Scent The nose is faster than the Eye



by Dave Rushworth

Powers of scent in various species

Scent and Smell play a very important role in most systems. Despite generally reduced olfactory senses due to abuse and industrial bombardment, most human beings are able to 'pick up' smells from considerable distances. Smoke from various sources, rain and other sources of water, dust, stink bugs and other insects, varied plant smells, dung and many smells associated with animals, chemical and industrial smells, food items and natural or cosmetic smells of humans.

We can manage without a sense of smell but some of the quality of life would be missing and we would lose the valuable sense for warning and recognition. In natural systems, the senses of smell and taste are vital to survival in many ways. Animals with faulty senses are at an extreme disadvantage in their fight for survival.

Smell and taste

It is necessary to understand that the senses of smell and taste originate from different sources. Most of what we 'taste' in good food we actually 'smell'. True 'taste' is only through the tongue. Taste buds respond only to Bitter, Sour, Salty or Sweet flavours. For those taking medicine, tr y to remember that 'Sweet' receptors are on the tip of the tongue, 'Salt' further back along the edge, 'Sour' about half way back along the edge and 'Bitter' right across the back of the tongue.

If you are taking bitter pills don't throw them to the back of the tongue. Rather place them on the front of the tongue before washing them down! So what about the other 'tastes' in food and drink? When you chew and breathe, minute particles are carried up into the nose where you register them as 'taste' because of the food in your mouth. You 'smell' most of the good taste in food. This is why food is tasteless when you have a cold or a blocked nose.

The 'smelling' or olfactory nerves are all in the nasal area in mammals and birds. The system differs in insects, where the olfactory senses are usually in the antennae. In some reptiles it may appear that they are 'smelling' with their tongues but they are in fact picking up particles by flicking their tongues. The tongue (often forked) is then withdrawn and inserted up into the nasal passages where the 'scent' is registered, hence the need to flick the tongues in and out.

Scent

There are certain 'ethereal' particles which can be picked up by some animals but the subject is not thoroughly researched and I will ignore it in this short article. Scent, as generally understood, consists of minute, material particles carried in the air. Even the 'Pheromones' secreted and released by many 'insects' and other animals consists of molecular particles.

These minute particles are carried by the flow of air. It stands to reason that 'smells' are picked up more easily in the direction of the airflow. In the evening 'smells' are dispersed over the land surface by descending and drifting cool air. In the morning 'smells' will be lifted by ascending air. Winds are strong carriers of 'smell' or scent. For this reason, plants, with often insignificant flowers, that rely mainly on 'scent' to attract insect pollinators, will be active in the evenings.

Others can use their 'colour' during the daylight. Smells can be carried for great distances and even human beings can 'register' them from many kilometres away from the source. As with shapes and colour in vision there is generally a learning process in understanding the meaning of various 'smells'. In nature, scent is used to detect sources of danger, food, compatibility, territorial marking, water, menstruation and other factors.

Generally, the larger the area for olfactory organs, the better that species is able to smell. Animals with long noses have a good sense of smell and animals with short noses have a less developed sense of smell. Thus Ungulates and Canines have a better sense of smell than 'Cats'.

There are specialised species such as the 'Aardvark' and anteaters that have particularly acute senses. Elephant trunks are not 'noses' as such but elongated nostrils which assist them in picking up scents that are often above the level of other species. In most cases mammals have well developed olfactory organs while those in birds and reptiles are poorly developed or absent. There are some notable exceptions to this statement.

Among birds, the New World 'vultures' generally have olfactory senses, particularly the 'Turkey' and 'Black' vultures, which can pick up rising scent from the forests below. All down the eastern United States and into Canada an extraordinary mole lurks in marshes and wetlands

.

Researchers at Vanderbilt University have been studying the mysterious star-nosed mole and have found that it can locate and gobble down food in half the time it takes a person to react to a red traffic light. In less than a quarter of a second, in pitch-blackness, the mole's nose can detect an object, decide if it is edible, and guzzle the snack.

The findings were published in the journal Nature. The researchers believe that the mole's speed gives the mole a competitive advantage over other burrowing animals, as it allows it to eat much smaller prey. The only way researchers were able to see what the mole's mouth was up to was to use a high-speed video camera. With an average of 230 milliseconds to identify and eat a bit of food, the re- searchers believe that the mole is moving as fast as its brain and nervous system will allow.

Given the speed of its movements, they estimate that it takes eight milliseconds for the mole's brain to decide if what it is touching is edible or not. In order to perform this amazing feat of speed, the mole has what might be the oddest-looking nose in the mammal world. 22 small fingerlike projections form a star shape around the little animal's nose, and these are in constant motion, tapping their surroundings as the mole burrows.

It was calculated that the star-nose allows it to find 14 times as many small prey animals in a given time than a close cousin, the eastern mole. The mole also has specialised teeth, with much smaller incisors than other moles that are shaped like tweezers to allow it to take advantage of the small delicacies its nose roots out as it burrows. The New Zealand Kiwis have nostrils on the tip of their long bills and can smell prey while probing underground

'Pelagic' birds of the open seas, the ones with 'sheath-bills' or 'tube noses', such as many of the Albatrosses, Petrels, Prions, Sheathbill and Skuas, have been recorded to follow ocean surface scent, upwind, from many kilometres away. It is not surprising as dogs can easily pick up the scent from bubbles of underwater putrefaction. Crocodiles, fish and other aquatic species are able to pick up minute particles of 'smell' underwater.

Among certain 'Insects' (notably some beetles and moths) you may have noticed that the females have thin antennae while the males have 'feathery' antennae. The females of these species release 'pheromones which are carried down wind. The males have been recorded receiving and reacting to these pheromones, which are detected through the feathery antennae, from distances of around 30 kilometres.

We don't know half of what goes on in the remaining, natural world around us but we are bent on destroying it anyway for our own material comfort and greed. Cutting, clearing, spraying, 'developing', quarrelling, 'grabbing', manipulating and destroying. There is nothing wrong with Earth that has not been caused by humanity.

No wonder our inner-selves, our souls, are dissatisfied, uneasy, discontented and searching. We are GOING FLAT OUT - BUT IN THE WRONG DIRECTION. We need to stop trying to change the world and concentrate on changing ourselves.



 
Kruger National Park - South African Safari
Kruger Park Safaris
Live Our Obsession

"travel planning done expertly"

Siyabona Africa - Your Informed African Travel Partner

Siyabona Africa (Pty)Ltd - The Definitive Kruger Park Guide
Kruger Park Reservations and Bookings