I've also noticed a change in visible bird populations. Even more so with
cliff swallows than anything. I think a combination of how structures are
built these days and increasing pressure from starlings and house sparrows
is having a negative effect on some species and causing others to adapt by
changing their preferred nesting habits that we interpret as population
decline. It's been hard for me to have a good grasp of it in my
neighborhood since I have a nesting pair of merlins which keep swallows out
of the area or keep feeding evaluations very high above the merlins.

No doubt the maturing of landscapes on some people's property forces a
change in nesting habits for these birds as they probably find it too risky
to nest and forage where they're at high risk for attack from accipiters
and it invites the pests like sparrows and starlings to launch attacks. A
dairy farm or other farm set up could arguably provide the same dilemmas
but the size of the building etc allows for room to spread out.


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Blake Iverson
Marysville,WA
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