On Sun, 31 May 1998, Leslie Ann Rose wrote:

> In the past week or so, we have noticed a goodly number of Purple
> Martins making virtue out of vice within the industrial waterfront of
> Commencement Bay. We have found them in old pipes and water lines (4-6"
> diameter) along abandoned industrial sites. These sites as well as
> cavities in old pilings in the area seem preferable to the birds.

So much has been made of Starlings being the likely cause of the
severe decline of Purple Martins in Washington post-1945. Now,
we are seeing a dramatic rebound. Starlings are no less abundant
are they? For awhile I thought that providing nest boxes on pilings
over the water gave Purple Martins the advantage (perhaps because
Starlings are simply not that well suited to nesting over water)
and therefore, it was human manipulation of habitat availability
that was bringing back the Purple Martins. Now, I am not so sure.
As more and more Purple Martins colonize the pipes and potholes
of the Puget Sound's shoreline inner cities, I will really wonder
whether there ever really was a Starling factor.

> In more than one instance, perfectly good, ready to use, unoccupied nesting
> boxes are found adjacent to the occupied sites.

In the east Purple Martins like to pile together in great colonies. Out
here, they like their space. Put two boxes next to each other and
likely only one of them will be occupied. That may be at least part
of the explanation for what you have observed.

Kelly McAllister