Sandhill cranes are large birds in the crane family, Gruidae. They are found primarily in North America. Sandhill cranes are omnivorous, eating a variety of plant and animal material. Their diet varies based on habitat and food availability. However, there are some foods that seem to be sandhill crane favorites.
Plants
Sandhill cranes eat a wide variety of plant material. This includes seeds, leaves, tubers, roots, and berries from aquatic and terrestrial plants. Some of their favorite plant foods include:
Corn
Corn is a major part of sandhill cranes’ diet across much of their range. They feed heavily on waste corn in harvested fields. Cranes seem especially attracted to corn and will flock to fields where it is available.
Berries
Cranes relish wild berries when they are in season. Some of their favorite berries include blueberries, cranberries, huckleberries, and raspberries. They will aggressively forage for ripe berries.
Tubers
Sandhill cranes dig in wetlands and grasslands to uncover edible tubers. These include tubers from native plants like bulrush, arrowhead, cattail, and nutgrass. The starch-rich tubers provide an excellent source of carbohydrates.
Seeds
A variety of seeds are consumed by sandhill cranes, especially cereal grains like wheat, oats, and barley. They also eat the seeds of wetland plants like sedges, rushes, and smartweeds. Cranes can digest hard seeds with their muscular gizzards.
Animals
Though sandhill cranes are primarily herbivorous, they do opportunistically feed on small animals to obtain protein. Some of their favorite animal foods include:
Insects
Cranes will eat a wide range of insects when available, including grasshoppers, dragonflies, damselflies, beetles, and caterpillars. Insects provide a good source of protein and fat for cranes.
Earthworms
Earthworms are a prized food source for sandhill cranes. They probe in wet mud and grass to grab earthworms to gulp down whole.
Snails
Cranes will crush and consume snails for their calcium-rich shells and soft bodies. Land snails and freshwater snails are favored prey.
Small vertebrates
Sandhill cranes opportunistically prey on frogs, snakes, rodents, and small fish. This provides them with a protein boost when available.
Favorite Foods by Season
The foods favored by sandhill cranes changes throughout the year as food availability shifts.
Spring
In spring, sandhill cranes seek out earthworms, snails, and insects on their northern breeding grounds. They also forage on new shoots and sprouting plants.
Summer
On nesting grounds in summer, sandhill cranes feed heavily on insects and other invertebrates to meet protein needs for raising young. They also eat local berries.
Fall
During fall migration and staging, corn becomes the predominant food as cranes fatten up for winter. They also eat many seeds, tubers, and insects from wetlands.
Winter
In wintering areas, sandhill cranes feed extensively on waste corn and cereal grains. They also dig up tubers and roots from marshes and fields.
Diet by Geographic Region
The diet of sandhill cranes varies across different parts of their wide range in North America.
Great Plains
In the Great Plains, corn is a major component of crane diets alongside seeds, roots, and grains.
West Coast
Cranes on the West Coast consume more berries from Pacific coastal habitats along with grains and invertebrates.
Southeastern States
In southeastern states, waste corn and pond snails are important foods for wintering cranes.
Northeastern States
Cranes foraging in northeastern states feed more on Atlantic coastal berries, seeds, and grains.
Florida
In Florida, corn, earthworms, acorns, and snails are key foods.
Importance of Corn
Corn is one of the most important foods for sandhill cranes throughout most of their range. The widespread planting of corn provided a abundant and nutritious food source that allowed crane populations to increase over the last century.
Some key points about sandhill cranes and corn:
- Cranes feed heavily on waste corn in harvested agricultural fields during migration and winter.
- Whole corn kernels provide cranes with carbohydrates for energy.
- Corn contributes to fat storage that provides energy for migration and winter.
- Increased corn production on the Great Plains gave cranes abundant food that fueled population growth.
- Cranes time migrations to take advantage of waste corn on the landscape.
In many areas, sandhill cranes have become dependent on corn as a major dietary component. This has benefited crane populations but also tied them to certain agricultural landscapes.
Foraging Adaptations
Sandhill cranes have several key adaptations that help them find and consume their favorite foods:
- Long legs for wading to capture aquatic prey
- Long necks for probing underground to find tubers
- Specialized bills for grasping and crushing prey
- Strong gizzards to grind seeds and hard food items
- Excellent eyesight to detect food sources from afar
- Flexible diet that allows them to take advantage of seasonal abundances
These adaptations allow sandhill cranes to thrive on a diverse diet of plant and animal material across North America. Their flexible foraging strategies are key to their wide distribution and large numbers.
Potential Threats from Changes in Food Resources
Though sandhill crane populations remain healthy, potential threats could arise from changes to food resources:
- Reduced waste corn from more efficient harvesting methods
- shifts away from corn and grain farming in some regions
- Draining or degradation of wetland tuber sources
- Climate shifts altering plant food abundance and timing
- Pesticide use reducing insects and snails
Sandhill cranes may be able to shift their diets to adapt to some changes. However, major reductions in food availability, particularly corn, could negatively impact crane populations. Conservation planning should consider important crane food resources.
Conclusion
In summary, sandhill cranes have a diverse omnivorous diet favoring certain foods like corn, tubers, insects, snails, berries and other plant foods. Corn is especially important for sandhill cranes across much of their range. Cranes time migrations and foraging to take advantage of seasonal food abundances. With ample food, sandhill crane populations have thrived and expanded. However, changes to food resources could potentially impact crane numbers in the future. Understanding crane diets and food resources is key for continued effective management of this species.