Quick Answer
Mountain plovers do not primarily eat grass. Mountain plovers are a type of shorebird that mainly eats insects like grasshoppers, beetles, ants, and flies. They may occasionally eat seeds or grass, but insects make up the majority of their diet.
What Do Mountain Plovers Eat?
The mountain plover is a medium-sized shorebird that breeds in the Rocky Mountain states and winters in California, Texas, Arizona, and Mexico. Their diet consists primarily of insects and other invertebrates:
Insects
– Grasshoppers
– Crickets
– Beetles
– Ants
– Flies
– Moths
– Caterpillars
– Mosquitos
– Dragonflies
Insects, especially grasshoppers, make up 50-99% of a mountain plover’s diet depending on location and time of year.
Other Invertebrates
– Spiders
– Snails
– Worms
Occasional Foods
– Seeds
– Grains
– Berries
– Grass and other vegetation
Seeds and vegetation make up a very small portion of a mountain plover’s overall diet. They may accidentally ingest some grass or seeds while hunting for insects in fields, but they do not actively seek out vegetation as a main food source.
Mountain Plover Hunting and Foraging Behavior
Mountain plovers have several key adaptations and behaviors to hunt insects effectively:
– Large Eyes: Mountain plovers have large, yellow eyes that give them excellent vision to spot prey at long distances.
– Camouflage: Their brown and white speckled plumage provides camouflage against dry grasslands as they hunt.
– Running: Rather than probing in the grass, mountain plovers usually hunt by running across the ground to pursue and capture insects. They can run quickly on their long legs.
– Following herbivores: Mountain plovers often associate with grazing herds of bison, pronghorn, and prairie dogs. The herbivores flush insects from the grass which the plovers then capture.
– Opportunistic: They take advantage of grassland fires and plowed fields that expose high densities of insects.
Specialized Adaptations for Insect-Eating
Several key adaptations allow mountain plovers to thrive on an insect-based diet:
– Long skinny beak: Their slender beak is perfect for picking up small insects.
– Big mouth: They have a large gape which allows them to scoop and swallow sizeable insects.
– Rapid digestion: Their digestive system is adapted to process insects quickly.
– Gizzard for crushing: The mountain plover’s gizzard (a specialized stomach) contains stones and grit that help crush the exoskeletons of hard-bodied insects.
– Toxin tolerance: They have evolved tolerance to the noxious chemicals some insects produce as defense mechanisms.
Do Mountain Plovers Eat Seeds or Grass?
Mountain plovers do occasionally supplement their insect diet with some plant material like seeds and grass, but insects make up the vast majority of their food.
Several factors influence their occasional consumption of seeds or grass:
– Season: During cold months when insects are less active, seeds and grass become a slightly bigger part of their diet.
– Semi-digestion: Since their digestive system is adapted for insects, they may unintentionally ingest and semi-digest seeds while foraging.
– Grit: They purposefully swallow grit such as sand and pebbles to aid digestion. They may accidentally ingest some grass or seeds along with the grit.
– Fat content: Some seeds provide higher fat content which helps plovers maintain body weight.
– Young birds: Insect larvae and soft vegetation can help meet the nutritional needs of growing chicks.
Overall, the intentional consumption of seeds, grains, or grass likely makes up less than 10% of a mountain plover’s total food intake. They preferentially hunt insects whenever available.
Comparisons with Related Shorebirds
Most other shorebirds in the plover family have diets similar to mountain plovers – made up primarily of insects with some supplemental plant material. Comparisons:
Species | Primary Diet | Occasional Foods |
---|---|---|
Mountain plover | Insects (grasshoppers, beetles) | Seeds, grass |
Killdeer | Insects | Earthworms, snails |
Semipalmated plover | Insects, fly larvae | Mollusks, crustaceans |
Piping plover | Insects, fly larvae | Mollusks, crustaceans |
Some variation exists depending on habitat and location, but all these plovers rely on insects as their major food source, not grass or seeds.
Conclusion
In conclusion, mountain plovers do not primarily eat grass. As a species adapted to drier grassland regions, mountain plovers fill an insect-eating niche. Their diet is comprised mainly of insects like grasshoppers, beetles, ants, and flies. They supplement minimally with seeds or vegetation. Although they frequent prairies and fields, mountain plovers do not actually consume much grass or agricultural grains. Their insectivorous diet and foraging behaviors are tailored to take advantage of the abundant insect life on the prairies.