Cherries are a highly desirable seasonal food source for wildlife due to their sugar content and easy accessibility. These stone fruits, members of the Prunus genus, ripen quickly and offer a concentrated burst of energy-rich carbohydrates. The fruit’s soft flesh surrounds a single pit, making them an efficient, calorie-dense meal for animals ranging from insects to large mammals. This high appeal ensures that virtually any animal capable of reaching the fruit will attempt to consume it during the short harvest window.
Primary Mammalian and Avian Eaters
Cherries attract a wide array of vertebrates, with birds and small mammals being the most visible consumers. Among birds, the American robin (Turdus migratorius) is frequently detected in sweet cherry orchards. Cedar waxwings (Bombycilla cedrorum) often consume a greater volume of fruit per individual visit. Other common avian pests include European starlings and common grackles, which feed in large flocks that can rapidly strip a tree.
Mammalian consumption involves both arboreal species and ground feeders. Squirrels and raccoons readily climb the trees to pick the ripening fruit directly from the branches. Larger animals, such as white-tailed deer (Odocoileus virginianus), browse on the leaves and young shoots of cherry trees. They also feed on fallen, fermenting fruit on the ground. These animals often swallow the fruits whole, allowing the pits to pass through their digestive tracts intact, which aids in seed dispersal.
Insect Threats to Cherry Fruit
While larger animals consume the whole fruit, insects focus on internal damage, often ruining the harvest from the inside out. The most significant invertebrate threat is the larva, or maggot, of the Cherry Fruit Fly (Rhagoletis species). The adult female fly lays a single egg just beneath the skin of the developing cherry, where it is nearly undetectable.
Upon hatching, the legless maggot burrows toward the pit and feeds on the flesh for one to three weeks. This internal feeding makes the fruit soft, shrunken, and unmarketable, often causing premature ripening. The mature maggot then creates an exit hole, drops to the ground, and pupates in the top layer of soil. Management efforts must target the adult fly before it lays eggs, as the maggot is protected once inside the fruit.
Safety Concerns Regarding Cherry Pits and Foliage
The primary safety concern relates to chemical compounds found within the non-flesh parts of the plant. Cherry pits, stems, and leaves contain cyanogenic glycosides, specifically amygdalin, which is also found in other stone fruits. When this compound is chewed, crushed, or digested, enzymes can hydrolyze it to release hydrogen cyanide (HCN), a potent toxin.
The risk is generally low for animals that swallow the pits whole, as the hard, intact pit prevents the release of amygdalin. However, the risk increases dramatically if the pit is broken or chewed, or if a large quantity of wilted leaves is consumed. This is particularly concerning for livestock like horses and cows, and household pets, where consumption of the wilting foliage can lead to signs of cyanide poisoning. For small pets, eating just a few crushed pits can potentially lead to toxicity, as the toxic dose of cyanide is relatively low.
Methods for Protecting Cherries
Protecting a cherry harvest requires a layered approach using physical and sensory deterrents.
Vertebrate Pests
For vertebrate pests, the most effective strategy involves establishing physical barriers, especially fine-mesh bird netting. The netting must be secured over the entire tree canopy and kept taut. This prevents birds from reaching the fruit and stops ground animals from climbing beneath it. Visual deterrents, such as reflective flash tape or mylar balloons, can be utilized to temporarily scare off birds, though their effectiveness diminishes as animals acclimate to them.
Insect Pests
For insect pests, management focuses on sanitation and timing. Promptly removing all fallen and old fruit prevents larvae from pupating in the soil. Using specialized yellow sticky traps helps monitor the emergence of adult flies to determine when treatment is necessary.