If You're Seeing Sick or Dying Pine Siskins

This is a Guest Post by Dan Gleason, Instructor of Ornithology, University of Oregon and Co-owner of Wild Birds Unlimited - Eugene, OR (opening April 2013)

During winter finch irruption years like we're experiencing right now, we unfortunately start to see birds that are obviously sick or find a dead bird near our feeders. The cause if often Salmonella bacteria.  Here's a good discussion on a sometimes confusing subject by Dan Gleason, who has taught ornithology at the college level for over 30 years.

---

The Many Types of Salmonella Bacteria

The usual cause of sick and dying Pine Siskins is Salmonella bacteria. There are two primary species of the Salmonella bacteria that often infect birds, but these are subdivided into over 2,300 variants.  To make matters more confusing, some of these variants are sometimes referred to as if they were a separate species; e.g., Salmonella enterica typhimurium (a common type of fowl typhoid) is often simply called S. typhimurium. This can make it confusing when trying to find information online about Salmonella.

One of the two species of Salmonella (S. pulorum) most often infects waterfowl and grouse, and most frequently, domestic fowl.  The other species (S. enterica and its many strains) is what infects many wild birds (and people).

Birds React Differently to the Bacteria

Different species of birds can react differently to infections of Salmonella.  One study on Herring Gulls showed they passed out the bacteria in their feces and showed no physical symptoms at all. Some kinds of birds show mild lethargy for a day or so, but little else.

On the other end of the spectrum are Pine Siskins, which seem to be more susceptible than any other species.  I don't know the physiological reasons for such differences (or if they are even known), but it seems to be the case that Pine Siskins have a much higher mortality rate from this disease.

A friend of mine who has an international reputation among wildlife rehabilitators and has over 30 years of experience, tells me that she has never successfully been able to save a Pine Siskin that has been infected with Salmonella. They always die before any treatment has time to work.

Salmonella is less frequent, but still very common in Evening Grosbeak, House Sparrow, Brown-headed Cowbird, Northern Cardinal, and Goldfinches (especially American). It occasionally occurs in House, Purple, and Cassin's Finch and is infrequent to rare in most other species of songbirds.

 

Sick Purple Finch.
Sick birds appear puffy, may exhibit difficulty swallowing, and are unusually approachable.

How the Bacteria Spreads

Salmonella as a disease in birds is relatively rare in the wild, but outbreaks do occur from time to time and then we often see the evidence at our feeders.  Many birds with mild infections can carry the disease without showing any symptoms and simply pass it out in their feces. But the bacteria is still active.

When a susceptible individual of an easily-infected species, like the Pine Siskin, picks up the bacteria, it proliferates quickly in the infected bird's gut and is passed along to others via the feces.

Salmonella is most easily passed between individuals by contact with the feces from infected birds.  Pine Siskins are especially social, allowing easy transmission of the disease.  Feeding in close association with one another makes it a certainty that the disease will be passed to other individuals from an infected one.

What You Should Do with my Birdfeeders?

It is recommended that feeders be cleaned with a 10% bleach solution (9 parts water to 1 part bleach) followed by careful rinsing and complete drying before reuse. 

Clean the area beneath the feeders as well, bagging the debris to be disposed of in the trash. Pine Siskins can be messy eaters and spill many seeds on the ground. It is inevitable that some of that spilled seed will be contaminated by feces.

It is also recommended that feeding be stopped for a period of time (2 weeks?) to let the birds move on and not get reinfected.

Keeping feeders clean is essential, but unfortunately, that alone will not prevent the spread of this disease.  The bacteria can survive for many months on uncleaned feeders, on the ground, on plant or other surfaces. It can be passed by other birds less susceptible to the disease, by reptiles, mammals, or even some invertebrates.  Total prevention is almost impossible.

Once brought to a communal feeding area (which can be a feeding area in the wild or a birdfeeding station), the disease quickly spreads. Even if you are very efficient about keeping your feeders and feeding area clean, Salmonella may be brought in from surrounding wild areas.

Because Pine Siskins are the most susceptible, and because they are so tame and can be numerous at feeders, we see it in them most often. However, be assured that there is nothing wrong with feeding the siskins and that this disease is just as frequent in wild areas as it is at feeders. We just see it more easily at feeders because of their high visibility.

Am I Safe from the Bacteria?

This form of Salmonella can be transmitted to humans and is the most common type of "food
poisoning." It will cause extreme diarrhea and very, very intense intestinal pain. Death has been known, but is uncommon; however dehydration is typical and may be what ultimately kills the Pine Siskins.

Having experienced Salmonella poisoning personally (from an unknown source), I can assure you that you do not want this. It is the single most painful experience that I have ever had.

If you handle a sick or dead bird, or after handling birdfeeders where lethargic siskins have been attending, be sure to wash your hands very thoroughly (a good practice ANY time you touch a birdfeeder - sick birds or not).

Keep your feeders clean and intensify doing so when many siskins are frequent, but be assured that your birdfeeders are not the cause of this naturally occurring and cyclic problem.

 

---

Thank you to Dan Gleason for sharing the information for this guest post.  Congratulations and good luck with your new Wild Birds Unlimited shop!

Post written by:
Dan Gleason, co-owner Wild Birds Unlimited of Eugene, OR (opening April 2013) and Instructor in Ornithology, University of Oregon. 
Author: "Birds! From the Inside Out" and "Looking for Yellowheads". 
Dan can be contacted at wbueugene@comcast.net.

 

Comments

[The Zen Birdfeeder]

Esther, sounds like all the symptoms of a sick goldfinch. Please follow the instructions in the post to help protect other birds.

[Esther Nix]

I think I may have a sick American Goldfinch. He is very puffy and ragged looking. He seems to have difficulty swallowing. Looks disoriented and sits out in the open alot. Could this be salmonella poisoning? He is the only one who seems affected. Should I be worried.

[The Zen Birdfeeder]

Susan, your best response would be to rake away all the waste beneath the feeders, and bag it up for the trash. Wear safety gear if you're stirring up a lot of dust.

[Susan]

I found two dead Pine Siskins in my yard a little while ago and there is another one that is sick and does not look like it will be long before it dies. Poor little things. It makes me feel so bad, but I have removed my bird feeder and am raking up the spent seed (as I do every few days). I was wondering if putting clean top soil on the area under my bay bush where a lot of them were feeding would help at all or what else should I do for the ground in that area?

[The Zen Birdfeeder]

Patricia, the cleaning of the feeders with bleach is a very good idea, but the taking down of feeders serves to disperse the birds, minimizing a congregation where disease is more easily passed from bird to bird.
Sometimes just 2 weeks will be enough. It's hard during that time, but good for the birds.
Thanks for asking.

[Patricia Duarte-Pocock]

I have found a couple of dead Pine Siskins around my feeder area. I do have quite a huge flock this year migrating through my area of Sierra Madre, CA (LA county). I'm not ready to take down the feeders yet as I recognize that there will be naturally occurring sickness and death, particularly in light of the very large number of migratory birds.
I am taking all precautions, have 2 sets of feeders that I change out at least every other week and clean them with bleach before rehanging.
I'd like to know if anyone else in this area is seeing this in which case I will have no recourse but to close shop for a while.

[The Zen Birdfeeder]

Randi, sorry to hear about your sick birds but thank you for doing the right thing! Good luck to you!

[The Zen Birdfeeder]

Glad to help, Jack. I hope things clear up.

[Randi Ciminski]

Hello, I was so glad to find your site and read all the information about the Salmonella poisoning. We live up on Whidbey Island in Washington State and we have been bird lovers, feed hundreds of them all varieties in the Northwest area and we have NEVER seen so many pine siskins dying in our yard. I put on my gloves and carefully put them in a little burial site away from the feeders, it just breaks my heart to see this. Again, we have never see this happen in our lifetime which really is alarming and quite frankly scarey! My husband is out cleaning all the bird baths and we will sanitize all the many feeders we have which will probably take a couple of days. We have been having a very unusually cold winter up here on Whidbey Island so we really thought the very cold nights we have been having had something to do with it, guess not. I hope we can help these wee birds get better......Hope to hear back from you if you have time. Thanks Zen Birdfeeder for sharing such valuable information for us bird lovers! R. Ciminski

[Jack Gilbert]

Hello Nancy I have had two sick Pine Siskins at my feeders it's so my feeders and water are down till after xmas. I feel so bad for the little guys, but it's for the best. Thanks for the great site. Jack

[The Zen Birdfeeder]

Joanne, thanks for keeping your feeders so clean. If you have to take them down, hopefully just a couple weeks will help clear out the sick birds. Good luck and thanks for posting.

[joanne hafner]

thank you so much for this information. i just thought they were either old or fledglings. once i started paying attention i realized they were sick. i've never had so many pine siskins for such an extended length of time. i'm cleaning constantly, throwing dirt over the ground around the feeders on a regular basis and keeping a close eye. the gold finches just showed up. if i see anymore sick birds i will take down the feeders, reluctantly, since they are such a huge part of my life!

[The Zen Birdfeeder]

Chris, exactly as mentioned in my post! Thanks for sharing your thoughts!

[Chris]

Spring 2015: We have had a large number of pine siskins dying in and around our feeders in Olympia this spring. We took down all our feeders for the meanwhile after finding five dead birds in two weeks. We suspect samonella because they are all puffed up and lethargic. Please do everyone a favor, if you find dead birds, wash all feeders with bleach and take them down for 30 days.

[Darla Daniels]

Dear Ms. Castillo,
This afternoon I had a mother & two young Pine Siskin Fledglings lounging in my front yard in the sun for quite some time. The mother kept a close eye on them & stayed very close. However, after about an hour the mother & one young flew off & didn't come back for the other youngster. Because I have many hawks, eagles, owls, etc., I went out to check on the baby & found that her eyes were shut. They look swollen shut. I have a picture if you can give me an email address to send it. She clearly could not see & she is not yet a strong flier, only making it a few yards before ungracefully landing. She first flew into the street & was able to finally get her into the safety of an ash tree, where she has remained for hours. I am concerned for her welfare & have not seen the mother return for her. I'm considering bringing her in (I have experience working with wildlife in PAWS's Wildlife Rehab in Lynnwood, WA (called HOWL) for the night & keeping her in a spare bedroom in a carrier with food & water, as it is very warm here & I am worried that if left outside through the night she will become prey or will succumb quickly to dehydration & starvation, being unable to see. I don't see the unopened or swollen eyes listed anywhere i symptoms for Salmonella & I do regularly clean & disinfect my feeders & bird baths & clean up the ground. This past two months we have had a large group of Cowbirds, Grackles & Blackbirds & some Starlings (along with the many various wonderful birds I have year-round & in season (all types of finches including Evening Grosbeaks, Stelar's Jay's, Violet-green Swallows, Robins, Pigeons, Quail & many more. I have been able to get rid of most of the Cowbirds, Grackles, Blackbirds & Starlings by changing the food I put out. I do a lot of wildlife photography & have a lot of birds. I have not found any dead birds & have never seen a young fledging with this, let alone an adult, that have this eye condition other than the occasional one that has been injured by another bird or predator.
Can you tell me if this sounds like Salmonella & if I should take her in to my vet to have her humanely euthanized. I cannot stand to let her suffer to death & without her mother & sibling, she seems completely lost with no way to find her way back. She is fully feathered, but as I said not strong & with no ability to see, if she is still counting on her mother to feed her (I did see her picking at the grass when they were all together), she will begin to suffer quickly. I don't want to put her down if she just needs time, but considering her siblings eyes were open…I am really worried that she won't survive on her own.

[erin]

Thanks for letting me know, especially so quickly! I've dismantled my station. I'll miss the birds!!! But I'd much rather miss them than kill them!

Thanks for the great article.

<3

erin

[The Zen Birdfeeder]

Erin, thanks for asking. The birds never become dependent on our feeding stations - they are supplemental food sources.
The birds will do best if you do remove the feeders and let them disperse - that will help the outbreak not spread further.
I know it's tough to do, but it's only temporary and it's best for the birds. Good luck!

[erin]

I have an outbreak here, apparently, but I'm concerned about removing the feeder at such a heavy feeding season. Don't the birds get dependent on it, and suffer without it... especially during nesting season?

[The Zen Birdfeeder]

Tim, good for you being so diligent maintaining your feeders and fountain. I have no experience with the UV light sterilizer but all your other efforts should be very beneficial. Thanks for your comment and for taking such good care of the birds.

[Tim Thoren]

Great article. I learned quickly about Salmonella from my local wildlife rehab place and realized I needed to be better about clean feeders. Now, I am militaristic about it. Anyway, my question is about water features. I try to keep a clean water source year round. I have a small pump flowing into a shallow basin and the birds just love it. I clean it every two - three weeks. All of the water runs through a UV light/sterilizer. I was wanting some validation that this will help kill bacteria and keep my birds healthy and happy. Any experience or thoughts? Thanks so much. What fun!

[The Zen Birdfeeder]

K.Andersen, thanks! Hadn't heard of any.

[K Andersen]

Here in the east, watch for this in American Goldfinches; small outbreaks have popped up this year.