For the Chimney Swift cutting down the forest and putting up lots of brick chimneys was probably accompanied by a large population increase. It's now unusual to find a Chimney Swift nest or roost in a tree.

For Vaux's, from Handbook of the Birds of the World Vol 5, "A study of 160 forested stands in 1991 revealed that this swift was present in 41% of old-growth stands, and only 8% of logged ones, reflecting increased availability of suitable nesting trees in old-growth."

In her published paper DECLINES IN THE BREEDING POPULATION OF VAUX'S SWIFTS IN NORTHEASTERN OREGON Bull writes "The hollow chambers formed in Grand Firs by Indian Paint Fungus are most commonly used as nest sites.

We have one large Redwood snag near Eureka that has good numbers in the southbound. Difficult to track them down in the forest. Between San Francisco and LA we've not been able to locate a man made roost and assume its warm and dry enough they spend the night on tree trunk bark.

100 Vaux's in the Monroe Wagner roost tonight.

Thunder shower in Issaquah.

Larry Schwitters
Issaquah

1001

On Aug 11, 2014, at 5:16 PM, Dan Reiff, PhD wrote:

> All,
>
> They did evolve pre brick and chimney.
> Larry, do you have literature on the specific characteristics of the tree cavities they used to use and were more available pre managed forestry?
> And are there known sites where this still occurs for groups of swifts on the West Coast of the US?
> Did they use brick chimneys preferentially over tree cavities when the stacks became available?
> Thanks,
> Dan Reiff
> Mercer Island
>