Sunday, 25 September 2011

Great Egret Rising


With its all white plumage that can often reach a meter in height, the Great Egret is a sight to behold as it soars up in to the sky.  Considered safe, only a century ago the species was highly threatened. Read on to discover how and why the species was able to make a dramatic come back.

Do you know, however, how to distinguish the Great Egret from other egrets and herons?  Well, apart from its sheers size, look out for its yellow bill and black legs – always a give away!

One of the best things about the Great Egret is that if you know where to go and look for it then it is usually easily seen – and there is nothing quite as exhilarating as watching these birds fly, hunt and interact with their families.

When you do find them they are easy to spot – especially when in flight – as their wingspan can stretch up to an amazing 85 inches, making it only a little smaller than the Great Blue Heron.  As these birds are in possession of such a large wingspan it is then unsurprising to discover that they can be found in most of the temperate and tropical regions of the world.

There are four sub-species and the first can be seen in Europe, although it is restricted to the southern areas. In North America the distribution of another sub-species is wider – you will see them all over the sun belt of the United States.  They can also be seen in the tropical rainforests of South America. A third sub-species adheres to the African continent while the fourth and last extends over India, Asia and Oceania.

Although the four sub-species are found the world over the Great Egret is not in any particular hurry to get anywhere and it is noted for its slow, elegant flight. In flight it retracts its neck – deliberately taking its time – looking unintentionally as if it is about to perform the first movement of the Egyptian Sand Dance. Again, if you want to distinguish an egret from a crane or a stork, look for the retracted neck in flight.

Despite its great wing span the Great Egret is only partly migratory – which may make you wonder why it has developed such long wings in the first place.  In the northern hemisphere the birds start to move in a southerly direction at the onset of winter, especially cold ones. 

The bird breeds in colonies – always in trees close to lakes with beds of reeds or in wetlands.  Over the course of several days the breeding pair will complete a bulky stick nest in which to rear their young.  The female will lay up to five eggs but rarely, if ever, do they all survive. Aggression is commonplace among nestlings and the larger ones will often kill their smaller siblings to gain the upper hand – and the lion’s share of the food the parents bring back to the nest.

If it survives the period of internecine murder and bickering the Great Egret does, however, live to a ripe old age – for birds. The record for longevity for monitored Great Egrets is 23 years old.

The bird feeds on fish, frogs, reptiles and insects - hunting in the shallow waters or along the water’s edge. They spear their prey with their long, sharp beaks.  Sometimes they stalk their prey but often they stand stock still, letting lunch come to them.  Then, with a single quick strike with that bill, their prey does not know what has hit them.

Even smaller mammals, such as this unfortunate gopher, make a meal for the Great Egret. 

Although the Great Egret is not considered endangered there has been at least one period in time when they were threatened.  You need not guess which species threatened them – inevitably it was our own.  At the end of the nineteenth century the feathers of large birds were used to decorate the hats of ladies.

As a result a large number were killed for their plumage (they are not considered edible) and the species was threatened as a result of what I call the humanity vanity factor. What made matters worse was the fact that they were often hunted after they had developed their fine breeding plumage (see above). This not only killed and would-be parents but ensured a smaller ensuing generation. No wonder numbers fell dramatically.

The fashion lasted only a decade or so and since then the numbers of Great Egrets have recovered – with a number of conservation measures put in place to protect them.  Indeed, they are sometimes even spotted in southern Canada. 

There has been a decline in numbers in some parts of the southern United States, mostly due to the loss of their natural habitat to development.  Yet even then there is some hope as they seem to adapt well to suburban life and they are often seen around wetlands in or near urban areas.

The Great Egret’s future looks safe for now, then. If you can, take the opportunity one day to see them spread their graceful wings and fly or slowly, poised and elegant, stalk their prey – there is nothing quite like it.


Luna Moth - Beautiful and Mysterious


Until he took this picture, Flickr Photographer Urtica was pretty sure he had never photographed a luna moth. It was on a short list of things he had decided if he ever did photograph, he would simply have to just retire the digicam.

Joking aside, he had the mercury vapor lamp and the white sheet out, and this little guy was hiding between the sheet and the shed door - he didn't find him until after he was breaking down the setup for the night. Patience it seems has its own rewards!

Sometimes...


...you just have to green and bear it. This turtle looks as if it has been spending a little too much time under water.  However, he or she has managed to acquire a lovely green carapace under which to keep out of sight from potential predators. And they say a rolling stone gathers no moss!

Sunday, 11 September 2011

The Tarantula Hawk - Ruthless ‘Raptor’ of the Insect World


They are among the largest species of wasp and their name is taken from both its prey and a ruthlessly efficient killing machine, the raptor known as a hawk.  Yet the Tarantula Hawk Wasp gains its fearful name and reputation from the simple urge to care for and nourish its young.

Growing up to two inches (5cm) in length the sight of a tarantula hawk would send the average entomophobic in to a state of palpitations.  So, perhaps if you are already frowning squeamishly, your knuckles rapidly whitening, then you should not read on.

The various species are found in Asia, the Americas (as far south as Argentina) and Australasia. The stinger of the female tarantula hawk moth is enormous, one of the largest and most painful in the insect world. At 1/3 of an inch in length (almost a centimeter) it has evolved to deal with the wasp’s prey as quickly and efficiently as possible – the tarantula.

When you are fully aware of how the female of the species deals with its prey you realise that Ridley Scott’s concept for Alien was not as out of this world as you may think.  After procreation the female has only one instinct – to provide for the next generation.  First, she must capture a tarantula.

She has long legs with hooked claws for grappling with her victims – and there will be many.  Each spider will sustain only one of her offspring so there will be many fatalities on the road to the production of the next cohort of spider munching wasps.

Once the tarantula is captured she stings it and the venom paralyzes the spider. She has prepared for this moment – a burrow or a nest is nearby and it is to this readymade larder that she drags her unwitting prey. There she will oviposit (lay) a single egg on the spider’s body and retreat, covering the entrance.

Once the female leaves, that is it - no more parental care. The larva hatches after a week. Instinct takes over and it rips in to the abdomen of the spider, thrusting itself in to its belly and begins to feed. The vital organs of the spider are the last to be devoured and once it has had enough to begin the process, pupation begins.

A few weeks later pupation is complete and the adult wasp will emerge.  Another belly burst (rather than the chest one to which we are accustomed in Scott’s movies) and the life cycle continues. Only females will hunt – the male lives off nectar. Yet once she is ready to breed she will attract the attention of a male and then the local tarantulas had better watch out.

Who now maintains that the female of the species is more deadly than the male is only a saying?

Amung Feedjit