Sunday, 17 June 2012

5 Things I have learned while counting

Spending hours on the cliff tops on your own concentrating on counting auks is an intensive experience and it gets you thinking about all sorts of things. Here are 5 things I have learnt from the experience:
Razorbill or Guillemot.
1) - Why do guillemots pack themselves in so tightly on the cliff ledges ? It doesn't always look much fun for guillemots pack in so tightly together, getting covered in poo, always arguing and fighting so why do they do it ? Well it is all about defence against herring gulls. When sitting there counting I often heard a groan move across the cliff face like a Mexican wave and look up to see a gull glide slowly across the face. The noise is like that of a football crowd that has just seen a shot go over the bar and it is a guillemot warning  for their most dangerous predator on the look out for poorly attended chicks and eggs. Every so often a gull will pounce on a likely prey and it is then that the guillemots massed ranks come into force. A forest of sharp bills like the sharpened stakes at Agincourt are a good defence against a marauding gull
Herring gull harassing auks on the cliffs
Guillemot chick and adult ready to defend against herring gulls,
2)- My defence against gulls the clipboard. In a couple of places my counting position was right next to gulls nests and they really didn't like me there. It is hard to concentrate with a great big gull dive bombing you, pooing and wailing and close enough for you to feel the breeze as it shots past. When you walk into position and walk out again you have the whole lot after you and that is where the clipboard comes in - great for deflecting attacks and for sheltering under from raining poo !

3) How do birds recognise each other ?  On a cliff face with thousands of others of you own species how do you recognise you partners and neighbours? Well it seems that birds are a bit like humans in that it might partially be the voice but also the looks. We are actually experts at noticing tiny differences in faces and though birds like guillemots initially look all the same they do have small differences that they can recognise. Maybe even in they way they fly just like difference humans have different gaits. Also birds may have visual differences that we can't pick up as they see the more of the ultra violet spectra that can show differences not visible in normal light. It is still amazing to see a guillemot start to call from a cliff ledge to its mate as it flies in amongst hundreds of others.

4) Razorbills and numbers of eggs. - After seeing a razorbill trying to incubate 2 eggs I went back at the end of the day and found out what was probably going on. Well it seems that it is possible that razorbills at one time laid and incubated 2 eggs on cliff ledges. In fact they actually still have 2 brood patches (bare skin areas on the breast which have extra blood vessels against which the egg is held to ensure warmth) and though most lay 1 egg occasionally 1 might lay 2 eggs but 1 will never develop. It seems that razorbills are evolving to be like the guillemot and lay and incubate only 1 egg.

2 doting parents and their single chicks.

5) Data Entry - Always use a sharp pencil for clear data recording but never, ever keep it in your pocket.

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