Larks are small passerine birds found throughout Europe, Asia, Africa and North America. There are over 90 different species of larks, characterized by their melodious songs and foraging habits. Larks mostly eat seeds and insects, supplementing their diet with green vegetation when available. The specific components of a lark’s diet can vary by species, habitat and season.
Main diet components
The key elements in a lark’s diet are:
Seeds
Seeds form a major part of the diet of most lark species. Larks will eat a wide variety of small seeds from grasses, weeds and other plants. These small seeds provide larks with carbohydrates and essential fats for energy. Some examples of favored seeds include:
– Grass seeds – Most grass species produce small edible seeds which larks will readily feed on.
– Grain seeds – Larks will eat seeds from cereal crops and spilled grain from farming activities.
– Weed seeds – Many broad-leaf weed species produce hard small seeds perfect for larks.
– Sedge seeds – Low growing sedges in moist areas yield abundant small seeds.
Insects
Insects and other invertebrates form an essential source of protein, fats and vitamins in a lark’s diet. Almost all lark species feed on insects to some degree. Examples of insects commonly eaten include:
– Beetles – Ground beetles, weevils, leaf beetles and many others are taken.
– Grasshoppers and crickets – Abundant in grasslands where larks forage.
– Ants – Small ants provide a good source of protein.
– Flies – Especially favorites are crane flies and midges.
– Butterflies and moth larvae – Caterpillars are readily eaten when found.
– Spiders – Provide a good source of taurine.
– Earthworms – More important in the diets of large larks.
Green vegetation
While seeds and insects make up the major proportion of food by weight, many larks will also take green vegetation, shoots, buds and tiny fruits when available:
– Grass shoots – Freshly sprouting new shoots are nibbled.
– Tender leaves – Young seedling leaves or sprouting buds are eaten.
– Moss and algae – Provide useful carotenoids.
– Fruit – Berries and small fruits add variety.
This fresh green food provides moisture and trace vitamins and minerals. However, most larks still depend primarily on seeds and insects.
Differences between lark species
While the general components described above hold true for most lark species, there are some notable differences between the various species:
Horned larks
Horned larks are found in open habitats like grasslands, deserts, tundra and alpine areas of North America, Europe and Asia. They eat mostly seeds, supplemented by insects and will also eat small fruits in season.
Skylarks
Skylarks inhabit open farmland and grasslands across Europe, Asia and North Africa. They feed predominantly on insects and seeds from grasses and cereal crops. They will also graze on green cereal shoots in early spring.
Crested lark
This sociable lark species is found living in arid grasslands and deserts from North Africa through the Middle East. It has a more varied diet including seeds, insects, green leaves and even occasional small lizards or rodents. They are also partial to feding in dung for insects.
Woodlarks
As their name suggests, woodlarks forage in more wooded and forested habitats than other lark species across Europe and Asia. They consume more green leaves, buds, tiny fruits and berries alongside seeds and insects.
Shore larks
Shore larks are found in remote, open tundra of North America and northern Eurasia. Their habitat provides limited food, and they subsist primarily on seeds, berry fruits and any insects they can find, including flies, beetles and grasshoppers.
Differences between seasons
The abundance of different food sources for larks varies considerably between seasons:
Spring
– Feeds on sprouting green shoots and leaves.
– Protein-rich caterpillars and beetle larvae are widely available.
– Builds up body reserves ahead of breeding season.
Summer
– Mainly insects like grasshoppers, crickets, beetles and spiders.
– Also feeds nestlings with insects.
– Some seeds and grains from ripening crops.
Autumn
– Wide availability of grains, cereals and weed seeds.
– Fruits and berries supplement diet.
– May form large flocks on farmland feeding on spilled grain.
Winter
– Harder to find insects, so more reliance on seeds of grasses, weeds and sedges.
– Also feeds on stubble in harvested fields.
– May take green leaves and moss if available.
– Food scarcity can lead to starvation.
Importance of location
The local environment and habitat determines what kinds of foods are available to larks:
Grasslands
Most larks inhabit open grassy plains and fields. Here they can find:
– Abundant grass and weed seeds.
– Insects like grasshoppers, crickets and beetles.
– Grain crops in agricultural areas.
Tundra
The remote tundra environments have:
– Very limited seeds from low growing plants and sedges.
– Fewer insects due to the cold climate.
– Lichens, mosses and small berry fruits are important.
Deserts
Desert-dwelling larks have adapted to make use of:
– Scarce seeds from dry grasses and scrubby plants.
– Beetles, ants and termites can still be found.
– Will drink water from puddles and oases.
Coastal
Shore larks living in coastal areas feed on:
– Seeds washed up from marine plants.
– Coastal invertebrates like molluscs and crustaceans.
– Flies, moths and beetles.
Farmland
Cultivated farmland provides:
– Abundant seeds from cereal crops.
– Spilled grain from harvesting.
– High insect numbers on crops.
– Weed seeds in fallow fields.
Foraging behaviors and feeding methods
Larks employ a variety of foraging techniques and methods to find their small food items:
Foraging on ground
– Walking over ground picking individual seeds and insects.
– Rapidly darting forward to grab freshly spotted prey.
– Running and suddenly stopping to catch prey disturbed from cover.
– Digging bill into soil to flick out hidden insects.
Probing in vegetation
– Pushing head into dense grass tufts to reach concealed seeds.
– Parting grasses with bill to uncover insects.
– Raking bill through moss or litter to dislodge prey.
Feeding in flight
– Catching insects like flies and aphids in mid-air.
– Plucking seeds from tops of swaying grasses and cereal stems.
Gleaning from plants
– Taking individual seeds from seed-heads of grasses and weeds.
– Skillfully picking insects off leaves, stems and branches.
– Holding plant stem in foot and parting vegetation to access hidden seeds or insects.
What do lark nestlings eat?
Lark nestlings are fed mainly on insects and other small invertebrates. The parents gather food and bring it back to feed the young chicks in the nest multiple times per hour. Favorite insects include:
– Caterpillars – Packed with protein and nutrients for growing chicks.
– Spiders – Contain taurine essential for juvenile birds.
– Ants – Abundant and easy to catch in quantity.
– Aphids – Can be found in large concentrated numbers.
– Flies – Readily available around nesting areas.
– Beetles – Provide essential amino acids.
As the chicks grow, parents may supplement with seeds. But the majority of food is insect-based to meet the demands of rapid chick growth in the nest.
Unusual food sources
While larks subsist mostly on seeds, insects and vegetation, some unusual food sources include:
Fruits and berries
Some larger larks like the horned lark will occasionally eat small berries and fruits like currants, elderberries and nightshade fruits. These provide useful sugars in autumn and winter.
Tree buds
During hard winters when other foods are scarce, some larks may feed on the buds of trees and shrubs. These provide nutrients and moisture.
Small vertebrates
The largest lark species like the crested lark will opportunistically take small vertebrates like rodents, lizards or frogs. These provide a good source of protein.
Carrion
In lean times, larks may scavenge for insects around animal carcasses killed by predators or road accidents. This utilizes a food source other animals cannot make use of.
Bird eggs
There is some evidence of larger larks raiding the nests of small songbirds and feeding on eggs. Again this supplements their diet with a concentrated protein source.
Nectar
Some larks have been observed feeding on nectar from flowers, likely as a sugar and water source. However most larks do not have adaptations for nectar feeding.
Adaptations for diet
Larks have evolved specialized features and adaptations to help them find and eat their small food items:
Conical bill shape
The long, pointed conical bill helps them pluck small seeds and probe into crevices.
Serrated edges to bill
These help grip slippery insects and cleanly cut vegetation.
Broad gape
Permits them to feed on insects of a relatively large size.
Excellent eyesight
Allows spotting tiny seeds, insects and other prey while walking.
Rapid darting on ground
Enables quickly pursuing disturbed prey over short distances on foot.
Fluttering flight
Fluttering erratically in air lets them snatch aerial insects.
Melodious calls
Many larks have beautiful, complex songs, possibly to communicate good feeding areas.
Digestive system adaptations
Key adaptations in the lark digestive system for their seed and insect diet include:
Powerful gizzard
The muscular gizzard grinds hard seeds and insect exoskeletons before they reach the stomach.
Long small intestine
A longer small intestine increases time digesting and absorbing nutrients from food.
Fermentation chambers
Blind sacs off the gut provide additional time to ferment and break down cellulose.
Enlarged liver
The liver is enlarged to produce bile and enzymes needed to process proteins and fats.
Fast metabolism
Larks have very rapid metabolic rates to gain maximum energy from their small food items.
Drinking
Most larks meet their water needs from moisture in food, but may also drink by various methods:
– Drinking rainwater collected in leaf axils or other natural containers.
– Sipping from drops of dew and guttation water on vegetation.
– Skimming and drinking from fresh temporary puddles after rain.
– Flying down to drink from lakes, rivers or wetlands.
– Obtaining preformed water from green vegetation and berries.
Desert species like the hoopoe lark can survive weeks without drinking in arid conditions. Other larks may excavate holes in dry ground to access subsurface moisture.
Importance of grit
Larks need to consume small pebbles and grit to accumulate in their gizzard. The grit helps grind and break down hard seeds and insect parts during digestion. Good grit sources include:
– Sand – From bare sandy ground or beaches. Small quartz sand particles work well.
– Crushed rock – Tiny fragments of rocks and gravel are ingested.
– Crushed shell – fragments of shells from snails or marine organisms provide grit.
– Ash particles – Fine ash and cinder particles can also be swallowed.
Larks that struggle to find natural grit in the diet may use small man-made materials like road grit or coarse concrete dust.
Conclusion
Larks have evolved to sustain themselves on a combination of small hard seeds and protein-rich insects. While they preferentially feed on seeds from grasses, cereal crops and weeds, insects become critical during breeding season and enable larks to successfully raise their chicks. The availability of different foods depends on factors like habitat, location, climate and season. Larks employ a range of foraging techniques and digestive adaptations to make the most of available food resources in their open country environments.