Nature Notes

Loyalty and Friendship

Details: Created: Tuesday, 23 April 2013 00:00; Written by Nadia O’Carroll

The increasing evidence of the commonality of genetics and biochemistry of all species suggests that the conventional thinking of a universe centred on only one species which is sharply divided from all other forms of life is an outdated relic, yet the scientific taboo of sentimentality and anthropomorphism means that important questions about our commonality with other species are often ignored.

One intriguing topic is that of friendship and loyalty in animals, both between unrelated individuals of one species, and between individuals of different species.

Highs and Lows

Details: Created: Tuesday, 09 April 2013 00:00; Written by Nadia O’Carroll

Weather reports usually mention low and high pressure systems, fronts and troughs because these terms relate to atmospheric air pressure which is a major driver of wind and weather.

Air pressure at any point is the total weight of the air above that point. This is determined by the number of molecules present. Dense humid air contains more molecules than less dense, dry air and therefore exerts more pressure.

Manta Rays – gentle and majestic giants

Details: Created: Tuesday, 12 March 2013 00:00; Written by Nadia O’Carroll

Manta Rays are the largest species of ray, and one of the largest living fish. The biggest specimens have a wingspan of 7 metres and can weigh over 1,300 kilos.

They have huge triangular pectoral fins which are flapped like wings to move through the water, although incredibly agile, and able to perform acrobatic breaches, flips and somersaults above the ocean surface, mantas are unable to swim backwards. To breathe they must also move constantly to keep water circulating in their 5 pairs of gill slits, these characteristics make them vulnerable to entanglement and suffocation.

More than Slithering - Snake Locomotion

Details: Created: Tuesday, 26 March 2013 00:00; Written by Nadia O’Carroll

Snakes live in a wide variety of habitats – terrestrial, arboreal, aquatic and fossorial (underground). They also vary in size from the world's smallest snake, a recently discovered Barbados threadsnake, which measures only 10 cm, to the world's most massive snake, the Green Anaconda, which may grow to 9m and weigh 220 kg. Apart from a few adaptations the structure of all snakes is basically the same – a limbless, cylindrical, scale covered body.

Animal locomotion is governed by Newton's third law of motion - to propel itself forward; an animal must push something backwards. In many animals limbs such as legs, fins, flippers, tails and wings are used to push against the surrounding environment of ground, air or water in order to achieve propulsion. In snakes a flexible skeleton, powerful muscles and strong scales are used to the same effect.

Mould – unwelcome but necessary

Details: Created: Tuesday, 26 February 2013 00:00; Written by Nadia O’Carroll

One of the consequences of the recent wet weather is the appearance of mould. In fact mould is an ever present form of fungus; its spores are in the air and on surfaces waiting for the right conditions to germinate. The spores are microscopic eggs (3-40 microns) most float and travel great distances in the air, some species live in fresh water. The spores remain viable for decades until suitable hatching conditions are encountered. While there is variation, for many mould species ideal conditions are relative humidity above 60%, temperatures between 10-32 degrees C and pH 3-8 and when these occur and damp organic material (material that contains carbon atoms), is present the mould reproduces rapidly.