Friday, February 18, 2011

Of Eagles, Rabbits and Partidges

It is quite remarkable how we often observe the world around us without fully appreciating the depth of time that we are observing. Three species are currently staging a "cat-and-mouse" saga that goes back to the Pleistocene. The game is at least 100 thousand years old!

The "cat" in our game is the majestic Spanish Imperial Eagle, an endangered species which is endemic to the Iberian Peninsula. I watched these birds hunting in the plains of La Janda this week.

There are two "mice" in this story. One is a bird - the Red-legged Partridge (above). The other is a mammal - the Rabbit (below). Both are Iberian endemics too. Hard to believe it may be but the Rabbit evolved within the Iberian Peninsula and has been introduced everywhere else by humans!

The eagle is one among a suite of species (including the endemic Iberian Lynx) that have relied to a large degree on these two prey species. Both reproduce quickly and in large numbers and have been an almost inexhaustible supply of food for these predators.

Rabbits are doing particularly well in La Janda, having recovered from epidemics that have reduced their numbers in recent decades. It is wonderful to see families of them sunning themselves close to their burrows under the cover of wild olives (above). Indeed a millennial sight! Rabbits must have been so numerous that they gave Spain its name. The Roman Hispania was derived from the Carthaginian Ispania which is thought to come from the word Sphan which meant Rabbit. Literally Spain means "Land of Rabbits"!

With the big eagles lurking Rabbits rely on camouflage and keeping still (above) to go by unnoticed. Partridges too are cryptic when seen from above or behind (below).

But Nature generates uncontrollable impulses which can expose prey. Partridges calling out to stake out territories may suddenly become visible (below).

...and the eagles are ready to pounce!

their strategy is to dive from great heights (above) or to approach low with stealth (below)

either way it is a long, tried and tested, method with great rewards...

Above: Spanish Imperial Eagle with Rabbit

It's hard to fathom, watching in awe as these animals play out this game of life an death, that the same sight was seen millennia ago by our Neanderthal cousins. They died out and we have put the eagle's future very much on the balance. How much longer will we allow this millennial game to continue to be played in our skies?

Sunday, February 13, 2011

Diary - The Common Crane

This is the month when the Cranes that have wintered in southern Iberia and Morocco return northwards to their Scandinavian and Russian breeding grounds. The gathering of thousands of Cranes in traditional spots like the old lake of La Janda might convince us that all is healthy with this species. But reading the accounts of the 19th Century naturalists leads us to realise that we are observing a meagre ration of what was once a real spectacle of nature.

One of my favourite accounts of the northward passage of Cranes across the Strait of Gibraltar is Irby's who wrote how: "On the 11th of that month (March), in 1874, Mr Stark and myself had the pleasure of seeing them (the Cranes) on passage; and a grand and extraordinary sight it weas, as flock after flock passed over at a height of about two hundred yards – some in single line, some in a V-shape, others in a Y-formation, all from time to time trumpeting loudly. We watched them for about half an hour as they passed, during which time we calculated that at least four thousand must have flown by. This was early in the morning, and we were obliged to continue our journey; but when we lost sight of the Vega of Casas Viejas, over which the cranes were passing in a due northerly direction, there appeared to be no diminution of their number, and, as my friend remarked, ‘One would not have believed that there were so many Cranes in all Europe.’"

Thirty years later Verner commented how the passage was as spectacular as in Irby's day and noted how: 
"The direction taken by successive flocks, in accordance with observations made by me for me for many years in the same district, is almost invariably the same, namely a line which when plotted on a map passes about 6 miles west of the old town of Tarifa."
It is a danger to highlight the spectacle today as it lulls us into a false expectation that all is well. But the real cause of the decline of the Crane is habitat loss. Places like La Janda, once Spain's largest lake and now sadly drained, and many other wetlands of the Strait of Gibraltar were part of a vast network that supported vast numbers of waterbirds of which the Crane was a spectacular flagship. Even as I write these lines wetlands like the Smir on the Moroccan side of the Strait are being filled to give way to developments. This is particularly ironic as this wetland forms part of an intercontinental UNESCO Biosphere Reserve!

The situation is even sadder. Cranes no longer breed in southern Europe but they did in Irby and Verner's day, la Janda being their last stronghold. Verner (1911) tells us how: "About thirty years ago, considerable numbers of Cranes remained to nest in south-west Andalucia: but constant egging by professional “collectors” has sadly reduced their numbers. In some districts they have ceased to nest altogether while in others where I can recall seeing over thirty pairs in the nesting season there are now hardly half a dozen to be found during the summer months."

So these images are a tribute to a wonderful species and its wetland habitats and a warning: just because we see large flocks of this species (or indeed other animals), it should not be taken to mean that all is well. The wetlands of the Strait of Gibraltar and its birds have been dying a long and lingering death for 150 years. Yet it seems that more emphasis is placed on the wonders of the region than on the rate of loss. In another 150 years it may only be the images that we are left with. And that will be our legacy...

Wednesday, February 2, 2011

Celebrating our First Birthday

We celebrate our first birthday today!

In this first year we have been viewed by close to 4700 individual visitors from 95 countries.

There have been close to 11,500 views of our pages.

In Networkblogs we have achieved a following of 759. In our theme categories we have achieved the second highest following in Nature, third in Environment and fourth in History.

Thanks to all our facebook friends and followers for your support. We will try and build on this in our second year!