Starlings are medium-sized songbirds that are found throughout North America. They are omnivorous birds that eat a wide variety of foods including insects, earthworms, berries, seeds and even human food scraps. However, there are some types of foods that starlings tend to avoid or dislike compared to others.
Insects
Starlings love to eat insects and insect larvae such as beetles, caterpillars, ants, flies, crickets, grasshoppers, spiders and more. They often forage for insects on lawns or fields probing into soil and grass with their strong pointed bills. Starlings will eat all types of insects but seem to prefer larger-bodied insects that provide more nutrients such as beetles, caterpillars and grasshoppers. Small insects like ants or gnats may be ignored or avoided since they provide little substance despite the energy spent to find and consume them.
However, starlings do not seem to favor eating stinging or biting insects like wasps, hornets or blister beetles. This is likely an evolutionary adaptation to avoid toxins or injury from defensive insects. Starlings will steer clear of beehives, wasp nests and areas with high densities of biting insects. They also do not seem to target heavily armored insects like some beetles which require more energy to crack open and access the nutritious interior.
Fruits and Berries
Starlings readily consume a variety of fruits and berries including mulberries, juniper berries, strawberries, raspberries, blackberries, figs and grapes. However, there are some fruit varieties that starlings seem to ignore or pass over even when abundant. These include hard, bitter fruits like crabapples, pine cones and acorns. Starlings may avoid these fruits because the hard shells or bitter taste make them difficult to open and consume compared to softer, sweeter options.
Citrus fruits with thick rinds and tart interiors like oranges, lemons and grapefruit also seem unappealing to starlings based on observations of bird feeders stocked with various fruits. Since starlings evolved eating naturally soft berries and drupes, they seem to favor easy-to-access fruits high in sugars.
Seeds and Grains
Starlings are granivores meaning they eat grains and seeds. They consume many types of grains, cereals, grasses and herbaceous seeds especially energy-dense oily options like sunflower, nyjer and millet. However, starlings tend to avoid larger hard seeds that require more effort to husk and dehull such as corn, peas, beans, acorns and nuts. Larger seeds are more difficult for a starling’s small beak to efficiently process compared to small seeds. Consumption of small seeds maximizes calories gained versus energy expenditure.
Starlings also do not favor eating dry, tough grains that require a lot of chewing and processing before swallowing such as wheat, barley, rice or oats. They prefer softer grains and seeds that can be quickly consumed. Dried corn kernels for example are often ignored while softer grains like soaked cereal, bread and roasted sunflower seeds are preferred.
Meats and Dairy
Starlings are not frequent consumers of vertebrate meats like small mammals, fish or poultry though they may opportunistically sample these protein sources. More often starlings acquire animal proteins indirectly by eating insects and worms. Direct consumption of meat requires hunting abilities starlings do not possess. They also lack the gut enzymes to properly digest meats.
Similarly, starlings do not directly consume dairy products due to lactose intolerance. Like humans, starlings lose the ability to break down lactose sugars after weaning. Therefore milk, cheese, yogurt and other dairy items are not attractive food sources and may cause gastrointestinal upset if ingested in quantity.
Human Foods
Starlings have adapted well to living in close proximity to humans and will readily eat discarded human foods. However, they avoid foods with strong odors or seasonings. This includes spicy foods like hot peppers or curry, heavily salted items, and foods with pungent alliums like onions and garlic. The strong taste and odors seem to deter starlings. They also do not favor hard or dry human foods requiring dunking like bread crusts, crackers, pretzels or chips.
Oily, toasted or roasted foods are preferred since they have a softer texture and higher calorie density. Foods like french fries, pizza, hamburgers, chips, cakes, pastries and candies are sought-out junk food items for starlings attracted to sugar and fat.
Conclusion
In summary, starlings have selective palates and will avoid foods that are difficult to access, hard to chew/digest, toxic, heavily spiced/seasoned or unpalatable in texture/scent. Preferred foods are high in protein, fat and carbohydrates while being easy to consume such as insects, soft fruits, small seeds and energy-dense human snack foods. Understanding starling food preferences provides insight into their biology and behavior that may help manage issues with starlings around homes and agricultural areas.