How do animals use the Earths Magnetic Field?

The Earth's Magnetic Field is responsible for keeping our planet shielded from the worst of the Radiation produced by the sun, however there are many examples of nature utilizing the Earth's Magnetic Field.

Across the earth, there are many examples of animals and plant life that use the Earth's magnetic field to accomplish many tasks, ranging from navigation to growth. The prime example of using the earths magnetic field comes from simple plant life, which, without the earths magnetic field could not grow. When a seed attempts to germinate and grow, it requires a magnetic field, without one the seed will fail. It has also been proved that a seed, when placed under a magnetic field stronger than the one produced by the earth, can show up to a 15% increase in growth rate. 

Bees are also affected by the strength of magnetic fields, for example when exposed to a magnetic field ten times stronger than the one produced by Earth they become confused and disorientated. This shows in the honey comb they create, which becomes random and uneven. The apparent reason for this relates to certain cells within the bees genetic make up. Bees have an amount of tiny magnetite crystals in their bodies, these cells are directly linked to the brain, and seeing as how magnetite crystals are effected by magnetic fields this would explain why stronger levels of Magnetic energy effect them in such a way. 

Many migratory animals, including fish, also have trace amounts of magnetite in their bodies. A key example is the salmon, which use the earth’s magnetic field to guide itself upstream to a birthing area. Other sea mammals, such as the dolphin, also use the earth’s magnetic field to aid in long distance migration. However, constant fluxes in the earths magnetic field is slowly damaging the migration guidance of certain animals are causing upsets in mating areas as well as other, similar problems. 

An interesting fact about Sharks is how, when in areas affected by strong enough magnetic fields, they produce their own electrical field, which is used to detect nearby wounded fish or other prey. If you look at a shark in an aquarium you'll notice how they swim close to walls, which helps to project their field out and detect prey or abnormalities in the water.

Keeping in line with the theme of sea life utilizing magnetic fields, the sea turtle is heavily impacted by the earth’s magnetic field, with even a slight alteration able to completely reverse the direction the turtle moves, and a significant alteration being able to alter where the animal goes to lay eggs. 

Over the course of its rather impressive life span a sea turtle returns to the same beach each year to lay its next clutch of eggs. This is a rather impressive feat as the atypical breeding beach can be thousands of kilometers from a Sea Turtles feeding ground and with no particular landmarks to work with, the Sea Turtle is left with only its ability to use the Earths magnetic field and its olfactory senses as a navigation tools. Scientists have determined (by attaching powerful magnets to the head of a Sea turtle) that the Sea Turtle does not use only the magnetic field to navigate, however it is still the main factor in the Sea Turtles ability to return to the same place year after year. 

It has also been shown that minor changes in the magnetic level around a Sea Turtle will affect the Sea turtles directional movement, for example an increased magnetic level of 10% above the base magnetic field causes the Sea turtle to swim eastward, whilst dropping it by 10% causes the turtle to swim westward.

It was discovered in 2004, that many small songbirds have small magnetite deposits in their beaks. The original theory was that these birds use these magnetite deposits to aid in migration, using them as an aid to sense the earth’s magnetic field. However over time, the theory has grown to the degree that many now say that the birds use magnetism over sight in migration flights. If you ever wondered why pigeons looked disorientated all the time, chances are that the magnetic energy produced in urban environments is disrupting the bird’s natural senses, causing them to become disorientated and lost.  

In fact, it appears that most birds, including chickens, are able to detect the Earth's magnetic field, and that the sensors that allow the bird to utilize this information lie in the eye. A test on chickens demonstrated that they could maneuver perfectly under blue lighting, yet when exposed to long wave white lighting they became disorientated and lost. 

It appears that birds may have developed this ability roughly 66 million years ago, long before they developed any form of migration instinct. It's been proven recently that Birds use a light connected mechanism in their right eye for navigational information and the magnetite receptor in the beak for sensing the changes in magnetic intensity.

It is widely accepted that the only way Bats can sense the world around them is via sonar, however this is far from truth. Bats also use the Earths Magnetic Field to determine the difference between north and south, mainly using it for the migration flight many bats must make each year to avoid encroaching cold weather, as well as using it to locate optimum points for foraging and nesting. A study in 2007 also showed that many species of bat possess Magnetite receptors, which also demonstrates that changes in magnetic fields could cause Bats a certain level of duress.

A few more species known to possess the ability to navigate via the earths magnetic field include Moles (whom, without this sense would be reduced to absolute blindness, lacking any way of directing themselves at all, essentially trapping themselves), Rats and certain amphibians, many of who need to utilize this ability to locate feeding or breeding grounds.

Unfortunately, as humanity further industrializes the Earth, we are slowly polluting the air with many more Electromagnetic fields, each of which is damaging to many species of animal causing the to lose access to their natural directional instincts or damaging their ability to precisely follow the earth’s magnetic field. After reading the previous information, you can see how damaging it would be to the natural world if we continue to hamper the abilities of the other creatures that inhabit it. Entire species could die off; others will simply try to breed in far more hostile areas. 

All in all, we can see how we are affecting the world now, the real question is, what can we do to stop this happening..?