As a bird lover, discovering tiny insects known as weevils in your birdseed can be alarming. You want to provide the best diet possible for your feathered companions. But are those creepy crawlies harmful? Will birds still eat seeds containing weevils? Let’s explore the science and observations behind this common bird feeding dilemma.
What Exactly Are Weevils?
Weevils are a type of beetle belonging to the Curculionoidea superfamily. There are over 60,000 species of weevils around the world! Most are identified by their elongated snouts. They use these snouts to bore into seeds, nuts, beans, grains and other plant materials to lay their eggs.
Once hatched, the larvae eat their way through their food source, damaging the interior. This can affect the germination rates of seeds. It also raises concerns about the safety of feeding infested seeds to backyard birds.
Common Weevil Species in Birdseed
Several weevil species frequently find their way into bags of birdseed:
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Rice Weevils Tiny dark brown or black beetles around 1/8 inch long They earned their name by infesting rice but also hide away in other grains and seeds.
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Granary Weevils: Slightly bigger at 1/4 inch long. Their smooth, shiny bodies are brown, black or red. As their name suggests, granary weevils primarily infest stored grains.
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Pea Weevils: A greenish-brown hue covers these 1/4 inch weevils. As larvae, they damage peas, beans, lentils, chickpeas and more.
Identifying weevil species can help track down infestations before they spread too far in your birdseed stash.
Do Weevils Decrease Nutritional Value?
Surprisingly seeds containing weevils often retain their essential nutritional content. The beetles themselves don’t remove significant amounts of fat protein or other nutrients birds need.
For example, black oil sunflower seeds infested with weevils still supply valuable fats and protein. Weevils won’t decrease the carbohydrates available in millet or sorghum seeds either.
In fact, some birds may even view weevils as an extra protein source! This supplemental nutrition comes from eating both the seed and any beetle larvae or adults inside.
Which Birds Consume Weevil-Infested Seeds?
Field studies reveal smaller bird species readily feast on weevil-ridden seeds Chickadees, finches, sparrows and buntings enthusiastically dig through seed mixes to snack on moving weevil larvae
Backyard observations show birds attracted to the increased movement and activity of infested seeds. The weevils’ jostling mimics small insects that many birds love to chase down and eat.
Larger birds like doves and pigeons will also eat weevil-filled seeds. However, their preferences vary more than smaller songbirds. Closely monitor your own flock’s reactions if you suspect seeds contain weevils.
Overall, the willingness of wild birds to consume infested seeds in natural settings is reassuring. It indicates that healthy birds can tolerate weevil presence without negative consequences.
Observational Studies on Birds and Weevils
Both field observations and controlled laboratory studies provide scientific evidence of birds consuming weevil-infested seeds:
Field Observations
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In backyard settings, insect-eating birds showed no preference between infested and uninfested seeds despite having a choice. This demonstrates their adaptability to readily available food sources.
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Chickadees and titmice preferentially chose infested seeds and extracted weevil larvae to eat in one field study. The movement proved irresistible compared to still seeds.
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During seasons when natural foods are scarce, even finicky birds ate more weevil-infested seeds out of necessity. Survival trumps dietary preferences when times get tough!
Controlled Lab Experiments
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When given both infested and uninfested seeds, captive zebra finches, canaries and budgies ate both options equally. This supports the idea that weevil presence doesn’t deter birds from eating seeds.
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Songbirds modified their typical seed cracking behavior to open infested seeds carefully and access the weevil larvae inside as a protein source. This demonstrates their ability to adapt feeding strategies.
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Analyzing bird health and condition during controlled weevil seed diet studies showed no ill effects compared to eating clean seeds.
Both wild and captive bird observations provide reassurance that consuming weevil-infested seeds does not appear to negatively impact healthy birds.
What Factors Influence Bird Feeding Decisions?
Bird feeding choices depend on a couple key factors that dictate their appetite for weevil-laden seeds:
Availability of Alternative Foods
When other food sources are scarce, birds become less picky and eat what they can find. For example, many birds readily switch to eating more infested seeds in winter when insects, berries and other natural foods are limited.
Monitoring neighborhood feeders and local habitat provides clues about what alternatives exist. This helps predict if birds will opt for weevil-filled seeds when options are low.
Seasonal Changes
During spring and summer, most birds can be more selective about their diets thanks to abundance. But as food supplies dwindle in autumn, birds become more desperate for calories and nutrition.
At these times, species like finches and chickadees that avoided infested seeds earlier in the year will resort to eating them.
These seasonal patterns demonstrate bird adaptability and prioritization of survival over preferences when the going gets tough.
The Bottom Line: Should You Worry?
Discovering weevils crawling amongst your birdseed certainly delivers an “ick” factor. However, observational studies offer scientific reassurance that bird health doesn’t suffer from eating infested seeds.
The key takeaways to keep your backyard birds happy and healthy:
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Monitor your flock after introducing weevil-laden seeds but don’t panic. Healthy birds adapt and tolerate their presence.
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Consider discarded heavily infested seeds. But seeds with minimal damage and weevils can safely supplement bird diets.
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Boost your bird buffet with more suet, nuts, fruits and other natural foods during periods of weevil seed consumption.
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Store birdseed in airtight containers and inspect regularly to help prevent weevil infestations from spreading through your home pantries.
While weevils are pesky pantry pests, backyard birds prove remarkably resilient in adapting their feeding habits. So take comfort knowing your feathered friends can weather the weevils while you tackle the insect invasion!
Avoiding Indian Meal Moths or Grain Weevils
Jim Carpenter, the founder of Wild Birds Unlimited, writes in his book, The Joy of Bird Feeding*, the following:
*Excerpt from The Joy of Bird Feeding – The Essential Guide to Attracting and Feeding Our Backyard Birds [2017] by Jim Carpenter, founder of Wild Birds Unlimited.
Rodents and Other Critters
Left: Mouse Species Photo by Kristen Martyn. Right: Eastern Chipmunk (Tamias striatus), Photo by Kristen Martyn.
Left: Eastern Gray Squirrel (Sciurus carolinensis), Photo by Kristen Martyn. Right: Raccoon (Procyon lotor).
To avoid problems with creatures such as mice, chipmunks, squirrels and raccoons, store all food in chew-proof containers made of metal or a very strong plastic. Do not store food containers outside on their own, ensure they are safely inside a shed, garage or cabinet.
Birdseed and Weevils
FAQ
Are weevils in bird seed bad for birds?
Grain weevils in and of themselves, will not harm the birds, and may provide extra protein, but depending on how infested the seed is, the weevils may have eaten most of the nutritious parts of the grain, leaving only the husks.
How to get rid of weevils in bird seed?
Avoiding Indian Meal Moths or Grain Weevils
Bird seed is more likely to attract insects in the summer heat, so this is when you must keep it cool and use it up quickly. I often put small bird seed bags and bird food cylinders in the freezer during the summer.
What is eating my bird seed at night?
Some of these animals that you might have seen during the day or at night include raccoons, mice, rats, rabbits, skunks, foxes, or even deer, though most …Jul 20, 2022
Will weevils go away on their own?
When weevils are found indoors, physically remove them with a vacuum or broom and dustpan. Pesticides are not effective or necessary. These weevils are harmless and temporary and will go away on their own. Their numbers can vary from year to year.
Are weevils harmful to birds?
Weevils are generally not harmful to birds. Healthy birds can tolerate the presence of weevils without experiencing negative health effects. Observational studies show that birds frequently eat infested seeds without issues.
Do birds eat weevil-infested seeds?
Observational studies show that birds often eat seeds infested with weevils without adverse effects. Research provides insights into bird behavior, preferences, and the impact of weevils on seed consumption. Field studies reveal that smaller birds, such as finches and sparrows, frequently consume weevil-infested seeds in natural settings.
What kind of weevil eats birdseed?
Several weevil species commonly infest birdseed. Here are a few notable ones: Rice Weevil: Small, about 1/8 inch long, and typically dark brown or black. They often hide in grains and seeds. Granary Weevil: Slightly larger than the rice weevil, around 1/4 inch long, with a smooth, shiny surface.
Can weevils get into birdseed bags?
Weevils can get into birdseed bags at any point between harvesting and packaging or after purchasing: Weevils lay eggs on crops in fields, infesting seeds pre-harvest. Infestations can spread during transportation in dirty trucks or storage facilities. Once you bring seed home, any eggs or weevils may continue reproducing.
What happens if a bird eats a seed?
However, weevil or insect damage to seed can allow mold, fungi, and bacteria to start growing. Seed infested with weevils has an increased chance of also being contaminated with dangerous molds like aspergillus. Birds eating moldy seed risk developing respiratory illnesses or aspergillosis infections.
How do I keep Weevils out of my birdseed?
Monitor your seed containers for any mold, clumping, or stickiness that could indicate microbial growth problems beyond just weevils. Here are some tips to keep annoying weevils out of your birdseed: Buy small quantities – The longer seed is stored, the more time weevils have to infest it. Buy smaller bags you can use up quicker.