We do have House Sparrows and Starlings.? I think over the 18 years we have had something like 4 House Sparrow nests, three in one year.? In the other year, they nested after the Tree Swallow.? Starlings can't use the swallow boxes; I don't know if they harass the other birds.



We do have both Cooper's and Sharpies.? They take a toll at the feeders and I am pretty sure thy nest around here.?



At the same time, I am pretty sure that nesting Towhees, Juncos, Song Sparrows, and White-crowns have increased.? As have the Scrub Jays and Black-headed Grosbeaks.?Takes some really long-term data (decades) to reasonably sort out.


Hal Michael
Olympia WA
360-459-4005 (H)
ucd880 at comcast.net

----- Original Message -----
From: "Blake Iverson " < coopershwk at gmail .com>
To: tweeters at u. washington . edu
Sent: Friday, June 22, 2012 12:31:56 PM
Subject: [Tweeters] Really: violet-green and barn swallows.



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.




---

Blake Iverson ?
Marysville ,WA

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