Laura Erickson's For the Birds

Monday, April 9, 2007

Is feeding jelly really okay for birds?


Back in spring 2004, we had an extreme cold spell in May, right at the peak of warbler, tanager, and oriole migration. Suddenly people were finding dead insectivores on walks through the woods, and my yard was simply hopping with birds, including a wayward Bobolink, 7+ Baltimore Orioles, 5+ Scarlet Tanagers, and 30+ Cape May Warblers all visible at any one time. I went through a huge number of mealworms, and vast quantities of suet, sunflower seed, white millet, and jelly. I've been feeding grape jelly for many years. When my 23-year-old daughter was a preschooler, she'd come home from Montessori school wanting a "pickanic" lunch. I'd fix a sandwich and set her up at the "pickanic" table. On the same table was the orange bowl pictured above (we've had these orange bowls for decades--they came free in dog food), with a plop of grape jelly. And every day while Katie sat there, in flew a catbird to feed at the table right alongside her. When I went out, the catbird wouldn't come anywhere near, but for some reason it approved of my tiny daughter. That orange bowl of jelly was EXTREMELY popular in 2004, when birds were cold and food-stressed!

Anyway, I've long fed jelly to birds. I plop it out in very small amounts usually, because it gets buggy fast and I'm sure bacteria thrives in it, so I don't like having out more than birds can eat in a day. But that spring with all those birds, one morning I filled that bowl half full with jelly because I was going to be gone for several hours and the temperature was in the teens. When I came home, I found a Red-breasted Nuthatch close to death, mired in the jelly so that the only parts sticking out were his beak and eyes. I fished him out and spent hours washing him in warm water, toweling him dry, and allowing him to preen, over and over, until he was releasable. I felt horrible about that, and ever since have been cautioning people about setting out only small amounts of jelly at a time.

But today I got a thoughtful email from Kay Charter, who writes:
I confess that I had a prejudice against this practice [feeding jelly] the first time I saw it...about twenty years ago in a relative's yard. It just didn't look right. So I did some digging...as much as it is possible to do, which isn't much and it certainly hasn't been quantified, but it all makes sense. One source was a good friend who is an internist...he said that high sugar foods may trigger a bird's satiety gland, much as it does in children, causing it to feel satisfied when it has had little in the way of nutritional value. He also said that sugar may be addictive for birds as it certainly can be in humans, and that a bird might develop a strong liking for jelly and spend less time searching for natural foods.

Then I queried my friend, Kent Mahaffey, who was manager of the San Diego Wild Animal Park's famous free-flight Bird Show for more than two decades. Kent had primary care responsibility for hundreds of birds from many families. He said he would never allow any birds under his care to have jelly. He added the following:

  • In general, any food that exceeds the balance of sucrose in a bird's natural diet is suspect. Natural nectars contain 12% to 30% sugars, while jams and jellies are more than half sugar. He also said that higher than normal sugar loads may outstrip a bird's ability to adequately process the sugar (as it does in humans); and products high in sugars are an ideal environment for bacterial growth.

He summarized as follows: "Birds developed the way they did by adapting to the environments in which they lived and the foods that sustained them. We do our best for them when we stick as closely as possible to their natural diets."

I know that people have been doing this for decades with no apparent ill effects. But since there is no way to check the effect on internal organs, or, as Kent suggested, bactarial growth, it just seems wise to me to stick with Kent's suggestion...which is to offer foods that are as close as possible to what they evolved with.

SBTH recommends an alternative: grapes. Birds love them, and they have real nutrients, not just sugar.

The bottom line is that while we don't know how this affects our birds, it may (as Kent and my doc friend suggested) be harmful. Why take the chance?

Thanks,

Kay
So what's the right answer? I think it's CRITICAL to stop feeding jelly if there is any evidence birds are feeding it to nestlings or bringing fledglings to it--growing babies need protein, not such a heavy carb load. And if an individual birds seems to be spending an inordinate amount of time at the jelly, I'd close down shop, too. At this point, I'm going to probably continue to feed it during migration, especially during cold weather.

Does anyone know of any studies about the relative benefits and harms of feeding jelly to birds? Let me know!

22 comments :

  1. I'm not sure I'm ready to jump on the anti-jelly bandwagon yet. Birds do have a way of regulating their diet. Orioles do stop eating jelly and that ends right about the time oriole chicks hatch--I think they know enough to switch to protein heavy foods.

    Also, when people tend to go through jelly the most is during migration, you aren't getting the same oriole coming all day long, you're getting several coming through out the day, they aren't eating only jelly.

    Of course, this is only based on anecdotal evidence so it's not scientific.

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  2. I feed Orioles with grape jelly and what a pleasure to watch them. However, after reading the comments, I started to add crushed grapes mixed with the jelly. I will add more grapes day after day, until they get used to it. They already love it. I will look for natural grape jelly or jam, even organic, no sugar, no preservatives added. Now, if it is harmful to feed Orioles with jelly, what about feeding Hummingbirds with liquid nectar. I make my own, without adding any dye. When you find feeders, tips and recipes for Orioles and Hummingbirds on websites like Cornell Lab, Audubon or Wild Birds Unlimited, you go with it without a doubt.
    Lucie, WNY

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  3. Hummingbirds naturally need sugar, They need the sugar for energy. Do other birds need sugar? Hummingbirds also eat insects for protein. I am going to buy a jar of grape jelly today and put out a little bit everyday. It sounds like no one knows for sure if it is ok or not. I will use caution.

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  4. I put out some grape jelly and the orioles found it but so did the honeybees.Does anyone know if this may not only hurt the orioles but the bees too. I don't want to harm anything so after dark I hosed all the jelly away. Any suggestions. I do have hummingbird feeders and regular oriole feeders.

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    1. Definitely will not hurt bees. But someone's honey may have a grape flavor at the end of summer. Lol

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    2. I feed the Orioles no high fructose grape spread, but the bald- faced hornets are attracted to it so they feed from the dish all day..unfortunately, by the next day, I found all the bees are dead..Iam not sure why..this happened twice..I called multiple environmental sources and they didn't have a clue why!!..
      The company that makes the spread confirmed that the spread was all natural...
      any one know? Are hornets unable to digest fructose??

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    3. Wow. I wouldn't try it ever again with that brand. I wouldn't eat it or let my children eat it, either.

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  5. Thanks so much for the comments. I attracted the orioles to the yard with grape jelly, but seems all the birds are dipping their beaks in it now....and was looking for the answers I found here. I will start crushing some grapes and adding some protein (hummers not incuded here). The sugar addiction connection makes lots of sense. Thanks, will remember oranges too

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  6. My girlfriend found a dead hummingbird in her jelly yesterday. Died the same way you described your nuthatch. Very, very sad.

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  7. I love your book "nomination!" Brilliant :)

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  8. I put out grape jelly and oranges, getting more house finch, wrens and even a downy wood pecker. Unfortunately no B. oreoles. I too will look for the unsweetened jelly. I'm in NY and maybe too early for them. I only have the pleasure of seeing one or two for very short time, and not every year

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  9. We have jelly meal worms 2suet feeders humming bird feeder and 5 different types of seed and I notice they tend to bounch from feeder to feeder to balance their own diet. My thought is they just might be better at balancing thier diets better than us humans.

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    1. It's gratifying to think that our feeders are providing a complete diet for birds, when we offer a variety as you do. After studying the types of insects and fruits that birds provide their young, by observation and reading, I know that nature provides a far wider spectrum of nutrients than even the best-stocked feeding station can. Fortunately, as you note, most birds really are better at balancing their diets than we humans are, and don't get all their food from our feeders.

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  10. we have been having orioles visit for about 4 months.... all of sudden they are gone. I had a female around for a few days but now she has left also. any idea why they left.

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    1. Oriole families begin to migrate in July. Jelly is a delicious dessert, but they feed on insects and a huge assortment of wild, fresh berries, and sort of wend their way south, munching as they go. They'll be back next year.

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  11. I have a winter-long flock of up to 2 dozen Baltimore Orioles here in southern Georgia (they arrive late August and stay till mid April). They started coming to the winter hummer feeders 20 years ago, but they clearly prefer jelly. They did not go for marmalade or strawberry or any of the no-sugar-added jellies; they only like grape jelly/jam. My attitude is that it's generally available in the morning, and I don't refill beyond noon. They go away and I presume find natural foods. There are stretches of days when they don't even come for the jelly (maybe avoiding the frequent accipiters). I see them up in the pecan and oak trees feeding many times. They are vigorously healthy. If they nested here, I would switch to mealworms.

    Dr. Brad Bergstrom

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  12. I live in eastern Ontario and have been feeding Orioles grape jelly for years. The middle of June, when the babies hatch, they look for meal worms to feed the hatchlings and are almost non-existent at the jelly feeder. After that, they are at the jelly feeder sporadically and by end of July early August the are migrating south. After they clean all the cherries off my cherry tree!! I think they are smart enough to know what and when to eat.

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  13. We have had prothonotary warblers coming back year after year - 13+ years and counting - and nest in nesting boxes on front porch and back patio. Easy to watch what is going on with them. When they are feeding babies, they are of course feeding insects. We keep jelly feeders out for them beginning in late March. They go straight for the jelly as soon as they arrive. They do go for frequent tastes of the jelly during the time of building nests and taking care of the nestlings. However, as soon as the babies leave the nest, we stop seeing them on jelly feeders for a month or more. They come back to the feeders later after the nestlings are not so dependent on them. Many of our smaller birds like the jelly, including hummingbirds also. Our jelly feeders are small cups in hanging feeder that would preclude any getting stuck in it.

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    1. It's HIGHLY unlikely that you are getting different Prothonotary Warblers each year. Your situation is pretty solid evidence that these birds are thriving, and the people so certain that jelly is necessarily bad are just plain wrong.

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  14. That's nonsense, and an irresponsible statement if you care about the birds' health. PROW do not live 13+ years; their average life span as given in various sources I consulted ranges from 2.5 to 4 years, with a maximum of around 8 years.

    They may well have been the same individual birds for portions of the 13+ years given that many small songbird species show strong year-to-year breeding site fidelity. But they may not have been the same individuals. Availability of suitable nest cavities in developed areas is extremely limited thanks to our propensity to cut down dead and dying trees, as well as competition for an unnaturally limited
    number of cavities with invasive exotic HOSP and EUST.

    The PROW will settle in any suitable cavity they come upon and the ones who arrive earliest from year to year will get the most desirable breeding sites. Given how weather dependent migration is, I don't see how you can reliably conclude that they are the same individuals in different years.

    So, there's a decent chance they could be the same birds but we don't know that they are without some sort of individual marking like color bands. And it's thus highly irresponsible to conclude -- and encourage others to believe, using your platform as a famous birder -- that PROW will thrive if you feed them grape jelly.

    If you really care about the birds, why not play it safe and put out natural, unprocessed foods like oranges and crushed grapes? Surely it's not that much more costly or time-intensive to feed them real fruit instead of sugary grape jelly.

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    1. Prothonotary Warblers have high nest site fidelity, and someone observing birds using the same box year after year is likely seeing returns or, if adults do not return, their now-adult offspring using the site, or neighboring birds that may also have been using the jelly. At least one banded individual Prothonotary Warbler returned to a nest site repeatedly at least four times--he was recaught when 5.5 years old. And at least one banded bird survived longer than 8 years. The Birds of North America Online and the Patuxent Bird Banding Lab are great sources for non-speculative information about birds.

      My job is to listen to reliable information with an open mind. I've provided sound information from both sides of the debate, have clearly outlined caveats about jelly, but have also talked with more than one person who feeds jelly who bands birds and has seen orioles and catbirds returning year after year. That information counts for something.

      You must realize that grapes get moldy very quickly outdoors, which is harmful, and most grapes sold in stores have a higher sugar content than would have been considered "natural" before hybridization and genetic modification. And many birds attracted to jelly are not particularly attracted to oranges, possibly because of the acidic content.

      You are keeping your identity secret, which is unfair if you're going to personally attack me for trying to keep an open mind. Meanwhile, you have not cited a single study showing that feeding jelly is harmful, or even a documented anecdote.

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