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The Colourful-Puffleg from Atlas of Rare Birds, published by New Holland Publishers

You've probably never heard of the Colourful Puffleg, because it is pretty obscure. It is a hummingbird found only in the Andes of Colombia, in South America. It was only discovered in 1967 and almost nothing is known about it. Recently, however, it has found itself on the Critically Endangered list. In many ways the Colourful Puffleg represents quite a number of bird species in the world. These are the ones which seem to have very small natural ranges, and as such can be plunged towards extinction by remarkably localized events. In the case of the Colourful Puffleg that range has been estimated as a mere 31km².

In a part of the world where deforestation is rampant, that precious 31km² is very vulnerable. After its 1967 discovery, at a place called Cerro Charguayaco in Munchique National Park in the south-west of Colombia, apart from one sighting this delightful hummingbird was pretty much ignored by birders (who probably hadn't realized what a stunner it is) until 1997, when it was rediscovered at exactly the same place. A study shortly afterwards made trips out from the type locality at a radius of 3km at various elevations, but never found the hummingbird more than 300m from its favoured location, and it was thought possibly to have the smallest range of any bird in the world. However, more recently it has been unearthed at three other sites.

To understand why the Colourful Puffleg has such a limited range, you have to appreciate some of the basics of Andean biogeography. These mountains are not a single chain, of course, but a parallel set of chains. On each slope of the three north–south chains different conditions apply, owing to variations in the moisture loads in the winds as they cross the mountains, creating different vegetation types. Now add altitude into the mix. The habitat at sea level will be quite different to the habitat at 7,000m and, focusing in, there will also be a quite different flora between, for example, 1,000m and 3,000m. If you then mix in rivers and other topographical features, and take account of the effects of glaciation, it becomes easy to see how Colombia manages to hold more bird species than anywhere else on earth. But it also enables you to understand that, with very specific conditions occurring very locally, different species can be confined to small areas.

That what seems to have happened in the case of the Colourful Puffleg. It occurs in the western Andean range. It appears to occur only at altitudes between 2,200m and 2,600m (possibly higher), and it is a bird of wet forest. With intense competition from other hummingbirds in the same area, it seems to feed mostly low down, between 2m and 4m above the ground. Thus it has a very narrow niche even within its strictly localized range. All this, naturally, is a recipe for trouble. One day environmental pressures were almost bound to come calling, and at the moment these pressures are seriously threatening the tiny population of less than a thousand individuals. Up until the 1970s the local economy of the people was based on a fruit crop called 'lulo' which was grown under the forest canopy.

However, in the 1980s there was a disaster: the lulo plants were hit by a double-whammy of fungal infection and pest infestation, and the cash crop collapsed. With no incentive to keep the forest, it began to be cleared. In other, newly discovered parts of the bird's range, forests were cleared to make way for coca production, even though this is completely illegal and inside the boundaries of a national park.

Little by little, but inexorably, the Colourful Puffleg's habitat is diminishing. The sheer small scale of this disaster needs to be recognized. The whole population of the Colourful Puffleg is confined to less than the area of, perhaps, a large town or small city. The loss of the lulo was a local event not much bigger than the closing of an employer in that same town. Upon such minimal matters does the fate of a whole species of bird hang. Interestingly, the Colourful Puffleg is not alone in having the difficult starting point of an abnormally small range.

There are other birds in the world in similar difficulties. The most obvious candidates are island species, but continental endemics do occur. Several also happen to be hummingbirds, and another is a puffleg, the Black-breasted Puffleg (Eriocnemis nigrivestis), which only occurs in a small part of neighbouring Ecuador. It is both a worry and a wonder. The wonder is that so many species have evolved in such small areas with such exacting parameters. The worry, of course, is how vulnerable these treasures are.

Extract taken from the Atlas of Rare Birds from New Holland Publishers, visit the book at http://www.newhollandpublishers.com/atlasofrarebirds

About the Author

New Holland is a publishing house dedicated to the highest editorial and design standards. Our publishing programme also features the cream of new illustrated books from Australia, New Zealand and South Africa.

New Holland publishes books on: Natural History, Travel, Food and Drink, Health and Fitness, Craft and Hobbies, Home and Garden, Reference, Sport and Adventure, Cadogan Guides, and Humour and Gifts.

www.newhollandpublishers.com

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The Colourful-Puffleg from Atlas of Rare Birds, published by New Holland Publishers

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