bat species drink nectar from plants, and this helps to pollinate many species of plants, allowing them to fruit and to feed other animals. Another tool against deforestation.
Even bat droppings are valuable as a rich natural fertilizer.
Bats are “keystone species” essential to some tropical and desert ecosystems. Without bats’ pollination and seed-dispersing services, local ecosystems could gradually collapse as plants fail to provide food and cover for wildlife species near the base of the food chain.
Amazing flyers
Bats are the only mammals that can fly. Their flight is so complex that it truly is inspirational. All of the acrobatic swoops and turns bats can do are so complicated and unique that they are used to inspire designs for flying robots.
Bat flight has in fact been referred to as the “Holy Grail of aerial robotics”.
Inspirational flyers
Scientists have studied bat flight, and they have used their patterns and agility to create a robot based on their flying skills. The “Bat Bot” can fly, turn and swoop just like a real bat.
The idea is that one day these bat bots will be used to deliver packages, and as complex drones to inspect dangerous areas.
Sophisticated wings
The reason why bats are such incredible flyers is down to their wings. Bats possess some of the most sophisticated wings in the animal kingdom. They have more than 40 joints in their wings, which enable them to make micromovements at great speed. This means that they can chase after tiny insects and feed mid-air on millions of insects a night.
Highly social
Bats are also somewhat surprisingly very much like us as they develop and maintain complex relationships with each other that last for many years equalling the complex social networking skills previously documented in elephants, dolphins and primates.
A 20-year study of a colony of Bechstein’s bats in Europe has demonstrated that bats cultivate long-term, stable personal relationships with other individuals and form networks with friends and relatives, including grandmothers, mothers and daughters and their ‘family friends’
Old females up to twenty years of age play a particularly special role in the development and subsequent cohesion of these networks, they instigate exchanges between different groups; and will often take their daughters and granddaughters with them when they join other social groups.
Just how individuals recognise each other is still unclear, but individuals were observed rubbing their noses against each other and bats have an incredible sense of smell and they communicate acoustically through a variety of calls both of which provide information on individual recognition. All of this helps them to distinguish which individuals are in and which are outside of their own social networks.
Bats are cooperative
The world’s only known blood-sucking mammals, the vampire bat develops trust with unrelated individuals first by grooming each other, then eventually regurgitating blood to share with each other, an act of altruism for a species that must eat every three days. Blood-sharing tends to be reciprocal, with bats more likely to provide a meal to a partner that has shared with them in the past.
Bats have individual voices
Bats are dependent on their vocalizations for orientation and communication due to their nocturnal lifestyle and their social nature, and they are able to differentiate the ultrasonic "echolocation" calls that other bats make and thus recognize the voices of other bats from within their social groups, helping them to keep in touch with bats that they have an individual relationship with.
Besides their social lifestyles, bats and people share a number of physical characteristics. Both produce sounds using a combination of the larynx, vocal cords, and nasal cavities. These structures work together with an animal’s physical makeup to produce an individual’s unique voice. In stressful situations, voices become higher pitched, or ‘squeaky,’ in bats as in humans. Also, each individual bat has a slightly different morphology, and thus its voice sounds different from any other individual, just as voices in humans differ individually.
The ability to recognize individuals by sound may govern the reunion of groups at night roosts. When isolated bats are observed, they emit calls which result in the bat being joined by members of its usual night roosting group, giving weight to the belief that others must recognize his call.
Bats synchronise their brain activities
When bats engage in social behaviours such as grooming or sniffing each other their brain activity is literally synchronised with each other.
Signals that include the bats' higher frequency brain waves, as well as electrical activity from individual neurons.
Strong correlations between the bats' brains, especially for brain waves in the high frequency band and electrical activity from individual neurons is present when bats share a social environment and increase before and during their social interactions.
Bats really are amazing animals!
Conservation:
Many bat species are listed as Vulnerable or Endangered. There are many threats to bats, including loss and fragmentation of their habitat, which in turn means a loss of food and roosting sites. Their roosts can also be destroyed, either due to persecutors or habitat destruction. Disease can also wipe out huge numbers of bats. Some bat populations are also hunted or killed by humans.
Other threats can include light pollution which can change the behaviour of some bat species and cause them to forage less, or to miss peak feeding times. Wind farms and wind turbines are also a potential threat to bats as they collide with them, and also through the loss of habitat that results from their construction.
The dramatic growth of wind energy throughout much of the world is also taking a huge toll on bats. Scientists estimate that hundreds of thousands of bats are killed each year in collisions with the spinning blades of wind turbines or rapid pressure change at turbines that can rupture blood vessels.
The International Union for the Conservation of Nature (IUCN) lists 26 bat species as Critically Endangered, meaning they face an imminent risk of extinction. Fifty-one others are Endangered, and 954 bat species are considered Vulnerable.
Because bats reproduce slowly, with females of most species giving birth to only one pup per year, recovery from serious losses is painfully slow and tenuous at best. It is often difficult to spot significant declines in such species until their situation is dire.
For more information about bat conservation projects around the world please see:
Bat Conservation International
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