Estimating numbers

[con <>]

I do it the other way around with flocks.

Step 1 guess total number
Step 2 count a ten and then see how many tens there are
Step 3 count them by twos, conditions permitting.

My bias is that I normally underguess in step 1. My guesss for the 
Starling number was 110.
Con

Geoffrey Dabb wrote:
> Thanks John.  It's not easy and it's one of those things where if you 
> don't have any measure of your estimates you don't get any better.  
> I'm sure that the experts mentioned by Dan learnt from the experienced 
> estimates of others.  Photos might have helped.
>  
>
> I'm not too good myself and I won't go on and on, but here are exactly 
> 100 waders:
>  
>
> 100 waders.JPG
>
>  
>
> -----Original Message-----
> From: John Brannan 
> Sent: Thursday, 18 March 2010 2:36 PM
> To: Geoffrey Dabb
> Cc: 
> Subject: Re: [canberrabirds] Estimating numbers
>
>  
>
> Geoffrey,
>
>  
>
> Thank you very much for this. It was highly instructive. My own hesitant
>
> initial estimate was 60-70 birds - serious undercounting, as it turns out.
>
> In future, I wonder whether it might be helpful if, when counting
>
> smaller numbers (20 or so) where counting of individuals is feasible,
>
> one were to take a step back after the count, take a fresh look at the
>
> group and say to oneself, "Right. That's what 20 birds looks like."
>
>  
>
> John Brannan
>
>  
>
> Geoffrey Dabb wrote:
>
> > 
>
> > Very interesting.  Estimates mentioned to me ranged from a wary ‘0 –
>
> > not starlings’ to ‘200-300’.  It might or might not be helpful if I
>
> > told you that each of the first 4 coloured sections represents 50 birds:
>
> > 
>
> > 
>
> > 
>
> > 
>
> > I would think that very few people would know, intuitively, what 200
>
> > birds ‘looks like’.  Barbara P mentioned the semi-counting method of
>
> > counting 10  -  then counting the number of tens.  That depends on
>
> > having the flock in view for long enough.  John Rawsthorne – an old
>
> > sheep-counter like a few others – said if it looks like 100 it’s
>
> > probably twice that number.  That is, in  a way, knowing what 200
>
> > ‘looks like’  -  it looks like 100.  That kind of knowledge comes from
>
> > knowing at some stage the actual number of estimated quantities, so
>
> > perhaps the sheep counters have an advantage.
>
> > 
>
> > 
>
> > 
>
>  
>
>  
>
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