Mike Smith wrote:

> A more useful measure might be to tally all the birders who
> travelled more than 100 miles to see the Ross' Gull, and then

> make some age/sex breakdown.
>


- stuff deleted -

> The same is true for those who don't twitch, how many little

> old ladies will look through a roosting flock of 5000
> calidrines for a juvenile stint?

It's probably a bit more complicated than that.

Driving 100 miles to see a Ross' Gull doesn't appeal, neither does
searching through 5000 calidrids for stints.

However driving 100 miles to catch a Ross' Gull or catching 5000
calidrids, now that is a different matter entirely :-))

Stuart