re: collecting birds - vagrants

My two cents(rounded to 5 with a couple of questions):

Has anyone done any research into the appearance of vagrants,
and the subsequent influx of significant populations of that species into
previously unoccupied areas? Are vagrants 'lost' or are they perhaps scouting
for new areas for a more substantial population to settle?

If the latter is the case, then shooting a vagrant is
not only detrimental to the bird that is killed and the population it may
inform, but also to the area and the 'scientic community' in that area,
who miss out on acheiving real insight into the behaviour and habits of
the species. (Not to mention the possiblity of collecting numerous injured
and roadkilled specimens)

In my short and uninformed experience, i can reference
two examples from the Geelong area: The Northern Shoveller and Crested
Pigeons.

The Northern Shoveller introduced me to the world of vagrants,
and i believe had appeared before at the WTP. If someone had of shot the
Northern Shoveller the previous time it appeared, i would never have seen
the bird (along with probably 50-100 others). Thus reducing the possible
'hooks' for others to be lured into to serious scientific investigations
on birds, migration etc. etc.

Re: Crested Pigeons: I'm guessing they were originally
vagrants (or an 'out of range' species), which are now building up significant
numbers in the area. A good example of what may have happened if the Yellow
Chat in question, had of survived. 

In any case, it sounds like the shooter and those who
commissioned the shooting of the Yellow Chat were just plain lazy! I'm
sure other museums have this specimen avaliable for study, and they are
usually stuffed away in draws and not on display anyway. Surely a loan
of the specimen could have been aquired for analysis on request from another
museum???

My two cents.

Peter