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The Gray-breasted Wood-Wren or The Bird Monitoring Data Set Analysed (cont.)

Not surprisingly the Gray-breasted Wood-Wren (Henicorhina leucophrys) is something like the star amongst our birds - at least when it comes to the monitoring. In almost any category / dimension that you can think of it comes up number one. We are working on a good display on visualizing the distribution across the reserve (R's a bitch).

For now we've created some simpler charts. Number one is basically the raw data translated into a bar chart. Since we are counting individuals at our observation points this chart simply reflects the lines in the raw data, not correcting for any bias such as distribution of the observation points across elevation etc. The chart is on the very left and shows the Top 25 species. The details for the Top 5 are:

(1) Gray-breasted Wood-Wren (Henicorhina leucophrys): 2768 individuals

(2) Dusky Bush-Tanager / Chlorospingus (Chlorospingus semifuscus): 1974 individuals

(3) Orange-bellied Euphonia (Euphonia xanthogaster): 1736 individuals

(4) Toucan Barbet (Semnornis ramphastinus): 1646 individuals

(5) Booted Racket-Tail (Ocreatus underwoodii): 1447 individuals

We'll have a closer look at this chart in on of the future entries. For now we take a bow to the Gray-breasted Wood-Wren for winning this competition by a huge margin.

The second chart is about the presence of the particular species in the ten minute monitoring session across all Santa Lucía. There have been 2.410 session so far (most of them done by Noé Morales) and the chart shows that here the Wren is particularly present. In 2/3 of all session is could be heard or seen (although in case of the Wood-Wren heard-observations are far more common). This emphazises its omnipresence in space and time within the reserve, but also shows this it is not so high up the first chart because it appears in high numbers of individuals. This often leads to a bias towards birds that appear in large numbers such as Parrots or Pigeons. It is - in fact - a more realistic view on the presence of the species. Common solitary birds (such as the Andean ... harhar ... SOLITAIRE) are better represented here. The Top 5 in details:

(1) Gray-breasted Wood-Wren (Henicorhina leucophrys): 65,39%

(2) Orange-bellied Euphonia (Euphonia xanthogaster): 46,89%

(3) Andean Solitaire (Myadestes ralloides): 44,27%

(4) Booted Racket-Tail (Ocreatus underwoodii): 42,16%)

(5) Violet-tailed Sylph ( Agleiocercus coelestis) 42,12%

Again - a huge margin. Can the data be interpreted that way that if you are at any point in Santa Lucía and wait for ten minutes you have a 65,39% chance of observing a Gray-breasted Wood-Wren?

The third analysis looks at the 127 observation points. Those are distributed across the whole elevation gradient ... 1.400m to 2.500m ... Primary Forest, Secondary Forest, Silvo-Pastures, near the lodge, on ridges, on well-trodden paths, near rivers, etc. and guess what: the Gray-breasted Wood-Wren is so far the ONLY species that has been reported on ALL possible points. Incredible, isn't it? Here the margin is not big though (as you would expect as this chart has an upper limit). However - it shows the distribution of the Wood-Wren and what makes it the star of the reserve amongst the birds. Of course a more in depth analysis is required to see how evenly distributed it is, but we have no doubts that it will also be the winner in that category. So, here's the details on the Top 5 in distribution across observation points:

(1) Gray-breasted Wood-Wren: (Henicorhina leucophrys): 127 points

(2) Slate-throated Whitestart (Myioborus miniatus): 123 points

(3) Andean Solitaire (Myadestes ralloides): 121 points

(3) Sparkling Violetear (Colibri coruscans): 121 points

(5) Plumbeous Pigeon (Patagioenas plumbea): 120 points

Species that rank high in the first chart but low in the last one (e.g. the Dusky Bush-Tanager drops from number 2 to 18) can expected to have a more limited area of distribution (either across elevation or habitat).

Playing with data is fun, isn't it? :)

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