Tuesday, 27 October 2009

Old Friends

These last three days we've had multiple visits to Castro Marim and to the Tavira and Santa Luzia saltpans. As a result and not surprisingly we've been seeing the same birds - that's not just the same species, we mean the same individuals.

Some individuals are easily recognised. Yesterday, for instance we saw both of the local hybrid 'grey egrets' that have been in the Tavira area for several years. They each have their favourite feeding areas and can be found most days without too much effort. They're like old friends.

Presumed hybrid Western Reef Egret x Little Egret

Colour-ringed birds are another obvious example of individuals that can be easily recognised. We're currently looking for a Black-tailed Godwit that has been on the saltpans here during the last three winters. We're hoping it has survived to return.

Black-tailed Godwit

There's currently a Black-tailed Godwit at Santa Luzia that has a damaged leg and can therefore be identified as an individual. It feeds in exactly the same place day after day. The likelihood is that the other Godwits feeding with it are also repeatedly using the same small area - not just day after day but perhaps, year after year.

Each year we find wintering Bluethroats in the exactly the same small patch of vegetation, Caspian Terns on the same saltpan, Stone-curlews in the same field. How many of them are, we wonder, like the colour-ringed Godwit, individuals returning to places they know to be safe and to have a good supply of food? And, of course, it's not only the repeated use of wintering sites, for birds heading for sub-Saharan Africa it's reliance on the same stopover sites for 're-fuelling'.


So then there is the question of what happens to migrant birds such as these when the places they know and rely on are changed from one year to the next. What happens to the bird that flies hundreds of miles and arrives tired and hungry to find that its familiar reedbed has been destroyed, its usual wetland drained, a golf course where that stubble field used to be? Some will no doubt be able to adapt, to find another site, but for some it will be the difference between surviving or not.

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