Tuesday, 13 May 2014

Micropterix calthella Abound

I'm checking the Buttercup flowers daily and there's still an abundance of moths in spite of the cool damp weather.  It raises the question of how to record these sightings, and I'd welcome advice on this.  Many of the flowers have 10-12 moths on them, so the total numbers I see every time are well into three figures, but it's only a guesstimate - I'm not going to count them!  Also, I'm probably seeing many of the same individuals day after day.  In short, I don't want to exaggerate the numbers yet it would seem important to record that they're very common just now.  Having said that, the majority of them are in one area, quite close to the pond, and there are other parts of the property with numerous Buttercups without any moths on them.


5 comments:

  1. You could achieve a fair estimation of the population by doing some random quadrats of a suitable size as per the info here: http://www.countrysideinfo.co.uk/howto.htm and then extrapolate the total population from your counts in the sample areas.

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  2. I'm afraid that you might have misunderstood me Steve, I'm not looking to do a population study of these critters, only to find the best way of translating my observations onto the Excel Data Sheets. If I just complete a single sheet for the initial observation last Friday of, say, 100 moths, that would probably be reasonably accurate but would only count as a single record (correct me if I'm wrong). On the other hand, if I provide the same count on sheets for several subsequent days (also reasonably accurate) I'm probably counting the same moths several times. But maybe that's what I've got to do - no system's perfect! It's not a problem I've encountered before, when for the most part I've been dealing with the modest contents of moth traps.

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  3. You're correct, Christopher; I have misunderstood - my bad. You clearly have greater knowledge of the recording system than do I. What are these Excel Data Sheets of which you speak? Should I be using such things to conform to a common and agreed standard for recording? I hope someone will put me right on this.

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  4. Steve, I've emailed you copies of the data sheets I use, which were provided by Jon Baker when I started trapping 4 years ago. However, although Sam seems happy to accept my records on these sheets he may prefer an alternative means of recording. It might be worth waiting to discover what others are doing.

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  5. I'm about to send round two alternative recording sheets that I have been working on recently, but would like to pass them by Jon first. Chris' data sheets (one per day/night) can be saved and then stitched together for submission at the end of the year. There will be a version of that coming up, just with a few names amended. There will also be a columns format, similar to the one Mat and Sally use, now that I have worked out a quick(ish) way of reformatting them.

    Personally I wouldn't bother with saving individual daily data sheets: I'd have a single spreadsheet for your site for the year and would just copy and paste a day's datasheet into that as I went along. For the repeat sightings of Micropterix I would put in an estimated total for each day and would just copy the name down the main yearly spreadsheet as I went along, as each one is a valid sighting and within a couple of weeks there will only be one or two (and M aruncella will be around in numbers).

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