One of the weaknesses of current CBC data on-line (and
I include data that I have extracted) is the compromises
made between interactiveness and access and the effect
this has on scale components of the data.

If one lumps Pine Siskin Data over the entire region, the
view at that scale is very differrent than on a count by
count scale. Pine Siskin fluctuations in Portland do not
correlate particularly well with Eugene or Medford.

Lumped data can produce patterns that don't necessarily
reflect the real picture of irruptive events. Snowy Owl
data, for example, when examined at these finer scales
shows a very different picture than the one that is implied
in many ornithology texts (Kerlinger et al. 1985).

Recent analysis of Common Redpoll irruptions (Wesley et al. 1999)
suggest that they may not be "textbook" irruptions either.

Kerlinger, P., M.R.Lein and B.J.Sevick. 1985. Distribution and
population fluctuations of wintering Snowy Owls (Nyctea scandiaca)
in North America. Canadian Journal of Zoology 63:1829-1834.

Wesley et al. 1999. Irruptive migration of Common Redpolls.
Condor 101:195-204.




Don Baccus wrote:
>

> And choose the "Graph annual variation for individual species"
> option. Pick "Pine Siskin". If you leave the location blank,
> it will compute a graph for the entire Pacific Northwest, or
> you can pick Oregon or another state, counties, etc...you don't
> have to register or login to generate such reports.
>

--
Mike Patterson The common view of science is that it is a sort of machine
Astoria, OR for increasing the race's store of dependable facts.
mpatters at oregonvos.net It is that only in part; in even larger part
it is a machine for upsetting undependable facts.

----- H.L.Mencken
http://www.pacifier.com/~mpatters/bird/bird.html