This article is provided by Bill Kampen, Leavenworth, WA. It is a longer article than our usual blog posts.

We are all concerned about the spread of disease in our wild birds. Bill took it on himself to not only respond to the need to exercise caution while feeding, but also to use the situation to learn. He kept a detailed record about which feeder types he was using, what type of food, and the bird’s that visited. We can all learn from Bill’s documentation. Thanks, Bill.

Two months ago (mid-December) large flocks of pine siskins began appearing in our yard.  We thought at the time that this was great, and responded by adding extra finch feeders to accommodate them—a big mistake in hindsight.  Within a couple weeks we started finding dead siskins, but at first rationalized this away (window strikes, natural causes).  But when It kept getting worse, we realized something was seriously wrong, so we closed down our birdbath for the winter and removed our seed feeders until we could figure out what was going on.  

We must have been among the first to deal with this here, because since that time there have been numerous articles appearing in newspapers from California to British Columbia warning people about the siskin irruption and accompanying salmonella outbreak. These articles have generally been very informative and helpful, but not always consistent, still leaving many questions unanswered.  So we decided to rehang a couple of our seed feeders, and monitor and adjust as needed.

Our efforts over the next month appeared to be successful, so last Monday (Feb 15), I decided to run an experiment.  I began with our current baseline feeder set-up which was now doing a nice job supporting the usual wintering birds, while not attracting huge flocks of siskins, which I believed to have been the cause of the earlier salmonella outbreak.  Over the next several days, by making a few subtle changes (number of feeders, feeder types, seeds being offered), I hoped to get a clearer picture of what worked, what didn’t, and why.  

In the initial baseline set-up, there were only three seed feeders:  A 1/4” mesh cylinder feeder (like a magnum feeder, but smaller) filled with black oil sunflower seeds (BOSS) hanging from our maple tree;  a 1’ square tray feeder with a mesh bottom hung below a squirrel guard five feet away; and a no-mess seed cylinder hanging from our birch about 50 feet away.  Four suet feeders were also present, and would remain throughout the experiment, but play no role.  The daily log below tracks this experiment in real time.

DAY 1 (Monday, Feb. 15)

Tray feeder filled with BOSS as usual.  Number of siskins observed: 0.  Goldfinches: 1  Lots of activity on all feeders, but mostly centered on tray feeder, since seeds are most accessible here.  House finches are numerous—maybe 20 in the flock, hanging around all day.  White-headed woodpecker, flicker, and downy woodpecker come in regularly to suet feeders.  Lots of b-c chickadees and r-b nuthatches as usual.  Up to 3 song sparrows still present.  2 pygmy nuthatches and 1 mountain chickadee also seen, the latter seen multiple times.  No “frantic activity” anywhere—the birds know what they can expect to find here, and even at the tray feeder they generally just “grab and go” without much fuss.  Stellar’s jay numbers have increased since I added the tray feeder—high count today was 10.  They visit all feeders, and the other birds back off when they are present.  All in all, nice balance and fun to watch.  No problems.

DAY 2

Light snowfall.  Lots of birds coming in early (7:30-8:00).  Mountain chickadee still here.  I refilled the tray feeder at 9:30, again with straight BOSS.  2 goldfinches showed up, along with lots of house finches (20 or so, like yesterday).  Even with the adjacent high-bush cranberry hedge and tray feeder now full of activity, the pace is still calm enough that our white-headed woodpecker felt comfortable coming in to feed on the suet feeder just two feet away.  The 2 goldfinches did not feed—just briefly checked out the tray from their perch in the hedge, and left.  Were they hoping for sunflower chips?  

When I checked the feeders again at noon, there was a healthy-looking siskin sitting in the center of the tray feeder, determined to defend it against all comers.  The house finch flock was in, so after a few seconds of dashing from side to side trying to drive them all off, the siskin gave up and retreated to the hedge.  It then flew to the mesh cylinder (BOSS) feeder and circled it once on foot, before flying off without taking a BOSS from either place.  Was it checking for sunflower chips like the goldfinches earlier?  

It’s 12:12 now and the siskin is back on the tray; behavior as before.  Very aggressive—wings and tail flared, rushing at birds that are attempting to join it on the tray.  This time it appears to be feeding, but unlike the other birds that grab and go, it apparently does not want to relinquish its spot at the feeder, or share with non-siskins.  It left after a couple minutes.
 
When I checked again at 2:20, the birds were distributed among the other feeders, so I figured the tray feeder was probably empty.  It was, so I cleaned it and refilled it with BOSS for the late afternoon crowd, if there was one. The house finches and a few juncos were all over it right way, up to 8-10 at a time.  The house finch flock has now grown to about 30.  The tray feeder is VERY busy now—lots of comings and goings—but still almost no disputes or aggression.  No siskins or goldfinches are present.

It is now 3:12 and activity has slowed.  The 3-5 house finches that occupy the tray feeder now tend to just stay and eat rather than grab and go.  Occasionally a new one comes in to replace one that leaves.  Most are males, and occasionally a junco or b-c chickadee will join them.  It is very peaceful—everyone seems to get along, and all are willing to share the space.

It is now 3:18, and the finches have all left.  A song sparrow now sits in the middle of the tray feeder, having it all to himself.  A few b-c chickadees are still working the suet feeders, and lots of juncos in the hedge, but they are not coming up to join the song sparrow on the tray.  Is it almost empty?  I’ll check in a few minutes.  

It is now 5:00.  The juncos left around 3:30, and the chickadees and song sparrows (2) stayed a little later.  At 5:00 I refilled the mesh BOSS feeder for tomorrow (about half eaten over two days).  The tray feeder still had a few BOSS, so the finches and juncos did not leave because the feeder was empty—they had just had enough.  NOTE: This time I made a change, refilling the tray with a seed blend containing sunflower chips, instead of straight BOSS.  So the real test begins tomorrow, and we’ll see if this makes a difference.

DAY 3

(Note:  I do Project FeederWatch every Wed-Thurs, so that starts today.)  A flock of 10 siskins arrived at 8:30, focusing on the tray feeder, and specifically the chips.  Seven of them are able to feed harmoniously on the tray at one time, but they like being IN the tray rather than perched on the edge of it, as most of the larger grab-&-go birds do.  When a new siskin wants to come in, a departing siskin will make room for it—usually not much fuss.  Non-siskins are NOT tolerated.  If a jay appears, the siskins depart quickly.  With the arrival of the siskin flock, then, the house finches have dropped one rung in the pecking order, so there is a longer wait for them to gain a seat at the table.  If only one or two siskins are on the tray, the juncos, house finches, and chickadees are welcome to join them.  All-in-all, not much disruption so far.  However, 7 siskins FEEDING IN the tray means the potential for 7 siskins defecating ONTO the chips, which have no protective shell.  When I was feeding straight BOSS, this was not an issue.

By 9:40 siskin numbers had increased to 16, so I added a 6-port tube feeder with the same seed mix as on the tray to accommodate them.  This is an EcoClean feeder with a weather dome and EcoClean seed tray, so should be easy to keep clean.

It is now 3:16, and a fluffed-up siskin is sitting on the lowest perch of the tube feeder, and hopping around on the attached seed-catcher.  There have been no problems up until this siskin appeared.  It just left (3:21), so if I hadn’t checked the feeders five minutes ago, I’d have missed it.  Was this siskin infected with salmonella?  Impossible to tell, of course.  If salmonella is only spread through feces, we should be fine.  If it’s also spread through saliva, maybe not.  I continue to believe that this flock would be better off foraging in the trees (native seeds), but probably worse off if it returns to wherever this one picked up the infection (if it was, in fact, infected).  So if I stop feeding the chips, there is no way to know if this will help or hurt the flock—a dilemma. 

Tonight I found this advice from the Canadian Wildlife Health Cooperative:  Avoid using tube feeders that require birds to stick their head inside openings to feed as infected birds may leave discharge containing Salmonella bacteria on the sides of these openings, which could easily be transferred to healthy individuals and cause them to become sick with salmonellosis. 

DAY 4

Tray refilled with mixed seed, so same set-up as yesterday, but with tube feeder removed following above advice.  First in this morning at 7:30 were the siskins—counted 18.  They crowded onto the tray feeder—up to a dozen at once.  They left after about 6 minutes and were replaced by 7 jays (probably why they left).  14 juncos were in the hedge, but mostly stayed there, with a couple venturing onto the feeder after the jays left.  House finches have not appeared yet.

At 7:50 a much larger flock of siskins appeared at the top of the 60-foot maple tree from which the feeders hang, and these siskins began working their way downward toward the feeder.  I counted at least 50—easy to count—bare tree limbs and birds silhouetted against the sky.  When I swiveled my chair around to write this on my laptop, I heard a bird hit the window, and when I looked back the flock was gone, so I suspect our Cooper’s or sharpie came through.  It’s now 8:04, and 4 siskins are back on the tray, with a few more in the hedge, but I don’t see the larger flock.  Still no house finches this morning, and, except for one chickadee and one nuthatch, not a single bird has shown any interest whatsoever in the almost-full mesh BOSS feeder just 5 feet away.

8:45—the siskin flock is back and probably closer to 60.  They’re starting to overwhelm the tray feeder, so I added one EcoClean finch feeder with weather dome and seed-catcher and filled with finch blend, just to see if I could disperse the birds somewhat, and also to see if there was any difference as to which seed blend they preferred.  

It is now 9:20, and siskins are all over both feeders, with house finches waiting in the hedge, as usual.  Also, with so many birds concentrated here, a secondary feeding area below has quickly developed—something that did not occur when I was feeding straight BOSS.  Lots of birds are dropping down here to feed, including siskins, which tend to forage in tight groups.  Meanwhile, the mesh BOSS feeder and winter-blend seed cylinder remain ignored by the siskins—their full attention is absorbed by the finch and tray feeders, and the ground below.

9:30—I’m looking at a feeding FRENZY now—I think it was the finch feeder that tipped the scales.  Both feeders and the ground below are now covered with siskins–a salmonella outbreak waiting to happen–so rather than wait for the first sick siskins to appear, I am pulling the plug now.  

9:40-9:45:  When I went out to retrieve the feeders, not all the siskins left.  I stood right under the finch feeder with my hand resting on the hanging tray, and siskins kept coming in.  I had 5 on the tray (all appearing healthy), while my hand rested there.  Two months ago I would have found this experience to be quite magical.  Now it seemed just strange and scary.  I removed both feeders, cleaned the tray and added 1 cup of BOSS.  I did not rehang the finch feeder.  When I approached the feeding area, I could see the siskins watching from the tops of the maple, birch, and tamarack.   I rehung the tray, and went inside to see what would happen.  

9:50:  The “changing of the guard” took only 5 minutes, and was fascinating to watch.  The house finches, chickadees, and jays seemed to realize immediately that we were back to normal (BOSS only), and they all started coming in as they had before the change in seed took place.  Probably coincidentally, both our flicker and white-headed woodpecker showed up right away, too.  A few siskins landed on the tray feeder and poked around a bit, but when they saw that only BOSS was on offer, they left the feeder to the house finches, which were arriving in numbers.  A jay came and went.  At 9:50, the entire siskin flock, which had been still observing all this from the treetops, flew off en-mass. 

10:25:  House finches now dominating—I count about 2 dozen.  About half the siskin flock just returned, and are mobbing everything.  They feed frantically under the tray (where there are still plenty of spilled chips); then fly up to the hedge; then to the tray where they push the BOSS around searching for chips that are no longer there; then over to the seed cylinder where there ARE chips, but they have to work to extract them; then up into the birch above the seed cylinder; then back to the hedge, and around again.  Occasionally one or two even check out the mesh BOSS feeder, which is where the house finches are going now that the siskins are crowding onto the tray and cylinder.

11:00:  The birds have pretty much finished off the chips on the ground, so while there are still a few siskins coming into the seed cylinder, most have now left.  Was this a second flock that came in after seeing the spilled seed, and then needed to check out the tray and cylinder?  Or was it part of the earlier flock back to make sure they were reading the situation correctly, and to finish off whatever nyjer and chips might be left?  No way to know, but I suspect the latter.  In any case, this was basically a repeat of an hour ago, but taking longer because of the spilled chips and nyjer.  With these pretty much gone now, this should be the end of it.  One fluffed-up siskin remains, sitting on the lower perch of the seed cylinder. 

11:35:  Only one siskin remains—hanging out near the seed cylinder.  Don’t know if it is the same one that appeared fluffed up earlier, but maybe.  Starting to snow.  Several birds feeding at the tray, including one goldfinch.  Hedge filled with a nice mix of birds, and one pine squirrel.  Good to have the large siskin flock gone.

1:00:  No activity at the tray, so I checked to see if it was empty, and it was.  I refilled it with two cups of BOSS and hung it back up.  About an inch of fresh snow has covered the few remaining spilled seeds and shells, so ground feeding is now confined to one or two juncos, or no birds at all.  The lack of visible seeds or shells against the white snow, and the lack of bird activity, means not much to draw in passing siskin flocks.  Mostly juncos here now (about 2 dozen), with 4 siskins also hanging around—hedge, tray, cylinder.  Pretty quiet out there, except for all the juncos.

1:20:  An adult Cooper’s hawk just came in, spent a minute or so perched near the hedge, and then flew off.  Juncos quickly resumed feeding after it left
.
4:00:  Birds gone, still snowing, normal feeding activity all afternoon.

DAY 5

I finished snow-blowing and shoveling by 7:45, and hung a second mesh BOSS feeder where the tube and finch feeders had briefly hung before.  This one is thinner with no seed-catcher, and has a weather dome, so it is about the same size and shape as the finch and tube feeders.  Siskins came in right away—likely were there before I started watching—but only a dozen or so.  Their behavior was interesting.  They continued to shun the mesh BOSS feeder that had been there the whole time, but were very interested in checking out the tray and new BOSS feeder, apparently still hoping to find nyjer and/or sunflower chips.  

I thought they’d leave when they found out there weren’t any, but instead they began actually eating the BOSS. This was fine with me—their behavior mimicked the house finches, and they seemed to just be gradually settling into the regular routine here.  Some also went to the cylinder where the chips WERE available, but where they had to work to extract them.  The siskins (and one goldfinch) all appeared healthy, so if this continues to be the case, maybe I can keep feeding the BOSS.  We’ll see.  A new bird for the winter, a male Cassin’s finch, also showed up (7:57; reported to eBird).

4:00:  The tray was empty, so I added a cup of BOSS, even though most birds should be done for the day.  There is little activity out there now.  Today overall was uneventful—all feeders very active, with still 10 siskins or so now apparently having joined the yard regulars.  I’ll keep an eye out for sick or dead birds, which would be most likely to appear either on or under the cylinder or tray feeder if they show up at all, and will make adjustments accordingly.

DAY 6

Siskins number around 20 today, with continuous use of the cylinder and tray mainly, but both mesh feeders, too.  With three BOSS feeders now up (2 mesh and 1 tray), no snow, and warmer temperatures melting the snow under the feeders and hedge, there is a noticeable accumulation of shells.  This would be highly visible to passing flocks, and may be contributing to the growing number of both siskins and house finches.  I’m a little uncomfortable with this, given the ever-present threat of salmonella, and wonder if I may now be pulling birds away from natural food sources which are safer for them. 

One fluffed-up siskin spent some time foraging on the ground below the feeders, along with the healthier birds—juncos, house finches, and other siskins.  It did not seem at all lethargic, though, which makes me wonder if some of the siskins get mildly sick and eventually recover.  This siskin seemed to have no trouble keeping up with the rest of the flock.  Am I getting hyper-sensitive?  I understand that the disease is almost always fatal—just wonder if some siskins can fight it off.  Also, should one puffed-up siskin be reason enough to take down all four seed feeders?

2:00:  No further signs of sick siskins, but in an abundance of caution I took down all but the original mesh feeder, which I re-hung under the squirrel guard where the tray feeder had been.  When I checked again an hour later, only a few siskins were present, with mostly house finches and a few chickadees using the feeder.  I’m liking this “less is more” concept—being able to dial up or down the feeding activity by simply increasing or reducing the number of feeders, changing the type of feeder, and/or changing the seed being offered.  Maybe I’m starting to get the hang of this.  If so, good news for the birds here.

DAY 7

At 7:35 a flock of about ten juncos arrived.  While they are able to perch on the seed-catcher attached to the mesh BOSS feeder, they generally prefer to forage on or under the hedge, or under the suet feeders on the south side of the house where patches of bare ground are beginning to appear.  chickadees and nuthatches are around, too.

8:25:  A dozen house finches are perched in the hedge, with two goldfinches.  All seem to be assessing the new one-feeder set-up.  The goldfinches left immediately, but the house finches just sit, perhaps waiting to see if the other feeders will reappear.  They are all used to me taking them down, refilling them, and hanging them back up, so… 

11:40:  Warmer, with a light rain.  The hedge and feeder have been pretty much empty since the now-reduced flock of house finches left.  Only a few juncos, and one pine squirrel, remain.  No chickadees, nuthatches, or woodpeckers either.  This is usually a quiet time anyway, so we’ll see if things pick up this afternoon.  This is the quietest the yard has been since I started the experiment a week ago, but that’s to be expected, with both the tray and cylinder feeders gone.  Whoops—spoke too soon—small flocks of house finches and chickadees are back (11:47).  No siskins, though.

1:55:  Still raining, and almost no activity near the feeder, though a few siskins and house finches remain in the hedge.  To see if I could generate a bit more activity, I moved the mesh feeder to its original spot and added the tray feeder filled with one cup of BOSS back under the squirrel guard.  We’re now back almost to baseline, but with the cylinder feeder still not there.  If the siskins don’t return in numbers by tomorrow, I’ll probably rehang that, too.

3:10:  No flocks, but a nice mix of individual birds coming in one at a time:  b-c chickadees, 1 mountain chickadees, 1 r-b nuthatch, 1 goldfinch, 1 siskin, and a few juncos, but no house finches.  The birds that have rediscovered the tray feeder clearly prefer it to the mesh cylinder, but the finch flocks have apparently found other places to feed, so we are off their radar, at least for now.  I suspect they will check us out again tomorrow morning, and finding the tray feeder back up, a few more will hang around.  Not enough seeds available here to pull in larger flocks, though, so hopefully we’re returning to balance now. 

This concludes the log, but of course feeding birds is really an endless experiment, so that will continue indefinitely.  Always new problems to solve, and new things to learn—part of the fun.

*******   
Tentative conclusions:  If we offer nyjer and/or sunflower chips, large flocks of siskins will come in and pretty much wreck havoc, ignoring not only the BOSS we’ve put out for them, but native seeds (still plentiful around here) as well.  If we keep supplying them with nyjer/chips, salmonella will soon begin spreading through the flock, killing siskins and needlessly putting our other feeder birds at risk.  We’ve already fully experienced this once, and I’ve tested this theory twice now (documented the second time) and don’t plan to go through it again! 

If we STOP feeding nyjer, chips, and BOSS, pretty much all the finches will disperse, hopefully returning to their natural buffet in the surrounding trees.  But we CAN still safely continue to scatter cracked corn for the quail, juncos, jays, and other ground- feeders, and our suet feeders can stay up for the woodpeckers, nuthatches, chickadees, and song sparrows.  So no need to stop feeding entirely.  

There may be a middle ground.  ALL of the birds in our yard like BOSS, so once the finches have left, one mesh BOSS feeder, one BOSS tray feeder, and MAYBE the seed cylinder can be re-hung, without causing the siskins to return in force—just too small an offering, and almost none of their favorite food, so as long as we can safely offer it, we will.  Individual or small flocks of healthy finches that happen by are always welcome, too, of course.
 
I’m really liking the little hanging tray feeder, and have a round, all-mesh one on order.  When placed under a squirrel guard/weather dome, these little trays stay surprisingly clean, with the dome also catching any droppings from birds perched above.  And, since the tray needs to be refilled every day or two, it can easily be cleaned frequently, too.  The new one I’ve ordered, being round, will be even better protected by the squirrel baffle (no corners sticking out to catch snow, rain, or droppings), and also should be easier to clean (no corners or edges).  Best of all, there are no ports into which all birds must repeatedly stick their heads or bills.  Since it is non-selective, we may have to take it down from time to time if a flock of starlings or house sparrows finds it, but that hasn’t been an issue here for a long time. 

With the siskins still in the area, rehanging the tube or finch feeders, or resuming use of seed mixes containing sunflower chips, is off the table, at least for now, and I am wondering about the wisdom of doing this even after they leave.  I think loose sunflower chips are just too attractive to siskins, and to finches generally– so much so that these birds will abandon native foods to seek it out.  Knowing what we now know about the susceptibility of siskins and other finches  to salmonella,  conjunctivitis, etc., and the danger of pulling them away from their natural food sources to our feeders where close-contact encourages infections to spread, I’m wondering if we should continue to do this.  Is it a coincidence that the 80% decline in siskin numbers over the last 40 years mirrors the explosive increase in the use of these pre-shelled seeds in feeders?  At the very least, I think we have to be very careful when using these seeds. 

That’s it for now.  As always, feedback is much appreciated. 
Bill