Category Science

What are the impacts on animals of Australian bushfires?

 Though it is estimated that nearly half-a-billion animals have been affected in one State alone, it is difficult to get the exact number until fires subside enough to allow surveys of the burned areas. Fires have been part of the Australian landscape for thousands of years. Many species and ecosystems have evolved to cope and later populate nearby unaffected land. But as climate change fuels longer five seasons and more frequent, intense fires, it could become increasingly difficult for animals to adapt newer escape strategies and for ecosystem to bounce back.

In the line of fire

Smaller mammals and reptiles can escape the blazes by burrowing underground or hiding in rocks.

But some are not good at coping heat or stress. Wombat, the small, stubby-legged marsupial, can’t run very fast or far. Kolas are particularly vulnerable to bushfires as their slow movement and tree-dwelling lifestyle make it difficult for them to escape. Koalas and kangaroos are primarily killed directly by the fires. In this season, nearly a third of all koalas in New South Wales have died and about a third of their habitat has been destroyed according to a government estimate.

Ecosystems are built on balance – once one element is thrown off, everything is affected. Even if animals don’t die from the flames or smoke, they would eventually do from the fire’s aftermath. After their habitat is destructed, there will be no shelter or food left to survive on. These animals’ recovery depends not only on their population size, but also on the condition of their habitat.

 

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What is wildfire?

An uncontrolled fire in an area of combustible vegetation that spreads quickly, wiping out large areas of land is called a wildfire. A wildfire can also be termed a forest fire, a grass fire, a peat fire or a bushfire depending on the type of vegetation.

During summer, when there is no rain for months, the forests become littered with dry leaves and twigs, which could burst into flames ignited by the slightest spark.

Natural causes: Lightening is the most common cause of bushfire. There are three conditions for a bushfire to spread – fuel, oxygen and a heat source. In the forest, anything that is flammable is a fuel. This includes tall, dry grass, bushes and trees. High temperature, drought and dry vegetation are a perfect combination for igniting a forest fire.

Human-made disaster: Human neglect such as downed powerlines, sparks from tools or forest machinery, abandoned campfires and discarded cigarette butts can spark fires. People also tend to clear forests by setting them on fire to pave way for cultivation. Sometimes they set fire to scare away wild animals and the fire could spread and turn disastrous.

In Australia:

Summer is the season of fire in Australia with hot, dry weather making it easy for blazes to start and spread. Most of the time, it is natural causes such as lightning that trigger a fire, but sometimes human are also to blame. New South Wales police have charged at least 24 people with deliberately starting bushfires, and have taken legal action against 183 people for fire-related offences since November, according to reports.

 

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Why are the Australian bushfires so bad this year?

Bushfires are almost an annual affair in Australia, but this fire season has been unprecedented in scale and intensity.

A series of massive bushfires has been burning across Australia since September 2019 and they intensified early this month, with a number of towns evacuated.

At least 27 people have been killed, 1200 homes destroyed, and 18 million acres of land – bush, forest and parks – have been burned. Of all the States, New South Wales has been the hardest-hit. Nearly half-a-billion creatures, including birds, mammals and reptiles, have been affected by the fires in New South Wales alone and millions of them are possibly dead, according to scientists. Many large cities have been shrouded in smoke for weeks. State and federal authorities are struggling to contain the massive blazes, even with firefighting assistance from other countries.

Why are the fires so bad? Persistent drought and record temperatures are the major drivers of the fire, but the role played by climate change in making natural disasters go from bad to worse should not be overlooked, say scientists.

 

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How far a dog can smell?

You have heard of sniffer dogs. Dogs are routinely used for catching thieves who have escaped. They are called in when the customs officials want to know if a package has narcotics or bombs. Some studies claim that dogs can sniff deadly diseases in their owners. But for all these dogs are trained.

Dogs have a great sense of smell and can detect tiny amounts of smell diluted in air, water, or far beneath the ground. According to the My Water Earth, the canine olfactory system works so well that dogs can pick up scents that are diluted to 1 or 2 parts per trillion; This allows them to smell things buried as far as 40 feet underground!

Dogs will take deeper, longer breaths for breathing, and use a short sniffing action when smelling something. When a dog exhales, air is pushed out of slits in the sides of the nose, creating an airflow that draws new smells into the nose.

 

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How do snakes smell?

Snakes have a highly developed sense of smell, but they don’t use their noses to smell. Instead, they “taste the air” with their tongues. They use the damp surface of their tongue to catch scent particles and carry them to a special organ in the mouth called Jacobson’s organ, where they can be identified as food or danger. But X-ray movies have revealed that the tongue does not move inside the closed mouth, it simply deposits the chemicals it has collected onto pads on the floor of the mouth as the mouth is closing.

It is most likely that these pads deliver the sampled molecules to the entrance of the Jacobson’s Organ when the floor of the mouth is elevated to come into contact with the roof following a tongue flick. The case for this is strengthened because geckos, skinks, and other lizards lack deeply-forked tongues but still deliver chemicals to their vomeronasal organs. Bears too have this organ.

 

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How good is a cat’s sense of smell?

Cats have twice as many receptors in the olfactory epithelium (i.e. smell-sensitive cells in their noses) as people do. That means cats have a more acute sense of smell than humans. In fact cats have 200 million odour-sensitive cells in their noses whereas humans only have 5 million odour-sensitive cells. A cat can smell stinky cat food which is several miles away, but would be less able to distinguish various types of odours. But a cat doesn’t care as long as it is able to smell its favourite food items!

Because their sense of smell is so sensitive, it’s important to be aware of things like scented litter, other animal’s smells on you or an unfamiliar scent in your cat’s environment (such as a new piece of furniture or a house guest). These things may upset your feline friend.

 

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