Friday, September 3, 2010

Alien invaders

I'm pretty sure that by now, nobody would call "alien" to a Cattle Egret or a Southern Lapwing. These birds are so common and familiar that they almost never are targets of our cameras' lens (and someone might ask what was I doing photographing Cattle Egrets?). The truth is that some years ago (in one case maaany years ago), the simple sight of one of these species would have been breaking news. And that is because they are "naturally" arrived birds to our country, and many others. I wrote "naturally" because, despite they were not directly introduced in Panama by us, its spreading along the Americas was favored by habitats changes made by us. Both species prosper in open habitats, like grasslands, gardens, football fields, pastureland and so on..., just like us! Of course, that is not the only factor that contributed to its successful history (in that case I would be expecting more Cattle Tyrants around). These are very adaptable birds, taking advantage of any opportunity to feed, to nest, to do their things. As all you know, the Cattle Egret originally accompanied the hordes of big mammals in the african savanna and other tropical zones in the Old World. Amazingly, the first report for our continent was from northern South America (way back in 1877) where they arrived having apparently flown across the Atlantic Ocean... what about that!!! In Panama, it was first reported in 1954 and then spread quickly (just to make it clear, I didn't witness that). In the other hand, the Southern Lapwing is original of South America, where it is particularly common in the basin of the River Plate. Its colonization of the isthmus was more recent than that of the egret. Back in the 90's, when I started to birdwatch, it was still an uncommon bird (while the egret was so abundant). One of my very first reports to the XENORNIS included a Southern Lapwing at the former Tocumen marsh. The particular individual pictured here was feeding alone. When I tried to approach it to get better photos, it ducked down, becoming undetectable... well, almost. They are noisy, but still good-looking birds, with an agressive attitude against the intruders. They are now common residents in many sites of Panama, and they are spreading towards the north, at least up to Nicaragua (with a report from Mexico). Well, so the next time you see one of these birds, think about the history that is behind them and, suddenly, they will not seem to be so boring.

2 comments:

  1. Interesting read Jan - I'm always fascinated by the way that non-native species (be they birds or plants)get from one place to another. Makes one realize how important it is to observe and record one's nature sightings! Great photos too!

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